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HomeMy WebLinkAbout19950087 Ver 1_Complete File_19960301a J ilk' 3 t q6 Soil & Environmental Consultants, Inc. . 244 West Millbrook Road ¦ Raleigh, North Carolina 27609 ¦ (919) 846-5900 ¦ Fax (919) 846-9467 Wetland Mitigation Plan Sunset West Development DEM Project # 95087 by J.M. Ortosky, Jr. February, 1996 Soil/Site Evaluation ¦ Mapping and Physical Analysis ¦ Wetlands Mapping and Mitigation ¦ Environmental Audits On-Site Waste Treatment Systems, Evaluation and Design f 1 Table of Contents General information and Mitigation Plan Narrative ..................................................... 1-6 Planting Plan and Specifications ............................................................................ Al 1 - 5 Proposed Sources for Plant Material ......................................................................... All 1 Site Maps and Photography .............................................................................. AIII 1 - 10 Intent This mitigation plan has been developed in response to the permitted filling of 0.57 acre of wetlands in the Sunset West Development (Devils Ridge) associated with construction of a road crossing and utility line placement. The mitigation will be an enhancement of in- kind and out-of-kind wetlands on-site at a 2:1 ratio, resulting in 1.14 acres of enhanced wetlands. The target site is a delineated wetland within a "hog pen" east of Holly Springs and southeast (about 1800') of the intersection of state roads 1393 and 1152 in southern Wake County (see accompanying site location map). The site is in the headwaters of an unnamed tributary of Basal Creek and intersects Basal Creek below Bass Lake and above Sunset Lake (see accompanying topographic map). Goals and Functions The goal of this mitigation is to restore functional value within the target wetland to levels similar to the original conditions in both the target and reference wetlands. Additional functional value is sought through the diversity of wetland types to be enhanced. Enhancement of the target site will result in forested and freshwater marsh wetland types. Some of the functional values of the target wetland will be; 1) water storage, 2) pollutant removal, 3) dispersal corridor, 4) wildlife and aquatic life habitat, 5) educational value of enhancement process. Measurement of the success of the mitigation project will be relative to those functional values. Enhancement of the water storage, pollutant removal, and aquatic life aspects of the site may be assumed through maintenance of the open water portion of the site via stabilization of the road fill and outlet and stabilization of the upslope portions of the hog pen. Further enhancement of pollutant removal in addition to enhancement of wildlife habitat qualities may be assumed though the successful re-establishment of a native wetland plant community. Additionally, the functional value as a dispersal corridor may be assumed once a native plant community connects the forested wetlands to the south to the headwater areas to the north. Overall, success is tied to the establishment of viable wetland plant communities in the areas designated and stabilization of the road fill and outlet. Site The site is within the headwaters of a small, first order stream in the Piedmont section of Wake County. The site represents the interface between groundwater and intermittent surface water flow and a true fluvial environment, There is little evidence of headwater flooding and overbank flow above the shallow impounded area (see below). Primary hydrologic input is from discharge of lateral groundwater flow and intermittent channel flow. The surrounding geology is material comprised of gneiss, schist, and granitic rocks. The soils on the upland are in the Appling, Cecil, and Pacolet soil series. The soil in the wetland area is mainly in the Worsham soil series, a poorly drained soil which typically occurs in headslopes. Most of the soils in the wetland sites of the area are poorly drained soils in flood plains or headslopes with bottomland hardwood forest cover. The target wetland is within a hog pen where about a dozen hogs and several ducks use the site. The surface of the site is degraded from the traffic and rooting by the hogs. Surface soil material is continuously trampled in wet conditions, resulting in poorly structured, soupy material in the upper portions (2" to 6") across the site. Significant amounts of organic material from feed and animal feces occur on and in the surface variably across the site. Erosion has occurred as a result of surface degradation, rainfall, and the resulting sheet and channel flow across the site. Many of the upper root systems of the site shrubs and trees are exposed as a result. In most cases the roots have developed bark and are adapting to the exposed conditions. The lower portions of the wetland are comprised of saturated and inundated alluvium. Additionally, there is considerable structural material (fencing of wood and wire other material) scattered around the southern portion of the site. Most of the target wetland is forested with a canopy of sweet gum, red maple, black gum, and some tulip poplar. The understory is sparse and comprised of holly, alder, and highbush blueberry. Ground cover is nearly non-existent due to grazing and degradation. A portion of the non-inundated areas are bare and open to direct sunlight. A portion of the site is a shallow ponded area and, although observed in a period of high rainfall, likely maintains some level of water throughout the wetter times of the year. The area may dry up in drought conditions. There are two small channels which converge in the lower part of the target wetland, one (east) flowing from the outlet of a pipe from the principal spillway of a small pond above the wetland, the other simply drains the headslope of the western drainageway. There was significant seepage of groundwater out of the lower sideslopes during the time of observation (June, 1995) which likely occurs throughout much of the year, as indicated by the hydric soil conditions within those areas. The edge of the ponded area within the hog pen has a dominantly bare edge with the exception of dead snag trees along the northwestern edge. The fencing along the southern portion is slightly above the soil road, just into the open water, leaving the edge vegetated with sedges, Juncus, lizard's tail, black willow, and other herbaceous and grass-like species. The only aquatic life observed during the June, 1995 site visit was an occasional frog and one water turtle. The bottom of the target wetland is bounded by remnants of an old soil road which lead to a field east of the site. Some portions of the road are fill, about 12" to 24' high, above normal grade which causes shallow (about 24" deep) impounding of water in the immediate upstream area. There is one small overflow area on the west side of the road fill which acts as an outlet to the downstream side. The freeboard (height above waterline) on the road fill was about 6" in June, 1995 and there is evidence of overflow at other points along the fill during high flow periods. 2 In general the target wetland area is comprised of three basic conditions: * Forested areas of dense canopy, sparse understory, and no ground cover. * Open areas of variably saturated (by horizontal flow in upper portions) soils, no vegetation. * Open, shallow, turbid water of fluctuating depth with no emergent or aquatic vegetation. Mitigation Plan The intent of the mitigation is to remove degrading factors from the wetland and restore a native plant propagule base to encourage infill of local, wetland native plant species in response to the existing hydrology. Plant material will be added to the site (see planting specifications and plan). Propagules from those plants along with existing site propagules will be relied on for regeneration of the plant community. No alteration to the existing hydrology is planned other than the minor renovation of the road fill in order to stabilize the fill, define the outlet, and provide outlet protection. Appropriate hydrology is assumed since hydric soil characteristics and indicators of wetland hydrology exist within the delineated wetland area. It is assumed that continuous site degradation by the hogs is the prime factor in the loss of the native ground cover and small understory wetland plant communities and that once this factor is removed and mitigated, the normal plant community will return. The proposed mitigation effort will involve two basic phases; I) enhancement and II) monitoring/maintenance. Enhancement The enhancement will be comprised of five steps; 1) remove all livestock and structural material from within the enhancement area, 2) temporarily lower water level (just prior to step 3), 3) plant marsh/emergent vegetation in pond edge zone (spring planting), 4) make minor modifications to the road fill and outlet and restore water to existing level, 5) plant and mulch non-ponded open areas anytime after step 1 (fall planting for shrubs/trees, spring for marsh/emergent) and plant ground cover in forested areas. Note: If the threat of depredation by ducks, geese or other wildlife or domestic animals is present in the area at time of installation, the enhancement site will be fenced appropriately to protect the installation. Plant material will be added to the site (see planting plan and specifications, Appendix II). Plants will be obtained from local sources (within 200 miles of the site). This is to be 3 certified by the registered nursery or installer. See Appendix III for location of proposed plant material sources. Propagules from those plants along with existing site propagules will be relied-on for establishment of the plant community. After appropriate surface preparation and mulching, marsh and emergent vegetation will be planted in littoral and wetland areas as per planting plans and specifications. It is strongly recommended that an installer with successful experience in handling and installing wetland plant material be used on this project. This is an extremely important aspect in a successful mitigation planting. Three basic planting approaches are proposed at the target site: 1) shade-tolerant ground cover species in forested areas (e.g. Saururus cernuus, Leersia oryzoides, Carex intumescens, Itea virginica). 2) sun-loving plants of various forms (ground cover, shrubs, trees) in more open areas (e.g. Juncus effusus, Alnus serrulata, Nyssa sylvatica). 3) marsh/emergent vegetation around littoral zone of ponded area (e.g. Saururus cernuus, Juncus effusus, Pontederia cordata, Peltandra virginica, Sagittaria latifolia, Cephalanthus occidentalis). Spring planting of marsh-type plant material is recommended. Some late season planting can occur, however, it is likely that significant additional planting will have to occur the following spring to re-establish failed areas. If the threat of depredation by ducks, geese or other wildlife or domestic animals is present in the area at time of installation, the enhancement site will be fenced appropriately to protect the installation. Planting of any woody species should be done during the fall or early spring. Monitoring/Maintenance The monitoring phase will begin prior to installation, be carried out by the mitigation designer and owner and will include; 1) Pre-construction/planting meeting with contractor. 2) Site inspection during installation. 