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WHITE OAK RIVER SYSTEM STUDY FINAL REPORT: A PLAN OF ACTION FOR THE WHITE OAK RIVER QH 541.15 .M64 F56 1981 COASTAL ZONE INFORMATION CENTER FINAL REPORT WHITE OAK RIVER SYSTEM STUDY (A Plan of Action for the White Oak River) MARCH, 1981 Jj Prepared For: The White Oak River Advisory Council and Town of Cape Carteret Town of Swansboro Carteret County t Onslow County 0) U. S. DEPARTMENT OF COMMERCE NOAA -41 COASTAL SERVICES CENTER 2234 SOUTH HOBSON AVENUE to 0 CHARLESTON , SC 29405-2413 Prepared By: Henry von-Oesen and Associates, Inc. Consulting Engineers & Planners 611 Princess Street - P. 0. Drawer 2087 Wilmington, North Carolina 28402 o4 La SECTION A: TABLE OF CONTENTS TABLE OF CONTENTS SECTION NO. TITLE A TABLE OF CONTENTS B LIST OF FIGURES AND TABLES c ACKNOWLEDGEMENTS 1 EXECUTIVE SUMMARY 2 INTRODUCTION AND BACKGROUND INFORMATION 3 EXISTING CONDITIONS IN THE STUDY AREA 4 IDENTIFICATION OF EXISTING PROBLEMS 5 PROPOSED SOLUTION(S) TO EXISTING PROBLEMS 6 RECOMMENDATIONS FOR ADDITIONAL STUDY 7 SUMMARY, CONCLUSIONS AND RECOMMENDATIONS 8 BIBLIOGRAPHY OF REFERENCES-' APPENDIX A: MEMORANDUM OF AGREEMENT WHITE OAK RIVER ADVISORY COUNCIL APPENDIX B: WORK TASK OUTLINE APPENDIX C: DESCRIPTION OF MATHEMATICAL MODELING STUDY FOR THE WHITE OAK RIVER A-1 SECTION B: LIST OF FIGURES AND TABLES Figure 2.1: Study Area Figure 3.1: DEM - Water Quality Stations Figure 3..2: Point Sources of Pollution, White Oak River System Figure 3.3: Transition Zone Between Salt and Fresh Water Figure 3.4: White Oak River - Hard Clam Harvest (LBS) Figure 3.5: White Oak River - Oyster Harvest (LBS) Figure 3.6: White Oak River - Blue Crab Harvest (LBS) Figure 3.7: White Oak River - Total Value of Seafood Landed Figure 4.1: Circulation Patterns In a Stratified Estuary Figure 4.2: N.C. Route 24 Bridge Plan by DOT, 1951 Figure 4.3: Proposed Highway 24 Bridge and Causeway Across the White Oak River Fi.gure 4.4: Bottom Profile under NC Highway 24 Bridge at Swansboro, N. C. Figure 4.5: AIWW In The Vicinity of The White Oak River Figure 4.6: Bogue Inlet Map 3.1: General.Soil Map Map 3.2: Urban or Built-Up Land Uses In The White Oak River Basin Map 3.3: Agricultural Land Uses In The White Oak River Basin Map 3.4: Silvicultural Land Uses In The White Oak River Basin Map'3.5: Prohibited Area Map Map 3.6: White Oak River Oyster.Management Areas Map 4.1: Map Showing Water Depth In River, Sound & Inlet, 1920 and 1977 Map 4.2: White Oak River In Vicinity of Swansboro, N. C., 1873 Map 4.3: White Oak River In Vicinity of Swansboro, N. C., 1910 Map 4.4: White Oak River In Vicinity of Swansboro, N. C.', -1928 Map 4.5: White Oak River In Vicinity of Swansboro, N. C., 1932. Map 4.6: White Oak River In Vicinity of Swansboro, N. 'C., 1933 Map 4.7: White Oak River in Vicinity of Swansboro, N. C., 1949 Map 4.8: Water Depth in the White Oak River in Vicinity of Highway 24 Bridge and Causeway Complex at Swansboro, N. C. Map 4.9 Bogue I 'nlet Area Map 5.1: Location of Proposed Flow Conduit Between White Oak River and AIWW Photo Plate 4.1: White Oak River Area, Aerial Photo, 1979 Photo Plate 4.2: White Oak River Area, Aerial Photo, 1979 Photo Plate 4.3: White Oak River Area, Aerial Photo, 1979 Photo Plate 4.4: White Oak River Area, Aerial Photo, 1979 Photo Plate 4.5: White Oak River Area, Aerial Photo, 1979 Photo Plate 4.6: White Oak River Area, Aerial Photo, 1979 Table 3.1: Principal Biotic Communities Table 3.2: Land Uses - White Oak River Basin Table 3.3: Point Sources of Pollution - White Oak River Basin. Table 3.4: Results of Monitoring of Tidal Creeks In New Hanover County, N.C. Table 4.1: Listing of Vessels Using the Port of Swansboro and Bogue Inlet Table 4.2: List of Landings Along the White Oak River Above the Swansboro Bridge Table 4.3: Current Velocities, White Oak River at Swansboro,- N. C. Table 4.4: Present (1963-1974) and Project Periodicity of Maintenance and Volume of Material Removed From AIWW in Vicinity of White Oak River, N. C. Table 4.5: Characteristics of Bogue Inlet B-1 SECTION C: ACKNOWLEDGEMENTS It would have be en virtually 'impossible to complete this study and report without the able assistance from the following individuals of diversified backgrounds and interests: A. U.S. Army Corps of Engineers, Wilmington District, Wilmington, N. C. Mr. Ron Fasher, Coast al Engineer Mr. Lim Vallianos, Coastal Engineer B. N. C. Department of Natural Resources and Community Development, Division of Marine Fisheries, Morehead City, N. C. Mr. Mike,Sireet, Director of Research Mr. Fentress H. Munden, Marine-Biologist/Coordinator C. U.S. Department of Agriculture, Soil Conservation Service, Raleigh, N.C. Mr. John J. Garrett, Coordinator, Water Resources Planning Staff D. C. Wildlife Resources Commission, Raleigh, N. C... Mr. Stuart Critcher, Assistant Director, Interagency Wildlife Coordination Section E. N. C. Department of Transportation, Raleigh, N. C. Mr. Ar@chie Hankins, Hydrographic Division F. Town of Swansboro, North Carolina Mr. Tucker R. Littlet on, Historian Mr. Alton Phillips, Commerical Fisherman The able assistance of many other individuals too numerous to list here is also gratefully acknowledged. C-1 SECTIONS- 2 through- .6 REPORT WHITE OAK RIVER SYSTEM STUDY (A Plan Of Action For The White Oak River I HENRY VON OESEN AND ASSOCIATES CONSULTING ENGINEERS AND PLANNERS SECTION 2: INTRODUCTION AND BACKGROUND INFORMATION 2.1 Introduction A study of the White Oak River was undertaken at the direction of the White Oak River Advisory Council. The.Council was formed in mid .1980 as a result of concerns that the viability of the White Oak River is being threatened by continuing siltation. The Council consists of six members representing the governments of the Town of Cape Carteret, the Town of Swansboro, Carteret County and Onslow County, as well as the Commercial Fishing Industry and-the Izaak Walton League. The Members of the Council are identified in Appendix A of this report. The Onslow County Planning Department acted as the Lead Agency for the study and administrator of the funding for the study. A memorandum of agreement forming the Coun cil and stating its specific aims is also found in Appendix A. The study was performed by Henry von Oesen and Associates, Inc., Consulting Engineers and Planners, under a contract with the White Oak River Advisory Council dated January 12, 1981. 2.2 Background The White Oak River Advisory Council was formed as a result of expressions of concern by local interests that the White Oak River is a valuable natural resource which is being threatened by continuing siltation and other forms of pollution, particularly in the lower portions of the estuary. The.Council has noted that the fisheries and shellfish productivity of the river and normal economic development of the ports of Swansboro and Cape Carteret are constrained by this continuing degredation process. In response to these concerns, the Council requested funds from the N. C. Office of Coastal Management (OCM) to perform a technical. study of the problem. In recognition of the need for such a. 2-1 study, the Office of Coastal Management provided a grant which was combined with funds from the participating local units of government to fund this study and report. 2.3 Stud Purpose and Scope The scope of the study has been defined in a detailed work task description which is a part of the contract for the study. A copy of this task description may be found at the end of this report as Appendix B. . Briefly, the study effort included a. review of existing data on the hydrology, tidal hydraulics, sources of pollution, fisheries resources, land use patterns, etc., of the White Oak River Basin. Th'is data, once compiled, was used to define the problems and to propose both structural and non-structural solutions (see Section 5). 2.4 Study Area The general area of concern for this study is the White Oak River Basin, as defined by the N. C. Environmental Management Commission in the White Oak River. Basin Plan as Sub-Basin 01. (See Bibliography, Section 8). A map of the study .area is shown in Figure 2.1. Although the study effort.includes the entire river basin area, the focus of attention is on the lower estuarine portion of the river south of the Seaboard Coastline Railroad Bridge near Stella. Specific emphasis is centered on the area in the vicinity of the N. C. Highway 24 causeway and bridge complex which links the Town of Swansboro with Cedar Point and the Town of Cape Carteret. The White Oak River is used by man for waterborne commerce, extraction of fish and shellfish for food, recreation, and to a limited extent, water supply withdrawal in the upper river basin (irrigation of crops). 2-2 At c lllp@ Cr cr A@ro X., b S 1011ES ca f4,ytter PVe h Al Coos Line -z- Cr. r jjadror swp. c') NJ rOn Prong ast le 41 41/1.1 F I G U R E 2.1 STUDY AREA HENRY VON OESEN a ASSOCIATES - CONSU1.7ING ENGINEERS a PLANNERS - WILMINGTON, N. C. SECTION 3: EXISTING CONDITIONS IN THE STUDY A REA 3.1 General Description of White Oak River System The White Oak River system is located in the south-central coastal area of North Carolina. The watershed lies entirely within the lower coastal plain with ground elevations ranging from 120 feet above sea level to sea level at Bogue Inlet. The White Oak River is relatively small and drains directly into the Onslow Bay area of the Atlantic Ocean through Bogue Iblet. The White Oak River forms the border between Onslow, Carteret and Jones Counties of North Carolina. 'Its source and origins are in the Hoffman Forest of Jones and Onslow Counties. The river has a length of about 48.5 miles (78 km). from its source to where it empties into the Atlantic Ocean through Bogue Inlet. The approximate extent of the drdinage area is 400 square miles. It. is esti- mated that about 77 percent of the watershed is covered by Hoffman Forest and Croatan National Forest. There is relatively little urban development in the watershed, with Swansboro being the largest town. The major tributaries of the White Oak River are Hunter Creek, Grant Creek, Pe ttiford Creek, Starkey Creek, Black Swamp, and Holston Creek. All the tributaries are small and densely vegetated.. The river itself averages about 0.9 miles (1.5 km).wide from- the Atlantic Ocean to the vicinity of Webb Creek (see Figure 2.1). The depth is about 4 feet (1.2 m) with numerous oyster reefs and a narrow, obscure channel. The river bottom is primarily sand and mud with sand shoals along the edges.- From Webb Creek to Grant Creek, the river is about 12 feet (3.7 m) deep, 490 feet (150 m)* wide, and meanders. The bottom type is primarily mu-d and detritus and is bordered by fresh and brackish marsh. Above Grant Creek,-the fiver flows through hardwood swamp at a depth of 5 to 14 feet (1.5 to 4.3 m). Below U.S. Highway 17, the river flows through seven distinct lakes of Ahe Martin Marietta 3-1 Belgrade Quarry. These lakes comprise approximately 140 acres of water and range from 15 to 31 feet (4.5 to 9.5 m) in depth with steep sides and a mud bottom. The lakes were dug between 1940 and 1960 during mining operations for limestone. Water flow is very slow in the lakes except where they are connec- ted. These lakes may act as sediment traps for upstream inputs. However', this has nct been investigated or quantified by previous investigators. From the Quarry to immediately above U.S. Highway 17, the river is narrow and from 2 to 3.9 feet (0.6 to 1.2 m) deep with a rock bottom. Stream velocities are very swift in riffle areas. Above U.S. Highway 17, the river is a small typical coastal stream;-with the water being highly stained from swamp drainage. The White Oak River system is predominantly tidal, except for the region above the 'limestone quarry and the headwaters of the tributaries. The stream velocity is slow when unconstricted. 3.2 Area Geology - General The Peedee formation forms the basement rock for the near surface (500 feet deep and less) geology of the area. Towards the coast, the Peedee lies under a thick wedge of the Castle Hayne limestone formation. The Yorktown formation (also limestone) overlies the Castle Hayne limestone and reaches a thickness of about 60 feet along the coast. A thin layer of sand and clay (chiefly sand) of Pleistocene age conceals the older formations in the interstream areas and forms the surficial sands which characterize the surface soils in the area. 3.3- Area Soils Map 3.1 shows the general soil associations within the estuarine portion of the White Oak River Basin south of Stella, North Carolina. 3-2 GENERAL SOIL MAP 0 1 2 3 4 APPROXIMATE SCALE IN MILES LEGEND ONSLOW LUMBEE ASSOCIATION: Nearly level to gently sloping moderately well to poorly drained soils with an Intermittent subsurface layer of thin hardpan and friable sandy clay loan subsoils. LEON - LYNNHAVEN ASSOCIATION: Nearly level somewhat poorly to very poorly drained soils with sand surface layers and dark reddish brown sandy hardpan subsoil. LAKELAND - BAYMEADE -DRAGSTON ASSOCIATION: Excessively drained sandy soils to somewhat poorly drained soils with sandy loom subsoil. TIDAL MARSH -COASTAL BEACH ASSOCIATION: Nearly level land overflowed by high tidewater and sand dunes. PONZER -PAMLICO ASSOCIATION: very poorly drained organic soils 12 to 50 inches of muck over sandy to loamy textured soils. JOHNSTON - BIBB ASSOCIATION: Nearly level very poorly to poorly drained soils on flood plains in drainageways. PORTSMOUTH TORHUNTA ASSOCIATION; Nearly level very poorly drained soils with black surface layers and gray friable sandy loom to sandy clay loom subsoils. SOURCE: U.S. DEPARTMENT Of AGRICULTURE SOIL CONSERVATION SERVICE RALEIGH, N.C. I6MAP 3.1 GENERAL SOIL MAP 3.4 Area Cl imate The White Oak River area is located in a humid mesothermal climatic regime that is characterized by mild winters and hot, moist summers. This regime is tempered by the effect of sea temperatures and breezes in areas within 1 to 2 miles of the Atlantic Ocean.. The moderating effect of the sea is clearly illustrated in the fact that Swansboro has. markedly fewer days when surface temperatures exceed 90 and fall below 32 degrees Fahrenheit than do such towns as New Bern and Elizabeth City which have more inland locations. The mean annual temperature for the North Carolina coastal region ranges from 61 to 64 deg@ees. July is the hottest month and has a monthly average temperature of.approximately 80 degrees F. January is thetcoldest month with monthly means ranging from 46 to 48 degrees F. in the southern coastal areas. Temperatures along the coast seldom exceed the 100 degree mark and virtually never fall below 0 degrees F. The average dates for the first freeze in autumn and the last in spring occur during mid November and March, respectively. Relative humidities along the North Carolina coastal region are high and average 70 to 75 percent annually. Seasonal variance is not great, but there is a slight tendency for highest relative humidities to occur in winter and lowest ,during spring. A distinct diurnal variation does exist with maximums generally being attained during the early morning and minimums usually occurring during late afternoon. The White Oak River Basin receives an average of 56 inches of precipitation annually, most of which falls as rain.' Precipitation in the summer is usually in the form of convectional thundershowers while in the winter it is principally of cyclonic origin. Though there are.no easily discernible wet-dry seasons, greatest monthly rainfall generally occurs during July, August and September. Each of these months receives 4 to 7 inches of rainfall annUally throughout the 3-3 coastal region. Fall, particularly October, is the dryest part of the year, even though monthly averages would not seem to indicate this.. Precipitation during this period is often associated with tropical storms and falls primarily in intense bursts of short duration. Snowfall may occur 1 to 2 times a year with a mean annual accumulation of 1 to 2 inches near the immediate coast. However, many years may pass with little or no accumulation. The prevailing wind direction along the coast is from the southwest, ex cept during the fall and winter months when northeasterlies' caused by offshore storms may prevail. Surface wind speeds average 10 to 13 mph with maximums commonly reached during mid-afternoon and minimums just before sunrise. The east coast of North Carolina including the' White Oak River Basin is vulnerable to hurricanes; at least 43 such storms affected this region between 1910 and 1966. During hurricane periods the River/AIWW Complex receives a tremendous influx of sediments. When storms are of unusual.5everity, new inlets may be formed or existing ones closed. The-hurricane season begins in June and .often extends into November. From June to September the greatest number of storms originate over the Atlantic Ocean, frequently in the vicinity of the Bahama, Windward or Leeward Islands. These storms will usually move inland well South of the State, or-move northward paralleling the coast. The latter is the type that most frequently crosses the North Carolina coast. However, most of these, have storm cent&s which pass wel.-I offshore and thus, damage is usually restricted to that associated with heavy rain, high tides, and seas. As the hurricane season progresses into late September and October, the' center of maximum activity shifts to the western Caribbean. Storms originating in this region frequently move inland over the Florida land mass and travel in a northerly to northeasterly arc. By the time they reach North Carolina, they have lost most of their intensity because of their overland passage. Northeast storms which occur primarily during the fall and winter are perhaps a more significant source of erosion a.long the coastal area than are hurricanes. These storms are created when low pressure areas move up the coastline causing a counterclockwise flow of moisture-laden air.. The storms are accompanied by heavy rain and strong northeast winds which may cause unusu ally high tides and seas. Duration of the storms is variable but they often persist for from 2 to 5 days. 3.5 Plant and Animal Communities The planning-airea lies within the coastal plain region of North Carolina. The area serves as a meeting ground for salt tolerant and fresh water biotic communities. The interaction of fresh water with saltwater and the mild climate provide numerous habitats for a1arge diversity of aquatic and terestrial. W *ldlife and flora. Table 3.1 enumerates the general biotic communities and , their respective residents for the coastal region, including the White Oak River Basin. "The Atlantic Coast Ecological Inventory" (see Bibliography) indicates that 'Ite Oak River area provide excellent the many marshes, inlet, and bays in the Whi habitats for a variety of species. Shorebirds, wading birds, and waterfowl .migrate along the coast and overwinter in many of the bays and sounds. Wild turkey is common in a broad band of upland forests paralleling the coast and several mammals, particularly deer, are recreationally important-. Croatan National Forest occupies over 123,887 hectares (306,000 acres) and provides sport hunting opportunities for a variety of game animals. This forest contains Great Lake, which has a shoreline that is considered to be one of the better localities for birds in North Carolina. Nesting birds in the forest include ospreys, herons, double-crested cormorants, and warblers. 3-5 TABLE 3.1 PRINCIPAL BIOTIC COMMUNITIES-L/ General Location(s) Dominant Dominant Dominant Principal E Relative to Soil Species In Species In Shrubs & Animal ommunity Associations Canopy Sub-Canopy Herbs Species Hardwood 1, 2 Water Oak, Post Same as for 'Pepper Bush, Birds-Red- Forest Oak, White Oak, Canopy. Wild Olive, ShouTd-ered Hawk, Red Maple, Tulip Flowering Catbrier, Screech Owl, Poplar, Sweet Dogwood Muscadine, Yellow-Shafted Gum, Southern Common. Bamboo, Wild Flicker, Downy Red Oak, Hickory, Ginger, and -Woodpecker, Blue and Black Gum.' Yellow Jay, Carolina Occassional Jasmine.. Chickadee, Tufted large single Titmouse, Carolina Loblolly Pines, Wren, Yellow-Throa or'L6ng Leaf Warbler and Cardin Pines may occur. (b) Mammals-Easter Gray Squirrel, Fly Squirrel, Cottonta Rabbit and Whiteta Deer. (c) Amphibia and Reptiles-(Very Common):77 Box Tu Green Snake, Black Racer, Southern Copperhead, and S1 Salamander. Mixed Pine 1, 2 Loblolly Pine Same as for ' Same as for Same as for Forest or Long Leaf Hardwood Hardwood Hardwood Pine associat- Forest. Forest. Forest. ed with species present in Hard- wood Forest above. TABLE 3.1 Continued PRINCIPAL BIOTIC COMMUNITIES General Location(s) Dominant Dominant Dominant Principal End Relative to Soil. Species In Species In Shrubs & S mmunity Associations Canopy --Sub-Canopy___ Herbs Species P Pine 1, 2, 3 Two Types Exist: Red Maple, Same as for (a) Birds-Red- Forest (a) Solid Pine 'Sweet Gum, Hardwood Shou7Te-red Hawk, Canopy dominated Sassafras, Forest plus Screech Owl, Red by Loblolly Pine Black Sweet Bay, Headed Woodpecker, or (b) Sparce Cherry. Dwarf Sumac Carolina Chickadee, Canopy dom 'inated.. and Fetter Tufted Titmouse, by Long Leaf Bush. Herbs Carolina Wren, Pine. include Yellow Throated Virginia, Wabler, Yellow Chain Fern, Throat, Hooded' Grasses and Warbler., Summer Sedges, Tanger, Indigo Go-lden Rod, Bun -ting and Blue Meadow-Beauty, Grosbeak. Yellow Eyed (b) Mammals- Grass, Milk Striped Sku k, Ea. Wort, and Gray Squirrel, Ea. Wild Vervena. Fox Squirrel, and Whitetai led'Deer. Reptiles and Amphibians-Rat !@nake, Black Rac@lr, Canebr6 Rattler, Oak Toad, Spade-Foot Toad, Narrow-mouth Toad, and Pine Woods Tree Frog. TABLE 3.1 - Continued PRINCIPAL BIOTIC COMMUNITIES General Location(s) Dominant Dominant Dominant Principal En Relative to Soil Species In Species In Shrubs & Animal immunity Associations Canopy Sub-Canopy Herbs -Species Swamp 4 Bald Cypress Younger Royal and (a) Birds-Downy Forest along with Red individuals Cinnamon and ?Tleated Maple, Swa -Mp of Canopy. ferns, Gall- Woodpeckers, and Gum, Ash, Water berry, Titi, Yellow Shafted Hickory, Swamp Bamboo, -Flicker are common'. Chestnut, Oak Catbrier, Carolina Chickadee, and Tupelo. Swamp Rose, Tufted Titmouse, Virginia Blue-Gray Gnat- Willow, Wax catcher, and Myrtle, Water Prothonatary Willow. Under Warbler. dense Canopy: (b) Mammals- Lizard's Tail, Opossum, Racoon, Royal Fern, Bobcat, Gray Pennywort, Squirrel, Marsh Cinnamon Rabbit, Rice Rat, Fern, and Flying Squirrel Spanish Moss and Muskrat. on trees. (c) Reptile*s and Amphibians-Mi ak Yellow Rat- 'Snake, Eastern Cottonmouth Canebrake Rattlesna Squirrel Treefrog, Green Treefrog, and Southern Lepard Fro, TABLE 3.1 Continued PRINCIPAL BIOTIC COMMUNITIES General Location(s) Dominant Dominant Dominant- Principal End Relative to Soil Species In Species In Shrubs & Animal S mmunity Associations Canopy Sub-Canopy Herbs Species P Mixed 1, 3, 6 Loose Stands N/A Giant Cord- (a) Birds-@Herons, A Marsh of Cypress, grass. EgreT-s-,7ucks, A Swamp Gum, and Vultures, Hawks, Red Maple occur Rails, Gulls, along banks of Sandpipers, the creeks in Plovers, Owl, the area. Snipe, Wood- peckers, etc. (b) Mammals- WhitTtailed Deer, Racoon, Mink,' Marsh Rabbit, Rice Rat with limited number of River Otters and Muskrats. (c) Reptiles and Amphibians-Tme-rican Alligator, Yellow- Bellied Turtle, Brow and Banded Water Sna Eastern Cottonmouth, Broken-Striped Newt and several species of frogs. TABLE 3.1 Continued PRINCIPAL BIOTIC COMMUNITIES General Location(s) Dominant Dominant Dominant Principal End Relative to Soil Species In Species In Shrubs & Animal S ommunity Associations Canopy Sub-Canopy Herbs Species P Pocosin 5 Pond Pine with Evergreen Where shrub (a)'*Birds-Carolina less frequent Shrubs. layer is Wren_,7a_tbird, Red Maple. continuous Robin, Hermit herb,layer is Thrush, White-eyed not existant. Vireo, Yellow Throat and Ea. Towhee. (b) Mammals-Marsh Rabb7, and White- tailed Deer. (c) Reptiles and Amphibians-Southern Cricket Frogs and a few other reptile@ Tidal 3, 4 None None Smooth Cord- (a) Birds-Marsh Marshes grass, in low Hawk-s-,-7parrows, marsh and Waterfowl and Salt-Meadow various'Seabirds.. Cordgrass, (b) Mammals'- Sea Ox-Eye,. Muskra-7-a-FE Nutria. Needle Rush, (c) Reptiles and Sedges Terrapins. in high (d) Invertebrates- marsh. Fiddler Crabs, Mud 'Snail, Ribbed Mussel, Blue Crab. Abundant populations of the American Alligator, several colonies of red- cockaded woodpeckers, and nesting ospreys make the White Oak River and its marshes an important habitat for rare or enda.ngered wildlife. The Loggerhead Sea Turtle, an endangered species, nests at Hammocks Beach at the mouth of the White Oak River. 