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HomeMy WebLinkAbout20010406 Ver 1_Mitigation Information_200109011 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 RESTORATION AND CONSERVATION MANAGEMENT PLAN FOR THE MINGO CREEK MITIGATION SITE US 64 KNIGHTDALE BYPASS WAKE COUNTY NORTH CAROLINA PREPARED FOR: NORTH CAROLINA DEPARTMENT OF TRANSPORTATION RALEIGH, NORTH CAROLINA PREPARED BY: . ECOSCIENCE CORPORATION 1101 HAYNES STREET, SUITE 101 RALEIGH, NORTH CAROLINA 27604 SEPTEMBER 2001 1 TABLE OF CONTENTS r 1 Y 1 1 l?? Page 1.0 INTRODUCTION ............................................................................................ 1 1.1 Project Description ............................................................................... 1 1.2 Methods ............................................................................................. 3 2.0 PHYSICAL RESOURCES .................................................................................. 6 2.1 Physiography, Topography, and Land Use ................................................ 6 2.2 Geology and Soils ................................................................................ 10 2.3 Water Quality ...................................................................................... 12 2.3.1 Water Quality Sampling and Classification ...................................... 12 2.3.2 Neuse River Nutrient Sensitive Waters Management Strategy............ 13 2.3.3 Nitrogen Loading and Reduction Assessment .................................. 16 2.4 Jurisdictional Stream and Wetlands ......................................................... 22 2.5 Wetland Functional Analysis .................................................................. 24 2.5.1 General Wetland Functional Analysis ............................................. 24 2.5.2 DEM Wetland Rating Procedure .................................................... 27 3.0 BIOTIC RESOURCES ....................................................................................... 30 3.1 Plant Communities ............................................................................... 30 3.2 Wildlife ................................................................................................ 34 3.2.1 Terrestrial ..................................................................................34 3.2.2 Aquatic ..................................................................................... 35 3.3 Rare and Unique Natural Areas ............................................................... 36 3.4 Protected Species ................................................................................ 36 3.4.1 Federally Protected Species .......................................................... 35 3.4.2 State Protected Species .............................................................. 39 3.5 Regional Corridors and Adjacent Natural Areas ......................................... 39 3.6 Environmental Education and Public Interest Program ................................. 41 4.0 STREAM AND WETLAND MITIGATION FEASIBILITY STUDY ................................ 43 4.1 Unnamed Tributary 1 (UT1) ................................................................... 43 4.1.1 Physiography and Land Use ......................................................... 43 4.1.2 Soils ......................................................................................... 45 4.1.3 Vegetation ................................................................................ 46 4.1.4 Hydrology ................................................................................. 46 4.1.5 Stream Discharge ....................................................................... 47 4.1.6 Channel Dimensions .................................................................... 47 4.1.7 Channel Plan Form and Substrate .................................................. 48 4.1.8 Jurisdictional Wetlands ................................................................ 49 4.2 Unnamed Tributary 2 (UT2) ................................................................... 50 4.2.1 Physiography and Land Use ......................................................... 50 ii 1 r Il it 1 1 1 1 4.2.2 Soils ......................................................................................... 52 4.2.3 Vegetation ................................................................................ 52 4.2.4 Hydrology ................................................................................. 52 4.2.5 Stream Discharge ....................................................................... 53 4.2.6 Channel Dimensions .................................................................... 53 4.2.7 Channel Plan Form and Substrate .................................................. 54 4.2.8 Jurisdictional Wetlands ................................................................ 55 4.3 Mitigation Suitability and Recommendations ............................................. 55 4.3.1 Mitigation for UT1 ...................................................................... 55 4.3.2 Mitigation for UT2 ...................................................................... 56 5.0 WETLAND FUNCTIONAL EVALUATION ............................................................. 57 5.1 Supporting Research ............................................................................. 57 5.2 Functional Assessment Methodology ....................................................... 59 5.2.1 HGM Methodology ...................................................................... 59 5.2.2 WRAP ...................................................................................... 65 6.0 SUMMARY AND RECOMMENDATIONS ............................................................ 68 7.0 REFERENCES ............................................................................................... 70 8.0 APPENDICES ...............................................................................................75 Appendix A: General Wetland Functional Assessment Methodology and Forms Appendix B: DEM Rating Forms Appendix C: Species Lists for Plant Communities 1 1 1 A 1 1 1 1 1 1 1 1 1 1 1 1 LIST OF FIGURES Page Figure 1 Site Location ..................................................................................2 Figure 2 Aerial Photograph and Site Boundary ...................................................4 Figure 3 Watershed and Sub-Watershed Boundaries ..........................................7 Figure 4 Physiography, Topography, and Land Use ............................................8 Figure 5 Soil Map Units .................................................................................11 Figure 6 Jurisdictional Streams and Wetlands ...................................................14 Figure 7 Buffer Zones ...................................................................................17 Figure 8 Current Land Use .............................................................................19 Figure 9 Future Land Use ...............................................................................20 Figure 10 Plant Communities ...........................................................................31 Figure 11 Regional Corridors, Parks, and Adjacent Natural Areas ...........................40 Figure 12 Preliminary Mitigation Design (UT1) ....................................................44 Figure 13 Preliminary Mitigation Design (UT2) ....................................................51 iv 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 LIST OF TABLES Table 1. Physical Characteristics of Streams ......................................................... 15 Table 2. Mingo Creek Watershed: Current/Future Land Coverage and Total Nitrogen (TN) Export Coefficients .............................................. 18 Table 3. Total Nitrogen (TN) removal along Mingo Creek On-site and Upstream ...................................................................................... 23 Table 4. Linear Distances and Acreage of Jurisdictional Wetlands ............................ 25 Table 5. General Wetland Functional Analysis Scores ............................................. 26 Table 6. DEM Wetland Rating System Scores ....................................................... 29 Table 7. Expected Functions for Wetlands in the Mingo Creek Mitigation Site............ 61 Table 8. Conceptual HGM Comparison ................................................................ 62 Table 9. WRAP Comparison of Functional performance .......................................... 66 Table 10. Weighted WRAP Scores ........................................................................ 67 v DRAFT RESTORATION AND CONSERVATION MANAGEMENT PLAN FOR THE MINGO CREEK MITIGATION SITE 11 US 64 KNIGHTDALE BYPASS 1.0 INTRODUCTION 1.1 PROJECT DESCRIPTION The North Carolina Department of Transportation (NCDOT) is proposing to construct the US 64 Knightdale Bypass (Bypass) that will redirect traffic south of the Town of Knightdale. When constructed, the 10.2-mile, multi-lane section of the Bypass will connect 1-440 (Raleigh Beltline) to US 64 (Wendell Bypass) near SR 1003 (Rolesville Road). The Bypass will include seven interchanges (including Hodge Road SR 2516), serving Raleigh, Knightdale, and Wendell. The completion date was expedited in July 2001 when the construction was changed to a design-build schedule to start in 2002. The project is to proceed through five phases, with a completion date in 2005; three years earlier than originally planned. This project will impact approximately 16 acres of Section 404 jurisdictional wetlands. A 2:1 mitigation ratio has been proposed to offset these unavoidable wetland losses. For mitigation of these impacts, NCDOT is pursuing a three- part mitigation plan including 1) a 1:1 credit ratio for approximately 16 acres with the Wetland Restoration Program (WRP), 2) a 4:1 credit ratio for enhancement/preservation on Marks Creek, and 3) preservation and stream and wetland restoration opportunities within approximately 205 acres of wetlands, associated buffers, and adjacent uplands at the confluence of Mingo Creek (Mango Creek on USGS mapping) and Neuse River. The combined credits of all three mitigation options will more than fulfill mitigation obligations for this project. The Mingo Creek Restoration Site (Site) contains approximately 205 acres located in central Wake County, adjacent to the east bank of the Neuse River and approximately 1.2 miles south of existing US 64 (Figure 1). The Site is roughly rectangular in shape, with the long sides extending in a generally east-west orientation. The northern boundary of the Site is the Norfolk-Southern Railroad bed. The eastern boundary is Hodge Road (SR 2516). The western boundary is a property line which stretches from the east bank of the Neuse River to approximately 250 feet east of the riverbank. The Bypass alignment will divide the Site, as it passes through in diagonal fashion from the northwest corner to the southeast corners of the Site. Positioned at the lower reaches of an intensely developing watershed, including the western portion of Knightdale, the Site offers numerous benefits including the following: • On-site mitigation for streams and vegetated wetlands, • Water quality enhancement in an intensely developing watershed, • Water quality function in the sensitive Neuse River Basin, and located in the proximity to the main stem, 1 1 1 1 1 2000 ft. 4000 ft. r 11 `=_?i_ ,'-? ??Z? /?-=-- , •':> ?- 1:24,000 . Source: USGS 7.5 Minute Quadrangle (Raleigh East. N.C.) ? ? ' '? • ? ? ? {` f ?` ? ?? ,? c ? lid / __\ ;, : ?. 4r.? , -° ?- ? ? ? ?/ - r ?? ? 4 . Pool / •;; ft' ?I / ii: ? ?? \? ?''' ?? ti`s • J \ o u ?. 1 ? Site - Location i 100 ? ? ,/ ? ? ( \1 /'-. / ? ? t ', g rho .: t ? ? \ -? ? ?, , ? i / ? ?! '\ 1- J,`- L_.11ii v v ?- 9? vr` EcoScience Corporation SITE LOCATION MINGO CREEK MITIGATION ANALYSIS Dwn. by: Ckdby: MAF FIGURE JG Date: Raleigh, North Carolina Wake County, North Carolina JUL 2001 project: 00-046.07 • Opportunity to preserve existing mature forest riparian buffer in the Neuse River Basin, • Opportunity to maintain and extend buffers beyond regulated limits, • Preservation of established, mature plant communities in unique proximity to each other, • Provide aquatic and terrestrial wildlife habitat/corridor in a suburbanizing area, • Opportunity to enhance and continue greenway trails and open space, and • Opportunity for recreation and public education diverse wetland/upland complex. This document describes natural features within the site including land use, soils, water resources, plant communities, wildlife resources, jurisdictional streams and wetlands, and results of a protected species survey. In addition, this report provides a summary of the amount and type of Section 404 jurisdictional areas (surface waters and wetlands) located within the Site, discussion of conceptual mitigation options, and a wetland functional evaluation. 1.2 METHODS Current (1999) low level aerial photographs were obtained from Wake County Geographical Information Systems (GIS) and used as base mapping (Figure 2). Additional layers for topography, soils, city parks, land use, hydrography, roads, and property boundaries were also obtained through Wake County GIS. The road alignment for the Bypass was obtained from NCDOT. Field reconnaissance was performed to validate published resource inventories and identify areas of particular environmental concern. Field investigations were conducted during June 2001. Resources utilized in support of the field effort include U.S. Geological Survey topographic quadrangle maps (Raleigh East, NC, Garner, NC, Clayton, NC, and Knightdale, NC 7.5 minute quadrangles), U.S. Fish and Wildlife Service (FWS), National Wetlands Inventory (NWI) mapping, and Natural Resource Conservation Service (NRCS) soils information concerning Wake County (SCS 1970). Water quality data for streams and tributaries at Mingo Creek were derived from available sources (DWQ 1997, DWQ 1998). Quantitative sampling was not undertaken to support existing data. Section 404 jurisdictional wetlands were identified using the three- parameter approach (hydrophytic vegetation, hydric soils, wetland hydrology) outlined in the Corps of Engineers Wetlands Delineation Manual (DOA 1987). Wetland functions were subjectively evaluated using Guidance for Rating Wetlands in North Carolina (DEM 1995). Vascular plant names follow nomenclature found in Radford et a/. (1968) with exceptions for updated nomenclature (Kartesz 1998). Wildlife and aquatic life distribution and habitat use were determined through field observations, evaluation of habitat type distributions, and available supportive documentation (Lee et a/. 1980, Martof et a/. 1980, Potter et a/. 1980, Webster et a/. 1985, Menhinick 1991, Fish 1968, Hamel 1992, Rohde et a/. 1994, Wilson 1995, and Palmer and Braswell 1995). 1 m m S i m i m m m m= gy m m m= i A4? '?a'1'• ?, i 1 Y '. R ?F•••? i''Sl?•yot' qk _40 , k4 -IA _?fi ?=??:?51h'_ f ? ? Pjt?.y? ? h".? rr? 4 ' . ?y' ?, ?,w? ,?' ? ?,?' • ? _ a '??' ? 1 q ?' ??-'M•'t ,ter ? • ,? a"? f. •,? ? r ? K ?' ? ?":w"? y .+t,?.q•?,^? ?ss'f?;? ? }ri T_ _t If _ ? 3 ! S ?,' ?; - I it ?'•yf, ? r , ? °? _` r ? J t si F i i. ? • i? - . ? , r. r'iE 4' ,r,c _, '?. Ll ..? . ?!-j'n ' _ Y_ ?r ? A f R3 W ?t ? .3 ,? '??' - 17r ?? y ? ,r,,} ? , ,. ? ? `?' o- - t * ` •' ."'+ k ,r, 1' "? r ? t .. • . tom} •' t, •'` ? ?!• # ?k. k . ? ? ? ` s? t '-? • t , r• A ? `, r1` I ? ?. .: y.'4?.?"? „ ?. 4 4 , ` • ? , ?.}Y - `L+I?v.. v i rf'r4 46. 40, .i q?4 ,f ? _ -r ? •. rny. ? .?r'• .i e 1F;irk' 4_,-??• =r?y?}? • r. ' ip' • ? ? 4 ,? 1 t• ? 4`? r ? . ?`: • . ? ??t? •1 ?ytr 4y;,y? "'? r? .s a: ?} Y?.'+..r Jk ?• +c ?; - t r t ? s- i ? ??#'?°' ? -a<, ''r , ?,`4 • x: 'fit N , , t ?., , ? ?i 5.. _ L '? i ?? :?f r ,rir*''?. .#• :.;N1:....?} s ?,? .4 ?•?''M `"' Vii? ? ?• }.. t .?i'ry._? y G '.'.i'"? f ?l„ ? ? '1 i I a + Sel "` 14 Ale a-,i 'w` ? ,-.n L ?"?' <t {l?' k. v i -S ??y ?l 3rry r,rx q. ?k •'? ,. is "°I t?,I7 ? h?y?_ t ti •ai ??' 1 .:SA 'f j 2 ?' S1 ? „? ..?.", ? .. ?? r r'ir{?•? ?'., 1 .''k"? d ` ?y .yt -? l ? ;fir. Y -iti .s• ? ?. ...w .+?' ?F? •y?? Oil J moo aL 10 41 IL ?`? `•? s ? ? .?. ?•. ?? 1' ? -??' ? mot.' ~ '. - 1 . N. I 2 .'.'ftti ar R J _ - ?•?.?7 . - 1-4 Awt F r' .a ? M a ? f 4h'?-? ;? ??p ;'rte} r ~ ,?F 1 81, 'M--? F.. tY. ?? ?• ? f 3 3 I' Ilk m n n n _1 m n z ° T m OD coD?rn? z=+czi =m D Z n ?c 0 "C3 N ? DO c? c: o o _ z??ca ? Do A 0 m o D D? z Oz (n?? Q °. A7 r'J rn 0 0 ?m D' ?Zm n o v 0 O = C 'J N 7 A listing of federally protected species whose ranges extend into Wake County was obtained from FWS (dated April 12, 2001). In addition, files maintained by the N.C. Natural Heritage Program (NHP) were reviewed for documented sightings of state or federally listed species and documented locations of significant natural areas. Field surveys for federally protected plant species were conducted on July 11, 2001. These surveys focused on identification of potential habitat areas, followed by a systematic investigation of each identified habitat site. Biologists conducted the surveys by walking overlapping transects through suitable habitat. Observed plants belonging to the same genus as the protected plant species were examined and positively identified. Areas of possible habitat for listed wildlife species were surveyed for suitable nesting and foraging sites, travel corridors, and any other parameters necessary to confirm a species occurrence. 1 1 1 LI J 1 t C1 2.0 PHYSICAL RESOURCES 2.1 PHYSIOGRAPHY, TOPOGRAPHY, AND LAND USE The Site is situated in the Northern Outer Piedmont Ecoregion. The landscape is characterized by broad, gently rolling interstream divides with steeper slopes adjacent to streams and drainages. Local elevations range from a high of approximately 300 feet National Geodetic Vertical Datum (NGVD) along upland ridges to a low of approximately 150 feet NGVD along the Neuse River floodplain. Extensive granite outcrops are commonly exposed from geologic stream processes. The Site is located between Raleigh and Knightdale at the confluence of the Neuse River and Mingo Creek. The Site is bounded to the north by a railroad and to the east by Hodge Road (SR 2516). The Neuse flows along a portion of the western property boundary (Figure 1). Mingo Creek flows east to west near the northern property boundary (Figure 1), and is heavily impacted by beaver. A breached dam associated with a drained impoundment remains a prominent feature within the Mingo Creek floodplain. The date of the breaching event has not been determined. The shoreline of the impoundment likely mirrored the boundary of the fresh water marsh complex. Mingo Creek supports a primary watershed of approximately 4.4 square miles (Figure 3). Beaver impacts to the Mingo Creek corridor include extensive ponding of the surrounding floodplain and low terraces, creation of a multi-threaded channel, and mortality to adjacent bottomland and previous upland tree communities. The pervasive tree mortality and flooding in the beaver-impacted areas have created an exemplary freshwater marsh community. Several tributaries flowing into Mingo Creek dissect the Site. Notable are two larger tributaries located in the eastern and south-central portion of the Site. The two secondary watersheds, unnamed tributary to Mingo Creek (UT1) and unnamed tributary to Mingo Creek (UT2) support drainage areas of 0.30 square mile and 0.16 square mile, respectively (Figure 3). These unnamed tributaries, designated UT1 and UT2, are described as such for mitigation purposes. UT1 corresponds to stream System 2 and UT2 corresponds to Systems 11 and 14, as described in Section 2.3.1. Two distinct, maintained power line corridors, approximately 100 feet in width, cross the Site. One corridor extends from the middle eastern Site boundary adjacent to Hodge Road, along a northeast-southeast axis to the northern Site boundary adjacent to the railroad. A 1 second corridor extends across the southwest corner of the Site, along an east-west axis from the middle southern Site boundary to the middle western Site boundary adjacent to the Neuse River. The Site also contains a sewer line easement that extends from the southwestern corner of the Site, in a northeasterly direction, before turning in a northerly direction over Mingo Creek, and off-site under the railroad tracks. Land use within the greater Mingo Creek watershed includes rural undeveloped land, new light-to-moderate density residential development, and new commercial establishments associated with expanding Raleigh/Knightdale (Figure 4). Undeveloped property within the watershed is concentrated around the periphery, away from Mingo Creek. However, residential development is rapidly encroaching from all sides on the watershed. The 1 6 fl L t 1 I 1 U LU fiV 00 8 LL C i Q ? 'rt 7 O N O CO a J ? O o f a ",A l e 1 , ?e ?<' w. '." , ? .,,e •?, ?? ? /, I i. a ?U 1 t? /?(. "E K. - LLI Ii W Cw? 41 ! • 111 ? ?T ??` y ? . _, .?? / , ?l //?"? •,? ? ;,may +? !( py)?`. { ,.? ? ? Z` ti .• r ? x r ) a , ) U.- 2 A _ ??-` ??? ,??-? =>b r ? ? ?? ' ,?' • ? ? ? ? ? _ ?i it F--_ ` /4 ; U O R \ ?? , alal?r it r? r ar rr? r ?r rr r? rr . r¦? rr r? r r. r rr rr E J undeveloped property is occupied by pine/mixed hardwood forest on slopes and ridges, 1 changing to predominantly mesic hardwoods along stream bottoms. In the vicinity of the Site, development is directed primarily along Hodge Road including several new residential subdivisions; Hodge Road Elementary School; a gas station; a small grocery/hardware; and several other small businesses. Most of the region to the west of Hodge Road is undeveloped, as are certain parcels to the east. The surrounding region is subject to increasing development pressures and natural communities are rapidly being replaced by I residential and commercial development with associated maintained environs. 