3) Final inspection after all site work is complete, preparation of appropriate completion of work statement, preparation of breif as-built report, sketch plan, and documentary photos and submission of that report to NCDEHNR-DEM for review within 30 days of completion. 4) Locate original mitigation site limits in the field with markers that can be seen from upland portions of the site (used in determination of vegetation coverage). 4 5) Site inspection early in first growing season. 6) Site inspection at end of first growing season and preparation of letter of evaluation, documentary photos, and suggested treatment of any failed areas and submission to NCDEHNR-DEM within 30 days of inspection. 7) Site inspection during late growing season of second and third years with documentary photos and letter of evaluation at end of third growing season (to NCDEHNR-DEM within 30 days of inspection). Success criteria is based on percent of vegetative cover within the target mitigation site. Vegetative cover must occupy a minimum of 75% of the target site and be comprised of at least three of the target species (existing or introduced). The estimated schedule for achieving 75% coverage is by the end of the third growing season, however, the site will be monitored until success is achieved. Coverage is defined as the percent of material alive based on the planted spacings (i.e. 3'x3'- marsh and 8'x 8'- shrubs), or volunteers within that area. At least 50% of the vegetation must be FACW or OBL status. At the end of the third growing season marsh/emergent vegetation should form a contiguous mass along the open water edge in the general mitigation area except where flowing water enters the open water area from the drain and prevents growth. The vegetation mass may vary in width along the shore. Unvegetated areas may occur within the target mitigation site (particularly in heavily shaded areas) and, conversely, wetland and littoral vegetation may establish somewhat outside the mitigation areas, however, the total area of wetland/littoral vegetation shall equal or exceed 75% of the target mitigation site. If after the second growing season coverage is significantly lower than what is expected in a normal progression to reach 75% by the end of the third growing season (<1/3 coverage), a plan to rectify the situation will be prepared and submitted to the NCDEHNR-DEM within 30 days of inspection. Maintenance of the sites will focus on establishment and protection and will consist of the following: 1) Re-plant any bare or sparse areas during season appropriate to plant species as necessary to achieve success. 2) Do not apply any herbicides within aerosol drifting or surface flow distance of the littoral bench plantings. 3) Maintain ground cover in adjacent upland areas to prevent sedimentation within littoral bench zones 4) Remove any degrading factors such as depradation, trampling, plant removal from destructive wildlife, domestic animals, humans. The success of the project as well as management of the site will be the responsibility of the owner. Long-term impacts to the wetland as a result of on and off-site development is an unknown at this point. Additional protection for the mitigation site from physical disturbance (excavation or filling) will be maintained except as need for maintenance or as permitted by NCDEHNR-DEM in the future. 6 Planting Plan and Specifications Appendix I AI I Legend Shade-tolerant species planting. (approx. 29,000 sf) Open site species planting. (approx. 18,000 sf) Littoral edge species planting. (approx. 3,000 sf) rr,,,r, Wooded areas. .? Channel. To SR 1393 0 Herbaceous plants to be planted on 3' by 3' spacing and woody plants to be planted on 8' by 8' spacing within areas shown. Individual species will be selected from groups listed in mitigation and alternated or grouped as appropriate. Alternate species may be used when approved in writing by NCDEHNR-DEM. Woody species should comprise between 2% and 5% of the total planting. Planting Plan Scale: V=100' AI 2 Plant Material Specifications (Adapted from Garbisch, 1995) Balled and Bagged (Woody Plants) The size of the earthen ball shall be at least as large as specified in the American Standard for Nursery Stock (1980). Where plants are to be planted in soils that will be saturated most of the growing season, the bagged root ball shall have a surface diameter that is at least 1/2 the diameter of the un-pruned drip-line and a depth that is at least 8" per 5' of tree/shrub height. If not planted immediately upon delivery to the job site, plants shall be stored in shade and root balls kept moist through periodic watering until the time of planting. If growing, the plants shall appear healthy with no leaf sports, leaf damage, leaf discoloration, chlorosis, leaf wilting or curling, or evidence of insects on the leaves. Container (Woody and Herbaceous Plants) The soil within the root ball shall be at field capacity (1/3 atmosphere) or wetter upon delivery to the job site. Any wilted, dry and/or light weight plants shall be rejected. If not planted immediately upon delivery to the job site, plants shall be stored in shade and root balls kept moist through periodic watering until the time of planting. The container size shall be at least as large as specified. Plants shall not necessarily be rejected when supplied in containers larger than specified. However, the soil/root masses shall be the size of the specified container size. If the soil/root masses are substantially smaller than the specified container size and loose soil exists on the sides and bottom of the containers, indicating that plants have not been in specified containers long enough to root into surrounding soil, the plants shall be