Loading...
HomeMy WebLinkAbout20061270 Ver 1_Mitigation Plans_20060809 1 i 1 1 1 1 ~~ ATTACHMENT 5 Cattail Branch Project Mitigation Plan and Cost Estimate '~l ~~~ '~ 1 1 Cattail Branch Mitigation Plan City of Clinton, Sampson County, North Carolina June, 2006 KO c4c ASSOCIATES, P. C. Cor~~ulling En~,~incers 1 EXECUTIVE SUMMARY Cattail Branch, City of Clinton Sampson County Mitigation Plan This document details a plan to restore approximately 450 existing linear feet of Cattail Branch in Clinton, NC. The Site may be used for mitigation credits by the City of Clinton to offset surface water impacts from a recently culverted section of Cattail Branch. The proposed mitigation site is located directly upstream of the portion of Cattail Branch that was recently culverted. The proposed mitigation site is bisected by Fisher Road and therefore is divided into two reaches (Reach 1 and Reach 2). Reach 1 is located in Fisher Park with the downstream limit ending at Fisher Road. Reach 1 contains approximately 135 existing feet of Cattail Branch. Reach 2 begins at Fisher Road and ends at East Johnson Street. Reach 2 contains approximately 315 existing feet of Cattail Branch. Both Reach 1 and Reach 2 have been straightened and incised in the past and are currently exhibiting signs of channel enlargement both horizontally, through bank failure, and vertically, as evidenced by channel incision. The site is located in a highly urbanized watershed in which impervious surfaces and channel disturbance are high. The proposed mitigation will restore the two reaches using Natural Channel Design and will be designed on a reach specific basis. Generally though, Reach 1 will be restored as a C5 type channel using Priority II techniques, and Reach 2 will be restored as a C5/B5 type channel using Priority II and III techniques. The design will have a restored length of approximately 500 linear feet when completed. Restoration of a degraded stream system to a stable condition leads to improvements in the aquatic and terrestrial communities that depend on the stream. The proposed plan will provide important benefits by improving the biological integrity of the stream, reducing toxicity from ' surrounding nutrient runoff, increasing dissolved oxygen, moderating pH levels, and moderating water temperatures of the stream through shading by planting a wooded buffer. i 1 a KO & ASSOCIATES, P.C. Cunsulting En~;inrers f 1 1 1 1 1 1 1 1 1 Cattail Branch, City of Clinton Sampson County Mitigation Plan TABLE OF CONTENTS SECTION PAGE EXECUTIVE SUMMARY ...................................................................................................... TABLE OF CONTENTS ...................................................................................................... i 1.0 PURPOSE ...........................................................................................................................1 2.0 GOALS ..............................................................................................................................1 3.0 LOCATION ........................................................................................................................1 4.0 WATERSHED ....................................................................................................................1 4.1 Land Use ..................................................................................................................1 4.2 Future Watershed Impacts .....................................................................................1 5.0 EXISTING CONDITIONS ....................................................................................................2 5.1 Physical Conditions of Stream ............................................................................2 5.2 Stream Classification and Substrate Analysis ..................................................... 2 5.3 Water Quality ........................................................................................................... 2 5.4 Soils ..........................................................................................................................3 5.5 Vegetative Community ............................................................................................3 5.6 Rare, Threatened and Endangered Species and Communities ..........................3 6.0 REFERENCE CONDITIONS ............................................................................................. 5 6.1 Existing Conditions ................................................................................................ 5 6.2 Reference Conditions ............................................................................................. 6 7.0 PROPOSED CONDITIONS ................................................................................................ 6 7.1 Design Constraints Analysis .................................................................................6 7.2 Stream Restoration (Natural Channel Design) .................................................... 7 7.3 Perpetual Conservation Easement .......................................................................9 7.4 Hydrologic Analysis ...............................................................................................9 7.5 Sediment Analysis ................................................................................................. 9 7.6 Flood Analysis ........................................................................................................9 7.7 Stream Summary ....................................................................................................9 8.0 TYPICALS .........................................................................................................................9 8.1 Structures and Channel Plugs ............................................................................9 9.0 PLANTING PLAN/RIPARIAN BUFFER ...........................................................................10 10.0 MONITORING PLAN ........................................................................................................11 10.1 STREAM RESTORATION MONITORING ............................................................11 a KO & ASSOCIATES, P.C. ii Cunsulfing En;~ineers t f t 1 1 1 1 Cattail Branch, City of Clinton Sampson County Mitigation Plan 11.0 STREAM RESTORATION SUCCESS CRITERIA ....... 