3.6 Land Use Land uses within the White Oak River Basin were characterized based on the Land Use and Land Cover maps published by the U. S. Geological Survey (see Maps' 3.2, 3.3 and 3.4). As can be seen from the maps, most of the land adjacent to the river and its tributari es is forest land or forested wetland. Agricultural .use of land is next in extent, followed by urban and built-up uses. It appears that silvicultural and agricultural' practices have the greatest potential impact on the river. Present urban uses have a relatively lesser impact. The Water Quality Management Plan, White Oak'River Basin (Subbasin 01),presents the distribution of land uses as shown in Table 3.2. 3.7 Water Quality Only limited data on the water quality.,of the White Oak River is available from existing references. Back in the early 1950's the State Stream Sanitation Committee of the N. C. State Board of Health conducted a pollution survey of the White Oak River Basin (see Bibliography of References, Section 8). The only significant source of pollution noted in the entire White Oak River drainage basin was the partially treated wastewater discharge from the Town of Swansboro. As a result of this survey, the Stream Sanitation Committee established a restricted area around the Swansboro discharge to protect the public health. The survey report also identified pollution from domestic wastes from individual homes from Maysville and Belgrade which discharged to the upper river from the 3-6 TABLE 3.1 Continued PRINCIPAL BIOTIC COMMUNITIES General Location(s) Dominant Dominant Dominant Principal En Relative to Soil Species In Species In Shrubs & Animal rnmun i ty Associations Canopy Sqb-Canopy Herbs 'Species Beach 3, 4 None None Sea Oats on (a) Birds-Laughing Dunes, and Dune- Gull , Herring Scrub Sea Myrtle, Gulls, Common Thicket Groundsel, Terns, and Black Marsh Elder Skimmers on Dunes a and Sea Ox- Grackles, Red-Winge Eye in Blackbirds, Mocking thickefs. birds and Warblers in shrub thicket. (b) Reptiles and Amphlibians-Toads in tickets. (c) Invertebrates- GhosT Crabs on dune Maintained 1, 2, 3 Scattered Pines N/A Low Grasses, Migrants from Fields may occur. Sedges, Weeds adjacent biotic, and various communities, agricultural e.g. Pine Forest. crops. Source: Swansboro Area 201 Facility Plan r 21 21 4Z 4) 42 42 cIri .21 n 4.* It 4 43 4.5 4 21 41 4 21 47 42 U 44 % 42 20 4j 42 4 13, 47 1 Caffloh - 52 21 bf 4 a *0 42-L 42 6 42 61 42- 21 2 6, 2. 2 to 42 52 v rl 42 42 21 42 43 21 ".t. 43 21 21 '4 4@ 41 21, 41 42 4S 42 41 2 42 42 rl 45 1 21 A2 43 41 12 45 4 4) O;L-231r,@l 21 21 5 4 4z 4!1 rn > 0 z a (0 ;u 41- 41 a ;u co . 61 > ;u > Do 43 43 0 CO U) 0 11 45 41 21 0 M 4, z It 43 < a) 0 m 0 4) a M cn m ;u A 5 z C: - 1 m Q r- ID p Z m I 4J- 41 '1 -4 - * C: C: N r- Q u I > x 43 41 1 1 z 76 r 4 It 41 > 1-1 z m 41 7 a 0 (D 0 -0 43 rn 4 > > 11 a . . . z > 11 t 4 42 a z 43 LF I -u A t 0 0 42 61 21 21 15 AZ 4 21 12 42 42 9'L-2i 11 43 43 4 45 < 47 34? 61 (3-12 er" (3-21 42 42- 4j- 43 TI 61 Cut f1s A n 61 Lake 42-D TI 9f 1 -1 61 At 42 61 45 42 61 j 4 21 61 w 42- 61 4 2. 6/ Greg 2 Lot 61 52 41 42 52 TI 41 42 1 @ 1_4 41 42 42 4,5 62 43 4r Q 4 21 71 4 12 42 42 4 61 43 45 211 21 AZ A 21 12 tz-t 0 p r- ch C= > 4z 0 z 42 At - co > 7ii C: J) 0 1 > C) cl :0 M M A@ 54 61 76 > (n ;U 0 m U) - -0 .0 43 r Z- C) m - 0 1 43 43 45 F- 0 . z 4) 43 #5 n CO < a CO c 42 76 0 M 6 1) 0 m J> Ow 43 1 1 a W 43 4 z > C: z ;U X r- r 43 41 m 12 z 0 41 4 m 4 f2 3 a > 7 p 0 z 12 43 W 41 a it > 4 z 42 '13 71 21 4 21 0 42 42 42 1 rn 4% 21 9) -21 43 6 F 4.5 01% < q 2.1 < 0 -V z 21- 0 21 4.1- m 61 43 (n ar 420 M z go 4 A 61 > 1 cn 2. CA 0 0 P Opt Al 42 43 C:@ 43 4, 41 z (n Al Q 42 42 45 C) 42 2( 43 13 .76 z 43 6 C) Q 21 z a 12 45 m A- rn Ma ONT 42 if x CA m C) 41 4z- Aj z 0 if 61 Z CD '11 C) 111 0 VO 0 < 42 M U) X ;D rn m V V) -Z @ m ;a G) 43 1 M-j 4.1 0 ;u :N 61 a > 2 ZM> -4> C) 16 > z z > 45 ;D >0 12 - 0 -< C: > 72 -4 z a 'I,1 .2 m a ;a 42 m A TABLE 3.2 Land Uses White Oak River Basinl Category No. of % of of Use Acres Total 1. Federal 116,100 28.9 2. Urban 1,000 0.3 3. Water Areas 50,000 12.5 4. Cropland 32,900 8.2 5. Pasture 2,000 0.5 6. Forest .167,800 41.8 7. Other -31,500 7.8 Totals 401,300 100 Source:' Water Quality Management Plan, White Oak River Basin, Sub-Basin-01. 1975. NCDEM, Raleigh, N. C. mouth of Grape Branch to the mouth of Hunter Creek (see Figure 2.1). Beginning in 1968, the N. C. Division of Environmental Management estab- lished several water quality sampling stations in the White Oak River. The locations and descriptions of the stations are shown in Figure 3.1. Detailed records of the results of the sampling are found in the Water Quality Management Plan published in September, 1975 by. the N. C. Environmental Management Commis- sion (see Bibliography). In summary, the results show good quality water with virtually no water quality standards contraventions. However, all stations show slight water quality degradation on occasion. These conditions have been attri- buted to land runoff and, in the case of stations near,Swansboro, discharges from. the Town of Swansboro'.s former primary wastewater treatment facility. In 1979, the Town of Swansboro began operation of a new tertiary wastewater treatment facility located at Fosters Creek southwest of the Town. Discharges to the White Oak River from the old facility have since ceased and a general improvement in water quality in the lower estuary has been noted by NCDEM from recent samplings. Certain zones within thestudy area have been degraded by pollutants to the extent,that the harvesting of shellfish for marketing has"been prohibited by the Office of the North Carolina Shellfish Sanitation Program, Division of Health Services, based in Morehead City, North Carolina. Those areas which have been closed to shellfishing are shown on Map 3.5. The prohibited areas include most of the upper river estuary north and west of Godfrey Branch, Hargetts Creek, Holland Mill Creek, Stevens Creek, Pettiford Creek, and an extensive zone in and around the Town of Swansboro including Queens Creek. The total shellfish harvesting area consists of some 8,500 acres of which 1,292 acres (15.2 percent of,the total) are closed to shellfishing. 3-7 FIGURE 3.1 DIVISION OF ENVIRONMENTAL MANAGEMENT WATER QUALITY STATIONS C r ft Cr C'f Sz, A Cr 0'.'0 Ar", Ca s )FES CO jq le We b 7r aLine rnaes ro Hadn0f C' 2 swp 017sh 10 P, Ong Sk' CN f _j LOCATION STATION TYPE STATION NAME NUMBER NUMBER 1 27- Secondary White.Oak River near Stella, NC Network 2 28 Secondary White Oak River near Peletia, NC Network 3 29 Secondary White Oak River near Swansboro, NC Network 4 30 Secondary White.Oak River at Swansboro, NC Network 5 31 --Secondary Bell Swamp at Starling,.NC Network (D 02092744 Old Primary White Oak River at Stella, NC 02092760 New Primary White Oak River at Swansboro, NC AREAS D-2 D-3 MAP 3.5 PROHIBITED AREA MAP Hargetts Ck. Godfrey Bronch PROHIBITED AREA *See Deer Creek Area Map for Hunting Island and Goose Creeks Holland Mill Ck. coordinates. Hancock Pl. Pettiford Ck. Stevens Ck. Jones Is. SWANSBORO Dudley Is. BOGUE BANKS 10-6-75 (Rev.) Rev.2-2-79 7-2-80 (Rev.) 7-17-80 (Rev.) No person shall take or attempt to take any oysters or claims or possess,sell, or offer for sale any oysters or clams taken from the following areas, at any time: (22) White Oak River Area: (a) In White Oak River and all its tributaries upstream from a straight line running from the south side of the mouth of Godfrey Branch 300 M, to a point of marsh, and in Pettiford Creek, from its origin to a point one mile downstream from the N. C. Highway 58 Bridge over said stream; in Stevens Creek, in Holland Mill Creek and its tributaries and within three hundred yards of 1ts mouth; and beginning at a point on Mt. Pleasant at 34 42' 03" N, 77 06' 50" W; thence in a straight line to a point on the northern end of Jones Island at 34 41' 54" N, 77 06' 30" W; thence in a straight line to eastern end of Highway 24 Bridge at Swansboro 34 41' 08" N,77 06' 58" W; thence to a point on the southeast shore of the ICWW at 34 40'13" N - 77 08' 00" W, near Beacon #49; thence following the southeast shore in a southwesterly direction, crossing all tributaries, to a point on the shore at 34 39' 19" N - 770 09' 31" W, near Channel Marker #53; thence straight accross ICWW to a point on the northwest shore at 34 39' 25" N - 77 09' 36" W. This is to include all the waters of Queens Creek. (b) All waters upstream from a line across Hargetts Creek beginning at a point on the north shore at 34 44' 54" N - 77 08' 12" W; thence to the south shore at 34 44' 44" N- 77 08'06" W. The sanitation requirements for approved shellfish growing areas are set by the U. S. Public Health Service in its National Shellfish Sanitation Program Manual of Operations, Part 1, Sanitation of Shellfish Growing Areas (1965 Revision) and are as follows: "Growing areas may be designated as approved when: (a) The sanitary survey indicates that pathogenic micro-organisms, radionuclides, and/or harmful industrial wastes do not reach the area in dangerous concentrations, and b,) This is verified by laboratory findings whenever the sanitary survey indicates the need. Shellfish may be taken from such areas for direct marketing." "Satisfactory Compliance This item will be satisfied when the three following criteria are met: (a) The area- is not so contaminated with fecal material that consumption of the shellfish might be hdzardous, and (b) The area is not so contaminated with radionuclides or industrial wastes that consumption of the shellfish might be hazardous (see Section C, Item 7 in the Manual of Operation, regarding toxin.s in shellfish growing areas), and (c) The coliform median MPN of the water does not exceed 70 per 100 ml.,, and not more than 10 percent of the samples ordinarily exceed a MPN of 230, per 100 ml. for a 5-tube decimal dilution test (or 330 per 100 ml. where the 3-tube decimal dilution test is'used) in those portions of the area most probably exposed to,fecal contamination during the most unfavorable hydrographic and pollution conditions. (Note: This concentration might be exceeded if less than 8 million cubic feet of a coliform-free dilution water are available for each population equivalant (coliform) of sewage reaching the area). The foregoing limits need not be applied if it can be shown by detailed study that the-.coliforms are not of direct fecal origin and do not indicate a public health hazard. This MPN value is based on a typical ratio of coliforms to pathogens and would not be applicable to any situation in which an abnormally large number of pathogens might be present. Consideration must also be given to the possible presence of industrial or agricultural wastes in which where is an atypical coliform to pathogen ratio." ,Thus, the areas shown on Map 3.5 have been closed because they have not met the above requirements. Due to the fact that there are no known sources of radionuclides or industrial wastes in the area, the closings are due mainly to 3-8 coliform levels in excess of the 701100 ml standard. The source of the coli- forms is presumed to be seapage from failed or malfunctioning septic tanks, from domestic waste point sources, from urban runoff or a synergistic combination of these sources. The reason for the closure of the area above Godfrey Branch where there is little or no development is unknown. In July of 1980',, the'Shellfish Sanitation Program Office issued a report of a sanitary survey of the White Oak River Area D-3 covering the sampling period of January, 1979 to June, 1980. The report noted that improvements have been made in the area resulting in the opening of some 600 acres of previously closed shellfish waters in the lower estuary. Most of the improvement was attributed to'the operation' of the new wastewater tr Ieatment facility at Swansboro. The report went on to conclude that unsatisfactory results were still being obtained from sampling stations between Jones Island and Stevens Creek (see Map 3.5). However, it was expected that this area would continue to improve because of the new wastewater-treatment *acility and the abandonment of the old discharge. 3.8 Sources of Pollution 3.8.1 Point Sources of Pollution The Water Quality Management Plan,.-White Oak River Basin' published by the N. C. Environmental Management Commission in 1975 identifies the point sources of pollution in the White Oak River System. Table 3.3 lists the sources and Figure 3.2 shows the locations of the discharges. All of the major dischargers are in compliance with State regulations and are considered by NCDEM to be providing.adequate treatment of wastes. If all the sources were to discharge the maximum volume of treated effluent as specified in their permits, a total of 1.43 MG.D could be discharged to the river system. However, the aver age daily discharge is more likely to fall in the range of 50 to 75 percent of the maximum (0.72 to 1.1 MGD). 3-9 TABLE 3.3 Point Sources of Pollution White Oak River Basin Maximum Figure 3.2 Dischar e Lat./Long. of Receivi Key No. Source Location Volume ?MGD) Discharge- Stream A. Municipal Facilities (1) Maysville WWTF Maysville 0.18 34053130" Lat. White 77*13'50" Long. 1,200 f Hwy. 1 (2) Swansboro WWTF Swansboro 0.30 Foster Tribut A.I.W. B. Industrial Facilities (3) Martin Marietta Aggregates White Quarry (gravel washing) 34*52'12" Lat. 3/4 Mi Facility Belgrade 0.81 77"13'_35" Long. Belgrac C. Private Facilities (4) Gatlin-Ramsey Trailer 34*43'05" Lat. Bell S Park WWTF Hubert 0.09 77*16'00" Long. Mi. ab Crossir (5) Hewitt Trailer Park WWTF Hubert 0.03 34*43'00" Lat. Bell S 77*15'40" Long. Mi. ab Crossir (6) Swansboro High School WWTF Swansboro 0.02 U.T. ol Br. Maximum Potential Total Discharge Volume (MGD) 1.43 C. 17 ilic el Qc cr Alro spr rlro Br lebs ca JOHES co -,@ol fers 4 14urlt We b Coos oLine r;z ol Cr. 5 sw-p CA 6 .2;7 S jh,; rong ON lp -Easi -@/ rc, a -le 7 F I G U R E 3. 2 SOURCE: WHITE OAK RIVER POINT SOURCES OF WATER QUALITY MANAGEMENT POLLUTION PLAN. (1975). WHITE OAK RIVER SYSTE.M. HENRY VON OESEN a ASSOCIATES - CONS 4LTING ENGINEERS a PLANNERS - WILMiNGTON, N. C. 3.8.2 Non-Point Sources of Pollution General Non-point or di ffuse sources of pollution include urban stormwater runoff, silvicultural and agricultural runoff and residuals from individual septic tanks, etc. These sources have not been quantified to the same.degree as have been the point source discharges within the basin. However, some estimates of their magnitude and influence have been made. Stormwater Runoff Water pollution originating from stormwater runoff from urbanized or developed areas is recognized as a complex. problem which has been only partially solved. Whenever it rains, the streams in the White Oak River Basin receive a variety of pollutants including heavy metals, chemicals, sediment, litter,- residual oils'and bacteria. The stormwater flows across streets, parking lots,, rooftops, lawns, and gutters carryi ng'pol 1 ut ants directly to waterways without treatment. The urban and built-up areas shown on Map 3.*2 would be most likely to contribute such 'pollutants to the White Oak River. The Maysville - Belgrade area in the upper river basin and the Swansboro - Cedar Point area in the lower estuary would be the major- generators of stormwater runoff. It is suspected, but not confirmed,, that higher coliform counts occur in the local receiving waters near these areas immediately after periods of heavy rain. Such runoff is probably a contributing cause of the closing of shellfishing waters as indicated in Map 3.5. The N. C. State-Wide 208 Area Management Plan, Water Quality and Urban Stormwater, indicates that nationwide research on the stormwater problem has been considerable but information on the effectiveness of controls is still rudimentary. The Plan recommends certain practice s that can benefit water quality along with serving other beneficial purposes such as flood control. The 3-10 recommended practices include street cleaning, catch basin cleaning, covering chemical stockpiles, use of small-scale detention basins and infiltration methods, 'erosion control, litter control, and pro tec tion of flood plains. Agricultural Runoff Another source of surface water pollution is agricultural runoff. The magnitude of this source depends upon the frequency and duration of intense rainfalls. The agricultural activities that are most likely to cause pollution and/or affect water quality include: (1) The use of fertilizers, pesticides, and herbicides on row crops and pastures, (2) Pollution from farm animals, especially livestock and poultry, (3) Pollution originating from farm based septic tanks used for the disposal of domestic wastes, and (4) Exposure of the land to erosion during the cultivation of. fields and land clearing for buil dings, roads, or other developments. The first three items are expected to increase the concentrations of substances-dissolved in water leaving the basins. The last item is expected to increase concentrations of suspended sediment and1constituents adsorbed on or in some way associated with.sediment. Th6 Department of Natural Resources and Community Development, Division of Environmental Management's Water Quality Management Plan for the White Oak River Basin (Sub-Basin-01) estimates that the pollution loading from agricultural runoff is on the order of 1841 pounds of B005 per day. The.rainfall. frequency in this ar"ea averages one significant rainfall event (one -inch or more) every thirty days. The pollutional loadings from one of these events can be estimated from the size of the drainage area and using a conservative runoff coefficient of 0.2. The calculation is as follows: 3-11 Drainage Area 400 square miles = 11,151,360,000 square feet. Volume of runoff resulting from a one-inch rainfall event (0.2) (1112 ft.) (11.151 36 b.l.sq.ft.) 185,856,000 cubic feet 1,390 MGD Waste Load =, (30 days) x (1,841 pounds BOD5/day) = 55,230 pounds BOD5 Waste Concentration = 39.73 pounds BOD5 per million gallons = 4.76 milligrams per liter. The pollution load associated with surface runoff in terms of BOD5 appears to be relatively less significant than point sources-within the sub- basin. A recent study of the environmental effects of agricultural land develop- ment on the drainage waters in the N. C. tide,water region was completed by the Agricultural Research Service.L./ While this.study focused mainly on the development of the high organic soils in Dare, Hyde, Tyrrell and Washington Counties of N. C., some of the findings are pertinent to this study on the White. Oak River Basin: (1) Peak runoff rates occur earlier and are three to four times higher on developed lands than on similar undeveloped lands. (2) The largest potential eutrophication hazard resulting from development may be the increase in phosphorus in drainage waters. The effect of development upon phosphorus losses in drainage waters is very dependent upon soil type. Inorganic soils react with fertilizer phosphorus to prevent its loss. The solubility of phosphorus in shallow and deep organic soils is much greater than in inorganic soils, so much of the added phosphorus can be lost to drainage water. The weighted average concentration in drainage waters from the two developed organic soils was 1 - 2.5 mg/l for a total phosphorus efflux of 7 - 10 kg/ha/yr. The amount of this phosphorus which reaches major streams or estuaries L-/.'Skaggs, R.W., etal. (August 1980). Effect of Agricultru'al Land Develop- ment on Drainage Waters in the North Carolina Tidewater Region. Water Resources Research Institute Report No. 159, Raleigh, N. C. 3-12 will depend on distance the water must travel to reach the outlet, the type of sediment in the collector ditches, and the soil material in the banks. If the sediments are from inorganic soils or the canals are cut into mineral layers, much of the inorganic orthophosphate may be removed from solution by these sediments. Fortunately, much of the current agricultrual development is on mineral soils where P losses are small. However, it should be recognized that agricultural development of organic soils low in mineral content immediately adjacent to estuaries or major streams will very significantly increase the entry of phosphorus into these waters. (3) The highly organic blackland soils are very flat so erosion is not a problem, but development does cause a small' increase in the sediment load of drainage water s. This increase is particularly apparent during the developmen- tal phase of farming. Turbidity of the drainage water is increased during clearing and land shaping. Once initial development is completed, erosion and turbidity during normal agr icultural production is not fikely to cause a water quality problem. (4) There are several water quality parameters which are measurably affected by development, but the change is relatively.small. For example, D.O., BOD, temperature, and pH, are all slightly higher in drainage water from developed areas. Other parameters which change upon development but are not generally considered critical in evaludtion of water quality in this region are- Ca, Mg, Cl, Na, and K. There is very little effect of development upon efflux of the metals Cu, Zn, and Fe. (5) one potential problem with development of the organic soils for pastures near shellfishing waters is the loss of fecal organisms in drainage waters. The counts of fecal and total coliform bacteria in drainage water from the pastured site were considerably greater than from natural waters. This 3-13 increase in coliform bacteria from grazed lands is common throughout the U.S. and apparently causes few problems. However, a problem could result if grazed land is located immediately adjacent to shellfish waters. Development also caused an increase in coliform bacteria from the cropped shallow organic soil even though no domestic animals were ever kept on this site. (6) Concentrations of the herbicide alachlor in drainage water' after application suggested that some applicators were careful to avoid spraying the V-ditches draining the fields but that some may have sprayed directly over them, or so close that heavy drift of sprays occured,, causing excessively high con- centrations of herbicide in drainage water during the first few days after some applications. More diligence and care during application of all pesticides used on many farms in the Tidewater Region of North Carolina, where ecologically sensitive areas exist in close proximity to large agricultural areas, would reduce or even eliminate significant hazards caused by direct spraying of, or drift onto water in drainage canals. (7) Transport of the herbicide alachlor and probably other pesticides as well in surface runoff from the high organic soils of the Tidewater Region of eastern North Carolina and similar areas elsewhere does not appear to pose a@ significant hazard to aquatic life. ---However,,' it appears that some hazard 'from overspraying of or drift into drainage ditches exists in ecologically sensitive areas which the experimental sites repr .esent. Most likely, more diligence and care during application would greatly reduce such hazards. Beginning in 1977, the N. C. Division of Marine Fisheries with the coopera- tion of the N. C. Office of Coastal Management began a study of the effects of upland drainage on the estuarine*nurse ry areas of Pamlico Sound. The results of thi s study are pertinent to *the White Oak River estuary. 