rejected. If growing, the plants shall appear healthy with no leaf spots, leaf damage, leaf discoloration, chlorosis, leaf wilting or curling, or evidence of insects on the leaves. For trees and shrubs, where spiraling woody roots exist on the outside of the soil/root mass upon the removal of the plants from the containers, the landscape contractor shall separate (cutting where necessary) and spread them out (frazzle) prior to planting. Fiber or Peat Pot (Herbaceous Plants) If not planted immediately upon delivery to the job site, plants shall be stored in shade and root masses kept moist through periodic watering until the time of planting. AI 3 The plants shall be well-rooted through the sides and bottoms of the pots and firmly contained therein. If the plants may be easily removed from the pots by holding the upper portion of the plant and gently pulling on the pots, the plants shall be rejected. If growing, the plants shall appear healthy with no leaf spots, leaf damage, leaf discoloration, chlorosis, leaf wilting or curling, or evidence of insects on the leaves. The pot size shall be at least as large as specified. Plants shall not necessarily be rejected when supplied in pots larger than specified. The number of plants or stems (culms) per port as specified shall be present at the minimum, and on the average, or the plants shall be rejected. Dormant Propagule (Herbaceous Plants) If not planted immediately upon delivery to the job site, the dormant propagules shall be stored out of direct exposure to the sun and wind and they shall be protected by covering with straw, peat moss, compost, or other suitable materials and shall be kept moist, through periodic watering, until the time of planting. The bodies and shoots associated with the propagules shall have turgor or be rigid to the touch. If the bodies and/or shoots associated with the propagules are soft or mushy, or appear rotten or decomposed, the plant materials shall be rejected. Rhizome (stolon) sections shall provide a minimum of two shoots per section. Or: Rhizome (stolon) sections containing at least a terminal shoot shall be a minimum of four inches (4") in length (in order to ensure sufficient stored energy to support the new growth). Rhizome sections containing shoots that are soft or mushy or otherwise appear rotten shall not be accepted. Plug (Herbaceous Plants, Woody Seedlings, or Rooted Cuttings) If not planted immediately upon delivery to the job site, the plugs whether in or out of their growing units shall be stored out of direct exposure to the sun and wind and maintained moist through periodic watering until the time of planting. If the plugs are not contained in their growing units upon delivery and will not be planted immediately, they should be treated as above and their root masses shall be protected by straw or other suitable materials and maintained moist, through periodic watering, until the time planting. Plugs shall have solid soil/root masses with the soil in place. Roots shall appear clean and white in coloration. AI 4 If growing, the plants shall appear healthy with no leaf spots, leaf damage, leaf discoloration, chlorosis, leaf wilting or curling, or evidence of insects on the leaves. If dormant (herbaceous), new healthy shoots shall be apparent. Plugs containing shoots that are soft or mushy or otherwise appear rotten shall not be accepted. If dormant (woody), stems shall be pliable and exhibit light green to yellowish green cambium. Plugs containing brittle stems and having unhealthy cambium shall not be accepted. Plugs (woody seedlings) shall have widths that are at least to the limb lines of the seedlings and have depths that are at least one-fourth the heights of the seedlings. Seed Shall be delivered in clean, unopened containers and labeled as to seed origin, purity, germination percentage, and date of germination testing. Fertilization Herbaceous plantings Spring plantings - Use Osmocote 18-6-12, eight to nine month release fertilizer, to be placed in hole at time of planting. For Dormant propagules, container/fiber pot, or plug seedlings use about 15 grams (0.5 oz.) per planting. Woody plantings Fall/Winter plantings - Use Osmocote 18-5-11, twelve to fourteen month release fertilizer, to be placed in hole or in soil fill/amendment mix at planting. Use 30 grams (1 oz.) per 1 quart container, 90 grams (3 oz.) per 1 gallon container (30 grams per each additional gallon). Use 15 grams (1 oz.) per unrooted cutting for willow whips. Soil Amendments Soil amendments are required only around tree and shrub plantings, with the exception of significantly graded areas (where stockpiled wetland topsoil may be used). The amendment used should be leaf or pine bark compost at rates of one part compost to one part soil (from planting hole). Fertilizer should be mixed in with soil/amendment mix. No surface mulch is required where plants are planted at or near original grade. AI 5 Appendix II Proposed Potential Sources for Plant Material (additional sources may be proposed prior to installation, for approval by USACOE). Herbaceous material: Campbell's Greenhouse Carlton Campbell/Larry Hobbs 2816 Campbell Road Raleigh, N.C. 27606 919-851-1162 (also has team of experienced installers) Shrub Material: Campbell's Greenhouse 2816 Campbell Road Raleigh, N.C. 27606 Fern Valley Farms 1624 Fern Valley Road Yadkinville, N.C. 27055 Specimen ornamental species: Campbell's Greenhouse 2816 Campbell Road Raleigh, N.C. 27606 Niche Gardens 1111 Dawson Road Chapel Hill, N.C. 27516 Carlton Campbell/Larry Hobbs 919-851-1162 Tom Clark 910-463-2412 Carlton Campbell/Larry Hobbs 919-851-1162 Kim Hawkes 919-967-0078 All 1 Appendix III Site Maps and Photography AIII 1 ;_ -'?/`?. _ =4?- f ??? 1 ?? ? ?