1 1 11 v 1 9 2.2 GEOLOGY AND SOILS The project is located in the Raleigh Belt geological province, which formed through a ' complex series of events beginning with the deposition of sediments in an ancient sea, the Theic-Rheic Ocean, about 800 million years ago. Over the subsequent 600 million years, the deposition of thousands of feet of sediment were intruded upon by molten magma and volcanic flows on several occasions, folded under tight crustal compression, fractured and vertically displaced during the Altlantic Ocean basin separation, deeply eroded through hydrological forces, and more recently exposed to erosion from the sea (Parker 1995). The project area is underlain by medium grained, foliated to massive gray granite rock (Parker 1995). The Site is located in an Appling-Louisburg-Wedowee association that extends from Rolesville NC (notheast Wake County), to just north of Auburn, NC (east-central Wake County). These soils are well drained to somewhat excessively drained soils derived from granite, gneiss, and schist (SCS 1970). The main creek channel and freshwater marsh contain Wehadkee and Bibb series (Fiuventic and Typic Hapiaquepts). A small section of Wehadkee lies adjacent to the Neuse River in the southwest corner of the Site. Within Wake County, Wehadkee and Bibb, Wehadkee silt loam, and Worsham soils are listed as hydric (NRCS 1996). Appling sandy loam (Typic Hapiuduits) is the dominant upland series south of (2 to 6 percent eroded) and adjacent to (10 to 15 percent slope) the marsh. Durham loamy sand (2 to 6 percent slope, Typic Hapiudu/ts), Louisburg loamy sand (10 to 15 percent slope, Ruptic-U/tic Dystrochrepts), and Wake soils (10 to 15percent slope, Lithic Udipsamments) are also adjacent to the marsh near Hodge Road. Wake soils extend and interweave with Appling soil in the Site's uplands establishing the codominant upland series. Soil mapping is depicted in Figure 5. ' Wehadkee and Bibb series are similar and often occur together. They consist of nearly level, poorly drained soils on the floodplains of most of the streams in Wake County. These soils form in loamy alluvium with Wehadkee having finer texture and, consequently, 1 less infiltration. Surface runoff is slow to ponded and the seasonal high water table is at the surface. The Worsham series consists of nearly level and gently sloping, deep, poorly drained soils. Worsham soils formed under forests from translocated material and weathered bedrock. Infiltration is good, permeability is moderately slow, and surface runoff is slow to ponded. ' The depth to bedrock ranges from 5 to 15 feet (1.5 to 4.6 meters) and the seasonal high water table is at the surface. The Appling series consists of gently sloping to strongly sloping, deep, well-drained soils of the Piedmont uplands formed under forest in material that weathered from granite, gneiss, schist and other acidic rocks. Infiltration is good and surface runoff is very rapid. Gently sloping to sloping, deep, well-drained soils on Piedmont uplands make up the Durham Series. These soils form under forest in material that weathered from granite, gneiss, and other acidic rocks. Infiltration is good and surface runoff is medium. The Louisburg series consists of gently sloping to strongly sloping, moderately deep, to somewhat excessively drained soils on Piedmont uplands. These soils form under forest 10 ? = = = m m = m = m = = m = = m = m m m m n C) Fn o 1 v n T D C O = f1jl Z n > o C ,n ?' zr G) O V, c ;10 g ? > 0 0 0 d -t ... '? m o D m D O Z U X O M N v o r No Zm D on N ? o cover in material that has weathered from granite, gneiss, and other acidic rocks. Infiltration is good and surface runoff is very rapid. Gently sloping to moderately steep, ' somewhat excessively drained soils that are very shallow over hard rock make up the Wake series. These soils form under forest in material that weathered from granite, gneiss, and other acidic rocks. Infiltration is good and surface runoff is very rapid. 2.3 WATER QUALITY ' 2.3.1 Water Quality Sampling and Classification The Site is located in the Neuse River basin (USGS Hydrologic Unit #03020201). The Neuse River basin is the third largest basin in the state, encompassing 6192 square miles, ' including portions of 19 counties, and containing 3293 miles of streams. Fourteen sub- basins comprise the Neuse River basin (DWQ 1998). Mingo Creek is located in Sub-basin 03-04-02, which includes the Neuse River and tributaries from an upper extent at Falls ' Lake Dam to a lower extent at the Neuse River confluence with Mill Creek. Raleigh, Cary, Wake Forest, Garner, Clayton, Selma, and Smithfield and portions of Wake and Johnston Counties are included in this sub-basin. The sub-basin suffers from severe water quality problems based upon 63 N.C.Division of Water Quality (DWQ) benthic macroinvertebrate monitoring sites. Urban stormwater runoff and, to a lesser extent, agricultural runoff and effluent from wastewater treatment plants are the main contributors to water quality degradation in this sub-basin (DWQ 1998). The Mingo Creek watershed is located within a priority sub-basin by the N.C. Wetland Restoration Program (WRP) (WRP 1996) Mingo Creek is a second to third order stream within a watershed (DWQ HU code #03020201070110) that is bordered by US 64 to the north, Knightdale to the east, Poole Road to the south, and Neuse River to the west. The proposed mitigation site is 7.3 percent (205 acres) of the entire watershed (2816 acres). The WRP (1996) has not designated this watershed as a high priority for restoration; however, because of the rate of development in this area and the planned future construction of the Bypass, preservation of this watershed will be instrumental in reducing nutrient inputs and siltation of the Neuse River. ' Mingo Creek has a State best usage classification of C NSW. The C classification denotes waters protected for aquatic life propagation and survival, fishing, wildlife, secondary recreation, and agriculture. Secondary recreation includes activities involving human body ' contact with water on an infrequent or incidental basis (Eaker 1992). The NSW designation is intended for waters needing nutrient management due to excessive growth of microscopic and macroscopic vegetation. Mingo Creek has also been given a use support rating of Partially Supporting. Two benthic macroi nverteb rate sampling stations (B-18 and B-19) were located below and above the Knightdale wastewater treatment plant (WWTP). Since Hurricane Fran (September 6, 1996), Knightdale wastewater has been routed to the City of Raleigh's Neuse River WWTP. Biological ratings for both stations were Poor when last sampled in 1987. Removal of the Knightdale WWTP has probably improved water quality downstream but has not been verified. 12 11 ' Location of jurisdictional streams and wetlands are indicated in Figure 6. A jurisdictional "system" refers to a specific stream or wetland. Physical characteristics of streams within the Site are provided in Table 1. 2.3.2 Neuse River Nutrient Sensitive Water Management Strategy Reducing nutrients and sediment loading into the Neuse River and down stream estuaries has been a top basin-wide priority over the past decade. Eutrophication of estuarine waters, resulting from both point and non-point sources, has had numerous deleterious effects including algal blooms, hypoxia, habitat modification, and fish kills. The situation climaxed during the summer of 1995 when numerous and intensive fish kills occurred in the Neuse estuary stemming from record rainfalls that delivered tremendous loads of nonpoint source nutrients. This loading produced large-scale algal blooms and anoxic conditions throughout much of the water column, which suffocated hundreds of thousands of fish. ' Over the past several years, increasing urban development and hog industry growth within the upper and middle reaches of the Neuse is believed to have further degraded Neuse water quality. In response to this threat, the N.C. Environmental Management Commission (EMC) revised the Nutrient Management Strategy in December 1997 to address point and nonpoint sources of nitrogen as well as the already managed phosphate pollution problem (DWQ 1993). The new rules were devised to meet and maintain a 30 percent reduction of nitrogen loading within five years. The regulations implement a rigorous manageable guideline for five specific areas of concern: point source dischargers, urban stromwater control, protection and maintenance of existing riparian areas, agriculture and nutrient addition management. Currently, progress is being made in implementing these control structures to achieve a 30 percent reduction of nitrogen into the Neuse system. The DWQ is investigating the response of the system to reduced nitrogen loading through a nutrient response model ' developed by state university researchers (Neuse Modeling and Monitoring [MODMOM). This interdisplinary modeling approach attempts to model the biogeochemical response of the Neuse River system to variations in nitrogen loading with differing physical forcing mechanisms (wind, rain/runoff). In this way, the sensitivity of the system to changing parameters can be evaluated/predicted and used to guide in important managerial decisions. ' The Site currently receives only limited amount of nitrogen loads, and is slotted to receive intensive urban development within its watershed. The planned increase of impervious surfaces within the watershed will undoubtedly add to the magnitude and delivery response of both sediment and nutrients into the Site following precipitation events. With its expansive floodplain and slow-flowing waters, the Site encourages sediment deposition and the initiation of denitrification processes, which effectively remove a portion of the water column's nutrient load. These advantageous processes associated with the on-site hydrological conditions make the Site an important contributor to the nutrient management strategies currently advocated by the state government. The DWQ Neuse River Riparian Buffer rule applies regulations which, prohibit with certain exceptions, clearing of existing forest vegetation, filling, and development activities within ' 13 m= i s i m== m= r m= m= m m k 4 v f ire, V ? r ,1. 4 o co At% .80 all 00 - if + ?."? < of y y;, 1 1 s • ^ ' +b fjr i s (.T , -Alm * r:? NJ -: Alt Ir If # lie -i Jim y $ w It, 4L. ti % Y t ? T 7'I C m it '1? • i?e' t ? ?'?' ? v 3 i "74 ?wr .r .-o + i ' M Alk 4L ' 4 ; , ' . ' ' i4.? !?.% '. -? 4 m n p N n n m 0 o . C) D T O o O d oA D D C Cl) ? r O N 4 0 0 C- > *c cnm v ?Dn C,^!nz v/ D o M Z D °,, z-+O =m D O >o D - Oz / ? V/1X ;? OM N D z m ?' fib. T Q 0 0 1 0 A 0 0 spa . • s t ,` i ws. at. .. ? ... ' ? ? Auk ?1 w: A ? Cr7 o A z o ? ? O •.C o m O ? r• m N J r• n o T /A Nr - T' _: b' i- ? m D cn m c co m D z o cn m z c 0- m n 0 m zz cn ? m m D ? zz cn ? m D ` ,. + 0 o 0 ? ' N-4i O ¦ b jpm 1 1 Table 1. Physical Characteristics of Streams. Characteristics of streams in the Mingo Creek Mitigation Site. System numbers are the same used in Figure 9. "UT" indicates an unnamed tributary. Channel width and depth measurements are given in feet, and water depth measurements are given in inches. System Channel Channel Water Observed Benthic Number System Name Width Depth Depth Flow Composition 2 UT to Mingo 6 6 2 Low Sand/Silt Creek 4 UT to Mingo 2 2 2 Low Sand/Silt Creek 5 UT to Mingo 2 2 3 Low Sand/Silt Creek 7 Mingo Creek 30 3 6 Low to Cobble/Gravel/ 9 UT to Mingo 6 Creek 10 Neuse River 80 2-3 6-24 10 -- Moderate Sand Low Sand/Silt Moderate Cobble/Gravel/ Sand 11 Perennial UT to 4 1.5 3 Moderate Sand Mingo Creek 14 Intermittent UT 7 4 0-1 Minimal Sand to Mingo Creek 50 feet of perennial and intermittent tributaries of the Neuse River. A protected, 50-foot zone on both sides of stream channels has been designated as the riparian buffer. The Site provides approximately 22 acres of wetland buffer, under the 50-foot buffer management zone (Figure 7). However, while the 50-foot buffer may be adequate for maintenance of physical and chemical protection, habitat suitability index models have demonstrated the ' need for buffers upward of 500 feet for minimum protection of the biological component. The Site will provide an additional 163 acres of biological buffer, within an ecologically important regional crossroad. See Section 5.0 for a more detailed account of upland/wetland buffers and their functional importance. 2.3.3 Nitrogen Loading and Reduction Assessment ' Land-Use and Nitrogen Loading Nitrogen loading supplied to the Neuse River by the Mingo Creek watershed has been ' estimated under existing and projected, post-development conditions. The nutrient export model was developed using coefficient values provided by the DWQ. Currently, the Mingo Creek watershed is primarily dominated by forest, successional/pasture, and cultivated-field habitats, with limited high- and low-density urban developments. Each of these land use types is characterized by different nutrient loading rates that currently export into Mingo/Neuse receiving waters. Planned future development calls for significant increases of high-density development upon currently forested and non- developed areas, which will alter loading rates into these waterways. Figures 8 and 9 ' depict the projected changes in land-use from current conditions to future build-out conditions, as allowed under current zoning. Table 2 outlines current and future land-use coverage for both the Site and the Mingo Creek watershed. The table also includes DWQ's ' (1998) nitrogen export coefficients (ExpCoef) for these specific land types. Nitrogen exports are given in kilograms per hectare per year (kg/ha/yr). Total nitrogen (TN) is given in kilograms per year (kg/yr). ' Under existing conditions, nitrogen loading into the Neuse River from the Mingo Creek watershed is projected to total 5290 kg/year. Future levels are projected to total 8249 kg/yr representing a 64 percent increase in nutrient loads discharged into the River due to changing land uses. Nitrogen loading from current on-site land use is estimated to total 158 kg/yr. Potential build-out levels total 684 kg/yr, a greater than four fold increase in TN. u 16 i i i i i ¦ r- 'Om °i3 a .-A i ? f f .y: 4 .Y .r aW5 94. * ?p t J's'' ` '4 v ? lk' ?' ', #. " 6 '?-_ F ff'r iM r • • Y c 3 . m n o m n j 1 v n ? _ l 1 c ` Z ? v Z Own NW Z C) ct - c`) D 0c =m DG)O ?J o o z-n ?D0 p off. m o y° L ? rn o z cn X 0 °. A? rD 0. ;o N Z? FOm o N) D Z V o k l CD X r. ? p }. t + d n if,I` :: 10, . ? 4 Is I 4 lI ? r .a 17 ?y t k i 4 •+ r r ??'+??*?Y may, •-'? ^? ?.S'? #?Y -;,? •? is 1`_ k y ?. 41 ?? ?;, 714 'r s amp Table 2 Mingo Creek Watershed: Current/Future Land Coverage and Total Nitrogen (TN) Export Coefficients. F1 i `77 LEI' 1 fl J Land Coverage DWQ Export Coefficients (k /ha/yr) Current Land Coverage (hectare) Current TN Load (kg/yr) Future Land Coverage (hectare) Future TN Load (kg/yr) Mingo Creek Watershed Forested 1.90 747.8 1421 135.0 257 Cultivated 15.2 151.8 2307 ---- ---- Pasture 4.90 216.1 1059 ---- ---- High Density 9.63 29.6 285 405.6 3906 Low Density 6.39 25.8 165 631.2 4033 Water 9.80 5.4 53 5.4 53 Total ---- 1177 5290 1177 8249 Mingo Creek On-site Forested 1.90 83 158 9 17 High Density 9.63 ---- ---- 60 578 Low Density 6.39 ---- ---- 14 89 Total ---- 83 158 83 684 *future on-site land use was ascertained from Stantec Consulting Services Inc. (2001) 18 i T ?ia. T 1• -1 ? f y?l i r., ? ' l . ?? ? ??? - it I y _ r 1 J PPPPP' A l cn ;o c c p-, p C< fr C rD L7 Q u a?? 3'" .g CL Q _ I i m a m j z ° D rn Dc °D D?z z?? Z o? 0 C) " C "' 0 U ? o Z D D n o z 0 Z ?. A? o D ? m W ti -4 J p D Z T /? o n j O Fm m m m m m m m m m m m m m m m m m m ' t 6 1 IF I+ I •9:* r Il ti - '1 I ` J I 1r ' 1 t ? ?' 11 r- i Appppo, l i l I ? ?r 1r: -- Ill's ar r ? T-? - I i m Dc Z Z -i? Z n Z 'sC "a ? On DG?O - v O c o o O C D o ! 0 r; m o D ` C? < O Z (n 0 0 ?. N m m O z:-< Fn m o N c 0 V Cf) 0 O m o rC 1 ' Nitrogen Consumption Percentages A system's ability to effectively remove nitrogen from the water column is proportional to ' the time exposed to denitrification dynamics along the sediment interface, whose end product is the release of nitrogen compounds into the atmosphere. The slow-flowing waters on-site will remove a portion of the nitrogen load entering Mingo Creek, and thus reduce the amount transmitted downstream into the Neuse River. Currently, the excepted nutrient consumption/export equation (DWQ 1998) for the Neuse River basin is approximated by the following equation: TN = e 100 where, TN = percentage of total nitrogen exported from a particular stream reach k = decay coefficient t = time of travel in days The current model framework chosen by DWQ assigns a single, global decay coefficient (k = 0.1) to the entire Neuse basin. It is assumed that this constant attempts to effectively average for the biochemistry-rate differences associated with high- and low-flow conditions. Denitrification, related to hypoxia development along the sediment interface is ' most likely to occur during low-flow conditions when there is little turbulent mixing/advection of water that would physically renew oxygen levels. Based on this premise, a range of decay coefficients will be utilized in the nitrogen reduction calculations ' for the site. DWQ is currently attempting to refine the decay coefficient within the Neuse basin to assess the possibility that low-flow conditions can consume more nutrients than the current model allows. In order to assess the yearly nitrogen-reduction potential of the stream-wetland complex (freshwater marsh), it is necessary to determine the time needed for water to flow through the stream-wetland complex (--- 0.6 miles) under average, annual conditions (average flow velocity). Unfortunately, computing average velocities within the Site was difficult, because during fieldwork in support of this project, stream flows were below the threshold of mechanical, hand-held flow meters. However, annual discharge rates were available over the Internet from USGS. When this data was analyzed together with field-noted flow- area cross sections, a determination of an annual flow velocity was calculated and is ' described below. Comparisons between cross-sectional flow areas within the stream-wetland complex and the downstream, non-beaver impacted reach, assisted in determining a transit time of water through the system. It was assumed that annual discharge measurements were equal upstream and downstream of the beaver-impacted boundary; this implies a continuity of flow through the downstream site boundary. This assumption is considered valid over periods longer than the swell/dissipation temporal lag, through which the system responds t 21 to localized rainfall events. With the measured cross-sectional areas, the following continuity relation holds: A,V, = A2V2 = Discharge where, Al and A2 = Cross-sectional flow area upstream and downstream of the beaver- impacted site boundary respectively V, and V2 = Average velocity through Al and A2, respectively Cross-sectional areas for Al and A2 were approximated during field visits as 150 and 15 square feet, respectively. Assuming constant discharge, this sets a flow ratio for V, as equaling only 10 percent of V2 flow velocity. In order to obtain actual velocities, USGS gauge-station data (1926-1981) for watersheds ranging from 2.5 to 6.5 square miles within the upper Neuse basin were compiled, which yielded a average, annual discharge (normalized to 4.4 square miles) of nearly 4.5 cubic foot/second. Based on field observations (sub-surface thalwag area determination) and archived reference stream site information, the downstream, free-flowing stream channel area needed to carry this discharge is nearly 6.0 square feet (A2). Dividing the average discharge by this flow area gives a flow velocity of 0.75 feet/second (V2), which results in a 0.075 feet/second (V,) value for an average, annual flow velocity within the stream- wetland complex under the 1:10 velocity component of the above continuity relationship. Under this average flow regime (0.075 feet/second), it takes nearly 0.5 day for water entering the system to flow through the 0.6 mile stretch of on-site stream-wetland complex. Furthermore, the time increases to nearly 1.3 days if the additional 1.0-mile reach of stream-wetland complex, directly upstream of the Site, is calculated. Tied together the entire system makes a significant nutrient management tool for the watershed. Nitrogen export percentages and load removal within reaches of Mingo Creek are computed below (Table 3) using the calculated transit times with a modified export coefficient value (k=0.15), to extremely slow flow conditions. A 7 percent TN reduction for the entire watershed can be expected from the stream-wetland, while an 18 percent reduction of TN occurs with the addition of the upstream floodplain. Better estimates of basin-specific export coefficients are needed in order to fully explore the Site's nutrient removal potential. 22 I Table 3: Total Nitrogen (TN) removal along Mingo Creek On-site and Upstream r 1 I Section of Mingo Creek with Percent Percent Percent Average Total Nitrogen Transit Time (days) Export Export Export Removal (kg/yr) -> (k=0.1) (k=0.15 (k=0.2) k=0.15 Current Land Use: 5290 TN (kg / year) On-site (---0.5) 95 93 90 370 On-site and Upstream 88 82 77 952 (-1.3) Future Land Use: 8249 TN (kg / year) On-site (-0.5) 95 93 90 577 On-site and Upstream 88 82 77 1485 (-1.3) 2.4 JURISDICTIONAL STREAMS AND WETLANDS Section 404 of the Clean Water Act (CWA) requires regulation of discharges into "waters of the United States." Although the principle administrative agency of the CWA is the U.S. Environmental Protection Agency (EPA), the U.S. Army Corps of Engineers (COE) has major responsibility for implementation, permitting, and enforcement of provisions of the Act. The COE regulatory program is defined in 33 CFR parts 320-330. Water bodies such as rivers, lakes, and streams are subject to jurisdictional consideration under the Section 404 program. However, by regulation, wetlands are also considered "waters of the United States." Wetlands are described as: Those areas that are inundated or saturated by groundwater at a frequency and duration sufficient to support, and that under normal circumstances do support, a prevalence of vegetation typically adapted for life in saturated soil conditions. Wetlands generally include swamps, marshes, bogs and similar M areas. (33 CFR 328.3(b) [1986]). Wetlands are defined by the presence of three criteria: hydrophytic vegetation, hydric soils, and evidence of wetland hydrology during the growing season (DOA 1987). Open water systems and wetlands receive similar treatment and consideration with respect to Section 404 review. Site jurisdictional areas include surface waters in bank-to-bank streams or vegetated wetlands. Site jurisdictional areas were delineated during the last week of June 2001 and were located using Global Positioning System (GPS) technology during early July 2001. The COE (Mr. Eric Alsmeyer, Raleigh regional field office) has not yet approved the delineation, although a field visit is scheduled with Mr. Alsmeyer's for the end of August 2001. The location of jurisdictional areas within the Site are numbered from 1 to 15 and indicated on 23 1 Figure 6. Linear distances of streams and areas of wetlands located within the project corridor are provided in Table 4. In total, the Site contains approximately 28.8 acres of wetlands and 6590 linear feet (1.25 miles) of stream. Stream acreage, calculated by multiplying width and length, yielded approximately 0.94 acres stream surface area. 2.5 WETLAND FUNCTIONAL EVALUATION Wetland functional analyses were conducted using two methods: 1) a general functional analysis derived through a combination of professional judgement and standard assessment procedure and 2) a procedure focusing on water quality benefits developed by the DWQ (formerly, the Division of Environmental Management (DEM), this methodology is referred to as the "DEM" procedure". Seven jurisdictional wetlands are included as part of this I analysis (see Figure 6). 