11.1 Long Term Land Protection ........................... 12.0 REFERENCES .............................................................. TABLES Table 1 -Federally Protected Species for Sampson County .......................................... 3 Table 2 -Conceptual Morphological Characteristics of Cattail Branch ........................... 8 APPENDICES APPENDIX A -Vicinity Map APPENDIX B - USGS Topographic Map APPENDIX C -Proposed Conditions APPENDIX D - DWQ Stream Form APPENDIX E -Pictures a KO & ASSOCIATES, P. C. Cunsulling Engineers 1.0 PURPOSE Cattail Branch, City of Clinton Sampson County Mitigation Plan The purpose of the Cattail Branch Mitigation Plan is to detail a plan to restore sections of Cattail Branch for use as mitigation. Credits obtained by the restoration of Cattail Branch within the study area will be used to offset impacts to Cattail Branch that occurred approximately 200 feet downstream of the study area. The impacts which occurred on Cattail Branch are detailed in the permit application of which this mitigation plan is attached. 2.0 GOALS ' The goals of the project include introducing a stable dimension, pattern, profile, and vegetated riparian buffer along Cattail Branch which will replace the existing degraded, concrete lined channel. Introducing a stable channel and vegetated riparian buffer will help to increase water quality in a highly urbanized watershed and will also increase the amount and diversity of both aquatic and terrestrial fauna and flora within, upstream of, and downstream of the study area. 3.0 LOCATION The section of Cattail Branch that is under consideration for restoration is located upstream of the intersection of East Johnson Street and Fisher Drive in Clinton, NC. This section of the channel flows for approximately 450 linear feet with Fisher Drive crossing over the channel approximately 315 feet upstream of Johnson Street in Clinton, NC. 4.0 WATERSHED Cattail Branch is located within the Cape Fear River Basin in the United States Geological Survey (USGS) Hydrologic Unit Code (HUC) 03030006090060, and North Carolina Division of Environment and Natural Resources (DENR) sub-HUC 03-06-19. The downstream point of the study area has a contributing watershed area of approximately 355 acres. 4.1 Land Use ' Land use immediately adjacent to Cattail Branch, within the study area, is dominated by maintained grounds with fescue as the dominant vegetative species. Land use within Cattail Branch's watershed is urban in nature with high impervious areas. Land use includes residential housing, private business, municipal buildings, public buildings and parking lots that channel stormwater flow into Cattail Branch. 4.2 Future Watershed Impacts The watershed is currently highly urbanized. It is unlikely that watershed characteristics will change significantly in the foreseeable future. a KO & ASSOCIATES, P. C. Consulting Engineers ' Cattail Branch, City of Clinton Sampson County Mitigation Plan 5.0 EXISTING CONDITIONS ' 5.1 Physical Condition of Stream The two reaches of Cattail Branch within the study area encompass approximately 450 total linear feet. The reaches enter the study area from a forested parcel owned by the Sampson Regional Medical Center. Reach 1 flows generally in a northwesterly direction through a public park for approximately 135 linear feet before entering a culvert under Fisher Drive. Reach 2 begins at the downstream end of the culvert at Fisher Drive and continues for approximately 315 linear feet through two parcels owned by one private landowner (Ms. Lillian Herring) until it enters a culvert under East Johnson Street. The channel has been straightened and incised in the past. Incision of the channel has led to a high degree of entrenchment of the bankfull flow within the existing channel. The invert of the box culverts at Fisher Drive and Johnson Street are acting as grade control by keeping the channel from incising to a greater extent than has already occurred. Incision of the channel has led to high shear stress on the channel's banks and subsequent bank failure and mass wasting. Concrete has been placed along the channel's banks in an effort to slow bank erosion. A conversation with Ms. Lillian Herring, who lives off of the left bank of Cattail Branch and owns two parcels along Cattail Branch, revealed that the channels were lined with concrete in 1953. Additional causes of channel degradation can be directly attributed to the loss of mature riparian vegetation and the urbanization of the contributing watershed. Currently there are virtually no mature rooted plants that line the channel banks. The loss of these rooted plants has led to lower soil cohesiveness and consequently a high degree of bank failure. Additionally, the urbanization of the contributing watershed has increased the impervious surface area, which decreases the water storage time during precipitation events. This leads to more frequent recurrence intervals for peak flows in the channel, which causes more frequent high stress periods on the channel banks and bed. A North Carolina Division of Water Quality (NCDWQ) Stream Classification Form, was completed for Cattail Branch. Cattail Branch scored a 37.5 on the form which indicates that the stream is ' perennial. 