3-14 The N. C. Division of Marine Fisheries established four sampling stations in tributaries of northern Pamlico Sound, N. C. The four stations received either heavy, moderate or no drainage through man-made water courses. The period of study was from 1977 to 1980. The following conclusions were derived from the study.:- '(1) Drainage of surface water from upland areas into nursery areas through man-made ditches and canals creates. unstable salinity conditions when rainfall exceeds one inch in a 24-hour period. The unaltered nursery areas showed much more stable salinity readings during the same rain periods. (2) The nursery areas appear to have the capacity to receive a certain amount of "unnatural" drainage and'buffer the effects of rainfall on salinity, except during periods of extended rain. (3) Extensive drainage into a single nursery area-reduces its value as estuarine habitat by reducing average salinities and making it more sensi- tive to the effects of rainfall within the drainage basin. (4) Relative productivity of estuarine organism,s (brown shrimp and juvenile finfish) was lower each year in'the nursery area with extensive drainage. (5) The data did not show that there were any mass or complete move- ments of juvenile brown shrimp from the nursery areas as a response to' rapid changes in salinity readings. The most serious effects of drainage into nurserv areas appear to be-the degree of alteration and the danger that alteration will be severe enough to create an unsuitable habitat during periods of normal rainfall. In recognition of the appeal and value of the seafood resources derived from the estuarine areas and the fact that changing uses of'lands surrounding 3-15 vital nursery areas is inevitable, given the current trends in the value of agricultural and recreational developments, the Division of Marine Fisheries made the following recommendations: (1) It is important that resource agencies stress the value and fragile nature of small estuaries and encourage development of adjacent lands in such a way as to minimize its adverse impacts. (2) Identification of critical nursery areas must be made and protec- tion of these areas enhanced with proper legislation. Local, state, and federal agencies should develop joint comprehensive programs which will allow the wisest use of coastal lands and minimize degradation of water quality and wetland habitat. (3) Particular attention should be placed on developing drainage progr@ms which promote: (a) strict controls over construction of new drainage systems discharging into critical nursery areas; (b.) maintenance of existing ditches and canals during periods of least biological activity in the receiving waters; (c) analysis of the hydrologic and biological impacts of expanding existing drainage systems; (d) development of water management and water control schemes which limit discharge points, and (e) consideration of the cumulative effects of extensive alteration of small estuaries. Silvicultural Runoff Due to the large percentage of land in the White Oak River Basin devoted to forests (see Map 3.4 and Table 3,2, above), silvicultural activities (harvest of trees) could have a significant impact on water quality in the White Oak River Basin. However, the pollution potential of these activities are perhaps the least studied and understood of all of the non-point sources of pollution in 3-16 the White Oak River Basin. The mechanical methods of harvesting timber have an obvious adverse effect on vegetation and the land with potential for adverse impacts on water quality. The State's Water Quality and Forestry Management Plan (see Bibliography) identifies the following areas in which additional information is needed: (1) The impact of intensive mechanical site preparation activities on water quality 'of receiving streams. (2) Acceptable alternatives to intensive mechan ical site preparation such as the use of her.bicides and/or controlled fire. (3) The frequency and degree of use of measures to protect water quality during timber harvesting and site preparation activities. (4) The extent to which forest management plans are requested and prepared early enough prior to harvesting to include recommended water quality protection measures. (5) The extent to which the recommendations in forest management plans are followed. (6) The water quality management impact of draining wetlands for intensive forest management in the coastal plain region. However, despite the prevalence of many unknowns in this area,-the Division of Forest Resources of the N. C. Department of Natural Resources and Community Development has independently developed a set of forest practice. guidelines related to water quality (see Bibliography, Section 8). The guidelines cover logging, site preparation and the use of pesticides, fertilizers and fire retardants. The extent to which these guidelines are or are not being followed in the White Oak River Basin is unknown. 3-17 -Septic Tank Effluent Pollution. Another source of non-point or diffuse pollution is from on-site wa stewater disposal systems, mainly from septic tanks. The State of N. C. has conducted limited monitoring of suspected problem areas and site investigations in order to define current water quality problems caused by septic tanks. As a part of the development of the State 208 Plan, the coastal area around Wilmington, N. C. was selected for monitoring by virtue of having high septic tank densities adjacent to shellfish waters. Monitoring was p eformed on four tidal creeks emptying into the Atlantic Intracoastal Waterway in this area. The creeks have no point source..discharges. Residential development on these creeks ranged from heavy (Whiskey and Bradley Creeks) to almost non-existent (Futch Creek). Bac- teriological (total and fecal coliform) samples were obtained from these creeks during the period of July to October, 1978. The test results along with density and soil factors which might be expected to affect coliform levels are shown in Table 3.4 following this page. The following conclusions were made as a result of these findings: (1) As the intensity of unsewered residential devplopment in the area increases, both total and fecal coliform cou'nts in the creeks rise. The highly developed Whiskey and Bradley Creek watersheds exhibited fecal counts far higher than the undeveloped watershed (Futch Creek). Total coliform counts i n Whiskey and Bradley were respectively 60 and 40 times higher than those observed in Futch Creek. (2) Residential development in the area has historically occured in watersheds containing the largest percentages of soils which are severely limited for septic tank installations. (3) An apparent dichotomy appearing in the data for Whiskey and Bradley 'Creeks (a much higher septic tank density in the latter', accompanied by no 3-18 TABLE 3.4 Results of Monitoring of Tidal Creeks In New Hanover County, North Carolina-V Whiskey Bradley Pages Futch Creek Creek Creek Creek Fecal Coliform* (colonies/100 ml) 196 228 64 21 Total Coliform* (colonies/100 ml) 3970 2452 2007 66 Estimated Septic Tank Density** (units/acre) .367 .563 .154 .036 Soils with Severe Limitations for Septic Tanks*** (percentage .of basin) 78 70 47 10 Source: North Carolina Department of Natural Resources and Community Development. July 1979. Water Quality and On-Site Wastewater Disposal, a Management Plan. Raleigh, N. C. Mean values determined by disre garding the high and low value samples. Estimate based on data from Wilmington-New Hanover Planning Commission map of dwelling units in New Hanover County, drawn from 1975 aerial photos. Estimated from detaile'd soils map of New Hanover County, U.S. Soil Conservation Service. appreciable rise in mean col iform counts). may be related to the fact that development in the Whiskey Creek watershed is concentrated more closely to the creek itself. (4) A much more elaborate study would be necessary to determine defini- tively that septic tanks are the cause of the pollution observed. However-, the fact that all residences in the area are served by septic tanks tends to support the hypothesis that the pollution is related to septic tank usage. In view of the above, it can be reasonably concluded that septic tanks are definitely a contributing factor to the closing of certain areas of the White Oak River to shellfishing and are a source of surface water pollution. 3.9 Fisheries Resources Several studies of the fisheries resources of the White Oak River have been completed in recent years. In 1964, the Division of Inland Fisherfes of the N. C. Wildlife Resources Commission conducted a survey of the White Oak River in order to determine basic reference data on the biological, chemical and physical characteristics of the streams in the watershed. The physical and chemical characteristics of the streams within the White Oak River'watershed were found to vary considerably from the headwaters to the coastal area. Generally, the waters were found to be relatively free from pollution and chemically suitable as fish habitat. The dissolved oxygen concentrations varied from 1.0 ppm to 8.0 ppm. The lower concentrations invariably were found in streams containing intense swamp drainage. Generally, the concentrati-ons-.of dissolved- oxygen were adequate for the fish life present. The chloride content (ppfn NaCl), expressed as chlorinity, ranged from 0.0 ppm in the strictly fresh-water habitat to 29,250 ppm in the marine habitat. 3-19 Lunar tides, which affect approximately 70 percent of the water area, are constantly chan ging the fresh-water habitat, and particularl y during extremes associated.with severe storms and hurricanes. During the study, the transition zone between fresh- and salt-water'habitats appeared to be a fairly well defined area, usually with only two to three miles separating the upper and lower limits. The transition zone between the fresh- and salt-water habitat is shown in Figure 3.3.L./ The fresh-water fish habitats are typical black@water, swamp-drainage streams usually with an imperceptible flow, sand-detritus bottom., and very little turbidity. Most of the small streams are choked with fallen trees and overhanging bushes. The lower coastal reaches of the watershed are typically marine habitat and support an important shellfish, sport-fish, and food-fish industry. The more important fresh-water 9 ame species found du ring the survey, listed in decending order of their frequency of occurance, were: Redfin pickerel Esox americanus americanus Chain pickerel Esox niger Warmouth Chaenobryttus gulo9jus Bluegill Lepomis macrochirus Pumpkinseed Lepomis gibbosus Redbreast sunfish Lepomis cyanellus Largemouth bass Micropterus salmoides Mud sunfish Acantharchus pomotis The more important fresh-water -non-game species found during the survey, also listed in decending order of their frequency of occurance: L/ Re'cent studies of sediment cores by UNC scientists, Mart6ns and Goldhaber (see Bibliography, Section 8), indicate that seawater influenced sediment chemistry farther upstream in the past than at present. 3-20-- C Cf. 94 c / sp Br Calebs lc4rs CO 14 unlers 0 ine coos not Cr. swl G' ro Of rang r-01 n Et@ F I G U R E 3.3 WHITE OAK RIVER BASIN TRANSITION ZONE BETWEEN SOURCE: SURVEY AND CLASSIFICATION OF THE NEW - WHITE OAK - NEWPORT SALT AND FRESH WATER. RIVERS AND TRIBUTARIES, N.C 1965 WILDLIFE RESOURCES COMMISSION RALEIGH, 14. C. KEY: TRANSITION ZONE HENRY VON OESEN a ASSOCIATES-CON31ji-TING ENGINEERS a PLANNERS- WILMING-1-cm, N. C. Banded sunfish Enneacanthus obesus Pirate perch AphredoderLIS sayanus Bluespotted sunfish Enneacanthus gloriosus. Golden shiner Notemigonus crysoleucas Ironcolor shiner Notropis chalybaeus Some of the more important salt-water species 'collected during the survey are listed in phylogenetic order as follows: American shad Alosa sapidissima Atlantic menhaden Brevoortia tyrannus Bluefish Pomatomus saltaltrix Spotted seatrout Cynoscion nebulosus Spot Leiostomus xanthurus Atlantic croaker Micropogon undulatus Black drum Pogonias cromis Red drum Sciaenops ocellata- Striped mullet Mugil cephalus Summer flounder Paralichtys dentatus South'ern flounder Paralichtys lethostigma', The dominant freshwater predator species collected in the watersheds were the redfin and chain pickerel. The fish populations were generally well balanced, with a relatively high ratio of game to non-game fishes. This ratio was attributed to several factors: High water quality, good physical habitat, and low fishing pressure. Detailed assessments of each of the major tributaries of the White Oak River are found in the apendicies to the study (see Bibliography) which is available from the Wildlife Resources Commission. 3-21 From October, 1973 to June, 1975, the N. C. Division of Marine Fisheries conducted a survey of anadromous fisheries of the White Oak River System. This study identified a total of six anadromous species which enter the White Oak River including the Striped bass (Morone saxatilis), American shad (Alosa sapidissima), Hickory shad (A. mediocris), blueback herring (A. aestivalis), alewife (A. pseudoharengus), and Atlantic sturgeon (Acipenser oxyrhynchus). All six species are considered both sport and commercial fish and are taken by standard commercial fishing gear. The objectives of the Marine Fisheries' study was to determine the distribution of migrating and spawning adult anadro- mous fishes, to determine. spawning areas and periods of major spawning activity for anadromous species, to determine nursery areas, and the growth and movements of juvenile anadromous fishes. The Marine Fisheries' researchers found that the White Oak River supports a substantial run of blueback herring and smaller runs of alewife, American shad, and hickory shad. Adult blueback herring were found to enter the river in January. Juvenile blueback herring were subse- quently found to use the Martin Marietta Belgrade Quarry Lakes,-the river below, and certain tributaries as nursery grounds. Their seward migration was found to occur in October. Adult alewife were found to enter the river in April. Only a few. juvenile American shad were found. All three species of anadromous fish used the Martin Marietta Belgrade. Quarry Lakes as spawning areas during April and May. Although the lakes repre- sent an altered environment, they still appear to support adequate populations of anadromous fish. In addition, in 1975, river herring were found to use Holston and Grant Creeks as spawning areas with spawning probably occuring in Hunter and Webb Creeks. 3-22 SECTION EXECUTIVE SUMMARY WHITE - OAK RIVER SYSTEM STUDY [A Plan Of Action Fbr Ilia White Oak River) HENRY VON OESEN AND ASSOCIATES CONSULTING ENGINEERS AND PLANNERS SECTION 1: EXECUTIVE SUMMARY A study of the White Oak River basin was conducted' to def ine existing conditions and problems and to suggest recommendations for further study along with proposed non-structural and structural solutions to identified problems. Also included herein is a plan of action for the White Oak River wherein each specific recommendation is identified and estimated costs are suggested for completion of the recommendation. While certain identified problems must receive'additional study, some actions can be undertaken immediately with little or no additional delay. The. first major conclusion of this study is that. the water depths in the lower White Oak River have decreased during the past century and particularly since the major construction projects of the AIWW and N.C. Route 24 Bridge and Causeway which occured in the early 1930's. The-redistribution of uncons'oli- dated spoil materials from the dredging of the AIWW to 'the area above the N.C. 24 Bridge/Causeway is considered to be a major cause of this major shoaling and depth loss problem in the lower estuary. -The construction of the bridge and causeway reduced the effective'width of -the river, blocked off one channel of the river, and presumably acted to contribute to the shoaling problem. A second major conclusion derived is that many of the seafood resources in the White Oak River are apparently underutilized. Pollution from septic tank effluents and other non-point sources have contributed to this underutilization by placing vast areas of productive shellfish bottoms off limits to commercial fishermen. While--an oyster replanting program- conducted -by --the --N . G. - Div-isi-on---- of Marine Fisheries has been successful, a similar program for relaying of polluted clams has not been attempted due to a lack of funds and the restraints imposed by current fisheries regulations. Aggressive initiatives on the part of responsible individuals and agencies will be required to fully exploit the fisheries resource potentials of the White Oak River Basin. In recognition of these problem.s, the following plan of action is recom- mended for the White Oak River:, A. Overall River Basin Management and Control (1) A study to be conducted under the UNC-Sea Grant Program to develop a mathematical'model of the White Oak River Basin with the goal of predic- ting futu're changes and.abating pollution. (2) A reactivation of the PL 83-566 Watershed Project on the White Oak River administered by the USDA-SCS with the goal of developing a comprehen- sive watershed plan. (3) Improvement of existing agricultural, silvicultural and septic tank installation practices throughout the White Oak River Basin. B. Fisheries Resources (1) A shellfish bottom survey of the White Oak River Estuary to be conducted by the N. C.,Division of Marine Fisheries. (2) -A new management regulation to be developed by the Marine Fisheries: Commission to permit -relaying of clams from polluted to clean areas for self-cleansing and subsequent marketing. (3) An expansion of the shellfish relaying program conducted by the N.C. Division of Marine Fishe ries in the White Oak River by greate-r utilization of private contractors. (4) A continuation of a study of the stunted oysters in the White Oak River by the Duke University Marine Laboratory. C. Sedimentation: An expansion of the existing Bogue Inlet study conduc- ted by the Wilmington District of the U.S. Army Corps of' Engineers to include 1-2 investigation of shoaling and the effect of canalized flows in the lower White Oak River estu*ary. 1-3 The Marine Fisheries study concluded that the greatest problem facing anadroinous.fish populations in small rivers like the White Oak is flood control activities such as channelization and watershed development. The impact of such alterations has been seen in the case of the New River' which once had a signifi- cant anadromous fish population prior to a significant channelization project for flood control above Jacksonville. As a result, the N. C. Division of Marine Fisheries recommends that future channelization projects be given close scrutiny, especially'where anadromous fish resources are involved..!/ Discussions held with Mr. Bob Chapoton of the National Marine Fisheries Service (NMFS).-in Beaufort, N. C. revealed that the White Oak River is an important nursery area for juvenile Atlantic menhaden. Menhaden are spawned in the ocean and enter the Whit e Oak River estuary as larvae from November to May. Once strong enough to swim against the tidal currents, they move upstream towards fresh water where they transform into juveniles by.mid-May. They remain in the estuary for their first growing season, gradual ly'moving down stream in the summer and reaching the lower estuary or open sea by autumn. Menhaden are ver important economically to North Carolina. Menhaden are y processed into fish oils and meal'for agricultural feed supplements. The menhaden are harvested in the nearshore ocean waters after they migrate to the ocean via Bogue Inlet. The NMFS reports that the White Oak River exceeds the Cape Fear River in importance as a nursery for menhaden. Martin Marietta aggregates recently received CAMA and Corps permits for the- proposed- construction of a 90--f.oot. wide,.A5--@50 -foot long fill roadway_ crossing the White Oak River at their Belgrade, N. C. quarry. As proposed, approximately 1,000 cubic yards of clay will be placed below the normal water level contour elevation for the crossing which is located immediately downstream from the existing quarry lakes. Three 90-foot long, 12-foot .diameter culverts are to be emplaced in the river channel to accomodate normal and 25-year flood flow requirements. 3-23 in addition to finfish resources, the White Oak River is very important as a product.ive area for shellfish, mainly oysters and clams. The N. C. Division of Marine Fisheries (NCOMF) is of the opinion that the resource is considerable. However, to date it has not been quantified by means of a shellfish bottom survey. Since 1972, the NCDMF has conducted a very successful, oyster relaying project in the upper river estuary. Oysters are relayed from over crowded oyster bars in mid river and emplaced in public oyster management areas. Map 3.6 shows the locations of the public oyster management areas and the quantities of oysters which were relayed in the years 1978, 109 and 1980. These public areas are opened and closed by proclamation. In addition to oysters, clams are another important shellfish resource in the river. At present, the river is opened to clamming all year long except for the areas closed due to pol lution (see Map 3.5). Significant clam resources are found in the closed areas. However, iack of funds and existing regulations have hindered any efforts to relocate these to non-polluted 'areas for self cleansing and ultimate marketing. (See Section 5.2.2. for a further discussion of this matter). 3.10' Seafood Landings The N. C. Department of Natural Resources and Community Development, Division of Marine Fisheries has kept records on the pounds and value of the seafood which has been obtained from the White Oak River system since the year 1959. However, the data prior to the year 1978 is often sketchy and incomplete making an accurate analysis difficult, if not impossible. Nevertheless, despite the difficulties with the data base, overall trends can be noted. The trends in landings of hard clams, oysters and blue crabs from the White Oak River are shown in Figures 3.4, 3.5 and 3.6, respectively. Up and down fluctuations from year to year are noted in each case. This may be due in part 3-24 Wli I TE 0 K R K E Y: OYSTER MANAGEMENT AREA 12,000 Bu. RELAYED 1978 20,000 Bu. RELAYED 1979 20,650 Bu. RELAYED 1980 C g. IN 0 -Z 19Pc) creek 0. ot gr C48 MAP 3.6 cc; ........... WHITE OAK RIVER ;, . OYSTER MANAGEMENT AREAS. N, 50 SOURCE: N. C. DIVISION OF MARINE FISHERIES. HENRY VON OESEN a ASSOCIATES -CONSULTING ENGINEERS a PLA NNERS- WILMINGTON. N. C. 100- FIGL 90- WHITE HARD CLA 80- 19 W 70- 0 z M 0 (L 60- 0 50- z 40- D 50- %0 20-q 10- Z@TA 0 1959 62 64 66. 68 70 72 74 76 78 80 Y E A R S HENRY VON 6ESEN a ASSOCIATES CONSULTING ENGINEERS a PLANNERS WILMINGT( t 12 10 FIGU 9- WHITE 0 OYST E R 195 co 7- z 0 a. U. 0 5- Z!j (n 0 4- z (n D 3- 0 4 N 0 DATA 0 13 1959 62 64, 66 68 70 72 74 76 78 80 Y E A R S HENRY VON @ESEN Ek ASSOCIATES - CONSULTING ENGINEERS a PLANNERS -WILMINGTON, 325.4 125 120 - 110 - FIGURE WHITE 0 100- BLUE CRAB 1959- 90 - 80- z 0 (L 70- LL 0 60- %0 z < 50- D 0 40- '3 0 - 20- 10- 1959 62 64 66 68 70 72 74 76 78 -80 Y E A R S HENRY VON 'OESEN a ASSOCIATES - CONSULTING ENGINEERS a PLANNERS WILMING to normal biological fluctuations, as well as errors or omissions in data collection or reporting. Data from 1978 to 1979 are to be' trusted more than data collected in prior years due to substantial improvements in the data collection program. Landings in recent years appear to be generally greater than those reported in the past. In the case of clams and blue crabs,- these increased landings have been attributed to increased effort. In the case of oysters, the increased landings have been attributed to the success of the NCDMF's relaying program (see Section 3.9). The trends in landings of finfish and shrimp are not as clear due to-a lack of data. Fi.nfi.sh landings in 1966 were 3,580 pounds, with 57,300 pounds in 1978 and 112,100 pounds in 1979. These increases appear to be due in part to better reporting and data collection methods. Shrimp landings have fluctuated from 25,795 pounds in 1966 down to a low of 4,100 pounds in 1978 and back up to 19,600 pounds in 1979. Shrimp landihg data appear here to reflect the poor biological conditions of the 1978/79 season. Shrimp Tandings statewide were less than average during both years due primarily to adverse weather conditions (low salinities an d low temperatures). However, the NCDMF personnel indicate that shrimp have never been a significant resource in the White Oak River-. This is due to the fact that most of the embayments in the river are' closed to shrimping because these areas serve as nursery areas for juvenile shrimp. Furthermore, the shrimp in the river tend to migrate from the estuary rapidly. Therefore, most of the White Oak River shrimp are caught in the ocean off of Bogue Inlet and are landed in other ports in the area rather than at Swansboro. The economic value (dockside value) of seafood derived from the White Oak River approached $315,000 in 1979. Trends are shown in Figure 3.7. The quantum jump in value in 1978 is attributed in part to better data collection and to inflation as well as increased harvests of shellfish from the estuary. 