2.5.1 General Wetland Functional Analvsis The goal of this exercise is to evaluate wetland systems in such a manner that allows for comparative analysis among wetlands. To this end, a direct evaluation methodology was devised by ESC staff drawing on best professional judgement and general wetland functional attributes identified in the Wet/and Evaluation Technique (WET /l) (Adamus et al. 1987) and Hydrogeomorphic Approach to the Functional Assessment of Wet/ands (Brinson et a/. 1994). The methodology, hereafter referred to as "General Functional Procedure", evaluates each wetland in terms of four, unweighted functional attributes: hydrology, bio- geochemistry, plant habitat, and animal habitat. Each of these attributes is comprised of two to five parameters, and each parameter is described by two to five variables that were assessed and scored during or following a site visit. Forms and attribute descriptions generated as part of this methodology are presented in Appendix A. The Wetland Functional Data Sheet lists four wetland functional attributes in bold type, each of which is followed by the parameters that characterize that attribute. A value for each parameter is determined by the sum of scores for ecological variables specific to that parameter. A total of 25 variables were scored for each wetland system and used to assess wetland functions. An alphabetic letter (A through Y) identifies each variable. The variables used to determine the score of each parameter are provided in equation form on the Wetland Functional Assessment Data Sheet. Variables score from 0.0 to 1.0 depending on characteristics of the wetland. The variables and rationale for scoring are listed on the Wetland Functional Assessment Score Sheet. A total of 41.0 points are possible for each wetland system. Although individual functional attributes are not weighted, this procedure does inherently allow higher scoring for wetlands associated with riverine characteristics. The functional assessment scores for each wetland system are shown in Table 5, and completed data sheets are provided in Appendix A. Table 5 also provides a column of percentile ranks for the wetland systems. Wetland Systems 8 and 3 received the highest scores, 32.2 and 31.1 points, respectively. These wetlands represent two very different community types. System 8 is a bottomland hardwood characterized by mature canopy trees and sparse understory. This wetland receives periodic inputs from flooding events from both Mingo Creek (System 7) and the 1 24 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 1 Table 4. Linear Distances and Acreage of Jurisdictional Areas. The acreage of wetlands and linear distances of streams within the Mingo Creek Mitigation Site are presented in this table. Linear distance is provided in feet. Wetland Area is in acres. The system numbers are the same used in Figure 9. "UT" refers to unnamed tributary. System Number System Name Wetland Area Stream Length 1 Hodge Road marsh 1.19 -- 2 UT to Mingo Creek -- 1 175 3 Mingo Creek marsh 26.4 -- 4 UT to Mingo Creek -- 267 5 UT to Mingo Creek -- 106 6 Railroad wetland 0.59 -- 7 Mingo Creek -- 1385 8 Mingo Creek floodplain wetland 0.20 -- 9 UT to Mingo Creek -- 300 10 Neuse River -- 150 11 Perennial UT to Mingo Creek -- 1632 12 Seepage wetlands 0.06 -- 13 Headwater wetland to perennial UT 0.16 -- 14 Intermittent UT to Mingo Creek -- 1575 15 Headwater to intermittent UT 0.20 -- Totals 28.8 6590 1 1 1 1 1 A 1 1 1 1 1 f 1 i o Cl) ? s= 0 > s= c06 (6 y co N Cl) ? O U 2? ED CM LL > O N !n O •? O ? O 4? •? c0 cB O O U 0 E c'a c to U S] (A a) CU cac 0 O L O o fQ a U U (6 U E O 07 O L (a ? 2, a) Cc r 'CD C Q c 0 N ? w+ (Q 0 S= M C .r U C U O = co a) to 3 .O E 4) cu 4) U U C O E E OOaa))cn v? Ica t/1 O c N cc ,? O ? O U 'a O) U = O Q N OL -0 CD t6 U >+ tL C ? r O O V O 0 M_ cn LL?? 0 C Y f6 0 a) _ w a) O 0U 0- O o O 0 N :3 CD m (D M o o a U) 0 c? Ea O S N cn M r l0 In r- rn O LO m r- M U-) LO LO O LO N L6 Ids M r? O M O O N CC) O C14 00 n 00 LO In U? M O CO LO O (0 n 4 4 LO M ? N (O 00 l0 Lc) O N r- N co to O Cif M M N N N V- d am m (0 l0 M 00 co O O r- O co co ItF d• 00 M LO r N r CD M r 0 4? y to c0 c0 c0 C O U E E O 0 0 -Y- O 4 4? ++ CD a) 0 a) (D 7 L C U 'm L U O 0 0+ 0 -a 0 ? !A o a o ? 'E m 0 . 3 0 CL a) -0 cm -a L a _ C C O C O 0 0 (6 L y unnamed tributary to Mingo Creek (System 9). System 3 represents the large freshwater marsh complex adjacent to Mingo Creek. This wetland in continually inundated or saturated from beaver activity and a shallow groundwater table. System 3 contains primarily herbaceous and shrub vegetation. Both systems received high scores for hydrology and biochemical processes. I' Ranked intermediately are Systems 1, 15, and 12. The wetlands in System 15 and 12 are primarily small headwater or toe of slope seeps feeding an adjacent tributary. These systems are characterized by continuous groundwater saturation, contain mature forest vegetation, and moderate habitat for wildlife and semi-aquatic insects. These wetlands feed the intermittent and perennial stream identified as Systems 11 and 14. The wetland in System 1 is a freshwater marsh found adjacent to Hodge Road. This wetland is similar to the System 3 marsh wetland but is considerably smaller. System 1 receives regular flow from the unnamed tributary to Mingo Creek (System 2). According to the analysis these systems are important both biochemically and hydrologically. The lowest-ranking wetlands (Systems 6 and 13) both scored a 19.5. System 6 is a freshwater marsh found adjacent to the railroad tracks and the old impoundment. This wetland provides low community structure and moderate wildlife habitat and lacks the plant diversity and structure found in System 3. This wetland receives regular flow from off-site drainage. The wetland in System 13 is a headwater system with a mature canopy. This wetland is characterized by seasonal saturation from groundwater seepage and provides moderate wildlife habitat. 2.5.2 DEM Wetland Rating Procedure The Water Quality Section of the State Division of Environmental Management (DEM) prepared a wetlands assessment procedure entitled Guidance for Rating Wetlands in North Carolina (DEM 1995), and NCDOT is considering this method as a standard procedure for assessing wetlands proposed for roadway impacts. The "DEM" procedure was used to rate seven wetland systems identified in the previous section (Table 5). This procedure focuses on the role of wetlands in the environment, so bank-to-bank stream systems were not rated unless they were involved in a stream/wetland complex. Completed DEM Wetland Rating Worksheets and COE Wetland Determination Forms are provided in Appendix B. The DEM procedure rates wetlands according to six functional attributes: water storage, bank/shoreline stabilization, pollutant removal, wildlife habitat, aquatic life value, and recreational/educational value. Each attribute Js given a rating of from "1" to "5". A higher rating for a functional attribute indicates a higher value for that attribute to the environment. A different multiplier is used with each attribute so that the highest possible sum of the six products is "100". These attributes are weighted (by the multiplier) to enhance the results in favor of water quality functions. Pollutant removal is weighted to be the most important wetland attribute. Water storage, bank/shoreline stabilization, and aquatic life functions are given equal weight as secondary attributes, and wildlife habitat and recreation/education functions are given minimal credit. The wetland rating system divided the wetlands in two, between high scores and low scores. Systems 3, 6, 1, and 8 received the high score (93, 83, 73, 67 respectively) and 27 F included the three various sized marsh wetlands and the Mingo Creek floodplain wetland. All the marsh wetlands received surface water inputs from adjacent braided or discontinuous streams, induced by beaver activity. System 8, the Mingo Creek floodplain wetland also is impacted from beaver activity in the adjacent unnamed tributary to Mingo Creek (System 9). These systems generally score high for pollutant removal, water storage, bank stabilization, and aquatic habitat potential. Systems 12, 15, and 13 received the lower scores (45, 33 and 29, respectively). These wetlands are headwater systems that receive little surface flow from adjacent streams and therefore score low for water storage and pollutant removal. These wetlands generally provide excellent aquatic and semi aquatic habitat. 1 4 1 28 1 1 1 1 1 1 1 1 1 1 i 1 1 i 1 1 N v N C c O O ?p 4- CO (0 C co M O M O O O cn (D 'tn CD U "O E (D w i C O in O Co LJ. U * V co _0 O Q- Q m t O O CD O N CO d cu O C p M N N ?- N r- LO N C .N c x ' in co "_ CO cn . .- > O N O M O 00 O N U) 'O O E U) :2 c U = co O C U N O? O E a) c: -c c> ? cu + O E O N Lo N O N O LO LO LO LO o co n N a In L c ca O O N o . c n ca m c a) > 0 U.) O U O O O N co 00 0 CD d 0*) fn 0 cn CO M Co +1 N N LO E CD W W in c rn cn N C N C ++ co co p O N CO e- co .- N ?- N d ?h - U C > 1 .? C O O N «. in c m 0 `O U M M M CO M tl? CO LO M M O N 00 O N M C O O •- V C CD N cn O y E M CD ? co N LO M N N 0 O O M Z _ a- 0 U O N m p a ? O _ +=? E O +O+ t t -O cu cc'X N > C Co 0 O Co :5 E E m p cu ai ,a C Y Q O C O -a O O +' ~ l4 N-C Q O O .Q V O U U V O CO N O '? O OQE 0 O O O a m a O c o c 0 a CO (D n W G 7- m E co OC 2 y- cA 2 S? 0) 2 a 0) m co m cc H fl 1 u 1 3.0 BIOTIC RESOURCES 3.1 PLANT COMMUNITIES The Site contains several distinct mature plant communities that provide unique mosaic within close proximity to each other. The mature canopy cover on the upland slopes provides an important buffer and natural filter for the on-site wetlands. Ten distinct plant communities have been identified within the topographically diverse Site. Nine of these plant communities approximate those described by Schafale and Weakley (1990), in the Classification of the Natural Communities of North Carolina. The publication by Schafale and Weakley presents definitions for natural plant communities as defined by vegetation, composition, and physioignomy. The plant communities recognized as such include mesic- mixed hardwood forest, dry-mesic oak-hickory forest, Piedmont semi-permanent impoundment (freshwater marsh), dry oak-hickory forest, Piedmont bottomland hardwood forest, Piedmont alluvial forest, low elevation seep, Piedmont levee forest, and Piedmont acidic cliff (Figure 10). Early successional land is the only plant community that was found on-site but is not described by Schafale and Weakley. See Appendix C for a complete plant list for each community. Mesic-Mixed Hardwood Forest The co-dominant plant community is mesic-mixed hardwood forest. This community covers 68 acres or 32 percent of the Site. The mesic-mixed hardwood forest, as documented by Schafale and Weakley (1990) is dominated by mesophytic hardwoods, including beech (Fagus grandifoiia), red oak (Quercus rubra), red maple (Acer rubrum), and yellow poplar (Lirodendron tuiipifera). This forest provides a well-stratified canopy, sub- canopy, and a diverse shrub/herb assemblage. The mesic-mixed hardwood forest serves as a buffer to over 80 percent of Site jurisdictional streams and provides protection to the headwaters of several on-site streams including the unnamed tributaries to Mingo Creek, Systems 2, 11, 14. Similarly, this plant community provides forested cover and buffer to both the north and south rims of the 27-acre Mingo Creek freshwater marsh community located in the northeast portion of the Site. Plant species diversity of trees, shrubs, and vines within the mesic-mixed hardwood forest is high. Dry-Mesic Oak-Hickory Forest Essentially equal in area to the mesic-mixed hardwood forest, the dry-mesic oak-hickory forest (75 acres) covers 37 percent of the Site. Dominating the uplands and southern extent of the study area, the dry-mesic oak-hickory forest adds an additional layer of buffer to the existing down-slope mesic-mixed hardwood forest, streams, and wetlands. Plant diversity within the dry-mesic oak-hickory forest is higher than the mesic-mixed hardwood forest and contains many species not seen in any other Site plant community. The forest canopy is dominated by white oak (Quercus aiba), black oak (Quercus veiutina), yellow poplar, and sweetgum (Liquidambar styracifiua). Notably unique, is a high diversity of blueberry species (Vaccinium spp.) and small shrubs within this community. The assemblage of herbs and climbing vines provide for a structurally diverse understory with a thick sub-canopy and a relatively thin canopy. 30 ¦ " m w=== m A= m w m m= m 4m m ¦r m 9 n _- n ^ O m M ? ^ A o ` ?D D Z Z c? C' D i DG)O ="' nC7 ^ " z s U m cm) Z z u I O ?. o y (n C: O U) ; O m ? ? • v o No D Z? ^ o ? U < ° Freshwater Marsh One of the most unique and dynamic Site communities is the 27-acre freshwater marsh, which occurs as a result of anthropogenic and beaver impoundment of Mingo Creek. This plant community is described by Schafale and Weakley as a Piedmont semi-permanent impoundment. These communities are typically in flux, as beaver establish and reestablish their control over the adjacent streams. The ensuing vegetation communities thus, must contend with frequent changes in hydrology, often leading to dead stems of non-tolerant trees. The continual procession of early successional renewal within these communities allows numerous wetland shrub species such as buttonbush (Cephalanthus occidentalis) and willow species (Salix spp.) and herbaceous species such as rushes (Juncus spp.), sedges (Carex spp.), and arrow arum (Peltandra virginica) to thrive. The Mingo Creek freshwater marsh receives water from all but two perennial streams within the 4.4 square mile Mingo Creek watershed. The freshwater marsh is structurally a stream/wetland complex, containing a mosaic pattern of braided stream channels. The freshwater marsh provides both macro and micro habitat for a broad range of aquatic and emergent flora. Extending for more than 0.5 mile, the marsh borders six of the 10 identified plant communities. Smaller freshwater marsh communities are found along the eastern Site boundary adjacent to Hodge Road and down stream of the impoundment structure within the Mingo Creek floodplain. Isolated trees, shrubs, and snags develop rooting surfaces for grasses rushes, herbs, and sedges to form thick hummocks. The freshwater marsh fringes are lined with a rich diversity of shrubs and tree saplings. The freshwater marsh has very high plant species diversity and a high diversity of structure. Early Successional Land Early succesional land transects the mosaic pattern of Site communities in two discrete locations as maintained power line corridors. Each corridor is approximately 100 feet in width and together comprise 10 acres, or approximately five percent of the Site. One corridor extends from the middle eastern Site boundary adjacent to Hodge Road, along a northeast-southeast axis to the northern Site boundary adjacent to the railroad. A second corridor extends across the southwest corner of the Site, along an east-west axis from the middle southern Site boundary to the middle western Site boundary adjacent to the Neuse River. The periodic maintenance of these corridors maintains a community structure that varies from short shrubs to young forest, and typically supports dense graminoids and a herbaceous assemblage. Plant species diversity is particularly high within this community. The presence of these maintained corridors within the Site increase available food and cover diversity for wildlife, and promotes wildlife travel corridors from the Neuse River and railroad across the Site. One unique area within the power line right-of-way along the south side of the Mingo Creek freshwater marsh is an exposed rocky bluff. Dry Oak-Hickory Forest Located at the highest points within Site is a dry oak-hickory forest. Isolated and surrounded by dry-mesic oak-hickory forest, the dry oak-hickory forest covers approximately 9 acres (four percent of the Site) and is located in the southeast portion of the Site. Due to the xeric nature of soils within this community, the species diversity is lowest of the Site plant communities. Although species diversity is low, the species makeup is unique and many species are found nowhere else in the Site. As described by Schafale and Weakley (1990), dominant canopy species include a diverse assemblage of oaks including white oak, black oak, scarlet oak (Quercus coccinea), southern red oak 1 32 1 (Quercus falcata) and post oak (Quercus stellata). The shrub layer ranges from sparse to dense including many viburnum (Viburnum spp.) species. Piedmont Bottomland Hardwood Forest A bottomland hardwood forest borders the last stretch of Mingo Creek before its confluence with the Neuse River, in the northwestern corner of the Site. Approximately 9 acres of Piedmont bottomland hardwood forest surround lower reaches Mingo Creek and its two unnamed tributaries (Systems 9 and 11) that slowly drain adjacent uplands. The activity of beavers and the resultant periodic ponding has limited the sub-canopy and shrub layer. The existing vegetation assemblage is a low diversity of mature hardwood canopy trees including river birch (Betula nigra), green ash (Fraxinus pennsylvanica), American elm (Ulmus americana), box elder (Acer negundo) and cherybark oak (Quercus pagodifolia). The herbaceous layer is well developed and includes a high diversity of grasses, sedges, rushes, and herbs. Piedmont Alluvial Forest Piedmont alluvial forest occurs at two Site locations where tributary streams and seepages reach the southern floodplain boundary of Mingo Creek. One occurs in the northeast portion of the Site where Systems 1 and 2 drain into the freshwater marsh, and the other occurs in the central portion of the Site where the freshwater marsh receives the flow from System 5. The area of these communities covers approximately 7 acres and less than four percent of the Site. Both areas are north facing and the soils remain moist but well drained. The community contains primarily bottomland hardwood species in the canopy, high diversity of shrubs, and a dense herbaceous understory. Dominant canopy species include yellow poplar, sycamore (Platanus occidentalis), sweetgum, and American elm. The underlying substrate within the alluvial forest is coarse to silty, unconsolidated fluvial deposition. Stream flow and flood-carried sediments provide nutrients and water to these lush and well-developed forests. These forested alluvial flats provide a natural filtering system similar to that of the adjacent wetlands. The alluvial forests exhibit a plant community transition point between the mesic-mixed hardwood forest and the freshwater marsh. This transition zone results in a diverse assemblage of species. Low Elevation Seep This plant community occurs in numerous locations through the Site in small areas characterized by ground surface expression of the groundwater table. These communities typically occur at the base of slopes or edges of floodplains. The Site contains a total of approximately 1.0 acre of this community. Diversity is high within these seepage communities, where structure is characterized by a well developed shrub and herbacous layer. Notable shrub and herbaceous species include netted chanin fern (Woodwardia areolata), lizard's tail (Saururus cernuus), Jack-in-the-pulpit (Arisaema triphyllum), Fringe tree (Chionanthus virginicus), and possum haw (Viburnum nudum). These areas are small ' enough to be shaded by canopy tree species rooted in adjacent communities. However, certain tree species such as winged elm (Ulmus alata), river birch, black willow and sweet bay magnolia (Magnolia virginiana) are found growing within these areas. Piedmont Acidic Cliff Piedmont acidic cliff occurs as two discrete areas totaling approximately 1.0 acre, along the southern border of the freshwater marsh. This community occurs on exfoliating, 33 1 ' exposed granite outcroppings which face north across the Mingo Creek marsh. The range of soil depths and moisture regime, provided by the underlying terrain, promote a high species diversity. This community supports a unique plant assemblage for this portion of the sate. One unique shrub found on these sites is mountain laurel (Kalmia latfolia). Several mountain laurel thickets were surveyed on the steep slopes of these north-facing bluffs. Several species that are typically found in dry upland sites were also noted including blueberries (Vaccinium spp.), various oaks, sassafras (Sassafras alba), and sourwood (Oxydendron arboreum). I Piedmont Levee Forest Piedmont levee forest occurs in the extreme northeastern corner of the site, adjacent to the Neuse River. This community accounts for approximately 1.0 acre and supports a mature forest, characterized by well-developed sub-canopy, shrub, and groundcover layers. The ground surface is elevated well above the river floodplain so the community supports both bottomland and upland plant species. The dispersal and deposition of seeds from the Neuse River also adds a plant species component to the levee that is rarely seen on smaller streams. River oats (Chasmanthium latifolium) occur in thick breaks on the crest and riverside of the levee, while herbs and other grasses occupy the wetter backwater areas. The levee is composed of loose alluvial soil, which provides little support for larger, mature trees. Periodic windstorm events and high water can fell large tree, which creates gaps in the levee forest. These gaps add a component of early successional flora, which increases levee forest species diversity. 