5.2 Stream Classification and Substrate Analysis Cross-sections were surveyed on Cattail Branch within the study area to help determine physical features of the channel. The cross-sections revealed that the bankfull elevation is entrenched within the channel, and that the channel has a very low width-to-depth ratio. These two factors coupled with the fact that the channel has relatively no sinuosity, and the bed material is comprised of sand indicates a Rosgen channel classification is a G5 type stream. 5.3 Water Quality Cattail Branch is classified by the NCDWQ as a C: SW. Class C is a best usage classification for which the waters in this class must be protected for aquatic life propagation and survival, fishing wildlife, and secondary recreation. SW is a supplemental classification of Swamp Waters of which have low velocities and other natural characteristics, which are different from adjacent streams. a KO & ASSOCIATES, 'P. C. 2 Consulting Engineers C' ' 5.4 Soils Cattail Branch, City of Clinton Sampson County Mitigation Plan ' The Soil Survey of Sampson County, North Carolina (USDA, 1985) identifies Bibb and Johnston soils as well as Marvyn loamy sand as the two soil complexes that underlie or are directly adjacent to the study area. Bibb and Johnston soils underlie the existing stream channel while ' Marvyn loamy sand lies on the extents of the channel. The Bibb and Johnston soils series are poorly drained soils found in floodplains along major streams. The Marvyn series is a well drained soil found on short side slopes along pronounced ' drainageways. 5.5 Vegetative Communities Land use within the study area is comprised of maintained yards and maintained grounds used for public recreation. Both the maintained yards and grounds are dominated by grass (fescue ' mostly) and common weeds. Few scattered trees are found within the abandoned floodplain. 5.6 Rare, Threatened and Endangered Species and Communities Some populations of flora and fauna have been in, or are in, the process of decline either due to natural forces or their inability to coexist with human activities. Federal law (under the provisions of the Endangered Species Act of 1973, as amended) requires that any action likely to adversely ' affect a species classified as federally protected be subject to review by the United States Fish and Wildlife Service (USFWS). Other species may receive additional protection under separate state laws. 1 1 Plants and animals with federal classifications of Endangered (E), Threatened (T), Proposed Endangered (PE), and Proposed Threatened (PT) are protected under the provisions of Section 7 and Section 9 of the Endangered Species Act of 1973, as amended. As of April 27, 2006, the USFWS lists four federally protected species for Sampson County (Table 1). A brief description of the characteristics and habitat requirements for these species along with a conclusion regarding potential project impacts follows. Table 1. Federal) Protected S ecies for Sam son Count Scientific Name Common Name: Status Alli ator mississi iensis American alli ator T (S/A Picoides borealis Red-cockaded wood ecker E Schwa/bea Americana American chaffseed E Lindera melissifolia Pondber E "E" -Endangered - A taxon "in danger of extinction throughout all or a signiticant portion of its range." "*" -Threatened due to similarity of appearance. No biological conclusion required. a KO c4c ASSOCIATES, P.C. 3 Consulting Engineers Cattail Branch, City of Clinton Sampson County Mitigation Plan ' Picoides borealis (red-cockaded woodpecker) Endangered Family: Picidae ' Date Listed: October 13, 1970 The red-cockaded woodpecker (RCW) is a mostly black and white bird with a barred back and ' wings and a large white cheek patch. Compared to other woodpeckers, RCWs are mid-sized (about eight inches long) and superficially resemble several other species, such as hairy (Picoides villosus) and downy (Picoides pubescens) woodpeckers. The RCW male's small red spot behind his eye inspired the name "cockaded". Otherwise, these birds are nondescript in appearance, and their habits tend to make them less conspicuous than other woodpeckers. RCWs establish colonies that include adult and nearly mature birds in addition to the primary breeding pair. The species' most notable characteristic is its dependency on old live pine trees, which the birds excavate in a unique manner. Cavity excavation in live pines may take a number of years. The ' birds typically build nests in pine trees at least 30 years of age with 10-inch or greater dbh, and prefer those with heart rot. Numerous cavities may be started in potential colony sites, and some may be abandoned before completion. Abandoned cavities may be reoccupied at a later date if not overtaken by some other inhabitant in the meantime. Occupied trees are pecked around the cavity entrance to exude sap, which runs down the tree's bole, creating a distinctively noticeable "candle" effect (USFWS, 2003b). ' While pure pine stands are required for nesting, RCWs will use mixed forests, woodlands, or savannas for foraging. Fifty percent or more of the dominant trees must be pines 30 years of age or older. ' BIOLOGICAL CONCLUSION: NO EFFECT ' Ground reconnaissance for RCW habitat within the project study area were conducted. There are no stands of old growth pines (preferred nesting habitat) within ahalf-mile of the project study area. The scattered pine and hardwood forests adjacent to the project study area are too young or contain too few pines to be preferred foraging habitat. Schwa/bea americana (American chaffseed) Endangered Family: Scrophulariaceae ' Federally Listed: October 1991 Flowers Present: late May-early June ' This species is known historically from Alabama, Connecticut, Delaware, Kentucky, Maryland, Massachusetts, New York, Tennessee, and Virginia in which it has been extirpated. The only confirmed North Carolina population is on Fort Bragg military base in Hoke County. ' The American chaffseed is an erect herb whose stems branch only at the base (if at all) and grow to a height of 3-8 decimeters. The entire plant is pubescent, with upwardly curving hairs. The narrow leaves are alternate, lance-shaped