\I ° { ?,'? a ?//)\\li/ll?.,/I 11 \\ /?//L\??tilll l ,•i• Topo/Location Map LL/ U 11 . C?? 11 II •,• V I 1 `• 11 u Site q fi? )\\S i / 1.V v ry • 1 "/ Bass l ,_ s 1 3 \ Lake -? ? I 41 ?• . ?? I 11 N 3I5 ? \ l: •II \ O I 111 \' - J I s`r 1; a O I 111 H -- I o (?'I ?• I f p •M ? 3! . ? mil; > ?,??? ? ? 5??\ c• ? ?\ 695 !696 50? FUOUAY-VAR/NA 3.3 Ml. (FUOUAY-VARINA) "9 5255 Ill S£ SCALE 1:24 000 1 p 0 1 1000 0 1000 2000 3000 4000 5000 6000 7000 FEET APEX, N. C. 1 .5 0 1 KILOMETER 35078-F7-TF-024 - - PHOTOIN974 D 1988 1 CONTOUR INTERVAL 10 FEET 1 PHOTOREVIS ISEO 1987 NATIONAL GEODETIC VERTICAL DATUM OF 1929 DMA 5255 111 NE-SERIES V842 AIII 2 F Y Y6? K n L J - -- •. _ „s•., .F 1. s"° is 41, s- t II ate, ?? ???? u Wx k x 7. t T n S , 12' f removed. and primary outlet. View from east side of ponded area showing typical structural material to be View from south side of ponded area showing structural material (barrels, fencing) site. View of forested wetland areas, lower photo shows a portion of the channel flow on degradation). View of ponded area from the south. View of ponded area from the north where main channel enters (note surface View of open site west of ponded area. View of open site north of ponded area. Area of sideslope seepage in northern portion of the site. View to the east along centerline of old road fill. C Y..:?? I.`.•?, fib`.: - _ .. .. '. - ? ? .:ti ?" `? h k^ fed M1r r %r ?v1 s I ?'?i Degraded depositional area resulting from upslope erosion and continuous livestock traffic. Typical eroded area resulting from surface degradation by hogs (rooting and trampling). State of North Carolina Department of Environment, Health and Natural Resources Division of Environmental Management Ja mes & Hunt, Jr., G ove mor Jonathan & Howes, Secretary A. Preston Howard, Jr., P.E., Director June 17, 1996 Mr. J.M. Ortosky Soil and Environmental Consultants 244 W. Millbrook Rd. Raleigh, NC 27609 Dear Mr. Ortosky: C) FE "F1 Thank you for providing a copy of the wetland mitigation plan for the Sunset West Development (DEM No. 95-087). We have discussed enhancement and restoration issues about this site on December 13, 1995 and on March 1, 1996. The plan you have submitted (February 1996) reflects the concerns we have discussed. I would like to provide additional comments on literature citations and the definition of cover. In future plans please list references in a Literature or References Cited section. Garbisch (1995) and the American Standard for Nursery Stock (1980) were cited, however there are no references listed for either of these citations. A more accurate definition of percent cover, than the one provided on page 5 of the mitigation plan, is "[the] fraction of the sampling area covered by vertical projection of the plant onto the ground" (NRC 1995; page 127). Note, however, that this definition may result in a total cover of over 100% because of species overlap. To help resolve this problem an estimate of the area of substrate or water not covered by vegetation should also be provided. Please keep me informed on when work will begin at this site. I apologize for the time it has taken me to respond in writing to the mitigation plan. Thank you for your patience. Please. call if you have any comments. Cordially, S cc John Dorney, DEM Danny Smith, RRO COE, Raleigh Regulatory Field Office Literature Cited NRC (National Research Council). 1995. Wetlands. Characteristics and Boundaries. National Academy Press. 308 pp. Environmental Sciences Branch • 4401 Reedy Creek Road Raleigh, North Carolina 27607 Telephone 919-733-9960 FAX # 733-9959 An Equal Opportunity Affirmative Action Employer 50% recycled/10% post consumer paper State of North Carolina Department of Environment, Health and Natural Resources • Division of Environmental Management Ja mes EL Hunt, G [D E H F1 Jonathan B. Howes, Secretary A. Preston Howard, Jr., P.E., Director January 2, 1996 Mr. Mike Ortosky Soil & Environmental Consultants, Inc. 244 W. Millbrook Rd. Raleigh, NC 27609 Dear Mr. Ortosky: Thank you for providing a copy of the draft mitigation plan for the Sunset West Development (DEM Project No. 95087), and showing me the site on December 13, 1995. During our site visit we noted the severely degraded conditions of the mitigation wetland resulting from its use as a hog enclosure. The degraded conditions included compacted soil, lack of an herbaceous understory, and erosion around tree roots. We also assessed the sources of water for the mitigation wetland. The pond immediately upstream from the hog pen was almost completely empty but wet conditions were prevalent within the mitigation site. Although some water was flowing from the upstream pond into the mitigation wetland, we noted seeps along the periphery of the mitigation wetland. This led us to consider that the primary hydrologic input may consist of lateral groundwater discharge. Comments on the draft plan submitted to you on August 14, 1995 identified problems with long term hydrological maintenance of the mitigation site if the upstream pond was drained. We noted that this pond was drained, but we could not determine when drawdown occurred. I recommend that qualitative observations of the mitigation site be made as long as the upstream pond is drained, This may help in determining the relative importance of this source of water. However, it is clear that lateral seeps are an additional source of water. The draft mitigation plant indicates that Myrica cerifera and Salix nigra may be included as part of the enhancement planting. These species are not recommended for the same reasons provided in our August 14, 1995 comments. Although the soil is severely trampled, aerating the soil may disturb tree roots. Therefore, aeration is not recommended. Thank