3.2 WILDLIFE 3.2.1 Terrestrial The mosaic of Site plant communities provides necessary components (food, water, cover) to support a number of animal species typical of the Piedmont region of the state. During field surveys, signs or observations of the following terrestrial mammal species were documented: white-tailed deer (Odocoileus virginianus), gray squirrel (Sciurus carolinensis), and raccoon (Procyon lotor). Other species expected include Virginia opossum (Didelphis virginiana), eastern cottontail (Sylvi/agus floridanus), eastern mole (Sca/opus aquaticus), southeastern shrew (Sorex longirostris), southern flying squirrel (Glaucomys volans), white- footed mouse (Peromyscus leucopus), eastern harvest mouse (Reithrodontomys humulis), cotton mouse (Peromyscus gossypinus), golden mouse (Peromyscus nuttalli), meadow vole (Microtus pennsylvanicus), red fox (Vulpes vulpes), grey fox (Urocyon cinereoargenteus), striped skunk (Mephitis mephitis), and longtail weasel (Mustela frenata). The extensively forested Site bottomland, slopes, and uplands provide habitat for a diverse bird assemblage. The following species were heard and/or seen: Acadian flycatcher (Empidonax virescens), American crow (Corvus brachyrhynchos), American robin (Turdis migratorius), blue jay (Cyanocitta cristata), blue-gray gnatcatcher (Polioptila caerulea), brown-headed cowbird (Molothrus ater), carolina chickadee (Poecile carolinensis), Carolina wren (Thryothorus ludovicianus), chimney swift (Chaetura pelagica), common grackle (Quiscalus quiscula), downy woodpecker (Picoides pubescens), pileated woodpecker (Dryocopus pileatus) great crested flycatcher (Myiarchus crinitus), hooded warbler ' 34 1 t 1 (Wilsonia citrina), northern cardinal (Cardinalis cardinalfs), pine warbler (Dendroica pinus), red-bellied woodpecker (Melanerpes carofinus), red-eyed vireo (Vireo olivaceous), red- shouldered hawk (Buteo fineatus), ruby-throated hummingbird (Archilochus cofubris), summer tanager (Piranga rubra), tufted titmouse (Poecile bicolor), yellow-billed cuckoo (Coccyzus americanus), and yellow-throated vireo (Vireo flavifrons). Although the majority of the Site is forested or wetland, a power line corridor and adjacent private holdings provide early successional habitat. red-tailed hawk (Buteo jamaicensis), common yellowthroat (Geothlypis trichas), white-eyed vireo (Vireo griseus), American goldfinch (Carduefis tristis), northern bobwhite (Cofinus virginianus), indigo bunting (Passerina cyanea), song sparrow (Melospfza me/odfa), and chipping sparrow (Spizella Passerina) were seen or heard in early successional land during site visits. Other species commonly associated with early successional/shrub habitat include eastern kingbird (Tyrranus tyrranus), prairie warbler (Dendroica discolor), gray catbird (Dumetel/a carofinensis), eastern bluebird (Sialis sialis), northern mockingbird (Mimus polyglottus), brown thrasher (Toxostoma rufum), yellow-breasted chat (lcteria virens), eastern towhee (Pipifo erythrophthalmus), and blue grosbeak (Guiraca caerulea). During site investigations, a single terrestrial reptile, five-lined skink (Eumeces faciatus), was observed. Pine woods treefrog (Hyla femorafis), cricket frog (Acris gryllus), and American toad (Bufo americanus) were the only terrestrial amphibians observed. Black rat snake (Elaphe obso/eta), worm snake (Carphophis amoenus), ringneck snake (Diadophis punctatus), box turtle (Terrapene carolina), green anole (Anofis carolinensis), broadhead skink (Eumeces laticeps), green treefrog (Hyla cinerea), barking treefrog (Hyla gratiosa), gray treefrog (Hyla versicolor), chorus frog (Pseudacris triseriata), and spring peeper (Pseudacris crucifer) are common reptiles and amphibians found in similar habitats. 3.2.2 Aquatic Site aquatic habitats include the third-order stream habitat of Mingo Creek, the freshwater marsh created by damming of Mingo Creek by beaver (Castor candensis), and several first order perennial streams (Systems 2, 4, 5, 9, and 11). Mammal species associated with aquatic habitats expected at this site include beaver, marsh rabbit (Sylvilagus palustris), rice rat (Orysomys palustris), muskrat (Ondatra zibethica), mink (Mustela vison), and river otter (Lutra canadensis). Belted kingfisher (Ceryle alcyon), fish crow (Corvus ossifragus), great blue heron (Ardea herodius), northern parula (Parula americana), prothonotary warbler (Protonotaria citrea), red-headed woodpecker (Melanerpes erythrocephalus), and common yellowthroat were detected during field surveys around wetland habitat. Other species that inhabit similar habitats include green heron (Butorides virescens), wood duck (Aix sponsa), and common snipe (Gallinago galfinago). A red-bellied watersnake (Nerodia erythrogaster) and yellowbelly sliders (Trachemys stricta) were the only reptiles seen in aquatic habitats. Green frogs (Rana clamftans) and southern 35 cricket frogs (Acris gryllus) vocalized near the freshwater marsh. Queen snake (Regina septemvittata), mud snake (Farancia abacura), cottonmouth (Agkistridon piscivorous), snapping turtle (Chelydra serpentina), greater siren (Siren lacertina), southern two-lined salamander (Eurycea cirrigea) and pickerel frog (Rana palustris) are common to similar aquatic habitats of the region. Mingo Creek is potentially a diverse fishery supporting species such as bluegill (Lepomis macrochirus), redbreast sunfish (L. auritus), pirate perch (Aphredoderus sayanus), bluehead chub (Nocomis leutocephalus), swallowtail shiner (Notropis procne), American eel (Anguilla rostrata), silver redhorse (Moxostoma anisurum), satinfin shiner (Cyprinella analostana), white shiner (Luxilus albeolus), flat bullhead (Ameiurus platycephalus), and tessellated darter (Etheostoma olmstedi). Species expected with the adjacent tributaries include eastern mosquito fish (Gambusia holbrooki) and Johnny darter (Etheostoma nigrum). 3.3 RARE AND UNIQUE NATURAL AREAS No NHP-designated Significant Natural Heritage Areas (SNHA) exist within the Site. A SNHA designation is given to an area due to the presence of rare species, rare or high quality natural communities, or geologic features. This designation does not confer protection or regulatory status. The nearest SNHAs include several locations on the Neuse River. Within 2.0 miles north of the Mingo Creek confluence with the Neuse, two rare mollusks, the notched rainbow (Villosa constricta) and Roanoke slabshell (Elliptio roanokensis); and two rare fish, the pinewoods shiner (Lythrus matutinus) and Carolina madtom (Noturus furiosus) have been found. In addition, approximately 1.25 miles south of the confluence the dwarf wedge mussel and a rare amphibian, Carolina mudpuppy (Necturus lewisi) has been found. Another rare mussel the yellow lance (Elliptio lanceolata) is documented approximately 1.5 miles south of the Site in a small tributary of the Neuse. Another SNHA is located approximately 1.5 mile south of the Site. This location contains a population of Rhus michauxii, a Federally Endangered plant. 3.4 PROTECTED SPECIES 1 Cl 11 it 3.4.1 Federal Species Species with federal classifications of Endangered (E) or Threatened (T) are protected under the Endangered Species Act of 1973, as amended (16 U.S.C. 1531 et seq.). The status of "Endangered" refers to "any species which is in danger of extinction throughout all or a significant portion of its range"; the status of "Threatened" refers to "any species which is likely to become an endangered species within the foreseeable future throughout all or a significant portion of its range" (16 U.S.C. 1532). The FWS has revised the list of federally protected species as of April 12, 2001 to include the following protected species for Wake County: Common Name Scientific Name Wake Status Bald Eagle Haliaeetus leucocephalus T* Red-cockaded Woodpecker Picoides borealis E 36 1 1 1 I?I 1 1 1 Dwarf Wedge Mussel Aiasmidonta heterodon E Michaux's sumac Rhus michauxii E ' Proposed for de-listing The status of these species is described below. Bald Eagle - The bald eagle occurs throughout North America, primarily in association with large lakes and coastal bays and sounds where food is plentiful. Mature eagles (usually 4 to 6 years and older) are identified by a white tail and head, dark brown to black body and wings (wingspread to 6 feet), and yellow eyes, bill, and feet. Juveniles are uniformly chocolate-brown and sometimes have whitish mottling on the tail, belly, and wing linings. Maturing individuals become lighter in color and the mottling increases until the adult plumage pattern is acquired. Nest sites occur close to feeding grounds in large trees (predominately pine or cypress), either living or dead. Eagles are opportunistic hunters and scavengers, feeding on a wide variety of aquatic-dependent organisms including fish, snakes, small mammals and large water birds. The primary source of food is carrion and fish taken from ospreys (Potter et aL 1980). Red-cockaded Woodpecker - This small woodpecker (7.0 to 8.5 inches long) has a black head, prominent white cheek patches, and black-and-white barred back. Males often have red markings (cockades) behind the eye, but the cockades may be absent or difficult to see (Potter et al. 1980). Primary habitat consists of mature to over-mature southern pine forests dominated by loblolly, long-leaf (Pious paiustris), slash (P. eiiiottil), and pond (P. serotina) pines (Thompson and Baker 1971). Nest cavities are constructed in the heartwood of living pines, generally older than 70 years, which have been infected with red-heart disease. Nest cavity trees tend to occur in clusters, which are referred to as colonies (FWS 1985). The woodpecker drills holes into the bark around the cavity entrance, resulting in a shiny, resinous buildup around the entrance that allows for easy detection of active nest trees. Pine flatwoods or pine-dominated savannas, which have been maintained by frequent natural fires, serve as ideal nesting and foraging sites for this woodpecker. Development of a thick understory may result in abandonment of cavity trees. This species is known to forage in pine or pine-hardwood stands where the pines are greater than 30 years old with an open sub-canopy and shrub layer. No suitable habitat for red-cockaded woodpeckers is located within the mitigation Site. The nearest red-cockaded woodpecker colony is approximately 4.8 miles east of the Site. Michaux's Sumac - Michaux's sumac is a densely pubescent, deciduous, rhizomatous shrub, usually less than 3.0 feet high. The alternate, compound leaves consist of 9 to 13 hairy, round-based, toothed leaflets borne on a hairy rachis that may be slightly winged (Radford et ai. 1968). Small male and female flowers are produced during June on separate plants; female flowers are produced on terminal, erect clusters followed by small, hairy, red fruits (drupes) in August and September. Michaux's sumac tends to grow in disturbed areas where fire or other disturbances reduce competition; the species may grow along roadside margins or in utility line right-of-ways. In the Piedmont, Michaux's sumac appears better adapted to clay soil derived from mafic rocks or sandy soil derived from granite. In the Sandhills, it occurs more in loamy swales (Weakley 1993). Michaux's 37 sumac ranges from southern Virginia through Georgia, within the inner Coastal Plain and lower Piedmont. Ground-truthing revealed potential or marginal habitat for Michaux's sumac. Most potential habitat occurs in the dry, upland portions of power line or telephone/cable right- of-ways and along railroad shoulders. The roadway and railroad corridors are narrow with sporadic maintenance, shade and dense growth of perennials, producing marginal growing conditions for Michaux's sumac. The areas with the most suitable habitat are two power line corridors located within the Site boundaries. Systematic field surveys were conducted in July 2001 within potential habitat areas. Stands of winged and smooth sumac (Rhus copa/iina and R. giabra) were found in several areas, but no Michaux's sumac was observed. A population of Michaux' Sumac (Rhus michauxii) is presently located approximately 1.5 miles south of the Site. Dwarf Wedge Mussel - The dwarf wedge mussel is relatively small, averaging 1.0 to 1.5 inches long. The shells are olive-green to dark brown in color and are subrhomboidally shaped. The shells of females are swollen posteriorly, while males are generally flattened ' (TSCFTM 1990). The preferred habitats are streams with moderate flow velocities and bottoms varying in texture from gravel and coarse sand to mud, especially in areas downstream of debris and on banks of accreting sediment. This species was previously ' known from only a few, disjunct populations in the Neuse River basin (Johnston Co.) and upper Tar River basin (Granville Co.). State-wide surveys conducted since 1992 have expanded this species' range in North Carolina; however, the dwarf wedge mussel range is still believed to be restricted to the Neuse and Tar River basins. The dwarf wedge mussel prefers deep runs with coarse sands. Other habitats for this mussel include bottoms of gravel beds, among submerged aquatic plants, and near overhanging stream banks. The lower reach of Mingo Creek may provide suitable habitat for the dwarf wedge mussel. 1 38 t 1 r Federal Species of Concern (FSC) listed for Wake County (list date April 12, 2001), their North Carolina status, and an indication of whether habitat for each species exists in the project corridor are listed below (Amoroso 1999, LeGrand and Hall 1999). Common Name Scientific Name State Status* * Potential Habitat Bachman's sparrow Aimophila aestivalis SC No Southern ho nose snake Heterodon simus* SR No Southern myotis Myotis austroriparius SC Yes Carolina darter Etheostoma collis lepidinion SR No Pinewoods shiner Lythrurus matutinus SR Yes Atlantic pi toe Fusconaia masoni T Yes Yellow lance Elliptio lanceolata T Yes Green floater Lasmi ona subviridus E Yes Diana fritillary butterfly Speyeria diana* SR Yes Sweet pinesap Monotropsis odorata C Yes Carolina least trillium TruUium pusillum E Yes * Historic record **SC = Special Concern; SR = Significantly Rare; T = Threatened; PE = Proposed Endangered; E = Endangered; W = Watch List 3.4.2 State Listed Species Species with the North Carolina status of Endangered, Threatened, Special Concern, Candidate, Significantly Rare, or Watch list receive limited protection under the North Carolina Endangered Species Act (G.S. 113-331 et seq.) and the North Carolina Plant Protection Act of 1979 (G.S. 106-202.12 et seq.). A review of NHP records indicates that two state listed species are known to occur within 1.0 mile of the Site. pinewoods shiner (Lythrurus matutinus), and notched rainbow (Villosa constricta), both listed as Significantly Rare, have been documented from the Neuse River above the confluence with Mingo Creek. The pinewoods shiner is small fish that prefers the midwater area in sandy runs and pools in creek sand of small rivers. The lower reach of Mingo Creek may provide suitable habitat for the pinewoods shiner. The notched rainbow is a mussel, that in Wake County, is known in the Neuse River, Crabtree Creek, Little River and Middle Creek. Its favored habitat is clean sand and gravel substrate in shallow waters of upland streams. Mingo Creek may provide suitable habitat for the notched rainbow. No in stream surveys for Pinewoods Shiner of the Notched Rainbow were undertaken in support of this document. 3.5 REGIONAL CORRIDORS, GREENWAYS, AND ADJACENT NATURAL AREAS The Site represents a potentially significant regional recreational and wildlife corridor providing connectivity to the Neuse River, city parks, and other natural areas (Figure 11). The Site is located within the rapidly growing Knightdale area, and within the rapidly developing upper Neuse River basin. As depicted in Figures 7 and 8, local forest corridors 39 ¦ II?! ! ! i ! ! ! ! i i ! i i ! i ! ! ! i m n p n z > ` , > n ? n A o L D 0;0 C Mo??rn z °D D z?0 Z n o r; -? v >> ?om DG?O o x m g y ??cnv0 Z >o ?Dn o D c D DZsu O Oz (1) ?z ' o o N rn?fl.ccn D m D7 T er m o o ?' ° (n i 1 11 t are expected to become increasingly more isolated as upland development encroaches on the Neuse River and Mingo Creek floodplains. The City of Raleigh has recently purchased Anderson Point, as an anchor for the greater Neuse River Regional Park System. Anderson Point Park is located on the west bank of the Neuse, at the confluence of Crabtree Creek, and directly opposite the Mingo Creek Site (Figure 11). This Regional River Park System will offer a variety of recreational opportunities including river access, greenway connections, corridor preservation, and wildlife habitat. As described in the Milburnie to Anderson Point Corridor Master Plan, land surrounding the Park is needed to protect views from the park and to facilitate connections to other city parks along both sides of the Neuse River. The master plan also calls for the proposed Bypass bridge over the Neuse to feature a pedestrian walkway connecting present and future greenways along the east side of the Neuse and Mingo Creek. The Town of Knightdale has also proposed a Mingo Creek Greenway to connect urban and residential areas with the Neuse. The Knightdale park system and open space program currently includes a substantial segment of the Mingo Creek floodplain upstream of the Site. Auxiliary wetland preservation and management projects should be considered to conserve the remaining regional wildlife corridor along the upper reaches of Mingo Creek. 3.6 ENVIRONMENTAL EDUCATION AND PUBLIC INTEREST PROGRAM An educational program can promote public interest and environmental education to acquaint the public with the local natural environment. The proximity of Hodge Road Elementary School to the Site can serve as a catalyst to promote regional conservation planning in the upper Neuse River Basin. The combination of wetlands and uplands, as well as the ecotonal boundaries between the various plant communities, provide a unique view of the ecological relationship between different species of plants and animals. The Site can provide education and research opportunities within these unique plant communities that are quickly disappearing in the region. Preservation of the Site along with long-term management will provide a contiguous bioreserve and potentially valuable education and research opportunity abutting the proposed Bypass. In order to assure preservation of a unique combination of undisturbed natural communities, agencies should consider enhancement ratio credits for preservation of the wetland/upland buffers. Educational elements may include: • Well-developed trails winding through the various ecological communities. • Access to area greenway trails and the local schools. • Boardwalks into and over the marsh community. • Maps and illustrated graphics enclosed in glass-faced boxes. • Free-standing, multi-sided kiosks. • Free-standing, threedimensional display units. 41 1 Each of these display options will be designed for easy maintenance and periodic updating. The educational components would be initiated through cooperative arrangements with NCDOT, various municipalities, and appropriate educational organizations in order to promote development of creative aspects of conservation education in the area. r, 1 1 42 4.0 STREAM AND WETLAND MITIGATION FEASIBILITY STUDY The purpose of this feasibility report is to provide a preliminary evaluation of stream and wetland mitigation potential on Site. Mitigation potential is based heavily on the professional judgement and visual assessments of hydrology, soils, vegetation, land use restrictions,, and jurisdictional area status. From initial site assessments, two unnamed tributaries to Mingo Creek were identified as suitable for stream and wetland mitigation. Refer to Figure 4 for general site location (UT1 and UT2). UT1, identified as System 2 in Section 2.3.1 (Figure 6), is a perennial stream located in the eastern portion of the Site. UT2, identified as System 11 and 4 in Section 2.3.1 (Figure 6), contains both perennial ' and intermittent stream reaches. UT2 is located in the in the western portion of the Site Additional topographic maps and low-level aerial photographs were obtained from Wake County GIS. These graphics were utilized to identify primary hydrologic features affecting the Site and relevant environmental features. Vegetative communities, wetlands, and surface flow patterns identified on aerial photographs were verified in the field. Field investigations were undertaken in July 2001. Preliminary characterization of streams was undertaken by surveying two representative cross-sections along each stream ' channel. The cross-sections were compared to regional curves in an effort to determine stable channel dimensions. The UT1 and UT2 stream restoration corridors were assessed based on visual estimations of the floodplain. The corridors were depicted on aerial ' photography relative to topographic features, which affect ease of channel relocation and/or repair. A study area profile was developed which categorizes the various factors associated with stream and wetland mitigation (soils, groundwater flow, overbank flow, vegetation, jurisdictional wetlands). 4.1 UNNAMMED TRIBUTARY 1 (UT1) G 1 4.1.1 Physiography and Land Use The UT1 corridor contains a forested, linear reach supporting an entrenched channel, a narrow floodplain bench, and an adjacent terrace. Herbaceous vegetation dominates the narrow floodplain bench area. Mesic and Dry-mesic hardwoods dominate the adjacent terrace and adjacent upland slopes (see Section 3.3). Elevational gradients extend from approximately 175 feet NGVD in the Mingo Creek floodplain to approximately 190 feet NGVD at a headcut within the upstream wetland (Figure 12). For mitigation planning purposes, the stream corridor has been subdivided into three primary physiographic landscape units for soil classification and stream restoration planning: 1) valley escarpment (upland slopes), 2) abandoned floodplain terrace, and 3) active floodplain bench. The primary variables utilized to segregate wetland landscape units include land slope, groundwater flow characteristics, soil features, and the primary hydrologic influence on historic wetland function. 43 r i r r r ?r r? r r r? ?r ?r ? i r? r J :* R 4 ?. M ? Y IV- T " ?'-. j _ Cpl N ? E i ? T F rrv VII » 4 " + s ? tee.. ,. ? zfp all I y `? -^ #? ? * • ea a '?. q E i a ?6 ?? k? i' # ?T k k, -.IN s:. i ILI jjF; •? 