to elliptic, stalkless, and 2 to 5 centimeters long. The ' leaves are three veined and become progressively smaller towards the top. It bears solitary flowers in the axils of the upper most leaves. The purplish-yellow flowers are arranged into racemes. The fruits are a long narrow capsule, enclosed in aloose-fitting sack-like structure. a KO & ASSOCIATES, P. C. 4 ' , Cunsulling EnKrnee~s ' Cattail Branch, City of Clinton Sampson County Mitigation Plan ' This species occurs in open, moist pine flatwoods, fire maintained savannas, ecotonal areas between peat wetlands and open grass-sedge systems. Soils are generally sandy, acidic, and seasonally moist to dry. Fire is important in the maintenance of open habitat for the American chaffseed. ' BIOLOGICAL CONCLUSION: NO EFFECT No moist pine flatwoods, fire maintained savannas, or ecotonal areas between peat wetlands and open grass-sedge systems are found within the project area. Lindera melissifolia (pondberry) Endangered Plant Family: Lauraceae ' Federally Listed: July 31, 1986 Flowers Present: March -early April Distribution in N.C.: Bladen, Cumberland, Sampson. ' The pondberry is currently known from 19 populations in the southeastern United States. North Carolina is home to only one known population; this population occurs on private land in Bladen County. ' Pondberry is a deciduous, aromatic shrub that has a distinct sassafras-like odor. It grows approximately 2 meters tall and spreads through stolons. Leaves in the pondberry are six to ' sixteen centimeters long and two to six centimeters wide, arranged alternately, have rounded bases, and droop downward. It has small pale yellow flowers that appear in early spring before the leaves. The fruit which matures in August or September is a bright red drupe. ' This plant grows in lowland habitats with hydric soils. These sites are generally flooded at some time during the growing season. It is associated with the margins of sinks, ponds, and other like depressions. The soils present are sandy with high peat content in the subsurface. Areas inhabited by this species show signs of past fire maintenance and now have shrubby conditions. The plants generally grow in shady areas but may also be found in areas that receive full sunlight. BIOLOGICAL CONCLUSION: NO EFFECT No lowland habitats with sinks, ponds, or other depressions are present within the project study area. The soils are sandy but do not contain peat in the subsurface. 6.0 REFERENCE CONDITIONS 6.1 Existing Channel ' A section of Cattail Branch directly upstream of the study area has a mature vegetated riparian buffer on much of the banks. This section of Cattail Branch displays many areas of stable hydraulic dimensions. This section of channel may provide some reference data that can be ' used in the design of the restored section of Cattail Branch. However, a survey will need to be conducted to determine if the reach upstream of the study area is stable. At a minimum, the reach upstream of the study area should provide stable cross-sections where a bankfull discharge and cross-sectional area may be obtained. a KO & ASSOCIATES, P. C. 5 ' , Consulting Engineers Cattail Branch, City of Clinton Sampson County Mitigation Plan 6.2 Reference Reaches ' Restoration designs use reaches of stable channels and buffers within the same physiographic region for design guidance. These reference reaches provide natural channel design ' dimensionless ratios that are based on measured morphological relationships from stable channels. A search for suitable sand bed reference reaches within urbanized areas will be conducted prior to the design phase for the stream restoration. The criteria for a reference reach include, similar watershed land uses, similar drainage area size, stream order, and slope, the ' absence of man-made alterations within and upstream of the surveyed reach, absence of beaver dams, the same stream classification as the design channel, and current stream condition. ' 7.0 PROPOSED CONDITIONS The proposed stream restoration will be designed using Natural Channel Design Methodology. ' Design parameters will be determined from data on the existing stream reaches as well as measurements on reference reaches. Reference reaches provide natural channel design criteria that are based on measured morphological relationships from stable channels. Dimensionless ' ratios are calculated from reference reach surveys in order to determine stable channel dimension, pattern, and profile ranges for the restoration. The project is designed as a Priority II/III restoration where an excavated floodplain will be ' constructed at the bankfull elevation. The stream design parameters must allow the stream to transfer sediment through the restoration reach without aggrading or degrading over time. Stabilizing structures will be added to the restored stream channel. ' 7.1 Design Constraints Analysis ' The study area of Cattail Branch is located in a highly developed watershed that poses numerous constraints on the design parameters. The following is a list of constraints that must be addressed during final design. 1. Two culverts are located within the study area. The upstream most culvert is located under Fisher Drive. The downstream most culvert is located under Johnson Street. Both culverts act as grade points that cannot be changed. Design elevations must meet culvert invert elevations. ' 2. Fisher Drive to the northeast of Cattail Branch is located approximately 25 feet off of the right bank through Reach 2. Additionally, the surface elevation of Fisher Drive is approximately 5 feet higher than the bankfull elevation of Cattail Branch. The drastic ' difference in elevation coupled with the close proximity of Fisher Drive to Cattail Branch will allow for only minimal bankfull benches (floodplain) off of the right (northeast) bank. This will be required so that an acceptable side slope up to Fisher Drive from the floodplain can be acheived. ' 3. A private garage is located off of the left bank. The garage is approximately 25 feet off of the bank and cannot be impacted during construction. 