3-25 300- FIGURE 3.7 WHITE OAK RI 2-50- TOTAL VALUE SEAFOOD LAND 200- c/) 0 LL 150- 0 z V) 100- 0 w 75- > 50- 25- 12. 4L. 1959 6.2 66 4 6 65 613 70 -72 74 76 -18 so YEARS Aak w HENRY VON OES'EN a ASSOCIATES CON SULTI N7FENGINEERS a PLANNERS WILMINGTQ@ The docksi4e value of seafood landed is only a fraction of the final value after it filters through normal marketing channels. Using an economic multi- plier of 2.0, the actual value of seafood to the area for the year 1979 is about $630,000. The data presented here does not reflect a general di minution of fisheries resources from the White Oak River. To the contrary, it appears to show an increase (whether it be contrived or real) in both po unds landed and dockside value. N. C. Division of Marine Fishereis personnel feel that increased effort to harvest seafood is a primary reason for these increases. 3-26 -SECTION 4: IDENTIFICATION OF EXISTING PROBLEMS 4.1 Sedimentation 4.1.1 General Pollution, sedimentation and shoaling, particularly in the lower river estuary, have been identified by the White Oak River Advisory Council as the key problems to be addressed in this study and report. The pollution problem was discussed extensively in Section 3 and will be addressed again later in the report. Sedimentation is a natural process which is influenced by several factors. The following section pres ents a brief consideration of the basic principles of estuarine sedimentation which is based primarily on the report entitled, "Hydrology'of Major Estuaries and Sounds of North Carolina" (se6 Bibliography, Section 8). 4.1.2 Principles of Estuarine Sedimentation The mechanics of transport and deposition of sediment in an estuary are far more complex than in ordinary streams. Yet, because of the impact of sediment deposition on aquatic life and on navigation, and because large sums of money are spent in dredging and maintaining navigation channels and boat facilities, it is important to develop a clear understanding of the principles of estuarine sedimentation. Sediment, whether moving in a freg-flowing stream or in an estuary, has t wo components--suspended sediment and bed load. Suspended sediment is comprised of particles that are held in suspension by the upward components of turbulent currents and finer particles held in colloidal suspension. Bed load consists of material. too heavy to be held in suspension but which nevertheless moves by sliding, rolling or skipping along the bed of a stream or estuary. In a free- flowing stream, however, net flow (and, therefore, sediment discharge) is always 4-1 downstream and usually changes in magnitude slowly, whereas in an estuary the tide-affected flow (and, therefore, sediment discharge) generally changes rapidly in magnitude and direction. Changes in chemical quality alo ng streams are usually small and have negligible effect on sediment concentrations, whereas quite dramatic changes in chemical quality occur within estuaries and these may profoundly influence sediment transport characteristics. In many estuaries, a characteristic zone of high concentrations of suspended sediment and high turbidity begins near the saltwater front and, in some estuaries, continues downstream for miles. Upstream from this zone, in the freshwater portion of the estuary, concentrations are less; downstream from this zone, in the ocean, concentrations are also less. The probable explanation for this zone is that such estuaries.act as sediment traps. This may be better understood by referring to the net circulation patterns on Figure 4.1 for a highly stratified estuary. Imagine suspended sediment being carried out to sea in the top layers of freshwater during ebb flow. As the time of slack water approaches where the estuary widens towards the mouth or as the freshwater spreads out over the bays and adjacent ocean, velocities decrease, thus allowing heavier sediment particles to settle. As they settle, they are-entrained in water moving upstream along the channel bottom. At the upstream end of the saline water zone, flow circulates upward and downstream, and sediment particles may again be entrained upward and flow towards the sea in the upper freshwater layers. Again, the particles may settle as velocities decrease, and thus a sediment particle may be caught in a loop pattern several times. This sediment-trap phenomenon is found to some extent in highly stratified situat ions, but is even more pronounced in partially-mixed estuaries where net upstrean. velocities near the channel bottom and net downstream velocities near the surface are much greater than in highly stratified estuaries. This pheno- 4-2 DOWNSTREAM x A. , -1 Sea WATER SURFACE River FRESHWATER SALTWATFR ON SALTWATER WEDGE CHANNEL BOTTOM .x 0. Section X-XI LL. C. Section X-X' cr 0 0 Cr Uj W 10 10 Tronsition zone Transiti.on zone 3:: 20 20 _j _j M 30 30 Uj U_ U_ 40 z 40 0 25 50 75 100 2 1 0 1 2 SALIN!TY, IN PERCENT Downstream Upstream OF SEA WATER. CL W VELOCITY, IN FEET PER SECOND FIGURE :4.1 .--A. Net ciAcutation patteAkiz in a h@ghty*,stAati6ied eztua,%y. B. Satijvity p4ojite th,%ough.,sect:iopL.X X1. C. Net.veXocity jxo6ite.th,%ough ACCti0fl. X X'. SOURCE: Giese, G. L., H. B. Wilder, and G. G. Parker, Jr. July 1972. Hydrology of Major Estuaries and Sounds of North Carolina. Report of Watbr Resources invest iqa'L-.i ons No. 79-46, U. S. Geological Survey, Raleigh, N. C.. HE NRY VON OESEN a ASSOCIATES -CONSULTING ENGINEERS a PLANNERS -WILMINGTON, N. C. menon is probably not found to any signif icant extent in wel I -mixed estuaries, where there is no significant net upstream flow along the channel bottom. The sediment trap zones in estuaries are, naturally enough, zones of high sediment deposition. Most of the deposited sediment in these zones is of clay or silt size. The particles tend to settle to the channel bottom wherev'er or whenever i nstantaneous or net velocities suddenly decrease or approach zero. The tip of a saltwater wedge is one area of rapid depo sition because net velo- city is zero in that 'Vicinity. Other potential areas of deposition are where tributaries enter a slow-moving main channel, in bays, and in boat slips. Another potential factor that may account for some sedimen.tation in the sediment trap zone is flocculation and subsequent deposition of clay-sized particles in the water. This process depends on the presence of electrolytes, such as sodium chloride, which neutralize the electro-negative characteristics typically,associated with sediment particles. Salt water is an electrolyte, and the setting of fine-grained particles is indeed observed in the saline water zone. However an additional or alternative binding mechanism brought about by filter feeding organisms has been advanced by certain researchers based on the results of an extensive size-analysis'study of particles in suspension at all depths -in Chesapeake Bay and the Susquehanna River. It was reported that many composite particles were observedi particularly in the lower layer, which were agglomerates weakly bound by organic matter and mucus. These agglomerates were probably produced by filter-feeding zooplankton. Preliminary experiments have indicated that suspension-feeding zooplankton probably play a major role in the agglomeration of fine particles in the water column, and in the subsequent depo- sition of those particles. The large population of filter-feeding zooplankton present in the Chesapeake Bay probably filter a volume of water equivalent to that of the entire estuary at least every few weeks, and pe@haps every few days. 4-3 Potential sources of silt and clay-sized sediment deposited in a sediment- trap zone are many. Studies or many United States estuaries have shown that sediment from upland discharge is i nadequate in most cases to account for the shoaling rates that are observed in river channels and harbors. Other sources of shoaling material are as follows: (1) marsh. areas adjacent to the estuary with runoff draining into the tidewater, (2) materials in larger estuaries being eroded from the shores by wave action and moving by'density currents into the deeper portions, (3) matenials being dis.placed by-dredging and propeller wash and moved by density or tidal currents, (4) organic materials as a result of the biological cycles of estuar-ine plant and animal environment. (5) industrial and human waste*s discha rged into the estuary, (6) windborne sediment. In addition to these sources, sediment resuspended from the channel bottom and later redeposited in shoaling areas may also be an important factor in high local shoaling rates in some ei,stuaries. In some cases, the open ocean adjacent to an estuary may also be a significant source of sediment. This, and (3) above are thought to be the primary sources for shoaling occuring in the lower White Oak River estuary. Regarding sediment deposition, and attempts to imp rove existing shoaling characteristics, the following points are made:. (1) sediments settling to the bottom zone in an estuary will on the average be transported upstream and not downstream, (2) sediments will accumulate near the ends of the saltwater intrusion zone and form shoals. Shoals will also form where the net bottom velocity is 4-4 zero due to local disturbances of the regime such as by tributary channels. (3) the intensity of shoaling will be most extreme near the end of the intrusion for'stratified estuaries and will be more dispersed in the well mixed estuary. Therefore, with regard to human interferences in existing estuary patterns, the follow ing general rules may be derived: (1) the major portion of sediments introduced fr om whatever source into an estuary during normal conditions will be retained therein, and if transportable by the existing currents will be deposited near the ends of the salinity intrusion, or at,locations of zero net bottom velocity, (2) any measure contributing to a shift of the regime towards stratifica- tion will cause increased shoaling. Such measures may be: structures to reduce the tidal flow and pri sm, diversion of additional freshwater into the estuary, deepening and narrowing the channel, (3) dredging 'of channels should be accompanied by p' ermanent removal of the sediments from the estuary.. Dumping downstream is highly suspected and almost always useless. Agitation dredging falls into the same category. Permanent removal is desired. Although the principals discussed in this section are useful in understand- ing general aspects of estuarine sedimentation, the actuall movement and deposi- tion patterns of sediment in real estuaries are usually extremely complicated in detail, and may require hydraulic model studies to adequately define. Model .studies of this kind are lacking for most sounds and estuaries in North Carolina including the White Oak River. 4-5 4.1.3 Sedimentation i'n the White Oak River Background In recognition of shoaling and sedimentation which was occuring in the Lo,wer White Oak River Estuary, members of the Cape Carteret Chapter of the Issac Walton League conducted an informal study of silting problems in the river in .1977. Depth measurements were taken at several locations at low ti'de and plotted on a map of the lower river estuary. Also, several local fishermen, boat captains and local residents were interviewed and asked to indicate to*the best of their recollection the depths in the river about the year 1920. The map was completed and subsequently published in the Tideland News of February 27, 1980. A copy of the map is reproduced in this report as Map 4.1. The map indicates a high rate of shoaling throughout the lower estuary. The publication of this map and the subsequent arousal of public concern over the matter represented one of the catalysts for the formation of the White.Oak River Advisory Council. -Histori cal Perspectives In an effort to obtain information on the historical depths of the White Oak River, we contacted Mr. Tucker R. Littleton, a private. historian from Swansboro. Mr. Littleton kindly searched his records for information which might shed some light on the historical depths in the river and Bogue Inlet. Table 4.1 presents a listing of Some fourteen ships which either were constructed at several waterfront shipyards in Swansboro and/or which used Bogue Inlet to obtain access to the Atlantic Ocean during the period from 1796 to 1897. Noting the drafts (when known) and--tonnages of the vessels,- it- appears that "the depth of the river and inlet must -have been much superior to its present condition," Mr. Littleton concludes. 4-6 Al@o @aCrc-ks, lillet A I< "DC Zi te CIO ILI,0 4L- IT 0 G@A C@l) 4r td 0 01 cc bi Ul P,,IC-.p Shoviing Vlater Dep-plij In River, Cound P, Inlet.....1-920 and 1977 Evidence of Shoaling Shown in Figures By Local Fishermen, 13oat Captaills, and Actual Depths Me Mr. Littleton also supplied some information on the history of Swansboro as a commercial seaport. Prior to the year 1787, the inlets of Onslow County were in the customs district of the Port' of Beaufort which is located in Carteret County to the east of Swansboro (the district office was actually located in New Bern, N.. C.). According to the State Records of North Carolina (Volume XI), in the 1740's vessels of 6 or.7 foot draft could navigate Bogue Inlet. in March 1752, some 24 years prior to the Declaration of Independence, inspectors of. exports were appointed for Bogue Inlet as one of the inspection points for. the Port of Beaufort.. On 26 December 1786, a Bill was passed creating the Port of Swansboro (spelled "Swann sborough " at that time), thereby establishing,a customs district which included Bogue, Bear and New River Inlets. This Bill took force in March of 1787. The importance of the port activity at Swansboro was demonstrated by the efforts of the Union forces against the Town and port during the Civil War. On 14 August 1862, a transport and seven Union steamers (the gunboat Ellis, Adelaide, Ocean Wave, Massasoit, Allison, Union, Wilson, and Pilot Boy) rendezvoused Jn the mouth of the White Oak River and landed Federal. forces the next day, occupying Swansboro until 19 August 1862, when the steamers 'departed for Beaufort. In October 1862, William B. Cushing was put in command of the gunboat, Ellis. Blockade running at Swansboro was considered important enough to merit giving Lt. Cushing, as his first assignment, the job of keeping an eye on Bogue Inlet. The White Oak River at various times in the past has been considered economically important enough to occasion several acts of the legislature to create or amend local navigation laws. For example, in 1800, "An Act to Clean and Keep Open The Navigation Of The White Oak River" was passed. In 1818, a program of canals and,internal improvements was proposed with the ocean terminus 4-7 to be at Swansboro. Col. Edward Pasteur of New Bern predicted that, if these improvements were in fact made, it would make Swansboro another Norfolk. Then, in 1859, the White Oak River Navigation Company was incorporated to improve navigation between Swansboro and Job Smith's Plantation. Records show that Job Smith lived near the head-of the White Oak River at 'least 10 miles above the Maysville Bridge. Table 4.2 presents a listing of landings along the White Oak River which indicates the importance of the river in early commerce and apparent greater .depths in recent history. This list was compiled by Mr. Littleton from verbal comments and written records of the period. In addition, Mr. Littleton indica- ted that there are piles of discarded ballast stones near the west-northwest end of Jones Island and also along the shore at Mount Pleasant Point which indi cate that there were early landings nearby, though 'no names for such are known today. In 1735, by an act of the Colonial Assembly, the people of. the White Oak River were ordered to pay their "quit rents" at Ross Bell's Plantation located at Mount Pleasant. At that early date, most of the settlers on the ,river would have.used water transportation, which certainly implies a landing there. Such a landing was probably a factor in the selection of Bell's Plantation as the place for paying the annual quit rents. In addition, at least 5 or 6 ferrtes were mentioned in early records as operating on the upper White Oak River. ' One ferry operated as early as 1731 across the river. Not long thereafter there is mention of a ferry operated from the Carteret side by Joseph Smith; another operated from Thurrell's Bluff on the Onslow County side by Francis Thurrell; and still further upstream there was a ferry operated by Francis Brice. Brice's Ferry appears on a 1733 map of N. C. by Moseley. Still another ferry operated at Smith's Mills. in the 1800's. Each 4-8 TABLE 4.1 Listing'of Vessels Using the Po t of Swansboro and Bogue inletj Item Draft Documented No. Year Vessel__Type/Name (Ft.) Tonnage Comme 1. 1857 Schooner D. W.Sanders 8 15� Docked' z 2. 1897. Barge Swansboro 188 Built at 3. 1841 Schooner Onslow 130 4. 1833 Schooner Caleb Nichols 10L./ 163 5. 1834 Schooner Zenith 103 6. 1832 Brig Solomon Status 316 7. 1828 Brig Onslow 150 8. 1825 Schooner Turpentine 118 It I 9. 1827 Brig Burdette 245 10. 1810 Brig Eliza Lord 159 11. 1799 Brig Hunter 109 12. 1797 Schooner Frederick 113 13. 1796 Brig Lewis 121 14. 1814 Ship (unnamed) owned by firm of Carroll and Dudley of Swansboro, North Carolina "about 600" Ld source: Tucker R. Littleton,.Private Historian, Swansboro, N. C. (compiled from ne accounts and nautical records of the period). Ld When loaded. TABLE 4.2 LIST OF LANDINGS ALONG THE WHITE ?AK RIVER ABOVE THE SWANSBORO BRIDG ITEM NO. NAME OF LANDING LOCATION A. Onslow County (Proceeding-Upstream) 1. New Harmony About 1/2 way between Swansboro New Harmon and Mount Pleasant Point on New recent yez Harmony Creek Corbett's 2. McGee's Southwest*corner of Jones Jones Isle Island Island 3. Freeman's On White Oak River at Swift's Also known Marshes 4. Machine Tract On river just above Stephen's Creek 5. Cahoon Point On river at Cahoon Point 6. Red Hill On river just below the Scott SE Place 7,8. Scott Place Two landings; one on ri ver front and one just. inside Holland's Mill Creek 9. Will bdum's- On port side going up Holland's Mill Creek 10, 11. Curt Holland's Two landings on starboard side S of Holland's Mill Creek above George Odum's Landing TABLE 4.2 Landings, Continued- ITEM NO. NAME OF LANDING LOCATION 12. George Odum's Just inside Holland's Mill Creek, on starboard side, going upstream 13. Elm On river just above Hargett's Shown o Creek 14. Freeman's At Freeman's Creek Note: N other 1 15. Freeman's Inside Webb's Creek 16. Sloan's On Webb's Creek 17. Koonce"s On Koonce's Bay opposite Ned's Creek 18. Brick Kiln Just below Stella Bridge 19. Mattocks's Just above Stella Bridge 20; Dorton's Above Stella Bridge Shown o Onslow .21. Bullock's Landing Up Grant's,Creek An impo 22. Bunga Up Grant's Creek. 23. Aman's About 0.5 mile upstream of mouth of Grant's Creek on Riverfront TABLE' 4.2 Landings, Continued ITEM NO. NAME OF LANDING LOCATION B. Carteret County (Proceeding Upstream) 24. Boathouse Creek Up Boathouse Creek 25. Salt Works /,On Salt Works Point across. channel from Jones Island 26. Charlie Dudley's Up Pettiford Creek on starboard Called Pc side, going upstream 27. Piner's Just below bridge on Pettiford Creek on starboard side 28. Meadows'@@s Just inside mouth of Starkey's Creek at confluence with Pettiford Creek 29. Unknown Near head of navigation of Starkey's Creek 30. Norris's On Morton's Point at Pettiford Creek 31. Windy Point Windy Point,at mouth of Pettiford. Creek 32. Truckner's Near where Pettiford Creek Bay joins the river 33.. Wiggins's On.river at Wiggen's Shore TABLE 4.2 Landings,.Continued ITEM NO. NAME OF LANDING LOCATION 34. Morse's Near Bernard Morse property Called .35. Watson's On Hadnot's Creek 36. Ned's Up Ned's Creek 37. Wetherington's On property formerly owned by Charles Wetherlington 38. Barker's Short distance below Stella 39. Unknown Immediately below Stella This la Bridge mill du in'the 40. Ervin's Short distance above Stella Bridge 41. Unknown Located where first high land touches Hunter's Creek near its mouth, on starboard side going upstream 42. Tantr,ough Located up Hunter's Creek half way between mouth of creek and NC 58 bridge TABLE 4.2 Landings, Continued ITEM NO. NAME OF LANDING LOCATION C. Jones County (Proceeding Upstream) 43. Long Point Above Hunter's Creek at Long At least Point 44. Haywood's Above Long Point A colonia 45. Holston's Creek Just inside mouth of creek An early. on port side, going upstream 46. Gillett's "Near Holston's Creek landing on the riverfront 47. Tom Coll'ins's On the White Oak River just. On'adjace above Gravelly Branch remains o Ld Listing compiled by Mr. Tucker Littleton, Historian, Swansboro, N.C. from oral and do of the foregoing ferries should add two landings to the list of White Oak River landing sites. The ferry landings may have received other use, since the court' directed in the case of Francis Thurrell that his ferry landing "be deemed a public landing" for the use of the public. Mr. Littleton also indicated that oral informants have indicated, that Jones's Island (formerly known as Bell's Island) which is located north of Route 24 Bridge in mid river was at one time (over 100 years ago) connected to the mainland by a low-lying land bridge. Access was gained at low tide from Mount Pleasant Point on the Onslow County side of the 'river. Remnants of farming activities on the island testify to the former use of this land. The main river channel also skirted the southeastern side of the island when Onslow County was established (see Map 4.2 following). In an effort to more clearly defin e the more recent series of events whi-ch have led to the existing conditions in the lower estuary, a series of maps of the lower White Oak River estuary were obtained from th e Wilmington District ,.Office of the U.S. Army Corps of Engineers. These maps accurately reflect the. changes that have taken place in the area over the period of 1873 to the present. An 1873 map, the first in the-series, (source unknown) shows very little development in the area except for the Town of Swansboro and scattered culti- vated fields and homes on the western and eastern mainland shorelines. There were no permanent developments on Bogue Banks or Bear Banks (Hammocks Beach). The area of the river between Swansboro and Cedar Point consisted of two deep channels,, called the "Swansboro Channel" and "East Channel", plus a narrow shallow channel (unnamed) near Cedar Point (see Map 4.2). - It is assumed from this map that the principal flow of the river was through the deeper channels, with sheet flows occuring over the easternmost 4-9 3r 'Ge 's rs. IL (t.., (t/0/70S rj. x A% 0. A ..k. IL A Qld 3, bo-rO chonnel V -o 7:p.jsb6r. channel) sw F7 V, (V, T-1 -7. e4l CV, 00 \t);p I .610 c1b -2 s ry X RMS Bay v V. 14. Cedar zzt Codair Poln-I <- 4i: CA M A .............. ... ... WHIT VICIN 0 *4yl. N. C. Cal ..... . .. . SOURCE OF ENG SOURCE HENRY VON 0 E S E N (k ASSOCIATES CONSULTING EN GINEERS a PLANNERS WILMi shoals and marshes during freshets, the higher spring/fall tides or during storm tides. The second map from the year 1910 (source unknown) shows little apparent change from 1373 (see Map 4.3). However, this map shows water depths in the West Channel of Bogue Inlet (between Dudley's Island and Bear Banks). Depths of up to 12 feet are noted in this area, which indi ,cates that this channel was navigable at this period of history. Some depths in Bogue Sound between West Bogue Banks and what is now Cape Carteret are also shown on this map. The third map in the series dates from the year 1928 (see Map 4.4). This map records a survey for the then proposed Atlantic Intracoastal Waterway. Of- considerable interest are the water depths shown on this map for the East Channel and the unnamed shallow channel nearest Cedar Point. The former channel had a maximum depth of 11.6 feet and the latter a maximum of 2.7 feet. This map also confirms the apparent navigability of the West Channel, the westernmost channel from Bogue Inlet to Swansboro, with depths.of up to 18 feet being recorded by the survey team. In contrast, depths in the easternmost channel of Bogue Inlet, incorrectly called the "West Channel" on this map, show a maximum of about 10.9 feet. However, this same channel at Swansboro only showed depths of 1.8 to 3.1 feet which are much more shallow than present depths. Thus, it is tentatively concluded that at' this time most of the flow of the White Oak River was through the East Channel near the midpoint of the river between Swansboro and Cedar Point. The next map is a 1932 Corps of Engineers map of the right-of-way of the AIWW which was apparently produced immediately after the construction of the waterway canal (see Map 4.5). This map shows the original uncontained spoil areas which were developed during construction of the waterway. The easternmost unnamed channel of the White Oak River near Cedar Point was -closed off at this 4-10 lu -,rr AC + 4*. 