1 ` a n C) c) b ? q n a ? ? v n o W _ ?? ? °D D?z ? Z A ?? c? ?' T Crn?r =m DG?O C7 "G C/ c _ N m o z Oz cnO?? Q met N ? zOD z:-< 0 Cl) No Z? D ZR1 0 O A- I I?mw 1 1 L 1 UT1 originates offsite, east of Hodge Road. Two first order streams converge directly east of Hodge road before passing through a culvert and entering the on-site wetland. One of the off-site tributaries originates from an agricultural pond and flows north for approximately 1000 feet between residential homes and an agriculture field before the confluence with second tributary (see Figure 3). The second off-site branch appears to originate from headwater seepage slopes above a second agricultural pond. The stream channel below the pond is obscured due to beaver impacts. A beaver dam is located directly above the culvert invert under Hodge Road. Off-site, upstream land use consists of low-density residential areas and agricultural uses including livestock grazing, hay, and crop production. Most of this area has been deforested in support of these land uses. Several agricultural roads cross the tributary, one across the dam to the first pond and a second fords the channel immediately upstream of the second pond. On-site land use includes primarily undeveloped property occupied by dry-mesic hardwood forest on slopes and ridges, changing to predominantly mesic mixed hardwoods along the stream bottom. A power line right-of-way intersects UT1 and the associated wetland (System 1). Vegetation within the right-of-way is mechanically maintained and subsequently is dominated by herbaceous and shrubby vegetation. Past land use practices appear to have impacted corridor soil characteristics. Early agricultural history in the region followed the rapid and near complete removal of forest covers. Land clearing paved the way for crop and livestock use. In concert with land clearing activities, large streams and tributaries were straightened and dredged to ameliorate flooding, drain wet areas, and increase usable agricultural area. Due to land clearing and lack of erosion control measures, massive amounts of surficial topsoil were eroded and deposited within the larger stream valleys. With the implementation of erosion control practices and the conversion of large tracts of previous crop and pastures into forest, sedimentation rates decreased dramatically. With the decease in sediment loads, stream channels incised into the valley floor with subsequent abandonment of adjacent floodplains. These described events were a common occurrence throughout the Piedmont physiographic province. The past impoundment of Mingo Creek induced heavy sedimentation behind the dam, creating a raised, level plain. Upon breaching of the dam, a braided stream system likely developed within the unconsolidated sediments. Ensuing beaver activity within the Mingo Creek corridor resulted in extensive ponding of the surrounding floodplain and low terraces, creation of a multi-threaded channel, and mortality to adjacent bottomland and upland tree communities. 4.1.2 Soils UT1 occurs along a landscape gradient characterized as the Appling-Louisburg-Wedowee catena. The valley escarpment (groundwater slopes) consists of gently to moderately sloping, somewhat excessively drained soils derived from granite, gneiss, and schist (SCS 1970). This physiographic area typically exhibits lateral groundwater flow and discharge ' toward the low-lying floodplain and stream channel. Soil series on these slopes include 45 n u ' Appling, Louisburg, and Wake. The valley floor portions of the corridor are dominated by nearly level, poorly drained soils associated with Wehadkee and Bibb soils. These soils ' form in loamy alluvium with the Wehadkee having finer texture and, consequently, less infiltration. Surface runoff is slow to ponded and the seasonal high water table is at the surface Alluvial deposition was noted within a narrow flooplain bench along portions of the stream below the wetland, and in adjacent terraces extending to the Mingo Creek Floodplain. The ' terrace areas will be targeted for stream restoration. 4.1.3 Vegetation ' Distribution and composition of plant communities reflect landscape-level variations in topography, soils, hydrology, and past or present land use practices. Three communities identified within the area include early sucessional land, freshwater marsh, and mesic mixed hardwood forest. See Plant Communities (Section 3.1) (Figure 10) for detailed descriptions. 4.1.4 Hydrology The corridor is situated in a hydrophysiographic region considered characteristic of the Piedmont physiographic province, which extends throughout north-central portions of ' North Carolina. This region is characterized by moderate rainfall and moderately steep valley walls. In central Wake County, precipitation averages approximately 47 inches per year with rainfall amounts occurring evenly throughout the year. ' Corridor hydrologic inputs are largely the result of surface water flows and precipitation and to a lesser extent, groundwater seepage. Overbank flooding of UT1 is not likely as the ' stream is entrenched and upstream agricultural and beaver impoundments dampen hydrologic pulses during storm events. The stream has long since abandoned it historic floodplain. The abandoned floodplain terrace directly below the upstream headcut, ' currently contains no wetlands. The UT1 watershed encompasses approximately 150 acres (0.23 square mile). Based on stream delineations, approximately 1200 linear feet of perennial stream channel has been identified for restoration. The abandoned floodplain averages approximately 120 feet in width and, although down-valley slope (0.014 based on USGS quadrangles) is relatively ' steep, the cross-valley slope is relatively flat. Groundwater discharge from adjacent slopes rapidly infiltrates the floodplain terrace, toward the tributary channel. Once groundwater reaches the tributary channel, steep down valley slopes rapidly transport surface water to ' the Mingo Creek floodplain. Headcut migration in the upper reaches of UT1 undoubtedly results in a lowering of the ' adjacent groundwater table and the functional loss of wetland hydrology adjacent to the stream. The groundwater gradient is expected to extend from near surface saturation within outer fringes of the floodplain to approximately 6 feet below the land surface immediately adjacent to the entrenched reach. Based on the preliminary assessment, restoration of groundwater-induced wetland hydrology may be achievable near entrenched reaches of the tributary. Although groundwater restoration is not likely to produce 46 ? 1 significant wetland acreage, from an ecological perspective, elevated groundwater is an important component of on-site rehabilitation. Based on visual assessments, overbank flooding from Mingo Creek is expected at a less than 1-year return interval. Hydrologic inputs from Mingo Creek are not expected to be significant in a water budget analysis; however, further studies, including a flood frequency analysis, may be necessary to quantify flood-flow patterns in Mingo Creek. 4.1.5 Stream Discharge The drainage area for the UT1 measures approximately 0.23 square mile in size. This drainage area suggests a tributary that is either marginally perennial or intermittent stream. ' However, stream data measurements and visual observations suggest that the existing channel exhibits characteristics of a perennial stream. Additional studies will be required to accurately determine the stream's hydrologic status. Discharge estimates for stream restoration utilize an assumed definition of "bankfull" and the return interval associated with the bankfull discharge. For this study, the bankfull channel is defined as the channel dimensions designed to support the "channel forming" or "dominant" discharge (Gordon et a/. 1992). Flow resistance reaches a minimum at bankfull stage as excess discharge is distributed within flood prone areas. Research ' indicates that a stable stream channel may support a return interval for bankfull discharge, or channel-forming discharge, between 1 to 2 years (Gordon et a/. 1992, Dunne and Leopold 1978). The methods of Rosgen (1996) indicate calibration of bankfull dimensions ' based on a potential bankfull return interval of between 1.3 and 1.7 years for rural conditions. A number of methods have been utilized to estimate bankfull discharge relative to drainage areas in the Piedmont Province, including regional curves and available research (Nunnally and Keller 1979, Harman et. a/. 1999). Based on available data, bankfull discharge for a rural, 0.3 square mile watershed averages approximately 22 CFS (Harman et. a/. 1999). A bankfull discharge of less than 10 CFS is not likely to support a perennial stream channel. ?I L The cross-sectional area of the tributary was measured based on field indicators to predict bankfull discharge. The average stable, bankfull cross-sectional area in the downstream reach of UT1 was estimated at 12 square feet, suggesting a bankfull discharge of approximately 36 CFS. This would indicate that the tributary is 1) discharging a greater amount of water than predicted by regional curves, 2) storing water in agricultural and beaver impoundments and releasing water in permanent flow patterns, rather than pulses associated with rainstorms, and/or 3) impacted by greater than usual sediment imputs, resulting in poor field indicators of bankfull cross-sectional area. Further studies, including stream gauge data, may be necessary to determine the effects of the impoundments on tributary morphology and discharge. 4.1.6 Channel Dimension Stream geometry and substrate data have been evaluated based on a classification utilizing fluvial geomorphic principles (Rosgen 1996). This classification stratifies streams into comparable groups based on pattern, dimension, profile, and substrate characteristics. 47 Primary components of the classification include degree of entrenchment, width/depth ratio, sinuosity, channel slope, and stream substrate composition. Regional curves estimate a stable bankfull cross-sectional area of approximately 9 square feet for UT1, suggesting the presence of an intermittent stream channel. Based on observations indicating that the system supports a perennial stream, a stable bankfull cross-sectional area of approximately 9 square feet has been assumed for use in this preliminary assessment of mitigation potential. Stream flow data will be required to establish an accurate estimate of bankfull cross-sectional area to be used in further studies. ' Existing channel dimensions were measured by placement of cross-sections along two reaches of UT1 (one in the lower reaches not impacted by headcuts and one in an area entrenched by headcut migration). The channel cross-sectional area measures approximately 9 square feet in areas not entrenched by headcut and 40 square feet in the headcut reach. The reach of the channel impacted by headcutting contains an entrenched stream that does not support functioning floodplains. The flood prone area is expected to average 9 feet in width with an entrenchment ratio' ranging from 1.0 to 1.4. The channel is actively ' down-cutting and widening. Based on channel dimension estimates, headcut reaches currently exhibit morphology and dimensions of a G-type (gully) stream channel. Even with top of bank vegetation, the roots do not extend far enough to reduce erosion, the banks ' are expected to continue eroding until a stable floodplain is established at the lower elevation. u P 11 As the stream enters Mingo Creek floodplain the slope decreases. Currently, this lower reach appears to support an active floodplain with a flood,prone area averaging approximately 130 feet in width and an entrenchment ratio averaging 18. This reach currently exhibits morphology and dimensions of an E/C-type (sinuous) stream channel. High sediment supply is common for C-type streams in alluvial fans. These streams are susceptible to shifts in both lateral and vertical stability, caused by disturbance and changes in flow and sediment regimes upstream. 4.1.7 Channel Plan Form and Substrate On-site upstream reaches of UT1 did not exhibit characteristics of a stable stream channel, and the historic nature of the tributary was difficult to ascertain. Under existing conditions, the channel has been classified as a G5-type (gully) stream in headcut reaches and E/C5-type (sinuous) stream in the lowest reaches. Current sinuosity (channel length/valley length) measures approximately 1.1, indicating a relatively steep (0.013 based on USGS quadrangles) and slightly sinuous channel. The channel substrate is dominated by sands and clays actively eroding from the stream banks, with riffle and pool, and point bar features developing in portions of the channel. 1 Entrenchment ratio = width of the flood prone area (Wfpa) / width of the bankfull channel (Wbkf). The width of the flood prone area is defined as the width of the area under the elevation equal to two times the bankfull maximum depth (D,a,). 48 I Historically, the floodplain is expected to have supported an E-type (highly sinuous) and/or C-type (moderately sinuous) stream channel. E-type streams are characterized as slightly entrenched, low-slope streams with low width/depth ratios (< 12). E-type streams generally exhibit a sequence of riffles and pools associated with a meandering channel. Although E-type streams are highly stable, they are sensitive to disturbance and may convert to other stream types. C-type streams are characterized as sinuous, low relief channels in well developed floodplains carved through alluvial sediments. The channels are generally slightly entrenched, low- to moderate-slope streams with moderate width/depth ratios (>12). C- type streams exhibit a sequence of riffles and pools, and generally have characteristic point bars within the active channel. C-type streams are generally stable; however, stability is dependent upon the natural stability of the stream banks. . The channels may be ' significantly altered and destabilized with changes in bank stability or when watershed conditions deteriorate. Currently, the UT1 corridor encompasses approximately 900 linear feet of entrenched G- type (gully) stream channel and approximately 300 linear feet of degraded E/C-type (sinuous) stream channel. Retrofitting the G-type channel and a portion of the degraded E/C-type channel with a stable, sinuous E-type or C-type channel may occur on new location adjacent to the existing channel. The reconstructed and enhanced channel is expected to support stable banks which dissipate energy and reduce erosive forces in the near-bank region. Reintroduction and stabilization of E- and C-type stream channels to on- site floodplains may restore approximately 1500 linear feet of stream channel. 4.1.8 Jurisdictional Wetlands Jurisdictional wetlands are defined by the presence of three criteria: hydrophytic vegetation, hydric soils, and evidence of wetland hydrology during the growing season (DOA 1987). UT1 corridor wetlands found above the stream headcut are characterized as a beaver impacted freshwater marsh system. The wetland is located primarily within the power line right-of-way. The vegetation within this portion of the wetland is therefore mechanically maintained, supporting the existing freshwater marsh A recent delineation of adjacent upstream wetlands (System 1) reports 1.2 acres of the floodplain is currently underlain by hydric soils. No wetlands were observed below the headcut in the abandoned floodplain terrace. These areas may have at one time supported forested seepage slope wetlands. Headcut migration along the current stream has effectively lowered the adjacent groundwater table within the floodplain terrace, potentially degrading areas where soil saturation has fallen below jurisdictional thresholds. Species turnover from mesic to hydrophytic vegetation may occur in these low-lying or seepage- induced wetland areas. The headcut at the top of UT1 is actively working its way through the upstream wetland. This condition has already degraded hydrology within adjacent wetland areas. If this condition continues, the groundwater table throughout the wetland will subside in response to the entrenched stream. In addition, the resulting entrenched stream will i abandon its former floodplain and overbank flooding will be reduced significantly 1 49 Restoration of the stream will allow the floodplain to perform wetland functions such as floodflow suppression, nutrient cycling, pollutant removal, and provide habitat for native species. Approximately 1.2 acre will be enhanced or preserved through the cessation or removal of the upstream headcut, and the potential for minimal wetland creation within the I former floodplain. 4.2 UNNAMMED TRIBUTARY 2 (UT2) 4.2.1 Physiography and Land Use The UT2 corridor contains a forested linear reach supporting an entrenched channel and a narrow adjacent terrace. UT2 is completely contained within the Site (Figure 13). Mesic mixed hardwood forest vegetation dominates the narrow terrace area and the adjacent uplands (Figure 10). A sewer line right-of-way crosses the lower stream reach. Elevational gradients extend from approximately 185 feet NGVD in the Mingo Creek floodplain to approximately 240 feet NGVD at the headcut below the headwater wetland. The stream contains three major headcuts 1) below the sewer easement; 2) at the transition point between perennial and intermittent stream (Systems 11 and 14), located near System 11; 3) and just below the headwater wetland (System 15) (see Figure 13). r For mitigation planning purposes, the corridor has been subdivided into three primary physiographic landscape units for soil classification and stream restoration planning: 1) valley escarpment (upland slopes), 2) abandoned floodplain (elevated terrace), and 3) active floodplain bench. The primary variables utilized to segregate wetland landscape units comprise land slope, groundwater flow characteristics, soil features, and the primary hydrologic influence on historic wetland function. Land use includes primarily undeveloped property occupied dry- and mesic-mixed oak- hickory on slopes and ridges, changing to predominantly mesic hardwoods along the stream bottom. Past land use practices appear to have impacted corridor soil characteristics. Early agricultural history in the region followed the rapid and near complete removal of forest covers. Land clearing paved the way for crop and livestock use. In concert with land-clearing activities, large streams and tributaries were straightened and dredged to ameliorate flooding, drain wet areas, and increase usable agricultural acreage. Due to the land clearing and lack of erosion control measures, massive amounts of surficial topsoil were eroded and deposited within the larger stream valleys. With the implementation of erosion control practices and the conversion of large tracts of previous crop and pastures into forest, sediment rates decreased dramatically. The current age class of adjacent forest cover is estimated at 30-40 years. With the decease in sediment loads, stream channels incised into the valley floor with subsequent abandonment of adjacent floodplains. These described events were a common occurrence throughout the Piedmont physiographic province. r 1 50 ! ?to- r'{ x i -- 7 ?io ' ,.* ? ? > yif?yy ? ice" ?'tt :?.?' -i•_. ,AT ?`. ?' t W.t •? 'art- t ? ? I ?.? ' ? • r ! ? .4 t fi • P ? we k /; . 44 . WA ' filar n s 79 : rra? `• Y . • 'MMt p S` {r opt d - ' ?'. ? a ?j L? ?" ? a ? -we, . A + ?r •?. 14 ,#•? ,? . 14 gil?? T`? '4''"XR"`?rR ?. ,?? ?'. .?'? `?? • ? ' ?' . -' # ' 4 '? ? • ? °: ? L- : ? -? - ?. .mot 411 OF f' ,tr' lR`T ! ?i ., 1 LA zA$ 4, 4i' AW C/) rgt { ` ?V .- A,• ,,?" '?{' ? h ,r ? TAD ' akS; ?'? -0 t_. -? i 10 lip, IM: CM/) D m m 14, j, r *4 .' .rr . ?' . 3-' ' -' Wit. ?? y''?F' . '''i?? ,_`? . 5n. _ ? vy ?1 ' Dm cn ?O z z O? ? Z n - O O Zm n o m? Z ?- no cU) x m m mm m D? m? O T m --j r m .. D O Z D ( ) m 7 .Z z p m M U A ? Z CI) Z a l ? I, Q Z F$ 4 ? • s VA v ?f m ? p a o v _? c M ?Cr 0 .-.vim Z oD D z? z C) Z -r G) C o -iz>> >o (n cm Z { N Z o v Cl) 0 O r N X Z m D T o ?v O yp { : r fry - ti yE " t . 3 ¢ S •L r a+x a- a'~ r a.{ a } r t`, 4.2.2 Soils UT2 occurs along a landscape gradient characterized as the Appling-Louisburg-Wedowee catena. The valley escarpment (groundwater slopes) consist of gently to moderately sloping, somewhat excessively drained soils derived from granite, gneiss, and schist (SCS 1970). This physiographic area typically exhibits lateral groundwater flow and discharge toward the low-lying floodplain and stream channel. Soil series on these slopes include Appling, Louisburg, and Wake. The valley floor portions of the corridor are dominated by nearly level, poorly drained soils associated with Worsham soils. The Worsham series consists of nearly level and gently sloping, deep, poorly drained soils. Worsham soils formed under forests from translocated material and weathered bedrock. Infiltration is good, permeability is moderately slow, and surface runoff is slow to ponded. The depth to bedrock ranges from 5 to 15 feet and the seasonal high water table is at the surface. 4.2.3 Vegetation Distribution and composition of plant communities reflect landscape-level variations in topography, soils, hydrology, and past or present land use practices. Two plant communities, Piedmont bottomland hardwood and mesic-mixed hardwood forests, were identified adjacent to the channel and floodplain. See Plant Communities (Section 3.1) for detailed description. 1 4.2.4 Hydrology UT1 hydrologic inputs are largely the result of groundwater seepage and, to a lesser extent, surface water flows and precipitation. Overbank flooding of UT2 is not likely as the stream is entrenched along most of its reach. The stream has long since abandoned it historic floodplain and currently contains few adjacent wetlands. Currently, adjacent wetlands include two headwater seepage wetlands and several small seepage slope wetlands in the lower stream reach. The total drainage area of the UT2 encompasses approximately 106 acres (0.16 square mile). Based on recent stream delineations, approximately 2500 linear feet of perennial and "important" intermittent stream channel has been identified for restoration. The abandoned floodplain averages approximately 30 feet in width and a moderately steep valley slope of approximately 0.017 (based on USGS quadrangles). Groundwater discharge from adjacent slopes rapidly infiltrates the floodplain terrace, towards the tributary channel. Once groundwater reaches the tributary channel, the over-steepened and straightened channel, rapidly transports surface waters to the Mingo Creek floodplain. Headcut migration throughout the upper reaches of UT2 has undoubtedly resulted in a lowering of the adjacent groundwater table and the functional loss of wetland hydrology adjacent to the stream. The groundwater gradient is expected to extend several feet below the surface within outer fringes of the floodplain to approximately 5 feet below the land surface immediately adjacent to the entrenched stream. Based on the preliminary assessment, restoration of groundwater-induced wetland hydrology may be achievable near entrenched reaches of the tributary. Although groundwater restoration is not likely to produce significant wetland acreage, from an ecological perspective, elevated groundwater is an important component of on-site rehabilitation. 1 52 Based on visual assessments, overbank flooding from Mingo Creek is expected at a less than 1-year return interval. Hydrologic inputs from Mingo Creek are not expected to impact the water budget analysis. 