you for the opportunity to comment on the draft mitigation plan. Please call (733-1786) if you have any comments. Sincerely Steven Kroeg r cc: John Dorney Environmental Sciences Branch • 4401 Reedy Creek Road Raleigh, North Carolina 27607 Telephone 919-733-9960 FAX # 733-9959 An Equal Opportunity Affirmative Action Employer 50% recycled/10% post consumer paper State of North Carolina I" I Department of Environment, Health and Natural Resources A • • Division of Environmental Management JamesB. Hunt, Jr., Govemor Jonathan B. Howes, Secretary ID E H N F1 A. Preston Howard, Jr., P.E., Director l [? Jjc D°n b ?? Mr. Mike Ortosky Soil & Environmental Consultants, Inc. 244 W. Millbrook Rd. Raleigh, NC 27609 Dear Mr. Ortosky: Thank you for providing a copy of the draft mitigation plan for the Sunset West Development (DEM Project No. 95087), and showing me the site on December 13, 1995. During our site visit we noted the severely degraded conditions of the mitigation wetland resulting from its use as a hog enclosure. The degraded conditions included compacted soil, lack of an herbaceous understory, and erosion around tree roots. We also assessed the sources of water for the mitigation wetland. The pond immediately upstream from the hog pen was almost completely empty but wet conditions were prevalent within the mitigation site. Although some water was flowing from the upstream pond into the mitigation wetland, we noted seeps along the periphery of the mitigation wetland. This led us to consider that the primary hydrologic input may consist of lateral groundwater discharge. Comments on the draft plan submitted to you on August 14, 1995 identified problems with long term hydrological maintenance of the mitigation site if the upstream pond was drained. We noted that this pond was drained, but we could not determine when drawdown occurred. I recommend that qualitative observations of the mitigation site be made as long as the upstream pond is drained, This may help in determining the relative importance of this source of water. However, it is clear that lateral seeps are an additional source of water. The draft mitigation plant indicates that Myrica cerifera and Salix nigra may be included as part of the enhancement planting. These species are not recommended for the same reasons provided in our August 14, 1995 comments. Although the soil is severely trampled, aerating the soil may disturb tree roots. Therefore, aeration is not recommended. Thank you for the opportunity to comment on the draft mitigation plan. Please call (733-1786) if you have any comments. Sincerely, Steven Kroeger cc: John Dorney Environmental Sciences Branch 4401 Reedy Creek Road Raleigh, North Carolina 27607 Telephone 919-733-9960 FAX # 733-9959 An Equal Opportunity Affirmative Action Employer 50% recycled/10% post consumer paper Existing Data Screen for PDATA PERMIT YRA: 95 PERMIT NOB: 39 COUNTYC: WAKE _ APPNAMED: SUNSET LAKE_LIMITED PARTNERSHIP PROJECT TYPEE: RESIDENTIAL FILL PERMIT TYPEU: NW14&26 _ COE #F.: _ DOT #V: _ RCD FROM CDAG: APP DATE FRM CD AW: 11395 _ _ DATE SENT ROH: 12095 _ _ REG OFFICEY,: RRO RI SUB BAS ##.I: 030403 STR INDEX NOY: 27-43-15-3 STREAM_CLASSJ: B _ _ SUP ST CLASSZ: NSW WL IMPACT?K: Y _ _ WLTYPEAA: HWF _ WL REQUESTEDL: .44 ACR_ WL EST?AB: N _ WL_SCORE(#)M: 54 _ _ WATER INPAC?AC: Y MITIGATION?N: N _ MITIGATE TYPAD: MITIGATE_SIZO: MORE INFO?AE: Y DATE_FROM_ROP: 22095 _ COE SUSPENCEAF: CAMA COMMEN?Q: N _ DCM SUSPENCEAG: _ FINAL _DATER: 50195 _ FINAL ACTIONAH: ISSUE GENERAL WL PERMIT'DS: .44 _ CERT #AI: 2664,2671 OTHER COND?T: N _ BLANKAJ: FOR NEW FIELD F4 : SHOW THE NEXT RECORD F8 : FIELD OPTIONS SCREEN PERMIT_YRA: APPNAMED: PROJECT TYPEE: COB ##F : RCD FROM CRAG: DATE SENT ROH: RI_SUB_BAS_##I : STREAM CLASSJ: WL IMPACT?K: WL_REQUESTEDL: WI._SCORE (## )M : MITIGATION?N: MITIGATE SIZO: DATE FROM ROP: CAMA_COMMEN?Q: FINAL DATER: WL_PERMIT'DS: OTHER COND? T : Existing Data Screen for PDATA 95 PERMIT NOB: 87 COUNTYC: WAKE DEVILS RIDGE-SUNSET RESIDENTIAL FILL APP 13095 030403 B Y .57 61 Y 22795 N 50195 .57 Y WEST DEVELOPMEN PERMIT_TYPEU: DOT #V: DATE FRM CD _AW: REG_OFFICEX: STR_INDEX_NOY: SUP_ST_CLASSZ: WL_TYPEAA: WL_ACR_EST?AB: WATER INPAC?AC: MITIGATE TYPAD: MORE IRFO?AE: COESUSPENCEAF: DCM__SUSPENCEAG-: FINAL_ACTIONAH: CERT ##AI: BLANKAJ: T NW26{12 12695 RRO 27-43-15-3 NSW BLH N Y E Y ISSUE GENERAL 26&4,2671 FOR NEW FIELD F4 : SHOW THE NEXT RECORD F8 : FIELD OPTIONS.SCREEN • Soil & Environmental Consultants, Inc. 244 West Millbrook Road ¦ Raleigh, North Carolina 27609 ¦ (919) 846-5900M Fax (919) 846-9467 Mr. John Dorney DEHNR-DEM P.O. Box 29535 Raleigh, N.C. 27626-0535 June 29, 1995 Re: Draft of mitigation plan for DEM Project # 95087 - Sunset West Development. Dear Mr. Dorney: Enclosed is a draft of the proposed mitigation plan relative to the above mentioned project in response to your request to review a draft version (to be submitted by July 1, 1995). This draft is represents our concept for the mitigation at this point and is submitted for comment by yourself, Ron Ferrell and others. It is not intended as a complete version. We are developing detailed planting plans and specifications to be added soon. Please review and contact me with comments and suggestions and/or if someone from your office would like to visit the site. Thank you. Sincere/ly,9erti _ Ort sky, Jr fied Pr essionai S S ntist cc: Ron Ferrell D. R. Bryan Doby Blackmon Soil/Site Evaluation ¦ Mapping and Physical Analysis ¦ Wetlands Mapping and Mitigation ¦ Environmental Audits On-Site Waste Treatment Systems, Evaluation and Design Intent This mitigation plan has been developed in response to the permitted filling of 0.57 acre of wetlands in the Sunset West Development (Devils Ridge) associated with