1L 31 AOI` 4. IL rK -3 M_,t I's 41 Nk Vnr PD AD it Ilk M A WHIT n c c e o VICIN N. C'. SOURC ENGINE H E NRY ..VO N OESAN a AS30P, I AT C S C 0 N S U L T I N 0 Etl.G.INEERS a P@LANNF':RS WILM V. -srj>q Ito, life- 'r; NA pip 0, Itz ISO MA WHI vicl N.. C PREC A.I. W 0 40 40 @OLIR yx 9NGIN C HENRY VON OESEN Di ASSOCIATES - CONSULTING ENGINEERS a PLANNERS - Wl 49 cr\ 0 0 0\\- 9-@q oll 4i -/10 0 0 0 CHA p""i 4: L MA WHI KEY vicl EXISTING MARSH ISLAND N. C i - . (MAP EXISTING SPOIL DISPOSAL AFTE 'AREA.- SOUR ENGIN HENRY VON OESEN ik ASSOCIATES - CONSULTINQ ENGMEERS Et PI.ANNERS - WIL point by uncontained spoil dredged from the canal. Also, the lower portion of the East Ch annel was closed off by spoil. Several other spoil islands were created along the right-of-way corridor in the lower estuary. Their locations are also shown on this map. The placement of these spoil islands and the construction of the AI14W itself certainly had a significant impact on circula- tion patterns and riverine flows in the area, and ultimately affected the shoaling process evident today. The next map in the series dates from 1933 (see Map 4.6). It shows the AIWW and the Route 24 bridge over the White Oak River under construction as of March, 1933. No water depths are indicated on this map. However, the map does show that.-State Highway 24 was placed on a hydraulic fill causeway at Cedar Point which closed off all water flow east of the East Channel of the river. This construction work certainly also had a profound effect on the circulation,- water flow patterns and shoaling patterns in the lower estuary. The last map of the series obtained from the Cor**os of Engineers is a portion of a 1949 USGS map of the Swansboro quadrangle (see Map 4.7). The map does not include any water depths, but does reveal that the causeway area at Cedar Point had by that year been developed for urban uses. The fixed wood bridge is also shown on the map. No development was shown on the hydraulic fill' section in mid river 'between the two spans across the channels. This develop- ment was to take place after this date,- perhaps following completion of the NCDOT's bridge replacement project of the early.1950's. Existing conditions in the lower river area are shown in a series of aerial photos dated March 12, 1979, which were flown by Precision Photo Laboratories, Inc., Dayton, Ohio for the Wilmington District Corps of Engineers. Photo Plates 4.1 to 4.6 were taken on the ebb tide on the above specified date. 4-11 IN L tZ v ptis borO 13a CJ55 G r." hodist k@ 10, N., N4et ,3's aIP/ 1-j ans- rO ru- '4@ C "'P 94, & "I'Lo "it 4 140. aGot, 4- T-1- 411<@Ny.:. it 17e/ 190- W NO. 22 con - 0nd Beaco a 13e Bogue 1950', RIJ55 0 0 Sland 9 CP M A P 0 Beac :Q51-N. soil ue 0 Bog.. WHITE VICINI P N. C. 190a SOURCE: -ARMY CO WILMING N, HENRY VON OE SEN a AS SOCIATES CONSULT10"...0 I L @10 I 7,; Irk S% -1 FIXED WOOD @RIDGE HCRIZ CL 33 FT \0 VERY CL u rT mmw OnCtfl. bUlkh.@Id am 12 USE c,camr.0 CABLE N11,CL 47 FT MHW C"lullk,hoad 5 It Contour parallel% both side of r;3d "'k City limit follows shoreline b.-kr.-4 001 "D11YRE-%C-)tI 6 (6 Kv Q, W' I x\p@/ LIGHT 464- N' WHITE OAK GOGUE SOUND -0 LIGHT 4 bul h,.d MEO WOOD BRiDGE HORIZ CL 16 Ff k VERT CL 7 FT MHW 4od N, OVERNEAD CABLE v. N N., Go Or CL 21 FT MHW 00 ..c (h' JnkChr.%I #d 0. e b 1, lck'h@@I I d L N Wood .D.i.It.h CP on Dolph.ns ;'el 4b 1: F.6: N, M A Q. WHI Vic ._Lt jZ. SOU N. ARM 00' _,. Nd WILM HENRY VON OESEN a ASSOCIATES CONSULTING ENGINEERS (k PLANNIERS W1 Plate 4.1 shows the bridge-causeway complex area and a portion of the upper river up to an area opposite Mount Pleasant Point on the Onslow County side of the river. This plate clearly reveals a series of fan-like shoals or bars which extend on either side of'the Swansboro and East Channels of the river north of the bridge-causeway complex.. These shoals extend north to Jones Island and beyond. The presumption is that these shoals were created in recent times by the redistribution of sediments from the unconsolidated spoil areas which were created during the construction of the AIWW, and by alteration in the flow patterns and channel hydraulics resulting from both the AIWW dredging and the causeway/bridge construction. Plate 4.2 shows the AIWW and portions of the lower river and the eastern channel of Bogue Inlet where they intersect with the AIWW. Remnants of the old East Channel in the vicinity of Huggins Island are clearly visible in this photo. The spoil islands created during the tonstruction of the AIWW are also visible in the photo as is a recurring shoal at the intersectim 'of the East Channel of- Bogue Inlet and the AIWW. Plate 4.3 shows a portion of the AIWW and the northern section of the eastern channel. of Bogue Inlet. Extensive shoals are visible in the upper inlet area. Plate 4.4 shows the mouth of Bogue Inlet including West Bogue Banks, Hammocks Beach (Bear Banks) and the gorge of the inlet. Plate 4.5 also shows the mouth of the inlet, but also a portion of the ebb tide discharge fan. Plate 4.6 concludes the series with a-view of the entire stained discharge plume or fan in contrast to the clearer ocean waters. Taken in perspective, it is clear that there are several factors which have influenced the shoaling in the lower river estuary. Sectio-n 4.1.2 shows that 4-12 PHOTO PLATE 4.1 "t z Ile @Eg -z @W; Q@ !WN, "W6 X -w@ @-R A 5 'M 'It J2@ sn 5-4 4 V-p 1-@ Mg - - M-101 M-11, gg "-' -2, Xv AN g& -p g, -:2 NN -1-0 - -- -- R,R - WOO -7i ?--, OR R A-R-i 505- @f% -7Z pg Z,7 3-5---M '41 ;aa 'N - - I :@- - -- Mas AT @ @_:Rz -k Vf, -w a Me la I @-O M MW @--, .1. @11 Ut - i-kz SW N Z@ - NO LEE iii--i w -e p 7A AMN "kqf Lk PHOTO PLATE 4.2 V"T', @7;; I, A It 10.3 e" 'I I Q, oI )a ST. g-, - I 'AW RIM _%f ZORN VI N1 1@ C p 8@- Z 06, MC 'A @v q -0 V 4 W4,1 oil Z, n zri@ W- _E@ ,7W @i Wt5_ 7v A- aF :@,aV K:-M 4f 5- 'XI A 0 I J - WM4 w;k -ln& wP - @ im, NtIM ON- Ye- fell-' rd & QO$ 1M, 6111 Mmmv IA 5 Ark Aw M -M W -y- WA, d4l 1@ -C 1 X_ -d_i W, Zl- IT AOM nm, I% AMM, 'K @17_ V- Q PC 7@ 7-- MUR ;2_25-1 -q- fmwa -J, n 0 4L MM, e @_ V 7_1 P t Nmkii- o MR! ffill5 N M@ Q5t,@sk._ , N MM, lg@, T ME Ar Sk 190 Na vgp@ Qn@ NNW -5 -:@5f, .4p M, -A t1l 4 V, I will Z_ W y2MR, %_ W-F-i n ". _ - _@r 11_1@w '[71 Ili - 15, 7 vl, I M @7, 4? 1, 'A"W" f 16 1, 'b' '4 1,@ r z A "0" 41 -4 011, yl/, @ 14 IV, 0, W, , V," A Y" % N', "to v, 1,, 7, q 1, I P, 4A-M, y 6 v J, ;j"" g "Pr"t Y, sli p" 11' 7'.. 7 If Iv, 47, gn g f@@ Xv ... . .. . .. .. Y, h Pfl,9'-9 A 8 p, 1.7 0 Vk JIffI 17, 3y, 'Uhl W, @q Ow" 1 'IlqpN "W1 f Alp RIM , /;P t %, 4! "hN 4# qljpT 77 ey ell o14 I I I I " d q,,q 74 x Vg,,,1111@,,; Y,, 0 . 1/1I',,WW@1/, , I "i, '4"o",@, ";j) Zz'v1ql '-4' 1 14, 1@, @'7 11-' 07 I bi, pie r3l" 7/,' 16"y WA@ /P %Z al Ilo j"; P/b "I" '11FU@M 7-1 Yleh r Y, i,. Ili- w i NO rw 9 1 7'@" qfJ7 d" A 1@ Al, 'S Id IV"4 IRA A NMI 7', 'D IN R H, 11", R, jj@z,,, /q,q4 d"d PON IR zffiwol 14 77!@ , ?"1'", 1 311 nqv 'I MV 71 IN 17 bt rw IV, 1 41 4 p, I vv/ ", W/1 V, 'ib/ 7/p ol" uar, o5 lo, IV.7 14, Ol 5 J., 6 1 . P/5, I Pf p Aj@ '4, .76 W "I I, III i, ,, q,,I jh) V'@ bi@ 14 'A 'pti 17' It 1@71,1011"4, 4V 51N, I'Ilv P in"', " - " --"L * --- 4*4 Tw VEIN,, 'I @/"'w v44# .IV @4 4k 1, j WP il ty 71 111" 0, /Io, f a, Al q4i 1"d AN " 6 " "'I " @ ;N11"I'lluid/. P/ Y, 'i,, U,b)II' A, vi, CD 49 $1 Ire g, IF IN Ip 114, 1 o/I ft 1/1 "'o, ZZ jpv 47 4@, I , 7, v" 1, 0 1 X N 117, A, ,tt iv wf!"Y"h, 'WP "MY' i0l' "1 0/1 pl, Irv mi 77 7 71 bk If A ',h 7, , P,4, %,I P "%',th 0 fell" 'I'A J, 4 r. -44" A@ Ij wr la h -71 't tl U. JY 1, PHOTO PLATE 4.5 CM. i@F Will h, -@6@ -@Ar, S 1-0 I-A man u W- g -a -6-V MIMS MW - - -40@@ v I MR.-M ELM I ORA- ON . omgg m r? .@C@T @R P,.@ -0 ILI wig -g-, -Ml M Ah -Mv Z ONE- M, M :NKS 15- R F M ME 4XI SIM MV ME VMS- M. M q Ilk g 300- 4 V V mgm- YA, N ROOM 0- gm IN- @U A L 44 A ubsom.-WA@ I ....... lowwwwr, PHOTO PLATE 4.6 Z@t zj vS 4 Irv< Pk@-, @-,n IL alm sedimentation is a natural proees-v-Mt4ch is-eTperted to occur in any estuary including the White Oak River without the intervention of man. In Section 4.1.3, we have shown that man's actions have also had an influence, especially during the last century. In the sections which follow, we discuss the factors' influencing sedimentation in greater detail including the construction of the Swansboro-Cape Carteret Bridge-Causeway Complex, the construction of the Atlantic Intracoastal Waterway, and'vth@e roles"6f Bogue Inlet, storm surge and upstream sources'of sediment in the overall regime of sediment dynamics. - Swansboro-Cape Carteret Bridge-Causeway Complex Contacts made with the Hydrographic Division of the N. C. Department of Transportation, Raleigh, N. C. revealed that plans for the original Swansboro to Cedar Point Bridge and Causeway Complex were drawn up in September,_1932. Based on the best available information, actual construction of the roadway complex took place beginning in 1933. The 1�32/33 project (NCDOT Project No.. 3690) consisted of a timber pile and structure bridge over the" Swansboro channel of the White Oak River at Swansboro, a roadway and hydraulic fill section behind a timber bulkhead in mid river between the West and East Channels, a second timber pile supported bridge structure over the East Channel and a roadway on hydraulic fill on the Cedar Point side of the river. The total length of the project was 1.413 miles consisting of 1.115 miles of roadway and 0.298 miles of bridge structures. As a result of this project- with the placement of the hydraulic fill exclusive of the bridge piles, the overall width of the river was reduced from about 2,200 feet to 850 feet. The remaining 850 feet of open water was divided into nearly equal segments, the West (Swansboro) Channel area (400 feet wide) and the East Channel area (450 feet wide) (see Figure 4.2). Based on interviews and discussions with several knowledgeable individuals, it has been suggested that the road-fill construction method'was employed at the 4-13 F- c 11A to 1'5. G 7 -Vol MAN. STORM TIDE! im. ?-o'l ZED M.L. Iq-Z S LEE \/.4-r 10 it (ul "PLAM Go CK =I-. ti y - y 71-italy lot m ML. Fbum 14.7 STORM TIDE 131- MrrAN LOW NVATLM 121-9=-00 E L- V-VA T k 0 @,l ..SWAN ssol;o CHA -P L (@AWT CHAM47-X-) FIG N. C PLA t4 0 T 21 M-rA C>BrA%WmV FWOM N.C. WjaMvAY @EWA #NSL F I G N P@ C A PUBLta WORKS SL)RVe%-( VAIRTY lo/ba/51. HENRY VON OESEN 81 ASSOCIATES CONSULTING ENGINEERS Ek PLANNERS WILM request of local interests who felt that this newly created land would provide a "developable asset". However, it is felt that economic considerations were the primary factor influencing the State decision to construct the crossing using the road- fill and bridge structure combination rather than an elevated span on piles. In the'fall of 1951, the NCDOT drew up plans for the replacement of the original wooden bridges and roadway with more substantial concrete bridges and new pavement. The new roadway and bridges were located about 32 feet north and .Upstream of the original system. Following construction, which we assume was conducted in 1951/52, the wood bridges and piles were removed by the Contractor. This replacement project did, not substantially alter the width of the river with the two aforementioned channels being retained. The water depths in the West (Swansboro) Channel in 1951 are shown in Figure 4.3. Based on plans furnished by NCDOT and limited field surveys conducted in January 1981, we have plotted the river depths in the vi cinity of the bridges and causeway for the years 1932,1951 and 1981 (see Figure 4.4). These profile plots show the changes to date which have occured since the bridge/causeway complex was constructed.', Figure 4.4 indicates that the Western or Swansboro Channel deepened from 1932 to 1951 with little change evident from 1951 to present. On the other hand, the profile plots of the East Channel reflect a condition of progressive shoaling (decrease in depth) from 193.2 to the present. These profiles indicate. that since 1932, the Swansboro Channel has apparently assumed the role as the main channel of the river while prior to 1932 the East Channel was the deeper of the two channels. These depth changes were in direct response to the construc- tion of the AIWW and the highway bridges begin ni.ng in 1932. 4-14 N 9.0 REA 0.0 LG 'E 0 19. 0 /0-0 LOFi A a.0 CARTE Iq0 014 cicso 0.0 -1110 ONSLOW 'COUNTY 0 SWANS ORO 0 K a SWANSBOR 0 0 1*0 4Z- 0 0 X4, 0 VICINITY SCALE 1: 5C 0 2 4 6 8 10 0 A@l F ROM U.S.G.S, MAP 0 VELOC lil VARIES .mt, WITH WIND. 8 T IDE PROPOSED HIGH AND CAU ACROSS WHITE ONSLOW AND CARI 1@sz N. C. STATE HWY. a m IN 2 SHEETS - SCALE 0 500 1000 200 ywe LOCATION CHECKED BY. RFN. 0 SOUNDINGS IN FEET DATE FROM USC ek 0. S. CHART REFERED TO MEAN LOW NO. 1234 IN N.C.S.H. 0 PWC TIDE SURVEY PARTY MAP TRAC90 FROM DWG. By N.C I COMM. DATED 10-30-51 PROJE H 9 N R Y V 0 N 0 E S E N a ASSOC. CONSULTING ENGINEFRS a PLANNERS, 10 0 -10 -20 SWANSBORO CHANNEL 10 Li 0 -to -20 rl EAST CHANNEL H E N R Y V 0 N 0 E S E N a A SS S 0 C I A T E S CONSULTING E N G I N E E R SEk PLANNERS Map 4.8 shows the existing rive*r depths. in the two channels both upstream and downstream of the N. C. Highway 24 bridges. A comparison of Figure 4.3 and Map 4.8 reveals that the Swansboro Channel has increased in depth near the bridge from 1951 to the present. Water depths in the East Channel are shallow except immediately under the bridge proper where the restriction has caused a pocket-like depression. (A similar depression occurs under the bridge span over the Swansboro Channel). In addition to the profiles, some limited current velocity measurements were made'on 18 February, 1981 during a full moon t idal cycle. The current velocity readings are shown in Table 4.3. Current velocities on the ebb tide are substantially higher than the flood tide velocities due to the additive effects of the river.'s normal discharge flow. Differences in velocity at different depths appear to reflect the effects of the salt 'water wedge and/or influences of the bridge structure itself (see Figure 4.1).. Flood tide velo- cities appear high enough to keep sediments in suspensio*n, but some velocities are near or below 2 feet per second which would allow for sediment deposition up stream of the bridge. The lesser velocities on the flood tide may be linked with the shoaling process which 'is evident north of the bridge complex. Atlantic Intracoastal Waterway The Atlantic Intracoastal Waterway (AIWW) cuts across the White Oak River downstream of the bridge/causeway comp lex. This section of the AIWW is operated and maintained by the Wilmington District of the U.S. Army Corps of Engineers. The River and Harbor Act of 1927 provided authorization for a channel 12 feet deep and 90 feet wide to be constructed from Beaufort, N.. C. to the Cape Fear @iver, N. C. This channel was completed on 23 December 1932 which means that the segment of -the Waterway near the study area was completed prior to the 4-15 TO JACKSONVILLE, NC TOWN OF SWANSBORO 4 W*H I T E 4b .0 14b \lb EAST CHANNEL CEDAR POINT M E N R Y V 0 N 0 E S E N A S S 0 C i A T E S. C 0 N S U L T' TABLE 4.3 CURRENT VELOCITIES WHITE OAK RIVER AT SWAMSBORO, N. C-1-/ A. Swa nsboro Channel at West Bridge, Highway 24 Ebb Tide (Tide +1.1) Flood Tide (Tide +0.5) Water Depth (ft) Velocity (ft/sec) Velocity (ft/sec) 5 6.50 0.4 10 7.26 2.34 15 (near bottom) 6.16 U1 B. East Channel at East Bridge, Highway 24 Ebb Tide (Tide +0.9) Flood Tide (Tide +0.7) Water Depth (ft)., Velocity (ft/-sec) Velocity (ft/sOc)_ 3 5.78 4.98 6 6.21 4.23 9 (near bottom) 7.34 3.44 Based on current meter studies conducted by Henry von Oesen & Associates, Inc. on February 18, 1981. Bridge/Causeway Complex built by NCDOT. Each year, the continued maintenance of the waterway is examined and justified by the Corps based on experienced and anticipated traffic. The Corps has subdivided the waterway into sections and units. The units are also called tangents.. The area of the AI14W in the vicinity of the White Oak River consists of parts of Sections I and II and several tangents. These sections and tangents are shown on F igure 4.5. Table 4.4 shows the history of maintenance dredging for the period of 1964 to 1974 and the projected frequency of dredging for the 50-year period beginning in 1975. The zone of the AIWW nearest the White Oak River (Section I, Tangent H.) was dredged in 1971. A total of about 24,300 cubic yards of material was removed. The Corps of Engineers predicts that this area will have to be dredged only one more time in the 50-year period beginning- in 1975 with another 24,000 cubic yards of material slated for removal. The infrequent dredging in this reach indicates that this area has apparently reached a relative state of equilibrium within the hydraulic complex. In Section I, Tangent G. the Corps notes a recurring shoal where the east channe] of Bogue Inlet intersects with the AIWW (see Figure 4.4 and Table 4.2). This shoal is located on the south bank of the AIWW near mile 228 and has length of 400 to 600 feet. The *approximate composition of the shoal sediment is 95 percent sand and 5 percent shell. Such shoals are usually caused by the inter- action of cross currents which cause current velocities.to decelerate and to allow heavier sediments to drop out of suspension. The Corps projects that this shoal will need to be dredged about 13 times over the 50-year period beginning in 105. A total of ab out 27,000 cubic yards of material will have to be removed each time. Thus, this segment of thereach has apparently not reached a state of-equilibrium. 4-16 0 COL. Nit J@WFA; tog 9p, JR@ nk P- rs kl lit -v 114 IBM Cie LA T 1610?< r-, A"N' L _j-0 C r BEAR INLEr A r A N r c FIG LEGEND: ATL A 1. W W. RIGHT OF WAY WAT A.I.W W CENTERLINE 9 vici DIKED DISPOSAL AREA 0 A MAJOR RECURRING SHOAL SOUR ENGI? DIST HENRY VON OESEN 61 ASSOCIATES - CONSULTING ENGINEERS PLANNERS - W1 TABLE 4.4 Present (1963-1974) and Projected Periodicity of Maintenance e Volume of Material Removed From AIWW in Vicinity of White Oak River, N Times Average Est. Years Dredged Cu. Yds. Dredgings Historic Dredged Since Per Next Disposal Location 1964-74 Opening Dredging 50 Years Count@ Practice Section 2 C2/ Jangent 1966,68,73 7 12j317 8- Onslow County Tangent B None 1 1 Same Tangent A None 1 0 1 Same Section 1 Tangent H 1971 1 24,286 1 Onslow and Carteret Counties Tangent C12 1966,71- 11 27,023 13 Carteret County Tangent F 1968 2 57,996 2 Same L/,source: U.S. Army corps of Engineers, Wilmington District (February 1975) Draft EIS Intracoastal Waterway, N. C. L / Major recurring shoal. L./ Form of Disposal: D: Diked, UD: Undiked. Therefore, it would appear from the published Corps data that the AIWW may be intercepting at lea st a portion of the sediment from Bogue Inlet before it can reach the White Oak River estuary north of the bridge/causeway complex. Also, 'discussions with Corps representatives revealed that, in their opinion, water circulation in the sections cited above increased (improved) after the construction of the AIWW due to improved flow patterns resulting from the channel deepening project. Boque Inlet Bogue Inlet,one of the larger North Carolina inlets, is located at the mouth of White Oak*R iver near Swansboro, North Carolina (see Map 4.9). - It is bound on the east by Bogue Banks and on the west by Bear. Banks (also known as Hammocks Beach) with.Dudley Islahd situated directly behind the Inlet. The Inlet has -two primary fresh water sources, the White Oak River and Queen Creek. The Inlet mouth is formed by-two cresent shaped spits of.-,sand. These spits are relatively unstable and are continuously in motion.as is thelentire gorge of the inlet. The motion of the gorge itself is, however, much sl ower than that of the sand spits. The sand spits may shift radically in just a few months or even a few days under severe storm conditions, but the gorge shifts usually occur over a period of several years. During the periods of 1938 to 1971, the net trend in migration for Bogue Inlet was-to the. east. The Inlet.swings from.east to west with the longest motion in the east direction, producing a net travel of approximately 1,300 feet. This Inlet has always been extremely wide compared to the channel flow which.is from the east and the west. The 1949.photography shows two main channels which may indicate the exce ssive width of the gorge (see Figure 4.6 and Table 4.5). 4-17 9 c=P 7 21 7 Romp % 0 1? 6 .11 :; %C% Q6 6 00 Qk 171 "45 N _*Z 22-Ar 4 k F1 151t"BS- CAST CHARNELM 26 FIXED BRIDGE -1 M 4 "OR. CL 30 FT VERT. CL 6 FT.2 5 FIXED BRIDGE 2 FI me G_ 4 -6 J, @...J. 24 HOR. CL. 30 ik PA VERT. CL 12 FT %.- _v I %Q f 27 C.-"- A -6'*.'- G 2 Swansboro V Area R' 7 a':PA 45C" 4 PA Ard -4fjA'M 12' 5 7 "468A. 0 GPA1. 8 3 TANK "4 3 26 29 -2- PA 4, SWANS R: 0 Qk F1 '40C.P.? '47' +C.G. % 14 12@%' and HuAains I I X'. 17 I $Ve3t S4,"* J 111 M.1h . 28 F1 G21 ec") 7" spool res 21 ?k FI R"4.1 ;< 3 14 R "48A" 23 2 R I) Qk 171 "49" 'v"501 21.1 23 e pile 28 34 70 11@1 -1 .24 Maf3h " ................. 4 33 4 10 4 eel's 4 A75 1 1, r*p 28 34 4 6. 5 ff Dunes /9 7 S 113 A'17* PdYm@aintd Aids ;I ff 4& 23 6R 2 6 33 R& 3 "IT, Spoil Area 26 3 0 4,v Cob 22 39 Is Are. All ;Q 2 0-- 1. 2 SCALE IN MILES MAP 4.9 BOGUE INLET AREA SOURCE: N.O. S. NAUTICAL CHART 11541 HENRY VON OESEN a ASSOCIATES -CONSULTING ENGINEERS a PLANNERS -WILMINGTON, N. C. FIGURE 4.6 BOGUE INLET 1938 1949 1 1956 ;for 1964 30, 1971. de APPROXIMATE SCALE 1 3333 1 1971 1 2000' TABLE 4.5 CHARACTERISTICS OF BOGUE INLETL/ INLET CHARACTERISTICS Year Gorge Gorge Channel Channel Migration Of Migration!Of Net Gorge Width Width Width Width Gorge W Side Gorge E Side Migration (ft.) Change (ft.) Change, (ft./yr.) (ft./yr.) (ft./yr.) (ft/yr) (ft/yr) 1933 2532 346 1059 71 75 W 270 E 97 E 1949 6519 1949 6519 -187 4246 291 6E 185 W 90, W 1956 5327 1956 5327 -300 2206 -473 379E 70 E 224 E 1960 3911 1960 3911 -15 698 -246 93 E 60 E '76 E 1964 3862 1964 3862 -72 1104 208 39 W 110 w .75'W 1971 3308 Total Gorge Migration (ft..) 1274.E Maximum Gorge Migration (ft.) 1300 E Ld Source: Langfelder, J. etal January 1974. A Historical Review of Some of North Carol *Coastal Inlets Report No. 74-1, Center for Marine and.Coastal Studies, N. C. State Uni -Ra-Te@ig@, North Carolina. In the 1972 to 73 period, Bogue Inlet underwent a large-scaled, short-term shift. The eastern spit extended a great distance out into the gorge and was cut from the main body of Bogue Banks, thus creating a new inlet. Bogue Inlet has a migration zone stretching 1,500 feet from the edge of the vegetation on the east and the west banks. Long-term migration is relatively small, but rather large short-term movements may be anticipated in the future. Bogue Inlet appears to be a major source of granular sediment for the lower White Oak River estuary complex. However, the quantity which reaches the Highway 24/AIWW Complex area is unknown. Discussions with the U-.S. Army Corps of Engineers coastal engineers revealed that regular transport of inlet materials to the causeway area is unlikely except during major storms. In the opinion of the Corps' experts, most of the sediments in thi-s segment of the White Oak River appear to have their origins in the original undyked spoil areas which were created when the Atlantic Intracoastal Waterway Canal was constructed and from upstream sources. However, none of these opinions can be confirmed without extensive field studies of sediment cores and their composition coupled with tracer and mathematical model studies. Storm",Surge Storm surge due to hurricanes and extra-tropical cyclones (norleasters) can have a profound short term effect on sediment distribution within the lower White Oak River Estuary. Under such circumstances, the Bogue Inlet Complex, AIWW and ca.useway areas can receive a tremendous influx of sediments due to bed load transport (see Section 4.1.2 for a discussion of this phenomenon) . The heavy rainfall which is usually associated with these events can also result in heavy sediment inputs from upstream sources and additional down stream bed load transport due to the freshet condition. However, another counteractive phenomenon which may a ccompany these events would be an, -increased ebb flow 4-18 (resulting from abnormally elevated tides) following the passage of the storm which would serve to transport sediments back out into the oce@n and scour out channels, etc. In fact, several local residents interviewed during this study mentioned that following each major hurricane which affected the area, the channel depths in the inlet complex improved (increased in depth), only later to shoal up again in the years following the storm's passage. The movements'of sediments during the recent storm events on record have not been adequately quantified in the existing body of literature on the study area. Upstream Sources of Sediment During peri-ods of heavy rainfall and subsequent runoff, sediment can enter, the White Oak River for transport down stream. The potential sources for such sediment were discussed in Section 3.8.2 above. However, in the absence'-of an extensive body of field data and amath model of the basin, it is impossible to quantify the sediment input from upstream sources. Also, the role of-the Martin Mar ietta Quarry Lakes as potential sediment traps for the upper basin and the role of mosquito ditching in sediment transport in the lower river basin have not been evaluated. Therefore, more study of this potential source of sediment is warranted. 