4.2.5 Stream Discharge The drainage area for UT2 measures approximately 0.16 square mile in size. This drainage area suggests that UT2 represents a marginally perennial or intermittent stream. Stream data measurements and visual observations suggest that the part of the existing channel exhibits characteristics of a perennial stream, with the remaining portion, including approximately 1500 linear feet, considered an "important" intermittent stream. Additional studies will be required to accurately determine the streams hydrologic status. Based on available data, bankfull discharge (see 4.1.5 for definitions) for a rural, 0.16 square mile watershed averages approximately 13 CFS (Harman et a/. 1999). This number is based on discharge at the lower reach of the watershed. Discharge for upper reach sections would be expected to yield smaller numbers. A bankfull discharge of less than 10 US is not likely to support a perennial stream channel. The cross-sectional area of the tributary was measured based on field indicators to predict bankfull discharge. The average stable, bankfull cross-sectional area in the downstream reach of UT2 was estimated at 5.5 square feet, suggesting a bankfull discharge of approximately 11 CFS. This would indicate that the tributary is discharging a similar amount of water as predicted by regional curves. 4.2.6 Channel Dimension Stream geometry and substrate data have been evaluated based on a classification utilizing fluvial geomorphic principles (Rosgen 1996). This classification stratifies streams into comparable groups based on pattern, dimension, profile, and substrate characteristics. Primary components of the classification include degree of entrenchment, width/depth ratio, sinuosity, channel slope, and stream substrate composition. Regional curves estimate a stable bankfull cross-sectional area of approximately 6 square feet for UT2, suggesting the presence of an intermittent stream channel. Based on observations indicating that the system supports both a perennial and intermittent stream channel. A stable bankfull cross-sectional area of approximately 6 square feet has been assumed for use in this preliminary assessment of mitigation potential. Stream flow data will be required to establish an accurate estimate of bankfull cross-sectional area to be used in further studies. Existing channel dimensions were measured by placement of cross-sections along two reaches of UT2 (one in the lower reaches not impacted by headcuts and one in an area entrenched by headcut migration). The channel cross-sectional area measures approximately 5.5 square feet in areas not entrenched by headcut and 25 square feet in the headcut reach. The reach of the channel impacted by headcutting contains an entrenched stream that does not support functioning floodplains. The flood-prone area is expected to average 8 feet in width with an entrenchment ratio ranging from 1.0 to 1.4. The channel is actively 53 11 down-cutting and widening. Based on channel dimension estimates, headcut reaches currently exhibit morphology and dimensions of a G-type (gully) stream channel. Even with top-of-bank vegetation, the roots do not extend far enough to reduce erosion, the banks are expected to continue eroding until a stable floodplain is established at the lower elevation. As the stream enters Mingo Creek floodplain the slope decreases. Currently, the lower reach appears to support an active floodplain with a flood prone area averaging approximately 80 feet in width and an entrenchment ratio averaging 50. This reach currently exhibits morphology and dimensions of an E/C-type (sinuous) stream channel. High sediment supply is common for C-type streams in alluvial fans. These streams are susceptible to shifts in both lateral and vertical stability, caused by disturbance and changes in flow and sediment regimes upstream. 4.2.7 Channel Plan Form and Substrate Upstream reaches of UT2 did not exhibit characteristics of a stable stream channel and the historic nature of the tributary was difficult to ascertain. Under existing conditions, the channel has been classified as a G5-type (gully) stream in headcut reaches and E/C5-type (sinuous) stream in the lowest reaches. Current sinuosity (channel length/valley length) measures approximately 1.2, indicating a moderately steep channel slope (0.014 based on ' USGS quadrangles) and slightly sinuous channel. The channel substrate is dominated by sands and clays actively eroding from the stream banks, with riffle and pool, and point bar features developing in portions of the channel. i? r t 1 Historically, the floodplain is expected to have supported an E-type (highly sinuous) and/or C-type (moderately sinuous) stream channel. E-type streams are characterized as slightly entrenched, low-slope streams with low width/depth ratios (<12). E-type streams generally exhibit a sequence of riffles and pools associated with a meandering channel. Although E-type streams are highly stable, they are sensitive to disturbance and may convert to other stream types. C-type streams are characterized as sinuous, low relief channels in well developed floodplains carved through alluvial sediments. The channels are generally slightly entrenched, low to moderate-slope streams with moderate width/depth ratios (>12). C- type streams exhibit a sequence of riffles and pools, and generally have characteristic point bars within the active channel. C-type streams are generally stable; however, stability is dependent upon the natural stability of the stream banks. The channels may be significantly altered and destabilized with changes in bank stability or when watershed conditions deteriorate. Along its total length, UT2 includes approximately 1500 linear feet of entrenched G-type (gully) intermittent stream channel, approximately 900 linear feet of entrenched G-type (gully) perennial channel, and approximately 700 feet of relatively stable E/C-type (sinuous) stream channel. Retrofitting the G-type channel and a portion of the degraded E/C type channel with a stable, sinuous E-type or C-type channel on new location is not feasible because of existing floodplain constraints. Stream restoration options are expected to include primarily in-place, in-stream measures due to the confined floodplain. 54 1 1 t t J The main objective of stream enhancement is to raise the water surface to within approximately 1.5 feet of the floodplain surface and to reduce channel size to approximately 6 square feet. Primary activities designed to achieve these objectives may include 1) installation of cross-vane weirs, 2) creation of a bankfull bench, and 3) hay bale bank stabilization revetments, 4) and headwater floodplain berms. In-stream structures and stabilization of existing channels may enhance approximately 2400 linear feet of stream channel. 4.2.8 Jurisdictional Wetlands Wetlands found above the headcut are characterized as forested headwater seeps (low elevation seeps). A recent delineation of adjacent upstream wetlands reports approximately 0.25 acres of forested headwater wetlands in the corridor. No wetlands were observed in the abandoned floodplain terrace, along the entrenched channel. The floodplain terrace may have at one time supported forested seepage slope wetlands. Headcut migration along the current stream has effectively lowered the adjacent groundwater table within the floodplain terrace, potentially degrading areas where soil saturation has fallen below jurisdictional thresholds. Species turnover from mesic to hydrophytic vegetation may occur in these low-lying or seepage-induced wetland areas. Similarly to UT1, the headcut at the top of UT2 is actively working its way through the upstream wetland. This condition has already affected hydrology within adjacent wetland areas. If this condition continues, the groundwater table throughout the wetland will subside in response to the entrenched stream. Opportunities may exist for enlarging the existing headwater wetland to replace areas proposed to be impacted by the construction of the Bypass. Through the use of low-slung, extended weirs or berms across the floodplain, the water table can be manipulated to restore and induce hydrology to former floodplain areas. Restoration of the stream will allow the floodplain to perform functions such as floodflow suppression, nutrient cycling, pollutant removal, and provide habitat for native species. Approximately 0.25 acre will be enhanced or preserved through the cessation or removal of the upstream headcut, and the potential for minimal wetland creation within the former floodplain. 4.3 MITIGATION SUITABILITY AND RECOMMENDATIONS 4.3.1 Mitigation for UT1 Stream restoration activities may include 1) channel reconfiguration/construction, 2) bank stabilization (plantings), 3) channel backfilling, and 4) floodplain depression construction (Figure 12). Reconstructing the channel on a new location, in place of the highly eroded, downcut channel will 1) reduce sediment and nutrient loading, 2) increase the frequency of pools and associated micro-habitat for benthic micro and macro invertebrates, and 3) provide storm water energy dissipation. Increased sinuosity within approximately 1200 feet of reconfigured channel may increase linear footage of restoration and provide the Site with a stable, self-sustaining reach. Incorporation of wetland restoration areas in conjunction with stream activities may include the construction of elliptical, or oval depressional areas adjacent to the abandoned primary 55 tributary channel to provide a wetland functional aspect to the floodplain. Wetland restoration areas will provide 1) nutrient and sediment/toxicant removal from floodwaters, 2) groundwater recharge in the adjacent floodplain, 3) general habitat diversity, and 4) additional aquatic habitat. Wetland restoration activities may include excavating shallow depressions, backfilling with surface soils and vegetative matter, construction of an embankment adjacent to the tributary, soil surface scarification, floodplain reforestation. Incorporation of wetland areas may result in the restoration/creation approximately 0.02 acre of jurisdictional wetland. Additional benefit from stream restoration will be the cessation of headcutting and the subsequent functional loss of the upstream wetland system. Therefore, approximately 1.2 acres of jurisdictional wetland will be restored/enhanced. ( 4.3.2 Mitigation for UT2 Stream restoration activities may include 1) installation of cross-vane weirs; 2) excavating a bankfull bench; and 3) hay bale bank stabilization revetments (Figure 13). Retrofitting the highly eroded channels to a stable channel configuration will 1) reduce sediment and nutrient loading, 2) increase the frequency of pools and associated micro-habitat for benthic micro and macro invertebrates, and 3) provide stormwater energy dissipation. In- stream structures and stabilization of existing channels may enhance approximately 2400 linear feet of stream channel. Incorporation of wetland restoration areas in conjunction with stream activities may include the construction of elliptical, or oval depressional areas adjacent to the abandoned primary tributary channel to provide a wetland functional aspect to the floodplain. Incorporation of wetland areas may result in the restoration/creation approximately 0.02 acre of jurisdictional wetland. Additional benefit from stream restoration will be the cessation of headcutting and the subsequent functional loss of two upstream wetland systems. Approximately 0.3 acre of jurisdictional wetland will be restored/enhanced by restoration activities. 1 1 56 5.0 WETLAND FUNCTIONAL EVALUATION ?i This Mingo Creek Restoration and Conservation Management Plan utilizes an ecosystem approach to wetland preservation and enhancement, thereby maintaining the array of habitat opportunities and physical properties historically associated with wetlands including the adjoining upland buffer matrix. In order to justify allocation of resources toward preservation of the upland buffer matrix within the Site, appropriate mitigation weight was determined for upland preservation and management activities. The ecosystem concept and associated lift associated with upland buffers is particularly relevant to this project because of the location, extent, and function of the upland buffer matrix in a highly developing watershed. The evaluation looks particularly at wetland functions that will change due to potential on-site development should the Site not be preserved. Under similar conditions, upland buffers have been shown to contribute significantly to wetland functional enhancement. Therefore, a substantial lift in mitigation credits should be afforded this Site. To evaluate the functional value of upland buffers, three strategies have been investigated 1) a literature review of relevant research documenting the value of integrating upland buffers within wetland systems, 2) the use of a conceptual Hydrogeomorphic Modeling (HGM), and 3) the use of the Wetland Rapid Assessment Proceedure (WRAP) parameters specifically applied to this project. 5.1 SUPPORTING RESEARCH Many of the historical functions performed by upland forest and wetland forest habitat complexes in the region have been modified by extensive anthropogenic activities, including farming, urban development, and forestry activities. Wetland buffers and wetland/upland ecotones are important in reducing sediment and nutrient inputs into local streams and rivers. In these areas, the scarcity of terrestrial environments may be a primary factor affecting regional diversity within riparian and wetland systems (Adamus and Stockwell 1983). The hydrodynamic and biogeochemical functions of wetlands are directly dependent upon surface and subsurface flow of water from surrounding uplands I (Richardson 1994, Peterjohn and Correll 1984). In addition, biological functions of wetlands are influenced by the size and condition of abutting upland communities and of the upland/wetland ecotone (Brinson et a/. 1981, Brown et aL 1990). The physical and biological functions of wetlands are invariably affected by land use practices that are both immediately adjacent and further upstream (up-slope) of wetland ecosystem. A wetlands ability to stabilize sediment inputs is related to the position of the wetland relative to uplands, incoming erosive forces, and erodibility of uplands being protected (Adamus et a/. 1991). Sediment/toxicant/nutrient entry is related to the acreage of cleared land and soil management measures in uplands immediately adjacent to the wetland (Karr and Schlosser 1978, Cooper et a/. 1986, Peterjohn and Correll 1984). Considerable research exists concerning the impacts of elevated sediment and nutrient inputs on wetland biological functions (Jurik et a/. 1994, Wang et a/. 1994, DEM 1991). Terrestrial soils, because of their generally higher cation concentrations, are probably more efficient than wetland soils in removing and retaining phosphorous and nitrogen 57 (Richardson 1985, Jordan et a/. 1986, Ehrenfeld 1987). Therefore, inclusion of upland buffers may attenuate nutrient inputs and enhance the ability of wetland ecosystems to sequester and assimilate elements, nutrients, and compounds. Undeveloped uplands may enhance recharge into adjacent wetlands. Abutting undeveloped uplands are usually more important than wetlands for groundwater recharge, groundwater flow rates, and wetland storage capacity (Adamus et a/. 1991). In addition, undeveloped uplands occasionally have greater flood storage value (greater recharge and 1 less runoff) than adjacent wetlands. Restored wetland buffers also dissipate floodwaters by frictional resistance and evapotranspiration to desynchronize runoff into wetland corridors (Young and Klawitter 1968, Chamberlain 1982, Schwan 1985). Subsequently, ' reductions in turbidity may be realized due to increased percolation of runoff into the underlying sediment of upland buffers (Adamus et a/. 1991). Criteria for determining adequate buffer size should be based, in part, on the quality of the wetland and the intensity of adjacent development (Castelle et a/. 1992). The wetland/upland edge is among the most diverse and productive environments for wildlife (Brinson et a/. 1981). Based on current research, the proximity and position of upland habitat influences the value of wetlands for wildlife guilds. In east central Florida, a buffer zone of 550 feet in width is recommended for flatwood/hammock/hardwood swamp I wetland associations to protect habitat for wetland dependent species. Edge effects have been shown to negatively affect native wildlife guilds within 300 feet of forest boundaries (Brown et a/. 1991, Harris 1984). Many forms of wildlife which utilize wetland habitat, including neotropical migrant birds, are characterized as forest-interior or area-sensitive species. Examples include the Acadian flycatcher, prothonotary warbler, northern parula, and wood thrush (Keller et a/. 1993). Unfragmented wetland forests and upland forest buffers provide better protection from predators and brood parasites and offer different food sources than fragmented wetland systems (Whitcomb et a/. 1976). ( Inclusion of uplands within mitigation land will inhibit impacts to wetlands by man-made disturbances such as noise, visual barriers, dust, or development. Man-made disturbances ' diminish the quality of available cover for wetland-oriented species, including green-backed heron (Kaiser and Fritzell 1984), ducks, geese, egrets (Burger 1981), bald eagle (Fraser et a/. 1985), and breeding waterfowl (Korschgen et a/. 1985). Man-induced disturbances on adjacent uplands affect physical as well as biological wetland functions. A 50 percent to 99 percent decrease in the deposition of fine sandy construction sediment in a wetland has been documented by establishing a 150-foot wetland buffer between construction activities and the wetland (Brown et a/. 1990). Protected wetland buffers will concurrently inhibit man-induced physical wetland disturbances and limit encroachment on wetland habitat requirements for characteristic interior wildlife guilds. The above-referenced literature represents a limited summary of research, which pertains to the influences of wetland buffers and the wetland/upland ecotone on wetland functioning. Data suggests that upland forest restoration areas should be imbedded in or 1 58 1 abutting wetland systems and should extend up to 550 feet from the wetland/waters edge. 5.2 FUNCTIONAL ASSESSMENT METHODOLOGY Research and functional assessment technology indicate that inclusion of appropriate upland restoration sites within wetland mitigation plans will enhance net physical and biological functions of restored wetlands to the extent that mitigation lift may be applied to wetland credits. The wetland/upland ecotone may allow the wetland system to support a greater distribution and abundance of native wetland species. Consequently, the net relative increase in a wetlands ability to perform these functions as a result of buffer/ecotone establishment should help determine the mitigation ratio or percent of total credit granted for wetland mitigation. Two methods were used for measuring functional gains from wetland restoration. Hydrogeomorphic Methodology (HGM) and Wetland Rapid Assessment Procedure (WRAP) assessment methodology have been developed by the U.S. Army Corps of Engineers (COE) specifically for this purpose. ' 5.2.1 Hydrogeomorphic Methodology (HGM) Methodology HGM models currently have been tested for numerous wetland classes. The HGM approach assumes that the hydrology and geomorphic setting of a wetland define a wetland class. Wetland class definitions dictate the types of functions a particular wetland can perform. HGM methods are. applied to each wetland class through the identification of reference wetlands with similar characteristics located in the same physiographic region or subregion. Reference wetlands define the target for functional performance of their representative wetland class and represent the variability in functional performance for that class in a region. Reference wetlands are required to be relatively undisturbed and typical of the regional land use patterns. Reference wetlands allow for the interpretation of functional performance relative to maximum sustainable condition and/or attainable condition for a wetland site. 1 Because functional assessment methodology is designed to provide a rapid assessment, the ability of a wetland to perform a particular wetland function is evaluated in the field by using indicators. Indicators are easily observed or measured attributes of a wetland that 1 are evidence that a particular function is occurring. For example, the presence of seeps, ephemeral channels, water marks, mud stains, or sedimentation along a wetland edge are indicators of the extent of riparian transport of overland flow and/or subsurface flow into ' the wetland. Indicators seen in the field are supplemented with published information such as county soil surveys and USGS gage data whenever possible. The information gathered from the indicators and published information are used to calculate indices of functional performance. Performance indices for various wetland functions are scaled so that the maximum 1 sustainable performance of the function is one (1). Wetland sites are evaluated relative to 59 maximum sustainable performance by assigning a rating of 1, 0.5, 0.1, or zero to ecological predictors of functional performance. Performance variables are entered into a mathematical formula to provide a performance index for a particular wetland function within the wetland study site. Performance indices for a wetland mitigation site would be compared to those of the reference to determine the degree of functional gain based on a "standard of achievement" (Brinson et a/. 1994) at which a fully functional site would be expected to perform. 