4. The channel is very incised in many areas. Excavation of a floodplain within such a ' constrained area will be difficult to accomplish. Therefore, a typical E/C5 channel with a wide floodplain may not be feasible in areas along the restored reach. A B-type channel that requires little floodplain may be required in areas that are very constrained. a KO & ASSOCIATES, P.C. 6 ' , C'unsulting Enkineers ~~I n ~~ 1 f-1 Cattail Branch, City of Clinton Sampson County Mitigation Plan 5. The existing channel is lined with concrete in many areas. Excavation of concrete will be required to restore the channel. The amount of concrete to excavate will increase project costs. 6. A pedestrian bridge is located at the upstream most point of the project in Reach 1. It is likely that a pedestrian bridge will be required to remain in place. 7. A retaining wall is located approximately 15 feet off of the left (southwestern) bank. The wall may be required to remain in place during construction. 7.2 Stream Restoration (Natural Channel Design) Reach 1 Reach 1 will be designed as a Priority II restoration. Priority II restorations establish a stable dimension, pattern, and profile, while excavating a floodplain at the designed bankfull elevation. Energy dissipation in Priority II restorations is accomplished primarily through the plan form. The restored channel type is expected to be a C5 type channel. The floodplain and easement area are expected to be planted with bare root, containerized, and ball and burlap plants. Containerized, and ball and burlap plant stock are expected to be planted because of the high visibility to the public of the site. Containerized, and ball and burlap stock will provide better aesthetics than planting only bare root stock in the floodplain. The restored channel will increase the sinuosity and stream length of Reach 1, reestablish a riffle/pool sequence, and provide instream habitat for aquatic fauna and flora. Instream structures, which will include rock cross-vanes, log vanes, log sills, and rootwads, will be installed to provide bank stability, profile integrity, and instream habitat. The existing length of Reach 1 is approximately 135 linear feet. The restored length of Reach 1 is expected to be approximately 150 linear feet. Reach 2 Reach 2 will be designed as a Priority II/III restoration. Priority III restorations establish a stable dimension, pattern, and profile, in or near the existing channel. However, floodplains that are excavated are either small in width or virtually non-existent because of vertical and/or horizontal constraints. Energy dissipation in Priority III type channels occur mainly through its bed from rather than its plan form. The restored channel type is expected to be a C5 type channel in sections that are Priority II restorations, and a B5 type channel in sections that may be a Priority III restoration. Sections of 65 type channels will be kept to a minimum, but are expected to be required in areas that are constrained on both sides of the channel. The floodplain and easement area are expected to be planted with bare root, containerized, and ball and burlap plants. The restored channel will increase the sinuosity and stream length of Reach 2, reestablish ariffle/pool sequence, and provide instream habitat for aquatic fauna and flora. Instream structures, which may include rock cross-vanes, log vanes, log sills, and rootwads, will be installed to provide bank stability, profile integrity, and instream habitat. The existing length of Reach 2 is approximately 315 linear feet. The restored length of Reach 2 is expected to be approximately 350 linear feet. A conceptual plan view and typical cross-section are attached in the appendices. A conceptual morphological table is listed below. It should be noted that proposed conditions in the table are 7 a KO & ASSOCIATES, P. C. r Consulting Engineers u J ~II J '~ 1 1 Cattail Branch, City of Clinton Sampson County Mitigation Plan strictly conceptual conditions and are not based off of a specific reference reach found for this site. A reference reach has yet to be found for this site, but one will be found and surveyed prior to design. Table 2. Conceptual Morphological Characteristics of Cattail Branch Restoration Plan: Cattail Branch County: Sampson, NC ITEM Existin Conditions , P ~ Ste, ~~ LOCATION Cattail Branch G1 STREAM TYPE G4 DRAINAGE AREA, Ac - Sq Mi 355.00 Ac - 0.55 S Mi . 3~S.OiR~c,- #1~.a~` BANKFULL WIDTH (Wb~), ft 9.3 ft ~~ ~ ~' BANKFULL MEAN DEPTH (db1~), ft 1.54 ft ~~1:~.25 ,~~s WIDTH/DEPTH RATIO (Wb~/dbkr) 6.0 '';'i2:0 BANKFULL X-SECTION AREA (Abkf), ft2 14.3 ftz '{~.S '~ BANKFULL MAX DEPTH (dmax), tt 1.84 ft ,~ ., .. 1'~E%3 .,~-' WIDTH Flood-Prone Area (Wfpa), ft 16.2 ft ~~3~~ i~~:, ENTRENCHMENT RATIO (ER) 1.7 ~ 2:~ MEANDER LENGTH (Lm), ft NA 3r~'.5 - ~f20,Q;~::;, RATIO OF Lm TO Wb~ NA ~ - $.a RADIUS OF CURVATURE, ft NA - 4a:~ft _ RATIO OF Rc TO Wb~ NA 2,.~ - ~;~?` ~ BELT WIDTH, ft NA ` ~~- ~~'~:A ft MEANDER WIDTH RATIO NA 2n `- B:`Qt SINUOSITY (K) 1.00 1~.'1 VALLEY SLOPE, ft/ft 0.0038 ft/ft ', Q$ ' AVERAGE SLOPE (S), ft/ft 0.0038 ft/ft ~ 4 ~:;~ (~;~ .+~ MAX POOL DEPTH, ft 2.15 ft `'`'` '~ 3u#6 ~ RATIO OF POOL DEPTH TO AVERAGE BANKFULL DEPTH 1.4 ~ 2,5 POOL WIDTH, ft 8.72 ft ~fi25~'~ RATIO OF POOL WIDTH TO BANKFULL WIDTH 0.94 1,C3$~ a KO & ASSOCIATES, P. G $ ' , Consullfng Engineers 0 ' Cattail Branch, City of Clinton Sampson County Mitigation Plan ' 7.3 Perpetual Conservation Easement The City of Clinton will place a perpetual conservation easement on the restored section of Cattail Branch and lands adjacent to Cattail Branch. The easement will be 50 feet from the top of both banks, but in an urban setting involving private landowners the easement width may need to ' vary in width. The final easement widths will depend on landowner cooperation and negotiations with the United States Army Corps of Engineers (COE) and the DWQ. The perpetual conservation easement will require exclusion of buildings, impervious areas, vegetation removal, crossings, or other detrimental actions to the restored stream and riparian buffer that fall within the easement. 