4.2 Fisheries Resources Depletion 4.2.1 General As indicated in Section 3.10, existing data on landings of seafood from the White Oak River system do not seem to indicate a general depletion or dimunition of fisheries resources. However, again it is emphasized that the existing data base-is very incomplete and so this conclusion may or may not be accurate. Improvements in data collection methods which were instituted by the N. C. Division of Marine Fisheries beginning in 1978 should help to confirm (or. deny) this conclusion over the next few years. 4-19 Although not reflected in the seafood landing statistics, two problems related to fisheries resourc.es depletion have been identified by fishery biologists, and commercial fishermen who have an intimate familiarity with the White Oak River system. These problems are: (1) stunted growth of oysters and (2) depletion of anadromous fish stocks. Each of these problems are discussed in greater detail in the following sections. 4.2.2 Stunted Growth of Oysters The lower White Oak River estuary has numerous intertidal oyster reefs. It has been recognized for some time that a sizable percentage of the oysters found in the extensive. beds nev,er attain the marketable size 'of 3 inches. In order to recover some of this unused resource, some limited private and. State interests have transplanted some of these "stunted" oysters from the White Oak River to beds in the nearby Newport River where they have attained marketable size. During the Summer of 1978, the Duke University Marine Laboratory, sponsored a student originated studies project on the factors influencing the stunted growth of oysters in the White Oak,River. This Duke University student study team, funded by a grant from the National Science Foundation, utilized an interdisciplinary approach to the problem. The disciplines included bio- chemistry, ecology, water chemistry and physiology. Their findings were set forth in an unpublished report entitled, "Factors Influencing Stunted Growth of the Oyster, Crassostrea virginica, In the White Oak River,_ North Carolina". (See Bibliography, Section 8). A summary of the results of their study follows: A. Water Chemistry (1) Determinations of several water quality parameters, as wel I as, the amount and type of suspended sediments, current speed, salinity and temperature revealed few differences between stunted and no rmal sites or between the White Oak River and other nearby coastal ri'vers, except for. the 4-20 fact that (a) current speeds were significantly different from site to site, .(b) mean temperatures are higher for summer months in the White Oak River than in other nearby estuaries and (c) the salinity gradient appears wider than is typical for other local rivers thereby inferring a larger percentage of fresh water inflow resulting in a wider range'of nutrient values. (2) Except for the temperature, the White Oak River appears well- suited to oyster growth. Consistently high s'ummer temperatures may contribute to stress on oysters throughout the river. B. Ecology (1) The stunted growth is apparently not caused by the oyster pests, Polydora sp. (a polychaete worm) or Dermocystidium marinum (a coccidian 'fungus), due to the fact that their relative numbers did not correlate with the size differences of oysters dt the respective sites. (2) Extensive sampling at each site revealed: a. A strong linear relationship between density (number of oysters/square meter) and oyster size (height in mm.). b. Stunted sites showed a much greater degree of mortality. c. The population size structure for each site revealed that the stunted sites have a higher degree of spatfall while the normal sites have a greater number of large" r oysters. None of the sites selected for study, however, support significant numbers of marketable oysters. d. Observations of cages deployed to each site containing juvenile oysters from a homog'eneous population revealed that growth (over a 3-month period) was significantly less for stunted than normal sites. 4-21 C. Physiology A current chamber was designed and constructed 'to simulate three current speeds common to the experimental sites in the river. The effect of current speed was determined on the growth of juvenile oysters from a homogeneous population. It was discovered that oysters in fast currents grew significantly less than those in medium currents with slow -currents showing intermediate growth rates.' D. Biochemistry (1) Although the growth rate of oysters,is influenced-by several factors, the'immediate cause for the phenomenon of "stunting" as observed in the White Oak River is early mortality. No oysters of market&ble size' are found at the stunted sites. This strongly implies that the oysters at. the stunted sites are dying before they are big enough to be taken. (2) The factors respons ible for mortality and slow growth at the stunted sites appear to be density and current i*elocity. High summer temperatures serve to amplify the stresses on the oysters due to the fact that at higher temperatures the pumping and metabolic rates of the'oysters decrease. Also, conditions favoring high spat set assure that dens,ity associated stress is continuously felt and self perpetuated. (3) The factors discussed above combine to produce a highly stressful environment in which young oysters can survive; although they are less viable than their normal site counterparts. As the metabolic demands of the oyster increases with size and the ability to compensate is diminished, the animal becomes less viable and eventually dies before reaching full size. 4-22 4.2.3 Depletion of Anadromous Fish Stocks Anadromous f i shbs have suf f ered a ge- n er a 1 dec 1 i ne i n re 1 at i v e ab u n d ance throughout the coastal region of N. C. and all along the Atlantic seaboard. This decline has been variously attributed to pollution (mainly from certain organic compounds which disrupt the reproductive processes), stream channeliza- tion and the construction of dams or a combination of these factors. This general decline is not reflected in the landings of finfish from the White Oak River because* of the minimal commercial effort devoted to harvest of anadromous fishes. - The N. C. Division of Marine Fisheries (1975) reported that the White Oak Ri.ver supports a recreational dip net and gill net fishery mainly for river herring. Fishing is primarily confined to the Martin Marietta Quarry Lakes at Belgrade and may involve between 15 to 20 local people per night with catches of 50 to 100 pounds.per person during the peak of the herring "run'. The inciden tal catches of anadromous fish by commercial fishermen is minor, -with little apparent value to the White Oak River.fishery. In view of the above, it would appear that the depletion of anadromous fish stocks, if it is indeed occuring, is not causing any alarm amongst commercial fishermen. In fact, certain 'anadromous fish potentials appear to be under-. utilized at the present time. 4.3 Pollution As indicated in Section 4.2.3 above, various forms of pollution are causing problems in the White Oak River system. The most important of these problems is the closing of shellfish harvest areas, due to high coliform counts. The nature of this problem has been clearly defined and discussed earlier in this report (see Sections 3.7 and 3.8 above). 4-23 SECTION 5: PROPOSED ACTIONS RELATED TO EXISTING PROBLEMS Based 'on the information and findings in the preceding sections of this report, suggested actions related.to identified problems are outlined in the following paragraphs. 5.1 Sedimentation 5.1.1 Non-Structural Actions Additional Study As indicated previously, general conclusions may be reached regarding the causes, sources and effects of sedimentation in the White Oak River. It is strongly presumed that the principal source of sediments which comprise the extensive shoals north of the N. C. Highway 24 Bridge/Causeway Complex are the original unconsolidated spoil areas which were created during -the construction of the AIWW. Little information is av,ailable related to what contribution, if any, the materials from the mouth of Bogue Inlet and materials from upstream sources have to the overall sedimentation problem. Additional. study of the problem.should take the form of a combined field data collection effort and a detailed mathematical model -study of the riverinet estuarine complex. The specific nature of the field investigations and subse- quent math model studies have been identified by NCSU scientists based on meetings and discussions of the problemland desired objectives. The suggested program is as set-forth 16 Appendix C of this report. Briefly the NCSU modeling study will be Uised to numerically analyse the hydrodynamics and the -associated pollution and sediment- transport. The numerical anal-ysis of the area will require the following inputs from field data collections of cross-sections of the river coupled with measurements of water level fluctuations, velocity of flow, density variations, salinity and sediment and pollutant concentrations at 5-1 several sampling stations. In the regions of the river where the flow can be considered one-dimen- sional, i.e, along the axis of the river such as near Webb Creek, a one-dimen- sional finite element mathematical model will be used. This model will then.be coupled with a two dimensional math model which will be used for regions of the river where the width is great enough to also cause predominant flows at right angles to the axis of flow. The 'proposed modeling studies should help to define the following: (1) The role of the Martin Marietta Quarry Lakes as potential sediment traps. (2) The contributions of sedimentation of the river. from agricultural and silvicultural practices. (3) The contribution of sediment from mosquito ditches. (4) The source(s) of granular sediments in the lower river estuary. (5) The specific nature of the salinity of gradieh ts -of the river. (6) The potential effects of any structural remedies or improvements on sedimentation. (7) Sources, concentrations and fate of pollutants. Expansion of Ongoing Studies of Bogue Inlet-and the AIWW by the U. S. Army Cor s of Engineers The Wilmington District of the U.S. Army Corps of Engineers is in the process of completing a study of Bogue Inlet which was authorized by congres- sional resolution. The Corps has accumulated considerable data on Bogue Inlet and adjacent waters as a result of this project. Due to the fact that spoil from the construction of the AIWW,has been tentatively identified as a primary source of granular materials in the shoals located north of the North Carolina 5-2 Route 24 Bridge/Causeway Complex, it may be possible for the Corps to expand I this study to study the matter in question. The interjection of the Corps' expertise, manpower, and physical resources into a study of sedimentation problem in the lower White Oak River as they relate to construction and maintenance of the AIWW and Bogue Inlet would contribute greatly to fixing cause and effects relationships. If it Js found,- that the Federal projects are (or have- been) major contributions to the problem, then additional remedies may be recommended. .5.1.2 Structural Solutions Shallow Dredging of Sed-iments Upon completion of detailed field investigations and math model studies, the extensive shoal areas north of the N.C. Highway 24 Bridge/Causeway Complex could be removed by dredging, if such action is found to be economically just if ied. It is presumed that. the shoals are now in a state of relative equilibrium and, if removed from the hydraulic complexr: .. they may not reoccur. This is due to the presumption that the source of these materials was primarily from the dredging associated with the AIWW and not from Bogue Inlet or *upstream sources. Before this structural manipulation of the ecosystem is undertaken, there, should be an addressment of (1) economic justification, (2) environmental effects including benefits and risks, t3) salvage of seafood resources (oysters and clams) and (4) identification of suitable spoil areas. Creation of Additional Flow Channel(s) The construction of the AIWW and the N.C. Highway 24 Bridge/Causeway. Complex resulted in pronounced changes in the hydraulic regime in the lower river as is documented in Section-4.1.3 above. The effective width of the river 5-3 was reduced and one channel was eliminated by the dredge and fill activities. These actions were conducted with a minimum of prior assessment of impacts on mitigative measures' were undertaken. at the time of construction and it is dubious whether such "after the fact" action would now be appropriate. However, if more detailed studies show such to be appropriate, environmen- tally desireable and economically feasible, it would be possible to partially restore the flow regime which existed 'prior to the early 1930's. This could be done "by reconnecting the upper river embayment north of Cedar Point (Hi I I I s Bay) with the AIWW and.the u'pper Bogue Inlet complex Iby the installation of large pipe. conduits emplaced under N.C. Highway 24. The specific area where such an interconnection. cound best and most logically. be constructed is shown on Map The proposed location for the connecting conduit would utilize an existing dredged channel on the north side of the causeway and an existing marina basin on the south side of the conduit. Prior to any con'ttruction actions, the following items would need to-be addressed: (1) Flow channel d-imensions and flow requirements. (2) Beneficial 'and adverse environmental impacts of altering @he flow regions and salinity gradients in the estuary. (3) Impacts on the marina complex.' (4) Sociological desireability of the project. (5) Movement of potential pollutants from the marina basin and area septic tanks to the vicinity of White Oak River shellfish beds. (6) Potential for shoreline erosion on developed properties caused by norma I diurnal flows or severe storm events (hurricanes and norleasters). 5-4 A F 4@,_ SUGGESTED-P LOCATION FOR INTERCONNECTING FLOW CONDUIT -OF PROP Eb" LOCATION Os Vr% FLOW CONDUIT3BETWEEN WHITE OAK RIVER AND" 5.2 Fisheries Resources Depletion and/or Underutilization 5.2.1 Stunted Growth of Oysters Non-Structural Solutions A. Additional Study The report entitled "Factors Influencing Stunted Growth of the Oyster, crassostrea virginica, in the White Oak River, North Carolina" by the Duke University Marine Laboratory study team, which was discussed above in Section 4, sugg .ests some additional experiments to confirm their findings. These suggested experiments are repeated here and include the following: (1) In,.order to.verify the correlation of density and growth, as well as mortality, a typical stunted oyster reef can be selected for manipula- tion. Clear cut a 10 x 10 meter (33 x 33 foot) section of the reef. Then uniformly distribute small oysters at some low density, say 10 to 20 oysters per square meter (1 to 2 oysters per square foot) . As a control, tag oysters. of a similar size on an adjacent section' of reef, leaving them at the natural density. Compare the growth and mortality of oysters subjectto each regime over a 2 to 3 year period. (2) Check 'the recuperation of different age classes of the, stunted oysters by transferring several hundred each of fresh spat, first year, and second year oysters from a reef like those near mid river opposite Stevens Creek (see Map 3.5 for location) to a suitable site up river or down river.. This experiment is designed to reveal the most advantageous age for transplantation. (3)' Deploy setting plates to verify the setting potential of oyster spat throughout the river. '(4) Initiate a well-coordinated study aimed at showing the changes of metabolic fitness with time. This woul.d include me6suring the pumping 5-5 rate/metabolic rate along with the glycogen, lipid and protein changes associated with aging. The Duke scientists surmised that young oysters have a hi gher pumping r ate/metabolic rate ratio. This study might indicate a crucial age and season at which an oyster is especially susceptible to mortality. If carried out at different temperatures, it would verify the Duke scientists' assumption that elevated water temperature is a major@ contributor to poor fitness and early mortality of oysters in natural waters of North Carolina. B. Oyster Replanting Program The above referenced Duke University Marine Laboratory study also recom- mended a replanting program for the stunted oysters. In recognition of the fact that these stunted oysters are potentially marketable, the Duke scientists suggested that they be transferred to areas which have more in common with ideal conditions described below: (1) A sandy bottom, covered with a few inches,'.of mud to prevent the sand from shifting and burying the oysters. (2) Salinity in the range of 15-250/oo. Although oysters will grow well above 250/oo,.the incidence of predation by,Urosalpinx (the oyster drill) becomes a severe detriment. (3) Medium range (5-50 cm/sec or 0.16 to 1.6 ft/sec) current speed, enough to allow for removal of wastes, but not so much,as to hinder growth. (4) Although oysters can grow well intertidally, it is best to avoid rivers like the White Oak which are almost uniformly shallow. High water temperature and increased effects of tidal currents result . Estuaries of mean depth greater than 3 feet with effective flushing by ocean tides are ideal. (The Newport River has been successfully used in the past as a. grow 5-6 out area for White Oak River oysters).L/ (5.) Use as low a density as possible. Spreading the oysters out is probably the key to effective use of White Oak River oysters. (6) Sufficient food supply - this is a difficult parameter to measure without access to a laboratory. In general, most North Carolina estuaries have sufficient food for oysters attain to marketable size. (7) If spat set proves to be-very high, it becomes essential to "work" the oyster bed in order for good yield to continue. Neglect in this area will eventually result in overcrowding and a return to conditions found at .19stunted" s'ites in the White Oak River. In addition to the above points-,, the 'Duke Marine -Laboratory study team concluded as follows: "Thus, we view the "nubben" oysters of the White Oak River as anything but useless. They will continue to exist as a concentrated but ignored food resource until such time as'it can be brought to the attention of fishermen and citizens that with proper deployment, North Carolina oysters can once again contribute to a tasty and nutritious diet." Structural Solutions A. Shallow Dredging to Create A More Favorable Habitat for Oysters The'above cited Duke University Marine Laboratory study indicates that the shallowness of the White Oak River estuary is acontributing factor to th.e stunted condition of the oysters in the river. Therefore, it is submitted that a carefully plann ed and.executed program of shallow dredging of certain areas of ld Also, the N.C. Division of Marine Fisheries has successfully used public oyster management areas in the upper estuary for grow-out of relayed oysters (see Map 3.6 for locations). 5-7 the river will enchance the productivity of the oyster reefs. Such a program should be instituted in conjunction with the relaying program recommended under non-structural solutions. The shallow dredging would also be coordinated with any recommended structural actions required to correct the shoaling in the estuary. (See Section 5.1.2-.1 above). Before a massive program is undertaken in this area, a test zone in the river could be selected to test the overall feasibility of the proposal. The environmental effects (both beneficial a nd adverse) and the economics of this potential solution would have to be carefully studied prior to any actual work. .5.2.2 Underutil..ization of-Clams In Polluted Areas As indicated in Sections 3.9 and 3.10, hard clams are. an important resource of the White Oak River which are currently underutilized. Recent increases in prices for clams have stimulated an increased harvesting effort mainly on the part of some Long Island, NY shellfishermen who ha,ve settled in Swansboro and local shellfishermen from the Maysville and Sneads Ferry area of the New River. The former have,employed wide multitong "bull rakes" imported from the north to hand tong clams. The latter have used locally constructed narrow clam,rakes for hand too'ging and some have employed more sophisticated hydraulic dredges 'to harvest clams. The N.C. Division of Marine Fisheries' Management Section personnel believe that there are significant hard clam resources in polluted areas which could be harvested if they were removed to clean areas for self- cleansing and subsequent harvest. Current regulations and lack of funds have prevented both the N.-C. Divisi on of Marine Fisheries and private interests from exploiting this under- utilized resource. Relative to existing regulations, N. C. Division of Marine' Fisheries' personnel explained that there is currently no closed 'clam season, nor is there a convenient time to close the season on a statewide basis. The 5-8 late fall, winter and early spring months are times of peak harvest of clams certain fu.11-time commercial fishermen. In the summer months while the full- time commercial fishermen normally divert their efforts to other fisheries such as shrimping, hand rakers (full time commercial)? school and college students and retirees on fixed incomes comprise the bulk of clammers harvesting the resource. Thus if a closed season were proclaimed in mid summer, the hand rakers, students and retirees would lose needed income'. While the Division of Marine Fisheries issues the proclamations for opening and closing of seasons, the Shellfish Sanitation Office is responsible for determining that the shellfish are suitable for human. consumpti,on and for regulating such openings or closings. At their current levels of funding these agencies would be hard pressed to conduct the necessary biological tests or to enforce the closings much less relay the shellfish. The solution to this problem lies, in part, in developing new regulatory procedures for handling clams. Two alternatives are po@sible: (1) Alternative A (A Statewide Closed Clam Season) Under this plan, a closed clam season of suitable duration .'would be proclaimed statewide. The months of May, June and July have,been suggested. by several fishermen as the "best time" to close the season on claims due in part to the fact that this period is the peak development time for seed clams. Also, the overall commercial harvest of clams usually falls.off due to diversion of interest to other fisheries (shrimping) and a usual decline in market value due to the introduction of clams from other areas," mainly Long Island Sound, etc. Du ring this closed period, no clams could be marketed statewide thereby removing any incentives for illegal harvesting. During this time clams from polluted areas coul d be moved to clean areas by the N. C. Division of Marine Fisheries and/or private interests by permit. 