1 Expected functional attributes of wetland classes in the Mingo Creek Mitigation Site are outlined in Table 7. These types of sites are typically associated with riparian wetlands and minor stream channels along low to moderate gradient slopes or terraces. fl HGM Application and Results During mitigation planning, wetland specialists evaluated the use of uplands in wetland mitigation to determine if buffer/ecotone establishment should be included in the wetland restoration project. Wetlands that contain upland forest buffers or wetland/upland ecotones, and wetlands isolated within urban/developed areas, were compared for functional condition. These areas, along with previous site evaluations, represent a subjective reference wetland set that can be evaluated through HGM functional assessment technology. The conceptual HGM model provides a numeric predictor of the functional lift gained from wetland buffers. For this project, imminent development on adjacent slopes threatens the integrity of the upland/wetland buffer. The model was used to assess functional loss to on-site wetlands, should such development take place. The approach utilized in this assessment should not be considered an HGM functional assessment because a reference wetland data set has not been systematically sampled to analyze the range of wetland function. This analysis represents a conceptual evaluation of relative advances in wetland function that may be realized from buffer/ecotone preservation. Of those wetland functions expected within the preserved mitigation site (Table 7), a number are influenced by the presence of wetland buffers. Wetland functions that will be enhanced by wetland buffer/ecotone restoration include 1) moderation of groundwater flow or discharge; 2) removal of elements and compounds, 3) retention of particulates (sediment stabilization), 4) maintenance of characteristic plant communities, 5) maintenance of spatial habitat structure, 6) maintenance of interspersion and connectivity, and 7) maintenance of the distribution and abundance vertebrates (Table 7). Other wetland functions are also expected to be enhanced indirectly by restoration of upland buffers and ecotones. Table 8 depicts the relative performance indices predicted for identified wetland functions for three reference wetland subsets: maximum sustainable performance (attainable condition), reference wetlands with no upland buffers/ecotones, and reference wetlands which contain upland buffers and ecotones. These performance index formulas are part of the HGM evaluation methodology (Brinson et a/ 1994). The potential increase in the performance of these wetland functions as a result of buffer establishment is also depicted in Table 8 (column 5). 60 1 I 1 1 1 1] 1 1 o `O c co m y U co O ` i U m rm+ O y O y C Y co 0 m Q .?! E ? y ' ' C: 2- 0 C +1 ? O O "O i O O Y C co cm O U O ° m ¦- E Q E 3 y O (D ` O a 'O c i o CL a E 0) -a cc co O ` U y w co co mn E m O O> „- (D i m O O O C w C YO O > cUl) C m a) m C ° Y m ry co mn ± x E C ° - cm ° E a) - ( (D ° CL m o N 0) C ? co m p ,F > W Q . 7 h 0 co O p 7 •}, O c O - () a) 'Y C U O N 7 0. L N C O U C C m m gym, U rm+ m y CD m O O O C C -° 0 0 m 7 .Q CO C ? E m +1 C: ° •«- O ? -C m m m d E 0 _0 0 co O -C m m an L y C m t U E rn 3 O > _ + N + > fl m (D C C C O) m ? O U O y ? m m o m E E L O 0 (D .) C +_C ' m C O r O t c m _ 0 0 C 7 ? +, C O U 0 - C O _ -C U m . Y O +! a) O ±' E O H m V 0) > C rn Y 0 r_ ° -0 O c m m •C Y CA Y fq Y O c O > O m E m U m U i m Y "a Q y C m a? O 0 N co 7 C c 6 > C 7 v- O O Q O m ++ m ? ++ m m ti O Y 3 0 y m N O Y V 1 y +m+ `O o o fl E ayi o C ' e m ° m -O cm i E c O ° m U Q m m} m 0 _ 0) a ° U 0 C O m Y Q m E E 41 m m m C _ N -a m +• Q '? O O cC6 "6 C m C O L .? m C .C] m m C ++ a) H m U Q m m Qv v i v CD m O ° C ° O m O O .0 O O> O O .? m to > c m V C7 > cp > cp Y C y m a) m 7 ?- C m C m C m C CU m C m O C m V) (D CD CD (D 4) 0 m -! m m 0 4- 0) O U y O C CO E C C > C O C( m • + + ° C Q . m m E co OL .0 x cc O m6 co m , c6 ? 5.. U rn U a Q Q I- W O lo rn C y m y N O = ? w O = r, O U H U 7 C) a) y m +?+ _ y O _ U O Y V L O i U 1 m ° m m cn O Q U C C C U O C W 0 0 Cm W U> y U -C U M-0 Y ??, V C N C Q y,.. Q L Q 0 m C ° c O O U +- m oZf O U O E n E C O >• U O Q U U c E ?- m O U C O m o U C V) O m m C +' cts E U C O mr = m o C j C j J ~ d O U C +m U Y m _ m N +m+ fl +m+ L 4; 0 Q O) ? L co °' c i +, ` °) C L y > C y O 2 7 m L a m N F- J Z cc: co o Q U c? O> co C') Cn C O M C m P 1 iJ 1 1 Table 8 Conceptual HGM Comparison of Functional Performance by Reference Wetlands With Upland Buffers/Ecotones and Reference Wetlands Without Upland Buffers/Ecotones Wetland Funrtinn and Parfnrmnnra VnrinhlPs Attainable Reference Reference Relative condition Condition Condition Change (reference Without With Without/ Qnnlpl Ri iffam Ri iffcrc With Pi iffurc Moderation of Groundwater Flow or Discharge V,: Subsurface flow into the wetland V2: Subsurface flow from the wetland to the _ _confininn layer or base flow - - - - - - Performance Index (V, + V2)/2 1 1 - - - - 1 0.5 1 - - - 0.75 1 1 - - - 1 0.5 --- - - - - 0.25 Removal of Elements and Comr)ounds V,: Frequency of overbank flooding 1 1 1 --- V2: Riparian transport/overland flow 1 0.1 1 0.9 V3: Microsite topography 1 1 1 --- V4: Microbial activity of surfaces 1 1 1 --- V5: Sorptive properties of soil 1 1 1 --- _ VL-Sinl in vegetation ---------- 1- -1 - - 1 - -_-- Performance Index 1 0.85 1 0.15 1(V1 + V2)/2 + (V3 + V4 + V5)/3 + V6]/3 Retention of Particulates V,: Frequency of overbank flooding 1 1 1 --- V2: overland flow from uplands 1 0.5 1 0.5 V3: surface roughness from woody plants and 1 1 1 --- debris V4: Surface roughness from herbaceous plants 1 1 1 --- V5: Microsite topography 1 1 1 --- _ VL -Retained sediments - - - - - - - - - 1- 0.5 - - 1 - - 0.5 Performance Index 1 0.8 1 0.20 [(V, + V2)/2 + (V3 + VI + V5)/3 + V6]/3 Table 8: continued u H 1 n I' iJ Conceptual HGM Comparison of Functional Performance by Reference Wetlands With Upland Buffers/Ecotones and Reference Wetlands Without Upland Buffers/Ecotones Attainable Reference Reference Relative Condition Condition Condition Change (reference Without With Without/ Wetland Function and Performance Variables scale) Buffers Buffers With Buffers Maintain Characteristic Plant Community V,: Species composition V2: Species regeneration V3: Canopy cover V4:_ Tree density and basal area - - - - - - - - Performance Index M + V2 + V3 + V4)/4 1 1 1 1 - - - 1 1 0.5 1 1 - - - 0.88 1 1 1 1 - - - - 1 --- 0.5 - - - - - - 0.12 Maintain Spatial Habitat Structure V,: Density of standing dead trees 1 1 1 --- V2: Abundance of nest cavities 1 0.5 1 0.5 V3: The number and structure of vertical strata 1 1 1 --- V_,:_ :- Vegetation array (patchiness) 1_ _ _0.5_ - 1 - 0.5 Performance Index - - - - - IV, + V2 + V3 + VJ/4 1 0.75 1 0.25 Maintain Interspersion and Connectivity V,: Frequency of flooding 1 1 1 --- V2: Duration of flooding 1 1 1 --- V3: Surface roughness/microsite topography 1 1 1 --- V4: Hydraulic connections between main channels, 1 0.5 1 0.5 feeder tributaries, surface and subsurface V5: Contiguous vegetation cover and/or corridors between wetland and upland, between 1 0.5 1 0.5 channels, and between upstream and - - - downstream sources- - -------- --- --- ---- ------ Performance Index M + V2 + V3 + V4 + Vd/5 1 0.80 1 0.20 Table 8: continued Conceptual HGM Comparison of Functional Performance by Reference Wetlands With Upland Buffers/Ecotones and Reference Wetlands Without Upland Buffers/Ecotones Attainable Reference Reference Relative Condition Condition Condition Change (reference Without With Without/ scale) Buffers Buffers With Buffers Wetland Function and Performance Variables 11 1 u Maintain Distribution and Abundance of Vertebrates V,: Distribution and abundance of migratory and 1 1 1 --- resident fishes V2: Distribution and abundance of herptiles unk unk unk unk V3: Distribution and abundance of resident and 1 0.5 1 0.5 migratory birds V4: Distribution and abundance of permanent and 1 0.5 1 0.5 seasonally resident mammals V5:_ Abundance of beaver 1 1 1 --- Performance Index 1 0.75 1 0.25 (V7 + V2 + V3 + V4 + V5)/5 Brinson et aL 1994, ESI 1994b C? 0 For example, the index for moderation of groundwater flow or discharge quantified in Table 7, is based on two variables; subsurface flow into the wetland and subsurface flow from the wetland to a confining layer or base flow. Based on field observations, sites that would maximally perform this function would contain groundwater seeps, ephemeral channels, and other drainage features at the edge of the wetland; contain meandering wet swales, which extend into adjacent uplands; and contain a permeable underlying stratigraphy. The indirect effects of this function on site characteristics include prolonged saturated soil conditions during summer months and longer growing seasons due to warmer soil temperatures during fall and winter months. Performance variables that change based on the condition of abutting uplands and ' wetland/upland ecotones include; the nature and extent of subsurface flow into the wetland; the condition of riparian transport and overland flow; species regeneration within approximately 500 feet of the wetland edge; the abundance of nest cavities within the entire system; hydraulic connections between minor channels and main channels; the presence of vegetated travel corridors; and the observed and documented differences in the distribution and abundance of birds and mammals. Therefore, relative change in performance indices suggests that wetland functions may decrease in performance by as much as 20 percent relative to a built-out condition (Table 1 8). Based on HGM methodology the capability of mitigation wetlands to perform long-term functions may decrease by as much as 20 percent if uplands buffers are removed or otherwise not considered as a total package. These calculations take into account only those tangible factors which readily have values assigned to them. Therefore, caution should be exercised in weighting only those functions listed. 5.2.2 Wetland Rapid Assessment Procedure (WRAP) ' Methodology The Wetland Rapid Assessment Procedure (WRAP) model was developed by the South Florida Water Management District to help evaluate wetland mitigation sites. (Miller and ' Gunsalus 1999). The model uses a matrix to establish a numerical score for broad ecological and antropogenic factors that influence wetland mitigation sites in south Florida. The WRAP model can be used to document baseline information prior to development. ' The model was modified slightly to account for geographical and biological differences between regions. The six WRAP variables (functions) include: wildlife utilization (WU), wetland overstory/shrub canopy (VO), wetland vegetative ground cover (VG), adjacent upland support/wetland buffer (AB), field indicators of wetland hydrology (HY), and water quality input and treatment systems (WQ). Each variable has a corresponding calibration description and score points. Wetlands are evaluated relative to maximum sustainable performance by assigning a rating of zero to three (3), among ecological predictors of functional performance. Incremental scoring by half (0.5) a point is allowed. Performance indices for various functions are scaled so that the maximum sustainable performance of the function is three (3). ' 65 ' Performance variables are entered into a mathematical formula to provide a performance index for a particular wetland function within the wetland study site. Each variable is scored, totaled, and divided by the total of the maximum score for that variable. The final rating score will be a number between 0 and 1. ' Both WRAP and HGM methodologies evalute changes in functional capacity. Unlike HGM however, WRAP can weight functions to measure the relative importance between functions. The anthropogenic value of any given function is a different concept than ' measuring a wetland's capacity to perform a function. The factor includes important societal considerations not captured by a single function alone. Issues such as watershed/ecosystem management issues, threatened species, and special adjacent land ' use designations. Relative weights are assigned to wetland functions by a series of weighting factors and equations. ' WRAP Application and Results Similar to HGM, WRAP provides a numeric predictor of the functional lift gained from wetland buffers. For this project, imminent development on adjacent slopes threatens the ' integrity of the upland/wetland buffer. The model was used to assess functional loss to the wetland, should such development take place. Table 8 depicts the relative performance values for the identified wetland functions using current and post ' development conditions. Table 8 WRAP Comparison of the raw functional performance scores and total unweighted scores using current and post-development conditions. Fianal Wildlife Ground Water Unweigh ighted Utilization Overstory Cover Buffer Hydrology Quality Scores ' Current Conditions 3 2.5 3 3 3 2.5 (Raw Score) Individual variable 1.0 0.83 1.0 1.0 1.0 0.83 rating score 0.94 Post-Development 2 2.5 3 1.5 2 1.5 (Raw Score) Individual variable 0.67 0.83 1.0 0.5 0.67 0.5 ' rating score 0.70 ' The following list of values was considered to assign relative weights to wetland functions, to yield a relative weighting criteria matrix. ' • Established watershed issues (water quality and sediment) • Benefits to Important Adjacent Areas ' • Scarce Habitat • Educational and Recreation Benefits 66 1 The total weight applied to each variable and final weighted scores are provided in Table 9. The final rating score assigned the Site wetland under current conditions is 0.93 and a final rating score of 0.64 post-development. This represents a 31 percent difference in functional value between current and post-development conditions. Table 9. Weighted scores for wetland under current conditions and developed conditions. ' Variable Total Weight Wildlife Utilization 0.205 Overstory 0.1 Ground Cover 0.1 Buffer 0.205 Hydrology 0.164 Water Quality 0.205 ' Final Rating Score Scoring Under Current Conditions (Pure WRAP Variables) 0.62 0.25 0.30 0.62 0.49 0.51 0.93 Scoring Under Developed Conditions (Pure WRAP Variables 0.41 0.25 0.3 0.31 0.33 0.33 0.64 ' 5.3 CONCLUSION The Mingo Creek Restoration and Conservation Management Plan utilizes an ecosystem approach to wetland preservation and enhancement, thereby maintaining the array of habitat opportunities and physical properties historically associated with wetlands including the adjoining upland buffer matrix. The functional evaluations and supporting research indicate that upland buffers and ecotones provide significant functional lift for wetlands. As suggested in HGM and WRAP, a 20 to 31 percent decrease in wetland functions may be realized if development occurs on adjacent upland areas. The difference in function strongly underscores the importance of upland forests as biological buffer for wetlands, and consequently justifies the allocation of resources toward preservation credits of the upland/wetland buffer matrix within the Site. 67 6.0 SUMMARY AND RECOMMENDATIONS NCDOT proposes to establish the Mingo Creek Mitigation Site as up-front, on-site, compensatory mitigation for transportation improvements associated with the proposed US 64 Knightdale Bypass. The approximately 205-acre site is located in central Wake County. The Site contains streams, adjacent wetlands, forested riparian buffers, forested uplands, and recreational and educational opportunities in a contiguous, relatively undisturbed tract extending on both sides of Mingo Creek just above its confluence with the Neuse River. The proposed US 64 Knightdale Bypass is planned to extend eastward from 1-440 (Raleigh Beltline) across the Neuse River to US 64 (Wendell Bypass) near SR 1003 (Rolesville Road). The Bypass will cross the Site from the northwest corner to the southeastern border and to an intersection with Hodge Road (SR 2516) in the vicinity of the ' southeastern corner of the Site. The Bypass will continue approximately another 1.5 mile east to an intersection with the proposed Wake Outer Loop. An interchange study of the proposed US 64 Knightdale Bypass (Stantec 2001) indicates likely future development in this region resulting from these road projects. If the mitigation site is not protected, this study predicts the eastern portion of the Site will be developed for mixed use (office, retail/service, hotel, meeting facilities, and multifamily housing) and part of the western portion of the Site will remain as open space while the majority will be developed as low- density residential housing. ' Recommendations for mitigation at the Site include 1) purchase and arrangement for long- term management of the entire tract including a total of 28.8 acres of vegetated wetlands, a total of 6590 linear feet of streams, and 22 acres of forested buffer (163 acres biological ' buffer) preservation adjacent to these jurisdictional areas; 2) restoration of 1200 linear feet of stream (2:1 ratio); 3) enhancement of 2400 linear feet of stream (3:1 ratio); 4) restoration/enhancement of 1.5 acres of vegetated wetland; 5) preservation of the ' remaining 27.3 acres of vegetated wetlands (2:1 ratio) and the remaining 2990 linear feet of streams (10:1 ratio). The proposed mitigation will protect and manage a stream/wetland complex and adjacent riparian buffers and upland forest at a strategic location in the embattled Neuse River basin. 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Richardson, C.J. 1985. Mechanisms controlling phosphorous retention capacity in freshwater wetlands. Science 228:1424-1427. Rohde, F.C., R.G. Arndt, D.G. Lindquist, and J.F. Parnell. 1994. Freshwater Fishes of the Carolinas, Virginia, Maryland, & Delaware. The University of North Carolina Press, Chapel Hill, NC. 222 pp. Rosgen, D. 1996. Applied River Morphology. Wildland Hydrology (Publisher). Pagosa Springs, Colorado. Schafale, M. P., A.S. Weakley. 1990. Classification of the Natural Communities of North Carolina: Third Approximation, NC Natural Heritage Program, Division of Parks and Recreation, NC DEM, Raleigh NC. Schwan, M.W. 1985. A study of land use activities and their relationship to the sport fish resources in Alaska. Volume 26, Study D-I, Job D-I-B. Alaska Dept. of Fish and Game, Juneau, Alaska. Soil Conservation Service (SCS). 1970. Soil survey of Wake County, North Carolina, U.S. Department of Agriculture. 118 pp. Stantec Consulting Services Inc. 2001. 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Wetlands 14(3): 166-173, September 1994. Weakley, A. 1993. Flora of the Carolinas and Virginia. Working Draft. N.C. Department of Environment, Health, and Natural Resources (DEHNR): Natural Heritage Program, Raleigh, NC. Webster, W.D., J.F. Parnell, and W.C. Biggs, Jr. 1985. Mammals of the Carolinas, Virginia, and Maryland. The University of North Carolina Press, Chapel Hill, NC. 255 pp. Wetlands Restoration Program (WRP). 1996. Basinwide Wetlands and Riparian Restoration Plan for the Neuse River Basin. N.C. Department of Environment and Natural Resources, Division of Water Quality. Whitcomb R.F., J.F. Lynch, P.A. Opler, and C.S. Robbins. 1976. Island Biogeography and Conservation: Strategy and Limitations. Science 193:1030-32. Wilson, L. A. 1995. The land Manager's Guide to the Amphibians and Reptiles of the South. The Nature Conservancy, Southeastern Region, Chapel Hill, NC, 360 pages. Young, C.E. and R.A. Klawitter. 1968. Hydrology of wetland forest watersheds. Pg. 29- 38 in Proceedings: Hydrology in Water Resources Management. Report no. 4. Water Resources Institute, Clemson University, Clemson S.C. 11 74 1 8.0 APPENDICES r t i I Fj 1 75 t M t 1 1 1 1 1 1 r 1 1 1 APPENDIX A General Wetland Functional Assessment Methodology and Forms 76 1 1 1 i i t A t r: t r r WETLAND FUNCTIONAL ASSESSMENT Aynamic Surface Water Storage - - - A__ Freq. of flooding . -B. Average depth C.' Surface roughness D. Vegetation roughness Long--term Surface Water Storage E. Presence-of-water C. - Topographic relief Energy Dissipation F. Reduction flow velocity G. Freq. of surface water with velocity C. Surface roughness Nutrient Cycling - . - H._ Netpri n. prod. (potential) 1. Detrital turnover (floor debris) Removal of Elements and-Compounds (long-term accum. of elements from incoming water) J.- Overbank flooding (from wetland) K. Riparian transport (from uplands, overland flow and groundwater discharge) I. Microbial activity H. Vegetation sink C. Topographic relief - Retention of Inorganic Particulates - J. Freq. of flooding from wetlands K. Overland flow from uplands C. -Surface roughness L. -Retained sediments Organic Carbon Export J. Freq. of flooding (from wetland) K. Riparian transport (from upland) - M. Surface connection with wetland 1. Organic matter (detrital turnover) Maintain Characteristic Plant Community (dynamics and structure) Species composition list (no measurement) N. Saplings of canopy species 0. Canopy cover . -P. Tree density/basal area (inidcator of maturity) Maintain Characteristic Detrital Biomass Q. Standing dead trees R. Abundance of down and dead trees S. Logs in several stages of decomposition T. Fine woody debris in stream channels Spatial Habitat Structure Q. Density-of standing dead trees U. -Abundance of nest cavities V. Strata W. 'Vegetation patchiness X. Canopy gaps (maturity) Maintain Interspersion and Connectivity A. Freq. of flooding E. Duration of flooding C. Surface roughness M. Hydraulic connections Y. Vegetated corridors (up and wet, up and down) 1 1 I t 1 1 N O U co O ca U_ z O LL O_ W _ -O ? a ? C cZ C 75 U y N ui t Q Q O Z O O (D Z n ca LL N o? Z y J .? W N N a? c t O O 4+ co 4- a? i N N U c L O a? U co U) 0 +r a? co (o 21 4+ c m 0 a c co c 0 cu O LA O > N C i 4- C N ? U O y ? N O O 41 N O' _p C cp O 0 co > co m co c0 (D Ea O = O 'a C C 0 E O c co O 0 > i C) ? O d 41 O 41 41 > c 7 a O c fl. O N i y (o .Q O z N C N 0 (o v- C O O ++ N fII CD U c i? C a N a vi . cm c Q O O co N CM .. M N O' C > C y i a U N Q O N y .Q N =O W , 00 > N 7 0 O .C + N L O ? N U O > ? + + U t c m c c ? a ? c ,p O O ? C i Y U co ar U fo .Q fo N c o 0) > N a cu U> 0 O O a N co a ?a co 0) 41 co O O U N C ` a c W O O C Q) .r. C O -0 U O> C N +1 to y O O Co > N N U p C t' a c . >, a +1 41 CO .p N U O N U N N N N U m ' C O 0 0 0 0 N > O O O i N C ?NMCttl? ` a; .;, N N N N N N CO N N N ~ N c N co co m m co a a n 000UU c . E _ U O a) o 03 cc > 1 1 F l 1 1 l I w t i t t i r r F W - W" c W- Y Z w U)) W Q J Q . Z O _ z LL O U O O OI 01 O a) cc m m Q U - 4? Q) co ° a M Y N c O 4? U L a) C a) 2? 0- y ? E =0 () o a) a) Y -f Y L L U) a) O -O i 0 i L C O 0 0 M M N o - m .. O O- E N ° w m +• > m m ° E _o '- to m co a LO co 75 7 O Q X a) 0 co tm cm a) O? m d U 0; O N O cn t a) a --C ?.: E r E n n to >. ca t o a? U - m w- L O a) ?d cu c a y E o (D ?. co 0 CC CD =+) -0 co LO (D 0 CU cu To (D E (a =cn E ° "MC cLo E c u U M ° tr' ?C L l/) fA L L to cu- .C V V M N E N t? C _ m m m O m m m ?p m m m m m C O a i= y C L C C C C C C C o d ) . a) a) N O O O O O a) O O O +'C+ a) O OD O O p 0 \ 0 0 0 0 CL 0 a to o ` CL m w 00 CL co to C O_ Q) S2 0, w N CL N N CL Q O N w U CL 0 6 CL co m m E iz m E _ - co 2 m m co m m o m m co r 2 to ca .C .C N v7t N L U_ .c t.? t .?p A.Ct? .C 6-2 F, t () f6 f0 ? C C CO a) (D c`ts a a) a) a) a) a) a) a) m a) O O a t1 m O O O O O O O O O O O O O O c c c c c c c c c c c c c a) C y > m a) + O m O U a, 0 w > a E a? Q a? v cn c C N N U O O N z- O O .2 1- M cn Q V) O O U 4- O >. y +L+ .C CL C co L (!? -0 -C O> 'a L jO C O C/3 2C U c U) C co ^ i a) C C U > ii E co L -0 a O L- •L cn O 4+ O O O Q- O E C D U a) m a O w >C 0 4) > > 4- CD CL > O O L L +J m° «- rL m O 0 0 y a U co a) += U -C co a CL) (MO ma .- 3: a -E C a) ?