7.4 Hydrologic Analysis Discharge rates for the design will be evaluated using the Coastal Plain regional curve and data obtained from stable cross-sections on-site and directly upstream of the Site. The existing and proposed geometries will be evaluated at the bankfull discharge rates using HEC-RAS (USAGE, 2004). The analysis should support the field identification of the existing bankfull area with a close approximation and confirm the proposed channel will adequately convey the discharge at ' bankfull stage. 7.5 Sediment Analysis The proposed stream design must be able to transport its sediment load without aggrading or degrading over time. A sediment entrainment analysis will be performed to ensure that the channel neither aggrades nor degrades due to too much or too little stream power. The sediment ' analysis will consist of comparing existing and proposed stream powers/unit stream powers of Cattail Branch with reference stream powers/unit stream powers to determine the capacity of the proposed Cattail Branch to move its sediment load during flood events. 7.6 Flood Analysis Analyses for the bankfull, 2, 10 and 100-year discharges will be performed on both existing and ' proposed conditions to determine flood stage elevations. It is expected that a no-rise certification will be required by the City of Clinton for the project. ' 7.7 Stream Summary The existing stream length is approximately 450 linear feet. The restored stream length will total ' approximately 500 linear feet. 8.0 TYPICALS ' 8.1 Structures and Channel Plugs A number of different structures will be used to control grade, stabilize the pattern, profile and dimension, and enhance aquatic habitat. These structures may include but are not limited to: rock cross vanes, log vanes, log vane/root wad combos, log sills, and floodplain interceptors. Some rocks and boulders will be used for grade control, but the use of rock and boulder will be minimized because the project is in a sandbed system and the closest rock quary will be a P. C. a KO & ASSOCIATES, 9 Consulting Engineers l I~ l ~I ~~ 0 Cattail Branch, City of Clinton Sampson County Mitigation Plan considerable distance from the site. Few woody materials for structures will come from on-site because of the lack of suitable, mature, available trees. Cross vanes direct the flow away from the stream banks towards the middle of the channel (Rosgen, 2002). This structure creates a scour pool below, while maintaining the grade for the upstream portion. Rock cross vanes will be used at the top and bottom of the Site and at drop structures where a stable grade control point is required. These structures will imitate many of the natural drops, such as large roots crossing the channel that act as grade stabilization in naturally stable streams. Log vanes will be used to direct the flow away from the bank and toward the center of the channel. Log vanes will be used to introduce woody material into the channel to provide habitat and a food source for aquatic life. Without this introduction it would be many years before the planted saplings would be able to provide the stream with this habitat feature. Log sills will be used in the channel as grade control. The log sills will be placed at an angle bisecting the channel at the head of pool near the beginning of the meander bend. The sill will be inserted so that the top of the sill will be at the same elevation as the channel bed. Bundle cuttings, using a species that roots quickly such as black willow (Salix nigra), or rootwads will be planted/placed on the edges of the sill to act as a deterrent to lateral expansion. Rootwads will be used in the channel for habitat enhancement, pool development, and bank protection. Rootwads are a good source for introducing woody material back into the stream channel which provides both cover and a food source to aquatic fauna. Rootwads enhance the development of pools when placed in outside bends by creating a downwell of flowing water when the flow hits the outside bend. Rootwads also act as temporary hardening structures which helps to secure the bank that it is placed on during high flows. Floodplain interceptors will be used where wet seeps intersect the channel. A floodplain interceptor uses riprap, filter fabric and vegetative plantings to stabilize banks where sheet flow or other forms of saturation enter the stream. ' Channel plugs will be used where the proposed channel intersects the existing channel. The plug will be composed of impervious select material that will deter channel avulsions and bank failures. 9.0 PLANTING PLAN/RIPARIAN BUFFER Seeding, mulching, live staking, and vegetation planting will be utilized to stabilize the restored streambanks and buffer. All disturbed areas will be seeded with anon-invasive grass species and either mulched or matted. Biodegradable matting will provide immediate protection for the streambanks against shear stress while the plantings develop a root mass. In time, the plantings will replace the matting in providing stability. Plantings will be used for streambank stabilization and buffer establishment and will eventually provide shade and wildlife habitat along the restored stream. Plantings will quickly develop a root mass and help protect streambanks and floodplains from erosive forces while absorbing nutrients. It is anticipated that plantings will be established within the entire easement area. KO & ASSOCIATES, P. C. 10 ' , Consulting Engineers ' Cattail Branch, City of Clinton Sampson County Mitigation Plan ' All plantings will be native species suitable for the hydrologic regime that they will be planted in (stream bank, floodplain, upslope). Plant stock will include live stakes on the channel banks, and bare root, containerized, and ball and burlap trees in the floodplain and upslope. Containerized and ball and burlap stock will be planted for aesthetic purposes and to establish a hearty root system quickly. It is anticipate that the species composition will be gathered from a mature ' forested area that is located directly upstream of the study area and from reference streams yet to be determined. 