5-9 To mitigate any adverse economic impacts on certain user groups, clams could be sold to shellfish dealers having private clam gardens. These clams would be placed in the gardens under the supervision of the dealer and the harvesters would be renumerated accordingly. The harvesting of clams from polluted areas would be halted 15 days prior to the reopening of the season to permit the clams to cleanse themselves of poll utants . After the 15 day waiting period, the season would be reopened statewide thereby' permitting normal harvesting and marketing to resume. The advantage of this alternative is that it represents a minimal level of law enforcement, effort due to the Jact that an one selling clams for human y consumption during the closed season is immediately obvious and subject to legal action. The entire coastline would not have*to be policed for "midnight raiders". as unscruplious clam thieves are often called. The major disadvantages of this alternative are (1) it -could create severe economic hardships to certain user groups (hand tongers).-'and (2) the season for, relaying clams conflicts with the season for relaying oysters by the N. C. Division of Marine Fisheries. (2) Alternative B (Local Closed Clam Areas) Instead of proclaiming a statewide closed clam season,, specific bottom- lands in the White Oak River could be designated as public clam management areas similar inconcept to public- oyster management areas. Polluted clams could be relayed to these areas which could be closed by proclamation until tests show that the clams have purged themselves of pollutants and are ready for human consumption. Then the area-can be opened for harvesting by proclamation. The advantage of this alternative are that the closure would be of relatively short duration (less than 30 days) and of@ limited geographic 5-10 area, that is, applicable to small specific areas within the White Oak River. Therefore, the impacts on specific user groups (hand tongers) or fishermen from other areas wo6ld be lessened or eliminated entirely. The major disadvantage to this alternative is that the closed areas would have to be policed constantly. Local fishermen indicate that night- time thefts from the closed beds filled with clams c6uld be a common occurence. 'Thus, the implementation of this alternative might require a substantial increase in funds and manpower for th'e N. C. Division of Marine Fisheries to enforce the closures. However, the N. C. Division of Marine Jisheries -personnel believe that these adverse conditions can be mitigated by careful selection of areas used for the relocation of the polluted clams and/or by closing the clam season in Onslow, Jones and- Carteret Counties. If clams are relocated to areas where daylight or nighttime thefts would be obvious such at the end of roads or adjacent to the Route 24 bridges, enforcement efforts would not have to be increased.,substantially. Also, if the sale of clams in the counties surrounding the river was banned,,then the likelihood of polluted clams reaching the marketplace is reduced. The selection of either alternative A or B would be based in part on public input from a series of public hearings conducted statewide by the N. C. Division of Marine Fisheries. The Division of Marine Fisheries turrently lacks the personnel and finan- cial resources required to op erate the hydraulic dredge plants which would be required to conduct a clam relaying program in the White Oak River. However, private interests, i.e. local commercial fishermen, have the ability and the equipment to harvest the clams. With the proper incentives and proper supervision of the N.C. Division of Marine Fisheries, these interests could be paid a small stipend (an amount in the range of $1 to $5 per bushel of clams has 5-11 been suggested) to go into the polluted beds, remove the clams and replant same in unpolluted public or private management areas which have been closed. Subsequently, after a period of time, these interests could be allowed to harvest and market the clam s from the same management areas once they have been opened by proclamation. Funds to conduct and manage this program could come from several sources. For example, Onslow, Jones and Carteret Counties may wish to provide funds to sustain the program in an effort to stimulate the local economy. Federal funds to aid in the development of the program and to create-jobs could come from the Economic Deve1opment Administration (EDA) or from the Comprehensive Employment and Training Act (CETA)L-/. These funds, combined with the willingness and devotion of private interests, could result in a workable solution to the problem of underutilized clam resources in the White Oak River. 5.2.3 Depletion and Underutilization of Anadromous Fish Stocks Certain anadromous fish such as Striped bass (rockfish) and American shad have suffered depletions due to several causes (see Section 4.2.3). Several State and Federal agencies are probing the- causes of their decline.- Little commercial fishing effort is now devotedto these species. On,the other hand, river herring seem to enjoy good population levels in the White Oak River. The N. C. Division of Marine Fisheries believes that the herring stocks could be further exploited as crab bait. Thus, 'with a li.ttle effort landings could be increased from less than 1,000 pounds to several tons annually. Therefore, the solution to this pro blem appears to be an educational .campaign amongst commercial fishermenand a general awareness of the use of. herring as bait by commercial crabbers in the arei. Such an educational effort The future of these funding sources is uncertain as of-this writing. 5-12 could be conducted by UNC Sea Grant through their regional advisory agents. herring 'as bait by commercial crabbers in the area. Such an educational effort could be conducted by UNC Sea Grant through their regional advisory agents. 5.3 Pollution 5.3.1 Point Sources of Pollution Non-Structural Solutions The Division of Environmental Management of the N.C. Department of Natural Resources and Community Development is the agency which regulates point sources of pollution. All sources must comply with provisions of their permits and must. monitor their effluent' discharges. Thus, the State has a good handle on point source discharges and adequate mechanisms exist to insure compliance with existing regulations. Future increases in population in the White Oak River Basin could result in additional point sources of pollution and possibly increased closings of shellfishing waters. Recognizing the importance of shelIfishing to the economy of the area, NCDEM should encourage the use of alternative technologies,, i.e.,. non-discharge alternatives for disposal of human wastes. Alternatives' such as land application or subsurface disposal of wastewater will helR preserve the surf.ace waters for shellfishing for future generations. County and Town planning boards in the region can also do their part by. insisting on high engineering standards for sewage treatment and disposal for housing subdivisions and industries which may locate within their jurisdict-ions. Thus, strict enforcement of existing laws should help to solve the problem of point source pollution. 5-13 5.3.2 Non-Point (Diffuse) Sources of Pollution, Non-Structural Solutions A. Further Study - Mathematical Modeling While it is known that non-point sources contribute pollutants to the White Oak River, the exact locations and extent of the contribution is unknown at this time. Mathematical mode,ling studies of the river and its tributaries could help to form a picture of what is happening-basin-wide. Of particular concern is the source of pollution which' has resulted in the closing 'of the upper river (above Godfrey Branch) to shellfishing (see Map 3.5). A math model program compli- mented by field, investigations has been defined in Section above and in Appendix C. The development of a basin specific model will help to enhance basin pollution control measures. B. Soil Conservation Services Watershed Programs Any future study of non-point sources of pollution should involve the. resources and expertise of the United States Department bf Agriculture (USDA),. including its component agencies, the Soil Conservation Service.(SCS), the Economics, Statistics and Cooperative Service (E'SCS) and the Forest Service (FS). Authorization for USDA to participate i.n' any study of this nature Js provided in Section 6 of the Watershed Protection and Flood Prevention Act of the 83rd Congress (Public Law 83-566, as amended) This legislation authorizes the Secretary of Agriculture to cooperate with other Federal, State and local agencies in their investigation of watersheds and river basins to develop a coordinated program. The Tar-Neuse River Basin Main Report (October, 1980) identifies an application for a Public Law 83-566 watershed project on the upper White Oak River basin. Some work was begun on the project in the late 1960's and early 1970's but was subsequently suspended. Based on the,information provided in this current study of the White 0 ak River, there appears to be 5-14 sufficient justification for a revival of this application with an expansion to include the lower river basin as well. A study of this nature could eventually evolve into recommendations for specific stru.ctural solutions to the problem.*-Struct*ura 1 Solutions. A. Central Wastewater Collection and Treatment Systems Effl-uent residuals from septic tanks are clearly suspected of causing pollution problems in the White Oak River basin as documented in Sections 3.7 and above. This pollution has resulted in the closing of 'many acres"of productive shellfish grounds as depicted on Map 3.5. As development in the basin.increases,,,. the septic.tank effluent problem is certain.to increase. Certain mechanisms already in effect can provide structural sol'utions for this problem. For example,. the Swansboro Area 201 FaciTity Plan provides overall plans to provide central sewers in certain developed areas west of Swansboro along Highway 24 which areas are now served by septic tanks These areas are programed to ultimately connect to the Swansbo@o Municipal Wastewater Treatment Facility at Foster's Creek. The selected facility plan for the Carteret County segment of the planning area-falls within@ the selected regional plan called "Plan C-l". in the 201 Plan. This plan calls for the future construction of two separate facilities, one to serve the Town of Cape Carteret and environs on the mainland and one to serve West Bogue Banks including Emerald Isle, Indian Beach and Salterpath. However, for the present, the plan calls for the continued use of individual privately owned septic tanks and small aerobic treatment systems due to the fact that publicly owned central sewer systems are now not economically feasible to construct.' The 201 Plan recommends that the plan be re-examined by local and 'State authorities on a regular basis to determine when it would economically feasible to implement. When it becomes economic'ally -feasible to build 5-15 wastewater treatment facilities for West Carteret County, the local governments have the mechanism in the form of Plan C-1 to pursue the project. When economic feasibility is assured, the selected plan for Cape Carteret provides for the construction of an aerated lagoon - land disposal system treatment facility located on private property northeast of the Star Hill Golf Course. The facility is*projected to have an initial design capacity of 0.3 MGD and will include effluent storage, -pumping and irrigation equipment. The facility will occupy an area of 80 acres consisting of treatment units, a 200 ft. buffer zone and Netted" land area of 45 acres. Crops grown on the site for nutrient uptake,wi 11 include Coastal Berm.uda grass overseeded by Winter Rye during the winter season. The plan calls for. some. additional planning in the form of a soil and hydrologic survey of the disposal site before the de.sign of the system is begun. The selected plan also calls for the construction of ancillary collection sewers and main interceptor and pump station to "feed" the facility concurrent with. the facility construction. This collection system could be extended to serve the Cedar Point area when necessary. Likewise, when it becomes economically feasible to construct a wastewater treatment facility on West Bogue Banks, the facility will be constructed on a 10, acre site at Emerald Isle in the Vicinity of the Cameron Langstone Bridge. The treatment facility will have an initial design capacity of 1.3 MGD'.and will employ the oxidation ditch modificatIon of the extended aeration-activated sludge process. Treated and disinfected effluent will be pumped to the beach margin via a force main and will be discharged to the Atlantic Ocean byan outfall and diffuser system of suitable length.- A collection system serving the developed areas of the Banks is also a part of the plan. 5-16 In the areas not covered by the comprehensive Swansboro Area 201 Facility Plan other mechanisms are available for dealinq with 'the septic tank pollution probl em. When reviewing plans for developments and subdivisions, local planning boards can insist on central sewers and package treatment systems with land application of effluent in lieu of septic tanks particularly for new high density development contingent with tributary streams leading to the White Oak River. When appropriate, these systems. later can be interconnected with existing or planned municipal systems. Prudent long range planning in the case of wastewater disposal will prevent future crisis situations and additional losses of shellfi-sh growing areas to the spector of fecal pollution. B. Improved Septic Tank Installation Practices In many areas within the White Oak.River Basin, individual on-site. waste- water disposal systems (septic tanks) Will continue to be used for the treatment and disposal of wastewater. Optimal operation of these systems is in large part governed by proper installation techniques. Rules and reg'ulations-l-/ govern- ing the installation of septic t anks are established the by North Carolina Department of Health.Services, Environmental Health Section based in Raleigh, N. C. These @ules' and regulations are enforced by County Sanitarians. Strict Adherence to these regulations will ensure that each septic tank installation is preceded by a soil test to determine suitability of the soil to adsorb treated effluent. Where soils are unsuitabl-e for standard nitrification fields, modified systems such as mounds or shallow low pressure injection systems may be 1-/ Laws and Rules For Ground Absorption_Sewage Disposal Systems of 3,000 Gallons or less Design Capacity Section 0.1900 of the N. C. Administrative Code, Title 10 Department of Human Resources, Chapter 10 Health Services, Environ- mental Health, Subchapter 10A Sanitation. July 1, 1977 as amended. 5-17 suitable. Each installation must be treated on a case-by-case basis to insure compliance with standards and to avoid environmental harm. Technical informa- tion on the proper design of onsite wastewater treatment and disposal systems may be found in the EPA manual entitled Design Manual, Onsite Wastewater ,Treatment and Disposal Systems October, 1980. U.S. EPA, Office of Research and Development, Municipal Environmental Research Laboratory, Cincinnati, Ohio. 5-18 SECTION 6: RECOMMENDATIONS FOR ADDITIONAL STUDY One of the stated objectives of this investigation and report was to identify specific problem areas that can only be resolved by broader based or more extensive study th'an was attainable with the lim ited resources available for thi's overall analysis of problems in the White Oak River basin. While it is recognized that "over studying" an area can be an exercise in redundancy, it is felt that in this case specific problems within the basin can be resolved by additional investigations that will confirm and suggest implementation measures for-corrective actions recommended. Finally, the White Oak River region represents a relative undeveloped but typical small Coastal Plains river basin area which, if proper plans and models are developed and implemented, can serve as a prototype for similar basin areas throughout the. southeastern coastal region of the United States. Therefore, based on the review of the present state of knowledge.on the.conditions and problems of the White Oak River and the proposed solutions to the problems, the following recommendations are made for additional study: (1) A study to.develop a mathematical model of the White Oak 'River. The math model will be used to define recent changes, to predict future changes caused by natural and man made impacts on the river system and to confirm the validity of solution alternatives suggested in this report. This study could best be-undertaken and performed under the auspices of the UNC-Sea Grant Program. .(2) A study by the N.C. Division of Marine Fisheries of the shellfi-sh resources in the White Oak River. The end product of this study will.be a shellfish bottom inventory and map of the shellfish beds in the river. 6-1 (3) Expansion of the U.S. Army Corps of Engineers Bogue Inlet Study to determine the origin, cause and appropriate corrective actions for control of shoaling problems north of the N.C. Highway 24 Bridge/Causeway Complex. (4) Additional study of the stunted oyster problem by Duke University Marine Laboratory personnel. This study should fill in the gaps of the previous study and recommend further corrective actions as indicated in Section 4.2.2. (5) A study of the sources and quantities of sediments and pollutants in the upper river. This study should be a joint effort by the U.S.D.A. and NCDEM under the auspices of the PL83-566 program. Further details on these and other recommendations are found in Section 7 following. 6-2 SECTION 7 SUMMARY9 CONCLUSIONS AND RECOMMENDATIONS WHITE --OAK RIVER SYSTEM STUDY IA Pl.an. Of Action, For The - White Oak River] Ll HENRY VON OESEN AND ASSOCIATES CONSULTING ENGINEERS AND PLANNERS SECTION 7: SUMMARY, CONCLUSIONS AND RECOMMENDATIONS 7.1 Summar and Conclusions The preceding study of the White Oak River bas in was conducted to def ine existing conditions and problems and to suggest recommendations for further study along with proposed non-structural and structural solutions to identified problems. The following summarizes the major conclusions reached in this investigation and presents a plan of action for the, White Oak River wherein each specific recommendation is identified and estimated costs are suggested for completion of the recommendation. While certain identified problems must receive additional study, some actions can be undertaken immediately with little or no additional delay. The first major conclusion of this study is that the water depths in the lower White Oak River have decreased during the past century, particularly since the major construction projects of the AIWW and N.C. Route 24 Bridge and Causeway which occured in the early 1930's. The redistribution of unconsoli- dated spoil materials from the dredging of the AIWW to the area above the N.C. 24 Bridge/ Causeway is considered to bea major cause of this major shoaling and depth loss-problem in the lower estuary. The construction of the bridge and Causeway reduced the-effective width of the river, blocked off one channel of the river, and pres umably acted to contribute to the shoaling problem. A second major conclusion derived is that many of thd*seafood resources in the White Oak River are apparently underutilized.. . Pollution from septic tank effluents and other non-point sources have contributed to this underutilization by placi ng vast areas of productive shellfish bottoms. off limits to commercial fishermen. While th e.oyster replanting program conducted by the N.C. Division of 11arine Fisheries has been successful, a similar progr am for relaying of 7-1 polluted clams has not been attempted due to a lack of funds and the restraints imposed by current fisheries regulations. Aggresive intiatives on the part of responsible individuals and agencies will be required to fully exploit the fisheries resource potentials of the White Oak River basin. 7.2 Recommendations (Plan of Action) Based on the overall findings and conclusions of this report, the.following recommendations and/or plans of action are suggested for consideration: 7.2.1 Overall-River Basin Management and Control. A. River Basin Math Model. Local interests should request a study to be conducted under-the UNC-Sea Grant program to.develop-a mathematical model of the White Oak River Basin. 1. Output. The math model of the river basin will be used as a management and planning tool to predict future changes and to verify the need for implimentatfon of proposed structural and/or non-structural solutions to identified problems. 2. Potential Sources.of Funds. N. C. Sea Grant College Program. 3. Estimated Cost. $30,000 - $50,000 (to be confirmed by N. C. Sea Grant). 4. Background for Recommendation,. Sections 3.8.2,, 5.3 and Appendix "C". B. Comprehensive Watershed Plan.- Local interests should press for the reactivation of the PL83-566 Watershed Project on the White Oak River administered by the Soil Conservation Service of the U.S. Department of Agric ulture. This PL83-566 project should be broadened in scope to include the entire White Oak River Drainage Basin. The purpose would be to define the impacts that agriculture and silviculture are havin-g on the White Oak River including inputs of sediments and pollutants. - The N.C. D@partment of Natural 7-2 Resources and Community Development, (Division of Environmental Management) should be a cooperating agency for the study., 1 Output. A comprehensive watershed plan for the White. Oak River Basin. This plan will define problems and propose long term solutions to these problems regarding flood control, sedimentation and diffuse sources of pollution. 2. Potential Sources of Funds'. (1) USDA - PL83-566, (2) NCDNR&CD, DEM PL92-500, Section 208.' 3. Estimated Cost. $80,000. (To be confirmed by.SCS.) 4. Background for Recommendation. Sections 3.8.2 and 5.3. C. Improved ... Management Practices. Local interests-should press for '7- implementation and/or- application of optimum agricultural, silvicultural and septic tank installation practices throughout the White Oak River Basin. These actions can best be implemented through the appropriate Federal, State an d local agencies and authorities (USDA, SCS-); U.S. Department.'of Interior (Forestry ,Ser-vice); N. C. Department of Natural Resources and Community Development (Division of Forestr Resources Division of Environmental Management); and y 9 N. C. Department of Health and County sanitation offices). (1) output. Improved and intensified enforcement of existing rules and regulations governing agricultural, silvicultural and septic tank installation practices. (2) Potential Source of Funds. (No new funding required.) (3) Estimated Cost. (No additional cost.) (4). Background for Recommendation. Sections 3.8.2 and 7.2.2 Fisheries Resources -A. -Shel-l-fish Bottom Survey. 'The N.C. Division of Marine F.isheries should conduct a shellfish bottom survey of the White.0ak River est6arine system. 