>?a) _C Co >,m ?m a -0 (o cc r a -a E -0 o (13 0. a) o CL .0 CD (D > ID CU .t Qcn>ti>tLZOu.t7C? cCAUF-c?QO?Zcn>U> Q Co U 6 tai ti 6 = _ a Y J ? Z O a: 0 C? O F- » § >C > ?O i 1 1 1 W W N 1-- Q Z CW G N N W (A U) J Z O_ H Z D LL c J W cv U J C a? 0 ^rn 1 co b A v 1 N a; Q H C m MI C MI? I? olol ?I?I 11 yl M II II II II II II II II II II II N oI , ?-I-1 + ` ai ?I -I ?I I 4IoI I o'I o -H -I n l-- I I I ?I I I II ii II o II 11 II II II II II II _ X + 3: + + + U U ±U? CL >U 00UC7 -YYY Oi= DW QLu L A N ca E O N j y E O m 0 U c o. •C Co ? O.4-0 0 U o c ? c?v O o v *' •? U G 0 (n cn L. U i -p O a .a m H y O 4m c CL t°at UO- I ; c X z • •y i • O O C U O 0 O m m W ? ' +N+ iO+ i + O IC ';= co v •0 N C or- ca L L ea a O 7 (n y W .0 E 0 4a cB c0 m -C ?.+ 4- V(n N 'Cf U ? V 0 U , UU m == _ O _ C •? 4-J a V ++ ca O_ O > ++ •? 0 c C _ +O+ +O•+ c to ca i?+ a. ? •L O r Cm D ' O •? ' • >- O c _ 0 .J W O 0 m a m z cr cc 0 R n. c 0. CO Q cn > M . ? I? o 0 II II II II II II II II II II II M O M of ol_I + + ?I?`I ?I IvI W + + + + + + + + + -1 + + + + + + + + + + + pl0 GI`"I O -4- II II II II II II II II II II II z W CO) S W X N U + + a ?-! o + _ 1- ?: 2 Z U U m C. (A > U p + + + + + + + + + O cc O w m L) (D U + + + + + + + + + + + Q uJ U_ _ n z d d Q LL -?' O >. 4- U) Q N ? co > o W `a m co O_ U p' •? cv. N M. o o N1 v m ` o U± o o O o ° °_ c'? U _ in U i co m 'C H - O N S ? .r.. cC ++ U U ? ? ?? m 4-0 +J C) 0 C* 0 4-1 -E CL Ag .9 o C o x N i •N 7 i m O cC •? E O W U U (n Q 4-J (a N Q. v ,C O C o m m O cn M Ca 4-01 0 o -r- -c H- vm ?•?' ?U o cU :cUU ca ca = o ?tx a_ i -p V ++ ?p O O O U l0 C __ ,?, .9 .9 E CD cc m CL (a =oJW mzccoc0 a22 Q(n2 > t 1 1 1 1 1 Sm T Vl w w N i- Q O z W N N W N N J z O_ H U z m w O J F- W E O a+ U O J c co m i 1 m co D m C. c ca m II II II L^I Ln I lf'I + + + II 11 II O U U m U C7 Qww 0 m ? L e` 0 *1 co c L ? cc N C aiOw o l0 L t? ? cn 'm wu Ep °•E:: a m L O >? L S?-i w 11 II II II ?I. + II ii II (I 4 ° I "I II 11 "I + ?I of II II II II + ? '?I ?fll of I + + ul II II X >- + + J F- + ± V c. cn > U + + + + + + + _ -Z 1& O CC D w zd dQ > _ O m UO CL E O U Ta O o M o v c G U ;r m c a U U V , r N O cr c Q• y cc •L •L +, ` 'vl c t (a W U U N a E ?cmc0 "? «•«` c E j p 0 ?° '?' U U 'o L s c - c c o == c 0 a E 0 E Co Eza:mo EMM Q62 > mil, i 1 1 I 1 1 1 t H W W N N Q O H Z W N N W N N J z O H V Z m LL O Q J W ry R O c0 U O J 'O C CO m a C td m Ir"n II 11 II II II II II 1( II II II ????+ `I?Il,nl ?I ?nl._I + + + + + + + II _IInl + + + + + + + + + + + II I! II II II II 11 II II If II x} O + U U ±L) ?-N >U + + + + + + + + + Ca - Y Y Y O CC O W QWLL =7?? ZO CJQ fA = cC O = O m E o_ G m c V N m « ' C o 0 0 0 'r U C N U z m ch 0 .0 a c CL a_ O m c ca m ? ?O lC 7 O C1 ` ??, 'C O U U ai C V O ' C C m X '`' 'C L i 4-0 O m 0 " m E O ui 0 0 n. E E %I- C ?. o- v W 0 r c0 co +? +O+ O 0 U O cn 'y . EE >. 0 0 8 U U +' U U ea 0 C C 0? O L r- C 2 a C C == C ?,, o E cC . O C > O c • C .. ? C i`.r C •? p =O-iul azlici0 0.22 Qcn2 > 1 1 A t 1 i 1 i r W W N H Q O H Z W 2 CO N W N CA J Z O V Z n U. 0 Q J W CC 0 'r U O J C O O a 1•- C m m I -I -I NI ?I ?I MINI ?I IYNI N Il II 11 II II II II II 1I it II ; _? + ++ od1`I of ii I II it '_{,"I °I II II II II { II II { { II II X } U U ± U? a m > U + + + + + + + + + mUC7 -YYY Oar W Q W LL S -? -? -? d Z d Q .a O O G E c ? ++ it O_ m m d Q. O U C H d O 4-+ O U U .r O O U G _ N 4.1 cc m -p a ?? V) (D c0 c a a O m r i +y+ O co ?? . O U` 'C O U V N m +7+ C U O ? r,. = V C c0 a O ? .i •?' L ` O v W C C C E Cn m N ? c o V i 7 2. ai C7 W ` 6- •+ to M + «+ .0+ m O V O U) 'y V (n to U '?' y V 0 0 0 O t L ?' U U r.+ ea ca C C ? U ? ? V ?,. ? p V A C C ' ' S S C . *, O N C ? ?, CD 0 _ ca cc C C O O ° 'YO C C ?? E m 0 :3 0) CD = O c0 •cII o c0 ' s0 iu mZa:QO a.22 Q(n2 > 1 1 1 i 1 1 1 1 1 1 1 1 1 1 Cf D `? W W N F- Q Z W N N W Cl) N J Z O V Z n U. in J W 3.1 II II II II II II II Vin, u'I v j i ? m ? (ill 'I 1 `I ?I ? I II 11 11 it II II II U • U U ± U ? + + CD (D + + + + + + -YYY + + + + -?- Qu,U- 2nn-? N ? A m o m M & E > - 4 VJ U ^ U) ca 3 ?o D ca N V i m c ? o•t°x O 0 o 0 V ° o "- `W m E o cC N i ? O. C C o v l1J ? 0 O CL fA _ 8 -j H o E ?' m o sU c U M c 10 c ? U 6. C •E r ++ O 0 0> «U .. cs m 37. m ?. > o C SD -j w O m y CDZmcc0 t`? _I N ( NI i??, II II 11 II ? I + + + + + I II II CL cn > U O2 Dw + + + + Zd dQ E o E v CL m ? v ? O N r CO ao 'D m ? m U U ? C V 1 y O C C U V Q coo w L r +r «• O U U U ao ca C ca = 2 c w _?;? TQ co ;° E-o? cc a?? CO acn2 > 1 1 1 1 1 1 1 1 1 t 1 1 1 1 1 1 1 1 1 W W N F- Q O Z W 2 CO) co W N N J Z O V LL G Q J W ,n t O E O U ? J !- >CD >0 7 N° It 11 II _I + + mill it It II NI?I INI II II II II II Il II it U +J- U U ±U? + + + + + mL)o -YYY Q W LL =77? N 'C no p m ? O o o cn E O U L Cl) 'O c0 a? c p ca N gy ., m U n o C a C• p X CD m O W C Co 7 d m C O ° U W 7 cn 'N E >• - ,O c`a N E a? U o U U IM p O c U C>. U , c m E o c r (D m SO?LU mZcc OCO NI r? M??I II 11 II II t +I nI ±I II II it 11 X a cn > U 0 cr Lu Zd dQ C ca E = p L E p O U C' U Tc c m V U ? ? C ? t A N U C C «m+ N OD- L- C.D ? C C = = C ?. T + N ? C _ c 4- ? C Cc C13 c m D 4) a2 2 Qcn2 > Cl u 1-1 1 1 APPENDIX B DEM Rating Forms 77 Aiy o "Crcc?- -TC. (I "e_ 51sf'm i ' Wetland Rating Worksheet Project name V%4 n GQ& . Nearest road Q of%G r Countys WIXV'E Name of Evaluator Esc Date ±-3-at Wetland location Adjacent land use (within 1/2 mile u stream) _ on pond or lake forested/natural vegetation % Yo"n perennial stream agriculture, urban/suburban _10% _ on intermittent stream impervious surface S % _ within interstream divide _ other Dominant Vegetation Soil Series V1 t 6AlLee- 06vJ Ci 6 (1) CA YU- SAD . _ predominantly organic-humus. •-? muck, or peat (2) JwinGV.45 5 tip. predominantly mineral- non-sandy ?predominantly sandy (3) :•m bay S Coc MS k Flooding and Wetness _ semipermanently to permanently flooded or inundated Hydraulic Factors _ seasonally flooded or inundated _ steep topography _ intermittently flooded or temporary 9ched or channelized surface water .1/wetland width >/= 50 feet _ no evidence of flooding or surface water Wetland Type (select one) _ Bottomland hardwood forest _ Pine savanna .. Headwater forest ;/Freshwater marsh _ Swamp forest _ Bogtfen _ Wet flat _ Ephemeral wetland _ Pocosin _ Other *The rating system cannot be applied to salt or brackish marshes Water storage * 4 = ! & Bank/Shoreline stabilization * 4 = IZ Total score Pollutant removal * 5 = 2.0 7 Wildlife habitat Aquatic life value * 2 = * 4 b Recreation/Education * 1 watersh d i if i i i dd I d > 10% di b i / ve e an nt n sens t po nonpo stur nt ance within 1 A 2 mile upstream G Wetland Rating Worksheet Sys *1:' 3 Project name Ai njo Oeek- Nearest road }fi p Jag Kpad County. Wtc14& Name of Evaluator SSG Date -7-3-01 Wetland location Adjacent land use (within M mile upstream) _ on pond or lake forested/natural vegetation 80 % ybn perennial stream _ on intermittent stream agriculture, urban/suburban 190/0 impervious surface S % _ within interstream divide _ other D i V om nant egetation SoiI Series We,hJVA-G "k ?I t ? (1) _ Cara spy. _ predominantly organic-humus. muck, or peat (2) Jwv%c ks _ predominantly mineral- non-sandy _ predominantly sandy (3) l hytPAh" Ga. POW L-C Flooding and Wetness _?sQpemmnently to permanently flooded or inundated Hydraulic Factors _ seasonally flooded or inundated _ steep topography _ intermittently flooded or temporary _ ditched or channelized surface water t/wetland width >/= 50 feet _ no evidence of flooding or surface water Wetland Type (select one) _ Bottomland hardwood forest _ Pine savanna .. Headwater forest yPreshwater marsh _ Swamp forest _ Bogtfen _ Wet flat _ Ephemeral wetland _ Pocosin _ Other *The rating system cannot be applied to salt or brackish marshes Water storage 7t" * 4 = 2.0 Bank/Shoreline stabilization t? * 4 = 20 Total score Pollutant removal- * 5 = ZO Wildlife habitat Aquatic life value 2 = 10 * 4 = Recreation/Education_ * 1 = h d i n sensitive waters e Add 1 point if and >10% nonpoint disturbance within 1/2 mile upstream t d 1 1 fl 1 1 1 1 Wetland Rating Worksheet Project name X M<j z? cf ee,i L. Nearest road_IALLci, County??? e_ Name of Evaluator E5 L Date I - 3 u 1 Wetland location _,on pond or lake Von perennial stream on intermittent stream _ within interstream divide other Soil Series _Wo-kAd Lte' Win.-4. predominantly organic-humus, muck, or peat predominantly mineral- non-sandy ?edominantly sandy Hydraulic Factors _ steep topography ditched or channelized Zwetland- width >/= 50 feet Adjacent land use (within 1/2 mile upstream) forested/natural vegetation --7-5 % agriculture, urban/suburbanZ 5 O/o impervious surface % Dominant Vegetation (1) A(A.5 he s (2) e.5 J (3) Ca +a Flooding and Wetness ,/semipermanently to permanently flooded or inundated _ seasonally flooded or inundated _ intermittently flooded or temporary surface water _ no evidence of flooding or surface water Wetland Type (select one) _ Bottomland hardwood forest _ Pine savanna Headwater forest freshwater marsh _ Swamp forest _ Bog/fen _ Wet flat _ Ephemeral wetland _ Pocosin _ Other *The rating system cannot be applied to salt or brackish marshes Water storage 4 * 4 = 1 U Bank/Shoreline stabilization 5 * 4 = 2-0 Pollutant removal .15_ * 5 = 5 Wildlife habitat 1_ * 2 = 2 Aquatic life value 5 * 4 = ? 0 Recreation/Education G * 1 = IC Add 1 point if in sensitive watershed and >I 0% nonpoint disturbance within 1/2 mile upstream Total score '3 -3 1 1 1 1 1 1 1 i Wetland Rating Worksheet Project name L i'tl Nearest road 14 P dG ?_7 'V? a z Name of Evaluator S C. Date ! _-3 -- 01 County f _J Wetland location Adjacent land use (within 1/2 mile upstream) on pond or lake forested/natural vegetation - ?;Sn perennial stream agriculture, urban/suburbanS _o , n intermittent stream impervious surface % within interstream divide _ other Dominant Vegetation Soil Series We-haA Lee nncL 6i bb _ predominantly organic-humus, muck, or peat _ predominantly mineral- non-sandy predominantly sandy t 1 1 (1) ,X Id e, (2) (3) Flooding and Wetness _ ;6,emipermanently to permanently flooded or inundated Hydraulic Factors _ seasonally flooded or inundated steep- topography _ intermittently flooded or temporary itched or channelized surface water - 'wetland width >/= 50 feet _ no evidence of flooding or surface water Wetland Type (select one) ?Bottomland hardwood forest _ Pine savanna Headwater-forest _ Freshwater marsh _ Swamp forest _ Bog/fen _ Wet flat _ Ephemeral wetland _ Pocosin _ Other *The rating system cannot be applied to salt or brackish marshes Water storage * 4 = . ?- Bank/Shoreline stabilization '' * 4 Total score Pollutant removal * 5 = i 0 Wildlife habitat- * 2 = 9 Aquatic life value * 4 = .21 Recreation/Education 1 * 1 = 1 Add 1 point if in sensitive watershed and >l0% nonpoint disturbance within 1/2 mile upstream 1 1 L Sysk.m 12 Wetland Rating Worksheet Project name Ki (12n CYFj k . Nearest road O? c 0_ KCL County "WoL a Name of Evaluator - Date J: ? I Wetland location _ on pond or lake Adjacent land use (within 1/2 mile upstream) forested/natural vegetation r 6o % Von perennial stream agriculture, urban/suburban on intermittent stream impervious surface % = within interstream divide other Dominant Vegetation Soil Series WJrSlnsltv?? (1) _ predominantly organic-humus, muck, or peat (2)? ;predominantly mineral- non-sandy ¦ _ predominantly sandy (3) Qak. Flooding and Wetness _ semipermanently to permanently flooded H d li F t or inundated Z ll fl d d i d d y rau ors c ac easona y oo e or nun ate r _ steep topography _ intermittently flooded or temporary _ ditched or channelized surface water _ wetland width >/= 50 feet _ no evidence of flooding or surface water Wetland Type (select one) Bottomland hardwood forest _ = Pine savanna Headwater forest Freshwater marsh _ Swamp forest _ Bog/fen - Wet flat - Ephemeral wetland Pocosin Other *The rating system cannot be applied to salt or brackish marshes Water storage 3 * 4 = i Bank/Shoreline stabilization _ - * 4 = 9 Total score Pollutant removal 1_ * 5 = 15 4s Wildlife habitat 4 * 2 = 9 Aquatic life value 4 = Recreation/Education C * 1 = Add I point if in sensitive watershed and >10% nonpoint disturbance within 1/2 mile upstream r 1 1 1 1 'J F 1 5 y,4,, -k J3 Wetland Rating Worksheet Project name A(m o ?y&k_ Nearest road RD u _ )9, J . County-W Name of Evaluator ES Date !- _ 3- 0 i Wetland location on pond or lake ;,6"n perennial stream _ on intermittent stream _ within interstream divide other - Soil Series IAfor56CUvN predominantly organic-humus, muck, or peat VP'redominantly mineral- non-sandy _ predominantly sandy Adjacent land use (within 1/2 mile upstream) forested/natural vegetation 1 C2c'? O/o agriculture, urban/suburban impervious surface % Dominant Vegetation (1) (2) (3) Flooding and Wetness _ semipermanently to permanently flooded or inundated Hydraulic Factors _ seasonally flooded or inundated _ steep topography _ intermittently flooded or temporary ditched or channelized surface water _ _ wetland width >/= 50-feet Zo evidence of flooding or surface water Wetland Type (select one) Bottomland hardwood forest Pine savanna 04eadwater forest _ _ Freshwater marsh _ Swamp forest _ Bog/fen _ Wet flat _ Ephemeral wetland Pocosin Other *The rating system cannot be applied to salt or brackish marshes Water storage 2- * 4 9 Bank/Shoreline stabilization * 4 = i (0 Total score Pollutant removal J- * 5 = 5 2q Wildlife habitat * 2 = lei Aquatic life value 4 = Recreation/Education c? * 1 = C) Add I point if in sensitive watershed and >10% nonpoint disturbance within 1/2 mile upstream 1 _ - _ _ -_ - - = Wetland Rating Worksheet Project name J V l? +r1 u t? +r a ,lL Nearest road ? sZ . Coun.a- Name of Evaluator C G Date :t _ _ Wetland locatlon - - Adjacent land use (within 1/2 mile upstream) on-pond or lake - -forested/natural vegetation 00 % - on perennial stream agriculture, urban/suburban % - - - on .intermittent stream - impervious surface % - - = - _within interstream divide _ Dominant Vegetation - -Soil Series O( C? h(Ut\n (1) ? C Z ?Cil1?iV? predominantly organic humus, _ r ' - muck, or peat (2) Zpredominantly mineral- non-sandy - pradominantly sandy (3) Flooding and Wetness _.semiperrnanently to permanently flooded or inundated - - Hydraulic Factors steep topography _ seasonally flooded or inundated _ intermittently flooded or temporary tched or channelized surface water _ wetland width >/= 50-feet _ no evidence of flooding or-surface water - - Wetland Type (select one) _ Bottomland hardwood forest -Pine savanna ` - Z eadwater-forest _ Freshwater marsh _ Swamp forest _ Bog/fen Wet flat Pocosin _ Ephemeral wetland Other *Me rating system cannot be applied to salt or brackish marshes Water storage * 4 = `??` Bank/Shoreline stabilization 4 Total score Pollutant removal Wildlife habitat * 5 2 = Aquatic life value- 4 Recreation/Education C * 1 = -? Add 1 point if in sensitive watershed and >I 0% nonpoint disturbance within 1 /2 mile upstream 11 1 1 'lJ 1 1 1 APPENDIX C Species Lists for Plant Communities 78 1 1 1 1 1 j i 1 I Mesic-Mixed Hardwood Forest Sourwood (Oxydendrum arboreum) Red maple (Acer rubrum) White oak (Quercus alba) Yellow poplar (Driodendron tulipifera) Mockernut hickory (Carya alba) American hazelnut (Corylus americana) Water oak (Quercus nigra) Blackgum (Nyssa sylvatica) Ironwood (Carpinus caroliniana) Parsley hawthorn (Crataegus marshallii) Elephants foot (Elephantopus tomentosus) Poison ivy (Toxicodendron radicans) Maple leaf viburnum (Viburnum acerifolium) Black haw (Viburnum prunifolium) Muscadine grape (Vitis rotundifolia) Black cherry (Prunus serotina) American holly (Ilex opaca) Service berry (Amelanchier arborea) Deerberry (Vaccinium stamineum) Flowering dogwood (Cornus florida) Pinxter-flower (Rhododendron periclymenoides) American beech (Fagus grandifolia) Southern sugar maple (Acer barbatum) Hop-hornbeam (Ostrya virginiana) DELMesic Oak-Hickory Forest ' Black cherry (Prunus serotina) Flowering dogwood (Cornus florida) Loblolly pine (Pinus taeda) Yellow poplar (Liriodendron tulipifera) Sweetgum (Liquidambar styraciflua) Hawthorn (Crataegus spp.) White oak (Quercus alba) Black oak (Q. velutina) Scarlet oak (Q. coccinea) Southern red oak (Q. falcata) Eastern red cedar (Juniperus virginiana) Red mulberry (Morus rubra) ' Ebony spleenwort (Asplenium platyneuron) Rattlesnake fern (Botrychium virginianum) ' Blackgum (Nyssa sylvatica) St. Johns wort (Hypericum spp.) Yellow jessamine (Gelsemium sempervirens) Virginia creeper (Parthenocissus quinquefolia) Service berry (Amelanchier arborea) Sparkleberry (Vaccinium arboreum) ' Persimmon (Diospyros virginiana) Strawberry bush (Euonymous americana) Snake root (Sanicula canadensis) Kidney-leaf rosinweed (Silphium compositum) American hazelnut (Corylus americana) ' Downy arrowwood (Viburnum rafinesquianum) Poison ivy (Toxicodendron radicans) Paw-paw (Asimina triloba) Ironwood (Carpinus caroliniana) False foxglove (Aureolaria virginica) Maple leaf viburnum (Viburnum acerifolium) 1 1 1 11 11 1 F I 1 ? 11 Semipermanent Impoundment (FreshWater Marsh) Red maple (Acer rubrum) Arrow-wood (Viburnum dentatum) Possum-haw (V. nudum) Arrow arum (Peltandra virginica) Asiatic dayflower (Murdannia keisak) Virginia-willow (Itea virginica) Soft rush (Juncus effusus) Jewelweed (Impatiens capensis) Muscadine grape (Vitis rotundifolia) Silky dogwood (Cornus amomum) Wool grass (Scirpus cyperinus) Lizard's tail (Saururus cernuus) Arrow-leaf tearthumb (Polygonum sagittatum) Black gum (Nyssa sylvatica) American potato-bean (Apios americana) Buttonbush (Cephalanthus occidentalis) Water hemlock (Cicuta maculata) Poison ivy (Toxicodendron radicans) Elderberry (Sambucus canadensis) Poison sumac (Toxicodendron vernix) Queen-of-the-meadow (Eupatorium fistulosum) Common boneset (Eupatorium perfoliatum) Winterberry (Ilex verticillata) Black willow (Salix nigra) River birch (Betula nigra) Tag alder (Alnus serrulata) Arrowhead (Sagittaria spp.) Common cattail (Typha latifolia) False-nettle (Boehmeria cylindrica) Swamp smartweed (Polygonum hydropiperoides) Water-horehound (Lycopus virginicus) Titi (Cyrilla racemiflora) Swamp chestnut oak (Quercus michauxii) Bitternut hickory (Carya cordiformis) I' Dry Oak-Hickory Forest 1 1 t Black oak (Quercus velutina) Scarlet oak (Q. coccinea) Southern red oak (Q. falcata) Post oak (Q. stellata) Mimosa (Albizia julibrissin) Black cherry (Prunus serotina) Flowering dogwood (Cornus florida) Loblolly pine (Pinus taeda) Shortleaf pine (P. echinata) Downy arrowwood (Viburnum rafinesquianum) False foxglove (Aureolaria virginica) Maple leaf viburnum (Viburnum acerifolium) Virginia creeper (Parthenocissus quinquefolia) Saw-tooth blackberry (Rubus argutus) Poison ivy (Toxicodendron radicans) Autumn olive (Elaeagnus umbellata) Groundsel-tree (Baccharis halimifolia) Tree-of-heaven (Ailanthus altissima) Piedmont Bottomland Hardwood Forest ' River birch (Betula nigra) Green ash (Fraxinus pennsylvanica) American elm (Ulmus americana) Box elder (Acer negundo) Sycamore (Platanus occidentalis) Cherrybark oak (Quercus pagodifolia) ' False-nettle (Boehmeria cylindrica) Asiatic dayflower (Murdannia keisak) ' Arrow arum (Peltandra virginica) Willow oak (Quercus phellos) Deciduous holly (Ilex decidua) Swamp smartweed (Polygonum hydropiperoides) Poison ivy (Toxicodendron radicans) 1 i 0 1 1 E P 1 Piedmont Alluvial Forest Crossvine (Bignonia capreolata) American elm (Ulmus americana) Yellow poplar (Liriodendron tulipifera) Sweetgum (Liquidambar styraciflua) Flowering dogwood (Cornus florida) Sycamore (Platanus occidentalis) Sweet Bay (Magnolia virginiana) Trumpet creeper (Campsis radicans) Winged elm (Mmus alata) Virginia creeper (Parthenocissus quinquefolia) Silky dogwood (Cornus amomum) Japanese honeysuckle (Lonicera japonica) Chinese privet (Ligustrum sinense) Arrow-wood (Viburnum dentatum) Possum-haw (V. nudum) Greenbrier (Smilax rotundifolia) Southern lady fern (Athyrium filix femina) Netted chainfern (Woodwardia areolata) Jewelweed (Impatiens capensis) Elderberry (Sambucus canadensis) Black cherry (Prunus serotina) American holly (Ilex opaca) Goldenrod (Solidago spp.) Red maple (Acer rubrum) False-nettle (Boehmeria cylindrica) Parsley hawthorn (Crataegus marshallii) 1 n 1 h L 1 H Low Elevation Seen Highbush blueberry (Vaccinium corymbosum) Possum haw (Viburnum nudum) Netted chainfern (Woodwardia areolata) False Solomon's seal (Maianthemum racemosum) Poison sumac (Toxicodendron vernix) White ash (Fraxinus americana) Southern lady fern (Athyrium asplenioides) Greenbriar (Smilax rotundifolia) Tag alder (Alnus serrulata) Jack-in-the-pulpit (Arisaema triphyllum) Winter berry (Ilex verticillata) Microstegium (Microstegium vimineum) Winged elm (Ulmus alata) Lizard's tail (Saururus cernuus) Jewelweed (Impatiens capensis) American burr reed (Sparganium americanum) Poison ivy (Toxicodendron radicans) Elderberry (Sambucus canadensis) Sweet bay (Magnolia virginiana) Cinnamon fern (Osmunda cinnamomea) Royal fern (Osmunda regalis) Soft rush (Juncus effusus) Yellow poplar (Liriodendron tulipifera) River birch (Betula nigra) Black willow (Salix nigra) Giant cane (Arundinaria gigantea) Sensitive fern (Onoclea sensibilis) Sweetgum (Liquidambar styraciflua) Japanese honeysuckle (Lonicera japonica) Water-horehound (Lycopus virginicus) False-nettle (Boehmeria cylindrica) Blackberry (Rubus spp.) Arrow-wood (Viburnum dentatum) White fring-tree (Chionanthus virginicus) Piedmont Acidic Cliff Forest ' American beech (Fagus grandifolia) Mockernut hickory (Carya alba) Maple leaf viburnum (Viburnum acerifolium) Yellow poplar (Liriodendron tulipifera) Low bush blueberry (Vaccinium pallidum) 0 1 ?n Sassafras (Sassafras albidum) Flowering dogwood (Corpus Florida) White oak (Quercus alba) Black oak (Q. velutina) Scarlet oak (Q. coccinea) Sourwood (Oxydendrum arboreum) Ironwood (Carpinus caroliniana) Poison ivy (Toxicodendron radicans) Muscadine grape (Vitis rotundifolia) Resurrection fern (Pleopeltis polypodioides) Mountain laurel (Kalmia latifolia) False foxglove (Aureolaria virginica) Kidney-leaf rosinweed (Silphium compositum) Partridge-berry (Mitchella repens) American holly (Ilex opaca) Rusty black haw (Viburnum rufidulum) False Solomon's seal (Maianthemum racemosum) Sweetgum (Liquidambar styraciflua) Smooth sumac (Rhus glabra) Winged sumac (R. copallina) Piedmont Levee Forest ' Box elder (Acer negundo) River birch (Betula nigra) Green ash (Fraxinus pennsylvanica) ' American elm (Ulmus americana) Silky dogwood (Cornus amomum) Chinese privet (Ligustrum sinense) ' Parsley hawthorn (Crataegus marshallii) River oats (Chasmanthium latifolium) ' Trumpet creeper (Campsis radicans) Poison ivy (Toxicodendron radicans) Greenbrier (Smilax rotundifolia) Giant cane (Arundinaria gigantea) Sugarberry (Celtis laevigata) Rusty black haw (Viburnum rufzdulum) False-nettle (Boehmeria cylindrica) Sycamore (Platanus occidentalis) Souther sugar maple (Acer barbatum) ' Flowering dogwood (Cornus Florida) Bitternut hickory (Carya cordiformis) Red mulberry (Morus rubra) 1 1