construction of a road crossing and utility line placement. The mitigation will be an enhancement of in- kind and out-of-kind wetlands on-site at a 2:1 ratio, resulting in 1.14 acres of enhanced wetlands. The target site is a delineated wetland within a "hog pen" east of Holly Springs and southeast (about 1800') of the intersection of state roads 1393 and 1152 in southern Wake County (see accompanying site location map). The site is in the headwaters of an unnamed tributary of Basal Creek and intersects Basal Creek below Bass Lake and above Sunset Lake (see accompanying topographic map). Goals and Functions The goal of this mitigation is to restore nal value within the target wetland to levels similar to the original conditions in both Oetarget and reference wetlands. Additional functional value is sought through the diversity of wetland types to be enhanced. Enhancement of the target site will result in forested and freshwater marsh wetland types. Some of the functional values of the target wetland will be; 1) water storage, 2) pollutant removal, 3) dispersal corridor, 4) wildlife and aquatic life habitat, 5) educational value of enhancement process. Measurement of the success of the mitigation project will be relative to those functional values. Enhancement of the water storage, pollutant removal, and aquatic life aspects of the site may be assumed through maintenance of the open water portion of the site via stabilization of the road fill and outlet and stabilization of the upslope portions of the hog pen. Further enhancement of pollutant removal in addition to enhancement of wildlife habitat qualities may be assumed though the successful re-establishment of a native wetland plant community. Additionally, the functional value as a dispersal corridor may be assumed once a native plant community connects the forested wetlands to the south to the headwater areas to the north. Overall, success is tied to the establishment of viable wetland plant communities in the areas designated and stabilization of the road fill and outlet. Site The site is within the headwaters of a small, first order stream in the Piedmont section of Wake County. The site represents the interface between groundwater and intermittent surface water flow and a true fluvial environment, There is little evidence of headwater flooding and overbank flow above the shallow impounded area (see below). Primary hydrologic input is from discharge of lateral groundwater flow and intermittent channel flow. The surrounding geology is material comprised of gneiss, schist, and granitic rocks. The soils on the upland are in the Appling, Cecil, and Pacolet soil series. The soil in the wetland area is mainly in the Worsham soil series, a poorly drained soil which typically occurs in headslopes. Most of the soils in the wetland sites of the area are poorly drained soils in flood plains or headslopes with bottomland hardwood forest cover. The target wetland is within a hog pen where about a dozen hogs and several ducks use the site. The surface of the site is degraded from the traffic and rooting by the hogs. Surface soil material is continuously trampled in wet conditions, resulting in poorly structured, soupy material in the upper portions (2" to 6") across the site. Significant amounts of organic material from feed and animal feces occur on and in the surface variably across the site. Erosion has occurred as a result of surface degradation, rainfall, and the resulting sheet and channel flow across the site. Many of the upper root systems of the site shrubs and trees are exposed as a result. In most cases the roots have developed bark and are adapting to the exposed conditions. The lower portions of the wetland are comprised of saturated and inundated a vium. Additionally, there is considerable structural material (fencing of w o wire other material) scattered around the southern portion of the site. Most of the target wetland is foresteddth a canopy ofsweet gum, red maple, black gum, and some tulip poplar. The understory is sparse and comprised of holly, alder, and highbush blueberry. Ground cover is nearly non-existent due to grazing and degradation. A portion of the non-inundated areas are bare and open to direct sunlight. A portion of the site is a shallow ponded area and, although observed in a period of high rainfall, likely maintains some level of water throughout the wetter times of the year. The area may dry up in drought conditions. There are two small channels which converge in the lower part of the target wetland, one (east) flowing from the outlet of a pipe from the principal spillway of a small pond above the wetland, the other simply drains the headslope of the western drainageway. There was significant seepage of groundwater out of the lower sideslopes during the time of observation (June, 1995) which likely occurs throughout much of the year, as indicated by the hydric soil conditions within those areas. The edge of the ponded area within the hog pen has a dominantly bare edge ith the exception of dead snag trees along the northwestern edge. The fencing alonwthe southern portion is slightly above the soil road, just into the open water, leaving the edge vegetated with sedges, Juncus, lizard's tail, black willow, and other herbaceous and grass-like species. The only aquatic life observed during the June, 1995 site visit was an occasional frog and one water turtle. The bottom of the target wetland is bounded by remnants of an old soil road which lead to a field east of the site. Some portions of the road are fill, about 12" to 24' high, above normal grade which causes shallow (about 24" deep) impounding of water in the immediate upstream area. There is one small overflow area on the west side