10.0 MONITORING PLAN 10.1 Stream Restoration Monitoring ' The stability of the stream channel will be monitored annually for at least five years or until success criteria are satisfied. Monitoring protocols will be based upon the Stream Mitigation Guidelines (USAGE et al., 2003) and will include photo documentation, channel stability analysis, ' plant survival, and ecological function of the restored stream. The Site will be visually inspected after construction and planting. An "as-built" report will be provided to the permitting agencies within 90 days of completion of all construction activities. The "as-built" wil! include final plan view, species composition and numbers, and photograph reference points. A monitoring report will be prepared annually for submission to regulatory agencies. The report will address stream stability and vegetative success aspects of the project. If remedial action is required, it will be identified in the report and implemented as soon as practical. 11.0 STREAM RESTORATION SUCCESS CRITERIA ' Success of the restored stream will be based upon criteria established in the 2003 Stream Mitigation Guidelines (USAGE et al.). 11.1 Long Term Land Protection The City of Clinton will place a perpetual conservation easement along the study area to protect ' both the physical nature of the restored stream and to protect the vegetative species that have been planted within the easement. The City may identify along-term steward to take over the easement to ensure perpetual land protection after a successful monitoring period. 0 a KO & ASSOCIATES, P. C. 11 ' , Consulfink Engineers Cattail Branch, City of Clinton Sampson County Mitigation Plan 12.0 REFERENCES NCDWQ. 1999. Internal Guidance Manual, NC Division of Water Quality Stream Classification Method, Version 2.0. North Carolina Department of Environment and Natural Resources, ' Division of Water Quality. Raleigh, NC. NCDWQ. 2001. Internal Technical Guide for Stream Work in North Carolina. North Carolina Department of Environmental and Natural Resources, Division of Water Quality, Raleigh, NC. NCDWQ. 2004. North Carolina Waterbodies Reports. Basinwide Information Management System, North Carolina Division of Water Quality, North Carolina Department of Environmental and Natural Resources. http~//h2o enr state nc us/bims/reports/basinsandwaterbodies/hydroCapeFear.pdf ' Rosgen, David L. 2002. The Cross vane, W-Weir, and J-hook Vane Structures...Their Description, Design, and Application for Stream Stabilization and River Restoration. Proceedings from the American Society of Civil Engineers. Rosgen, David L. 1997. A Geomorphological Approach to Restoration of Incised Rivers. Proceedings of the conference on Management of Landscapes Disturbed by Channel Incision. ' Rosgen, David L. 1996. Applied River Morphology. Wildland Hydrology, Pagosa Springs Colorado. ' USACE, USEPA, NCWRC, NCDWQ. 2003. Stream Mitigation Guidelines. USDA, 1985. Soil Survey of Sampson County, North Carolina. USGS. Clinton North Quadrangle, North Carolina, 7.5 Minute Series (Topographic). 1986. Denver Colorado or Reston, Virginia. USGS. Clinton South Quadrangle, North Carolina, 7.5 Minute Series (Topographic). 1986. Denver Colorado or Reston, Virginia. 12 KO & ASSOCIATES, P. C. Consulting Engineers 1 i 1 C L 1 APPENDIX A: VICINITY MAP 1 1 1 1 1 1 1 1 i 1 1 1 1 1 I Sampson Co North Caro STUDY A~F~A ------- ~~ C~into~~ 1835 1352 j I 1749 ~_A~=~ -=''!!i~ 1781 ~~ ~ ~~ 1834 1870 ~,~ / ~ ~--- -- _ I ~ \~ - ~ ~ ~~ ~ \ ~` `j 1782 ~ a2~ ~ ~ ~-/ 135 ~ ~ ~ ~ ' as ~ ~ ~ ~ ~ 1751 1356 ~ I~? - I 1311 1 53 \~, 1753 ~ ~ i I I ~ ~' 70~ I--- / i ~ I ,\ is '~~ -~ 13 ~ 1839; J~ _,~ ~~ ~ ~,~ ~' ~ ~ ~ ~ 403 ~ ~ I \ i r - ~'J~~~ .,\ ~ ~ \!t 1838 I ' ``\ -___~-- _ __ _ ~ ~~ ~ 185 ~~I ~ 1923 .--1 -\J ~~~ 1 ~. ~ ~~ 1751 \> I %/ \`\~i -/ ~ / 1852 a°8 \\1 ~ ~~ ~> ~~_ -. `\ 52 ~ 1855 -1 ~/~ 1851 1 8 1 5 ~ 2a ~' 1314 e~, 127 5 ~--__ ___-- --- im ~, ~ 1281 1231 1931 296 1232 I 214 R~Iroed ~ O I ~~ 1277 24 1281 1231 24 ~ ~ I 1229 ~_ _-~' ~~ 1287 ~~~ j -- j j G\ 'f 1275 O , 1227 _ `~ ~~~ _ ~ U it 1931 ~ m \` I ~ i~,\ 24 ~ 1'231~~ ~^~ \~l City 1222 i - 1276 ~ I e \ - --- --- ~ne ~ I 0 2000 3000 Vicinity Map FEET Mitigation Plan of cattail Branch ~ KO ~ ASSOCIATES P.C. Sampson county, North Carolina Consulring Engineers Date: June 2006 Appendix A lOII SCHAUB DR., SUITB #202 RALBIGH, N.C. 27606 (9l9) 85I-6066 1 7 ~:~ 1 1 APPENDIX B: USGS TOPOGRAPHIC MAP fl t V 0 ~l i STUDY ,. / ~ ~ ~~ ~~.~...~.~..._.~.,+~~ ~ ~~, _ ~ _ Qom;, ~. ~BI I A V L~Ca9 !` ~ T~ ' i { ~ ' ~ y i..e i r ~ 1 ~ «ne ~~ _ • ~.. ,. 1 ~Q~ ~4.~ ~ -. i4.F.;i ~4 ~ ~G.. L ~ f -° - J- ~ ~ .r ,,~' `, . ~ ,~~ ` ~~ ~. 5 h. - .. ..-._...._... ~.. _ t .'... .... ... ~. T ~ ,.~~~ _ 1 ((rr • *~ ~1. ~..~,, ~ ~ \ CLINTON NORTH USGS TOPOGRAPHIC MAP, 1986 CLIN'rON SOUTH USGS TOPOGRAPHIC MAP, 1986 o iooo Zooo USGS Topographic ~ I ~ Map FEET Mitigation Plan of h il B C ~ KO ~ ASSOCIATES, ranc atta P.C. Sampson county, North caroling Consulting Engineers IOIl SCHAUB DR., SUITB #202 RALEIGH, Date: June 2006 A~ endig B N.C. 27606 '''Yp (9l9) 851-6066 i~ 1 i J L APPENDIX C: PROPOSED CONDITIONS 1 ~ ~ ~ i~ ,~ i>• ~ iw~ iii ~ iii ~ i~ ~^s ~.~. ~ ~ i~ i>r i ~I II ~I ~I I oI I mI I I I_ Fisher Drive __ _ -~\ ---------- 1 Reach 2 I I I~ I~ I -- - - --1 - ~ ~ I i i I~~ I I Garage I I I I II c I I a~' III I ~ II I I II I I II I I I ~~ m ~ryn~ wall ~ proposed Channel I I F~dstinp Channel Rock Cross-Vane I I ~R-oOooVar e/ I I / Lop Sill I I Fisher Drive Park Reach 1 Mature Woods Co munity Center i 1 1 i~ 1 APPENDIX D: DWQ STREAM FORM 1 North Carolina Division of Water Quality -Stream Identification Form; Version 3.1 Date: ~/Z'7/Q~ Project: ~,~,•~~'2,K~ Latitude: - O3,S° pp~ 13.