7-3 (1) Output. A map showing the location and extent of clam and oyster beds in the White Oak River. (2) Potential Sources of Funds. (1) Funds appropriated by Carteret Jones and Onslow Counties and funneled through the N.C. Division of Marine Fisheries; (2) EDA or National Marine Fisheries-.L./ (3) Estimated Cost. $40,000 first year, $40,000 at five-year inter-I vals thereafter to update data to'reflect existing conditions; (4) Background for Recommendation. See Sections 3.9, 3.10 and 5.2. B. New Clam Manageme nt Re7qulation.. The N.C. Division of Marine Fisheries' and Shellfish Sanitation Office (through the Marine Fisheries Commission) should adopt new regulations either: (1) allowing closure*of specific areas to claming; or, (2) a 3-month statewide closed clam season. (1) Output. A new clam management regulation will pave the way for the relaying of clams from polluted areas to. clean areas for self-cle.ansing and ultimat e marketing by commercial fishermen. (2) Potential Source of Funds. Special legislative appropriations. (3) Estimated Costs (a) Change regul'Ations and conduct public hearings $5,000. (b) Enforcement of New Regulation $5,000 per year to police closed areas. (c) Shellfish Testing $.5,000 per year to test shellfish for purity and suitability for marketing. The status of funds from these Federal agencies-is uncertain at this t ime. 7-4 (4) Background For Recommendation. See Sections 3.9, 3.10 and 5.2.2. C. Expansion of Shellfish Relaying Program. The N.C. Division of Marine Fisheries should maintain, expand and enhance its shellfish relaying program in the White Oak River. The program should be expanded to include. the stunted oysters in-the lower river and enhanced by encouraging the participation of private interests through relay contracts. (1) Output. The application of -this program will increase the utilization of high-value shellfish resources in the White Oak River. It will stimulate-the local shellfishing industry, and by the ripple effect, it will stimulate the local economy. (2) Potential Sources of Funds.. (1) Special legislative appropria- tions, (2) Carteret, Jones and Onslow County funds, (3) EDA funds (c reation of jobs)_1-/1, or (4) CETA funds.L/ (3) Estimated Costs (a) Oyster Relay Program - $20,000/year (b) Clam Relay Program - $15,000/year (c) Private Relay Program - $20,000/year (for payment of.stipened to private-. individuals to relayshellfish)' (4) Background for Recommendation. See Sections 3.9, 3.10, and 5.2. D. Research on Stunted Oysters The Duke University Marine Laboratory should continue its study of stunted oysters in the White Oak River. The status of available funds from these agencies is uncertain at this time. 7-5 (1) Output. A study report which will specify the ideal time locations, conditions and procedures for relaying of stunted oysters within .the White Oak River estuary- (2) Potential Sources of Funds. National Marine Fisheries Service or Sea Grant (3) Estimated Cost. $15,000 (To be confirmed by Duke University Research Team.) (4), Background for Recommendation.. Sections 4.2.2 and 7.2.3 Sedimentat.ion. A. Expansion of Bogue Inlet StudX Local interests should request the Wilmington District of the U.S. Army Corps of Engineers to expand its Bogue Inlet Study to include investigation of, the shoaling and the effect of Canalized flows in the lower White Oak River estuary. This study effort should be directed towards a determination 'of the origin of the sediments and causative factors involving the shoals north of the Route 24 Bridge/Causeway complex. The investigation should include an analysis of the feasibility of removal of these primary shoal areas by shallow dredging and proposed actions to minimize. reshoaling processes. The study should also investigate the feasibility of establishing a new hydraulic connection between the restricted estuary and the AIWW. Due to-the influence of the Route 24 Bridge/Causeway complex on the hydrology of the area, the N.C. DOT should be involved as a cooperative agency for the study. The rationale for involvement of these combined agencies relates to the nearly simultaneous construction of the AIWW and Bridge/Causeway in the early 1930's. 1-/ The status of available funds from these age ncies is uncertain at this t ime. 7-6 (1) Output. This study should clearly define the origins of shoaling problems in the lower estuary and determine the economic f eas i bi I i ty of a shallow dredging program or other corrective actions to reduce shoaling rates and to improve the hydraulics of the lower river. Also, the benefits and effects of installing another connection between the river and the AIWW should be defined. (2) Potential Source of Funds (a) Corps-of Engineers (congressional ap propriations) M NCDOT (Planning funds) (3) Estimated Costs (To be confirmed by the responsible agencies). (a) U.S. Army Corps of Engineers $75,000 (b.) N.C. DOT $10,000 (4) Background for Recommendation See Sections 4.1.3 and 5.1. Almost all of the above rec ommendations involve actions by outside*agent.s or agencies; however, it is pointed out that these actio.ns will be taken based only on the initiatives promulgated by l.ocal interests who want to solve the problems and restore the White Oak River Basin to its full productive and esthetic potential. Therefore, it is finally recommended that the White Oak River Advisory Council and supporting units of government work cooperatively to pursue the objectives and recommendations set forth in this report. Respectfully submitted, HENRY VON OESEN AND ASSOCIATES, INC. Paul S. Denison, P.E. William E. Burnett----- Vice President Environmental Planner 7-7 SECTION 8: BIBLIOGRAPHY OF REFERENCES The following reference Sources were utilized in the preparation of this report: Barmeier, J., etal. 1978. Factors Influencing Stu nted Growth of the Oyster Crassostrea virginica in the White Oak River, N. C. Student Originated. Studies Project Report, Duke University Marine Laboratory, Beaufort, N. C. Beccasio, A.D.; Weissberg, G.H.; Redfield, A.E., et al. 1980. Atlantic Coast Ecological Inventory: User's Guide and Information Base-. Biological Services Program, U.S. Fish and Wildlife Service, Washington, D.C. Davis, J. R. and E . G. McCoy. 1965. Survey and Classification of the New-White Oak-Newport.Rivers and Tributaries, North Carolina. Final Report, Project F-14-R, North Carolina Wildlife Resources Commission, Raleigh, N. C. Davis, J. R. and E. G. McCoy'. 1965. Appendicies to the Survey and Classification of the New-White ' Oak-Newport Rivers and Tributaries, North Carolina. Final Report Project F-14-R, No r*th Carol ina Wi I dl i f e' Resources Commission, Raleigh, N. C. Environmental Management Commission. September, 1975. Water Quality Management Plan, White Oak River Basin, Sub-Basin 01 . Division of Environmental Management, N. C. Department of Natural Resources and Community Development, Raleigh, N. C. Giese, G. L., H. B. Wilder, and G. G. Parker, Jr. July 1972. Hydrology of Major Estuaries and Sounds of North Carolina. Report. of Water Resources Investigations No. 79-46, U. S. Geological Survey, Raleigh, N. C. Henry von Oesen and Associates, Inc. November, 1977. Swansboro Area 201 Facility Plan. Wilmington, 'N. C. Langfelder, J. etal., January 1974. A Historical Review of Some of North Carolina's CoastaFInlets. Report No. 74-1, Center for Marine and Coastal Studies, N. C. State University, Raleigh, N. C. Littleton, T.R. January, 1981. Person-al Communication Regarding History of Navigation and Shipping at Swansboro and Bogue Inlet. Swansborb, N. C. Littleton, T.R * February, 1981. Personal Communication Regarding Landings Along the Shoreline of the White Oak River. Swansboro, N. C. Martens, C. S. and M. B. Goldhaber. May 1978. Early Diagensis In Transitional-Sedimentary Environments of-the White Oak River Estuary, North Carolina. Limnology and Oceanography 23(3):428-441. North Carol ina Department of Natural Resources and Community Development, Division of Environmental Management. Jul y, 1979 . Yater Quality Management Plan Implementation Summary. Raleigh, N. C.' 8-1 Water Quality and Wastewater Discharges. Raleigh, N. C. July, 1979. Water Quality and Urban Stormwater. Raleigh, N. C. July, 1979. July, 1979. Water Quality and Agriculture. Raleigh, N. C. July, 1979. Water Quality and Onsite-Wastewater Disposal. Raleigh, N. C. July, 1979. Water Quality and Forestry. Raleigh, N. C. North Carolina Division of Forest Resources .(undated) Forest Practices Guidelines Related to Water Quality. N.C. Department of Natural Resources ..and Community Development, Raleigh, N. C. Pate, P.P., Jr. and R. Jones. August, 1980. Effects of Upland Drainage on Estuarine Nursery Areas of Pamlico Sound, North Carolina. Cooperative Study Report by N. C. Office of Coastal Management and N. C. Division of Marine Fisheries, Raleigh, N.- C. Peterson, C. H. and N. M. Pete *rson. November, 1979. The Ecology of Intertidal Flats of North Carolina:-A Community Profile. U.S. Fish and, Wildlife Service, Office of Biological Services, Report FWS/OBS-79/39. Sholar, T. M. November, 1975. Anadromous Fisheries Survey of the New and White Oak River Systems. Report for Project AFC-9, N. C. Division of Marine Fisheries, Morehead City, N. C. Simmons, C. E * and R. C. Heath. December, 1979. Water-Quality Characteristics -of Streams In Forested and Rural Areas of North Carolina. Report of Water-Resources Investigations No. 79-108, U.S. Geological Survey, Raleigh, N. C. Shellfish Sanitation Program. July 21, 1980. Report of Sanitary Survey, White Oak River Area, Area D-3. N. C. Division of Health Services, Morehead City, N. C. Skaggs, R. W. etal. August, 1980. Effect of Agricultural Land Development On Drianage Waters In the North Carolina Tidewater Region. WRRI Report No. 159. Water Resources Research Institute of the University of North Carolin-a, Raleigh, N. C. State Stream Sanitation Committee, 1954. White Oak River Basin, Pollution Survey Report No. 2. N. C. State Board of Health, Raleigh, N. C. U.S. Army Engineer District. February 1975. Draft Environmental Statement, Maintenance'of Atlantic Intracoastal Waterway, North Carolina. Wilmington District, U.S. Army Corps of Engineers, Wilmington, N. C. 8-2 U.S. Department of Agriculture, Soil Conservation Service. October, 1980. Tar-Neuse River Basin Main Report. Raleigh, N. C. U.S. Department of the Interior, U.S. Geological Survey, 1979. Land Use and Land Cover, 1972-74, Beaufort, North Carolina. Map L-64, USGS, Raleigh, N. C. Wilkens, E.P.H. and R.M. Lewis. 1971. Abundance%and Distribution of Young Atlantic Menhaden, Brevoortia tyrannus, In The White Oak River Estuary, North Carolina. Fishery Bulletin 69 783-789. 8-3 APPENDICES HENRY VON OESEN AND ASSOCIATES CONSULTING ENGINEERS AND PLANNERS APPENDIX A ADVISORY COUNCIL REPRESENTATION AND MEMORANDUM OF AGREEMENT WHITE OAK RIVER ADVISORY COUNCIL APPENDIX A The White Oak River Advisory Council Name Affiliation/Represent4tion Mr. Kenneth Windley, Jr. Planning Director Onslow County (2) Mr. Charles Daley Carteret County (3) Mr. Andy Ennett Commissioner Town of Swansboro (4) Dr. Alfred,Norton Izaak Walton League and Town of Cape Carteret (5), Mr. James Phillips. Commercial Fish'ing Industry A-1 MEMORANDUM OF AGREEMENT The parties share a common sense that the White Oak River is a valuable resource which is threatened by continuing siltation at its inouth. We note that fisheries productivity, shellfish productivity, and the norTnal 'economic development of the ports of Swansboro and Cape Carteret are constrained by the continuing siltation of the river. It is the sense-.of the parties that all possible efforts to reverse the river's de-cline be undertaken. The following recommendations specify. a course of action which will begin the process of the restoration of the White Oak: (1) The- parties hereby form the White Oak River Advisory Council and hereby request the Town Boards of Swansboro and Cape Carteretf-zMd'tVT_e Boards of Commissioners of Onslow and Carteret Coun*ti&s to each appoint a representative to the Advisory Council. The Issac Walton League and the Fisheries. Industry are also requested to appoint a representative to the Council. The local staff function for the Advisory' Council will be performed by the Onslow County Planning Department. (2) The parties hereby request the appropriate Boards and Councils to endorse the formation of the White Oak River. Advisory Council. (3) The parties hereby request that the Office of Coastal Vianagement recd-ive a joint proposal for the first phase of a t6cbnical study of the flushing of the White Oak River. This proposal will be transmitted by the Onslow County PlannVing Pepartment and endorsed by the Advisory Council. (4) The parties request each of,the four local governments. toequally participate in 'the locdl natching share.for Phase 1 of the technical study. (5) The parties request participating local governments to endorse the Council's efforts to obtain the widest possible funding base for the completion of the technical 'study, subject to review add approval by the cal Boards and Councils. Swansboro -Issac Walton Lea e .9u '-Cape Carteret Representing the Fishing Industry ni., th Onslow Codnty Carl-cret County June 9, 1980 A@2 APPENDIX B WORK TASK OUTLINE WORK TASK OUTLINE WHITE OAK RIVER SYSTEM STUDY For The WHITE OAK RIVER ADVISORY COUNCIL I. DATA COLLECTION PHASE Work Task Description: This phase of the study will consist of the collection of'existing data on the hydrology, tidal h .ydr alic�,sources of pollution, fisheries resources, etc., of the White Oak River. Existing .published and unpublished data sources will be carefully and thoroughly scrutinized. Contacts will be made and interviews will be conducted with representatives of all local, regional, state.and federal agencies which have conducted (or are in the process of conducting) research on the.White Oak River System. Special efforts will be made to contact rep- res6ntatives of the following agencies and institutions: NCONR & CD, Division of Marine Fisheries and Division of Environmental Management; U.S. Army Corps of Engineers; U.S. Geological Survey; U.S. Environme ntal Protection Agency: Duke Marine Laboratory, National Marine Fisheries Service, etc., Also, local fishermen and other knowledgeable individuals in the private sector will be contacted and interviewed. OutPut: The output from the collection of existing data will be a written review of existing conditions of the White Oak River. II. DEFINE THE PROBLEM(S) PHASE Work Task Description: This Phase of the study,will draw upon the results of phase I in order to define the problems in the White Oak River Basin. The existance of such problems as hydraulic system restrictions, ,sedimentation, disappearance of fish, stunted oysters and point and dif- fused sources of pollution will be defined. B-1 Output: The results of this phase will be a written description of existing environmental problems. Where existing data is insufficient .to accurately quantify supposed problems, recommendations for additional study will be made. III. PROPOSE SOLUTIONS Work Task Description-.@ This phase of the study will involve the formulation of structural and/or non-structural solutions to the prob- lems defined in Phase II. output: "Output from this work task will be propoted solutioh(s) to identified problems, including conclusions and recommendations for future work. .IV. COORDINATION AND REVIEW Work Task Description: The preliminary results.of the s'tudy.efforts defined above will be reviewed with the White Oak River Advisory Council in order to receive their input. Output: The results of this effort will be a critique of thd@ study, effort and an opportunity for additional input and guidance. V. FINAL REPORT Work Task Description: All of-the data gathered in the above phases will be synthesized into a final written report to-the Advisory Council. The report will be prepared in bou.nd, brochure form and will include ap,- propriate illustrations and text to facilitate public understanding and acceptance. A suggested report ou tline is attached. Output: 10 copies of the final report will be provided to the Advisory Council. B-2 APPENDIX C DESCRIPTION OF MATHEMATICAL MODELING STUDY FOR THE WHITE OAK RIVER Developed By: Mr. T. C. Gopalakrishnan Department of Marine, Earth and Atomosphere Sciences North Carolina State University School of Physical and Mathematical Sciences P. 0. Box 5068 Raleigh, N. 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GOPALAKRISHNAN Lecturer of Civil Engineering, Indian Institute of Technology, India and J.L. MACHEMEHL Associate Professor of Marine Science and Engineering, North Carolina State University. U.S.A. 1 INTRODUCTION city or stage at an end-section it should be recog- nized that.such ratt-s can be different for the One-dimensional gradually varied flow analysis of same stage and velocity depending on whether the tidal hydrodynamics in inlets has been the subject flow is accelerating or decelerating and whether of study in the last few decades and many mathe- the flow is inward or outward of the inlet. matical models have been developed based on those studies. A common feature in all these models is By grouping the geometric and dynamic parameters- that the boundary conditions at th -e ends of the to form appropriate non-dimensional numbers it reach are supplied from measured val4es of stage, would be possible to predict with a fair amount discharge or velocity. These boundary conditions of accuracy the time rate of change of velocity form an integral part of the mathematical models. or stage at the end sections of a channel system. lit the case of implicit schemes, without the In the present study, the rate of change of velo- supply of these boundary conditions there will be city.2U/3t has been used as the downstream boun- more unknowns than equations. Even though in the dary condition. explicit schemes they are not neede-d to supply enough equations.it is obvious that the flow will not be properly simulated-without imposing pro- 3 APPLICATION OF THE 7r-THEOREM per end conditions of flow. f A functional relationship of the dynamic parameters Normally two end conditions will be required, the involved can be written as follow, remembering upstream and downstream conditions, even though in that we are looking for 3U/at. a net work of channels there will be more than two end conditions. Of these two, the upstream F(13, U, g,TI) - 0 condition is usually the forcing function and the downstream one is the result of the flow due'to where U is the velocity, 0 is time-derivative e forcing function. The downstream condition of U. g the acceleration due to gravity and pends on what happens to the flow outside the the water level. oystem. In other words, it depends on the shallow water wave reflections from the continuation of the Using n and g as the repeating variables, the channel beyond the downstream end of the system non-dimensional numbers i. and Tr are considered. These reflections are characterized 1 .2 by the expansion or contraction of the channel, a b the rate of change of the side slopes and other 7t T1 9 U channel characteristics. As mentioned earlier, a b the downstream end condition is supplied fro 71 1 1 m mea- 2 in 9 U sured values of'flow parameters so that the channel features (outside the system) mentioned above are On applying the dimensional equations, it is automatically simulated. However, if it is re- found that a 0, b = -1, a and b quired to know the response for any given forcing Therefore, function the corresponding measured downstream values may not be available. This means that the 117/g downstream boundary condition cannot be imposed in the usual way. This study describes a method by 7r U/ Vg--n" which the downstream boundary condition can be 2 imposed in the absence of measured downstream As can be expected, n2 the Froude number of flow response to a given forcing function. However, is a governing factor. the method presupposes that measured values for at least one forcing function are known as part of the features of the channel or channel systems. 4 DETERMINATION OF 3U/'Dt 2 PARAI-MTERS INVOLVED From a given set of velocity-stage relationships at a given end of a channel system a relationship The rate of change of velocity or stage at a point between the two non-dimensional numbers nl, and is a function or geometric and dynamic parameters. W2 is obtained using a least squares fit of The geometric parameters include the shape of the fourth order polynomial. From this relationship channel cross-section and the rate of change of one can compute 3U/'Qt once the velocity and stage t section beyond the point under consideration. the point for a given time is known.. This to stag? n (see Figure 1) and velocity U at the is imposed as the downstream boundary condition. point are the dynamic parameters, in addition, of Irie steps involved in th@ procedure are shown cours2, to the acceleratio@ due to gravity. How- in the accompanying flow charts (see Figures 2 ever, whon luDking for .the rate of change of velo and 3 311 data of the Carolina Beach Inlet, N.C., U.S.A. This inlet (see Figure 4) comprises of a small INPUT inlet-channel connecting the ocean to the Atlantic U(t,xe) for all t. Intercoastal Waterway. That part of the channel Step size A t system taken for study is shown in the dashed section of Figure 4. The Calerkin finite element approach coupled with a Hermitian Cubic shape Group the velocities function was used to analyze the inlet. The under the four channel system requires the rate of change of categories indicated velocity, i.e. qu/qt at the two points range 1 and 2 Independent relationships between A, and A2 were obtained for these two points in order Compute 11 and 11 to impose the two downstream boundary conditions. 1 2 The upstream boundary condition was the forcing at x e for the function which is the tidal fluctuation at the four categories mouth of the inlet. independently The results of the analysis are shown in the form of tidal fluctuations at range I and range Call subroutine for 2 (An example is given in Figure 5). least squares fit to get the coefficients in II =a +a II +a (II) 2+a (II) +a (II)4 1 a 1 2 2 3 2 4 2 A set of a , a , a , a and a will be 6 CONCLUSION 0 1 2 3 4 obtained for each of the four categories A method for supplying downstream boundary Stop given forcing function has been developed. This method is based on non-dimensional members U = one-dimensional velocity govern the dynamics of flow. These numbers were X = x coordinate of the channel end determined by a simple application of the II- e Theorem to the dynamic parameters of flow. II = U/8 1 The above method was applied to the Carolina Beach II = U/8II. inlet anlysis. As shown by Figure 5 the method 2 yields values which are in good agreement to,the measured tide at the two points considered. This., no doubt, depends on the numerical method of Figure 2. Flow Chart analysis also. The non-dimensional numbers can be used to yield the downstream boundary con- Start ditions for any numerical method chosen to analyze t0= initial instant the flow provided qU/qt is the downstream con- INPUT t = final instant dition needed for all time. If it is An/At,then Channel parameters in computational a different set of non-dimensional numbers are INPUT period required. Initial Conditions x = x coordinate of U(t ,x),II(t ,x) e the channel end. The advantage of the method developed here is 0 0 that one can know the response of a channel system for all x to a hypothetical but possible forcing function for which measured downstream values are not INPUT t>t Stop available. This situation is especially relevant t and t - e to power canals, inlet channels where the flow 0 0 is affected by man-made alterations in river dis- Step size At charge or construction, etc. t'= t 0 Compute Solve for the flow II using U(t,x ) in the channel 2 e system using a numerical method. and II (t,xe) using the relationship between II and II 2 2 compute II and hence t = t + A t 1 U (t,x ), i.e. U at e the downstean end Figure 1. Definition Sketch Figure 3. Program Flow Chart i iUt- Ui, Ij L: CURR'17--NT MEASUREMENT RANGE SELECTED HYDROGRAPHIC CROSS SECTION DAY MARKER 150 MEAN HIGH WATER LINE MARSH RANGE I DAY MARKER 156 eo, INTRACOASTAL WATERWAY RANGE 2 Ar. J: call Z2> R GE 5 ANGE 5. JL :k CAROLINA BEACH .. ......... CAROLINA BEACH INLET FISHING PIER Figure 4. Carolina' Beach Inlet. + MEASURED TIDE AT RANGE 1. j RESPONSE TO HYPOTHETICAL TIDE + + ................ RESPONSE TO ACTUAL TIDE > C) A@ t 0 2 3 4- 5 6 7@ 8 9 10 it T I PA E(PIRS) Fi,,,ure 5. Tidal Fluctuations at P,3nse No. 1. k: 313 D A; D'u,-- A T 3 6 368 14108 6761