of the road fill which acts as an outlet to the downstream side. The freeboard (height above waterline) on the road fill was about 6" in June, 1995 and there is evidence of overflow at other points along the fill during high flow periods. In general the target wetland area is comprised of three basic conditions: * Forested areas of dense canopy, sparse understory, and no ground cover. * Open areas of variably saturated (by horizontal flow in upper portions) soils, no vegetation. * Open, shallow, turbid water of fluctuating depth with no emergent or aquatic vegetation. Mitigation Plan The intent of the mitigation is to remove degrading factors from the wetland and restore a native plant propagule base to encourage infill of local, wetland native plant species in response to the existing hydrology. Plant material will be added to the site (see planting specifications and plan). Propagules from those plants along with existing site propagules will be relied on for regeneration of the plant community. No alteration to the existing hydrology is planned other than the minor renovation of the road fill in order to stabilize the fill, define the outlet, and provide outlet pr tion. Appropriate hydrology is assumed since hydric soil characteristics and indic fetland hydrology exist within the delineated wetland area. It is ass tinuous site degradation by the hogs is the prime factor in the loss of the nati and cover and small understory wetland plant communities and that once this factor is removed and mitigated, the normal plant community will return. The proposed mitigation effort will involve two basic phases; I) enhancement and II) monitoring and evaluation. The enhancement will be comprised of four steps; 1) remove all livestock and structural material from within the enhancement area, 2) temporarily lower water level (just prior to step 3), 3) plant marsh/emergent vegetation in pond edge zone (spring planting), 4) make minor modifications to the road fill and outlet and restore water to existing level, 5) plant and mulch non-ponded open areas anytime after step 1 (fall planting for shrubs/trees, spring for marsh/emergent) and plant ground cover in forested areas. Note: If the threat of depredation by ducks, geese or other wildlife or domestic animals is present in the area at time of installation, the enhancement site will be fenced appropriately to protect the installation. The monitoring/evaluation phase will begin prior to installation, be carried out by mitigation designer, and will include; 1) pre-construction/planting meeting with contractor, 2) daily site inspection during installation, 3) final inspection after all site work is complete, preparation of appropriate completion of work statement, preparation of breif as-built report, sketch plan, and documentary photos, 4) site inspection early in first growing season, 5) site inspection at end of first growing season and preparation of letter of evaluation, documentary photos, and suggested treatment of any failed areas, 6) site inspection during late growing season of second and third years with documentary photos and letter of evaluation at end of third growing season. The success of the project as well as management of the site will be the responsibility of the owner. Long-term impacts to the wetland as a result of on and off-site development is an unknown at this point. It is assumed that once the site is deemed a success by the appropriate regulatory agency it will maintain all of the protection afforded to jurisdictional wetlands in the future and may incur additional protection as a result of its status as a mitigation site (i.e. any proposed impacts within site may require additional mitigation). Planting Plan Three basic Planting approaches are pA osed at the target site: 1) shade-tolerant ground cover species in forested areas (e.g. Saururus cernuus, Leersia oryzoides, Carex intumescens) 2) sun-loving plants of various forms (ground cover, shrubs, trees in,mpre open areas (e.g. Juncus effusus, Alnus serrulata, Myrica cerifera, alix nib ?--? ?1? 3) marsh/emergent vegetation around littoral zone of ponded area (e.g. Saururus cernuus, Juncus effusus, Pontederia cordata, Peltandra virginica, Sagittaria latifolia, Cephalanthus occidentalis) i /./ /?\? \? \\\\\ I I II • \/\\ - - ,? • ? 1K_ Topo/Location Map ree o?V 4 1 045 1152 ??- T ?' ? I II Ilr?,j 11 7, ? ?? _IIJ u - Sit 4 5 ?(r ll ? - -? vG?r Bass e s 1 4B Lake n _-?j?'?. /? 8 I \ p •ii 325 • \ ? ?? ?4Cj =cam \ D I 111 `s i O ' it I < ?!' ?• lI t??' II • M - O Cem ) i 6951 • ?6 50FUOUAY-VARINA 3.3 MI. (FUQUAY-VAR(NAI 699 5255 III S£ SCALE 1:24 000 1 2 0 1 T?? 1000 0 1000 2000 3000 4000 5000 6000 7000 FEET APEX, N. C. 1 .5 0 1 KILOMETER 35078-F7-TF-024 ?- a PHOTOIN974 D 1988 1 CONTOUR INTERVAL 10 FEET 1 PHOTOREVIS ED 1987 NATIONAL GEODETIC VERTICAL DATUM OF 1929 DMA 5255 111 NE-SERIES V842 lm? Concept Planting Plan To be followed by detailed planting plans and specificatio Scale : V = 100' removed. and primary outlet. View from east side of ponded area showing typical structural material to be View from south side of ponded area showing structural material (barrels, fencing) View of open site west of ponded area. View of open site north of ponded area. degradation). View of ponded area from the south. View of ponded area from the north where main channel enters (note surface site. View of forested wetland areas, lower photo shows a portion of the channel flow on trampling). traffic. Typical eroded area resulting from surface degradation by hogs (rooting and Degraded depositional area resulting from upslope erosion and continuous livestock View to the east along centerline of old road fill. Area of sideslope seepage in northern portion of the site.