~tf Evaluator: ~,,^~j(~q;~ Site:+~tr~.~/t C~~V~* Longitude: O7$° 19t 3Z3`f Total Points: , other Stream is at least intermittent Coun ~ I .n~ , I ri' ~ m S~''~ IVo it t 19 or erennial if t 30 P e. g. Ouad Name: , ~ 1 1 A. Geomor holo Subtotal = ) Absent Weak Moderate Strong ' 1a. Continuous bed and bank 0 1 2 3 2. Sinuosity 0 2 __ 3 3. In-channel structure: riffle-pool sequence 0 ~ 1 3 4. Soil texture or stream substrate sorting 0 1 _ ___ __ 3 5. Active/relic floodplain 0 1 2 3 6. Depositional bars or benches 0 1 ~ 3 7. Braided channel -,- i 1 ~ 2 - 3 8. Recent alluvial deposits 1 ~ 0 2 ___ 98 Natural levees 10. Headcuts _ 0 ~_ _.' 1 ~ 0 1 i _2 2 __3_._.___.___ 11. Grade controls 0 0.5 ~ 1 1.5 12. Natural valley or drainageway 0 i__ 0.5 1 1.5 13. Second or greater order channel on existin USGS or NRCS map or other documented evidence. No = 0 ' Yes = 3 Man-made ditches are not rated; snnee discussions in manual B. H drolo Subtotal = '"I.5 r t 14. Groundwaterflow/discharge 0 i 1 ! 2 __ __ 3 ___ 15. Water in channel and > 48 hrs since rain. Q Water in channel --dry or growing season 0 I 1 , 2 16. Leaflitter 1.5 1 0.5 0 17. Sediment on plants or debris 0 0.5 1 1.5 18. Organic debris lines or piles (Wrack lines) 0 0.5 1 1.5 19. Hydric soils (redoximorphic features) present? No = 0 Yes = 1.5 C. Biology (Subtotal = I ) ---- --------------------- 20 . Fibrous roots in channel -- - 2 - 1 0 21 .Rooted plants in channel -- - -- ~ 2 _ --- 1 --0~~ - 22. Crayfish _ 0.5 1 1.5 23. Bivalves 0 1 2 ~ 3 '~ 24. Fish 25. Amphibians 0 .5 0.5 1 ~ 1.5 1 ; 1.5 26. Macrobenthos (note diversity and abundance) 0 0.5 __ 1 ~ 1.5 27. Filamentous algae; periphyton _ 1 2 ! 3 28. Iron oxidizing bacteria/fungus. ~~ _ 0.5 __ 1 i 1.5 29 . Wetland plants in streambed FAC = 0.5; FACW = 0.75; OBL = 1.5 SAV = 2.0; Other = 0 Items 20 and 21 focus on the presence of upland plants, Item 29 focuses on the presence of aquatic or wetland plants. Sketch: Notes: (use back side of this form for additional notes.) ' - IJ 1 1 APPENDIX E: PICTURES 1 f ~~ ,;ti, ,; z . n ~ . 1 °7!~ ; ~. oe. _ .~. r., .~ ~. -r ~.Y r ..` , .,~~... * i ~ fr~~ ,.. .C 2. Reach 1 looking off right bank at playground equipment in abandoned floodplain. Reach 1 looking downstream from Pedestrian Bridge. ... r z •-~ i ,~ ~; a ti i ~,, :. 41 .y ~~°, r ~ ~, Y. .1, ~' j4 s .. ~ l i:s.a -~ s `" ' t ~~ ra\; _ ,a 1` - . ' fi~ }} • Y lawYp d~f .~ Pw- ~1Y~ ' ' .'~. F°F~~ 1Y}M1 ~iR p ~ 4.0^, .R ~ ~ 4 '~ ~ (~ „~ ,,, - , t ', f 1 ~~ ~ ~~ ~.~ ~. Y ~ r 4,, k~tf+rr -~~ " i ~ ~y u o~;.f~ tG i ~} N ' ~`~ ~~. t ~. r ~ r~ ;:~.~'is~ . ~ J f~ G ~' e ~' c' "~~ ~:. ~- `'= cy r,R~'' s, 3. Reach 2 looking downstream from upstream most culvert at Fisher Drive. 4. Reach 2 looking upstream, at upstream most culvert at Fisher Drive -. ,SR ~~ ~_ . T ~~ .~ i, - r. ~ ~ a,` n ..,Ta'e'~f Y n ~f :~a ~ ~ ~ J ~ ~F~ .! - qtr ~ 1}~ ,+, ~'S- ~rry~r+r~~ ""„~:L -a ., .~, ~a t~ p~ y Reach 2 looking downstream. Residence's garage can be seen aff of left bank. 5 py ~n_ 6 .~~ - ~ _~ '~.? °r ~ 'S . ~. i.''p -.. < - - K ~,.: t ,: ..~ ~'M.: ~. ,'",~, ~ w~~ ,. , ~ ~ ~ ~ ,•= ~~ 1 -., rr.~ - v ,• r,. {~ "b ,°, ues"r~a~~" '~~'..tY4'..~' r'"Fa. ~j' ~+.. Reach 2 looking upstream from downstream most culvert at Johnson Street. PROJECT: Cattail Branch PREPARED BY: Ko & Associates, P.C. Consultant Costs Task k Task Task Cost 1.0 Project Administration $2,320 2.0 Topogra hical Survey $4,560 4.0 Stream and Buller Desi n $25,080 5.0 Restoration Plan $3,000 6.0 Construction Administration and Oversight $9,700 7.0 Mitigation Plan/As-Builts $1,310 8.0 Monitoring $11,880 Expenses $1,641.00 Total Design Fee $~8,-;~ Lu) Construction Costs Task l~olal Conslrucliun ('usl ~1'nlal Pruiccl (bsl Task Cost S.f?! ~r,~~ r;5g Page 1 of 1 6/7/2006 1 L~ 1 1 r ATTACHMENT 6 Figures w ~ ~~ ~' ' ~` Qy ~ ~: ~ . ,~~ ~ ~ ~ ~~~~ p t ~~ ~ ^ ~~~` ~ ~ A ~ ~ ~~ ~ ~ s ~ ~ a 3 ~~ ,rte ~ ° >~ ~~ ~ ~ `~ . ~ ~ ~ guest, rtiGia~ ~~ ~I FIGURE NUMBER: 1 PROJECT LOCATION MAP SOURCE: SAMPSON COUNTY GIS Cattail Branch Project "~"'~'®"` PROJECT NUMBER: ENM006 089 Butler Drive and Johnson Street '~ Clinton, Sampson County, North Carolina ENVIRONMENTAL INVESTIGATIONS, INC. SCALE: As Shown Sti wIR~ s {~d~ ~~~ p arkwa~ G~e'~~ ~°~~~ ~ ~ ~ ~ 2a, ~5`~e ~ ~' Qro~ec ~ ~ t,f~ N ~ ~ ~ ~~~ 5~ c~tc;,~ c~ a ~ °~~ ~ ~~ ~~ ~ ~~ ~r~ N ~ ~ <<~ J C L 1 Downstream Reach- ~~ existing piped section .~ i ~•~ ~,L,t~., ~ if /~ .r''+ Zh~1.52722.34 ~ ;~ ~, ~~ ~r ?~85 / f. ~~ ~~ ~~~~, ~~~ iiE 'I _~.~i1$~~D~ 1 1 1 1 1~iFs~R.'~ ~~ `~~ Mitigation Reach 2 - 315 ft ~fi~~- 1 ~.~ ``~ ~351$15~39 ~` ~~' FIGURE NUMBER: 2 DRAWN BY: VAH PROJECT NUMBER: ENMO06 0689 SCALE: As Shown •''~ / f J ~~. ~ ~' .~ ~''1~ 5 k , ~~~,J~~~~~~ '~ y'.r'.J/'~ ~~ +., ~- 4 ~~~J ~JL~~ J v _ ~ ~,~ ~J f ,~f f ~ ~~ ~ X ~ f ~~~ Y ~ ~ ~' 0 Mitigation Reach 1 -135 ft SITE MAP Cattail Branch Project Butler Drive and Johnson Street Clinton, North Carolina ~4{5± ENVIRONMENTAL INVESTIGATIONS, INC. 2~~.5?TA~1$ -~'` ~ ~ ~ 24C.5~~v 1 ~4 x ~~~ ~. .~ ~ ~,_ ~~ ~ Project Reach - 163 ft e ~' ~`~, ,_: ~, ~ :_ 1 ~~ ~, 1~ ~ J 5~ '~' 4 L'~u ry~~ ~ ~~ `_.ti` Upstream Reach - `~ .,. x open stream Parcel No 2405168904 401 Butler Drive ~O ~~ UPSTREAM REACH PROJECT REACH Headwall Stream impact area 1 -------------------- ------ ------ I r 23' I Stormwater drop i I ' mTT- I~ - Proposed locatiol 15' R \ Pine tr I I r I I t------------------------------------ Butler Drive (asphalt paved) DOWNSTREAM REACH o Existing Ptpe ~ I location d o < W n m 0 m ~.....~ -~ 1 FIGURE: p Project Drawing _:,~ PROJECT NUM BER: ENM0080889 Cattail Branch Project ~~ ~ ~' DRAWN BV: VAH Butler Drive and Johnson Street ~ SCALE: N'S Clinton, Sampson County, North Carolina ENVIRONMENTAL INVESTIGATIONS.INC Stream bed width