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Home My WebLink AboutSTR_StrmBnkStab_2016_ProjectDescriptionSOUTH TOE RIVER STREAMBANK STABILIZATION PROJECT Brady Dodd, NFsNC Hydrologist, June 28, 2016 Project Background This project is located on the Pisgah National Forest, Appalachian Ranger District in Yancey County, North Carolina, on the South Toe River (Figure 1), in the French Broad River Basin. t r 47 3W } Maple Eamp 4a:a , 4 FEETRdDo _ F' i�4 i- ^ i \ "C� .,. cevcf �. y WN L= C J South Toe River. Streambank Stabilization i �s SITE LOCATION Figure 1 - South Toe River Streambank stabilization project, Celo Quad. In the hurricane storms of 2004, this same road segment was eroded away and the channel relocated into the road prism. Repair following the damage included the relocation of the channel away from the road by a large fill constructed of large sized boulders (Figure 2 & Appendix A). The new river location was constructed at the toe of the fill. The top end of this reach of the South Toe River is oriented at a near 90 degree angle to the Forest Service road. As 1IPage South Toe River Streambank Stabilization Project— PROJECT DESCRIPTION a result, during high streamflow events, flow energy is high against the road fill as streamflow hits the fill material and turns the bend and flows at the toe of the fill for about 350 feet. Over the years high streamflow against the slope have eroded fill material from spaces between boulders and a notable amount of flow resides in the boulder wall. Figure 3 shows the longitudinal profile of the river upstream and through the project reach. The tight river bend and boulder wall cause extensive deposition of channel bedload and a reduction in habitat diversity compared to the upstream section. Additional erosion of the road fill and continued loss of quality aquatic habitat in the reach are a concern. Figure 2 - Existing channel located at the toe of the road embankment. Note water going into the rock embankment. 21 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION South Toe River gybed—tersrf +bankfull n x -section o riffle orest • pool ■ run o glide x point -bar — - -- 102 100 98 . ___ 96 x --- - — ----- —?------- p 94 x x _. 90 x 92 x x > 88 Fu 86 _ 84 z 82 ._. ..... .. i x x 80 78 0 50 100 150 200 250 300 350 400 450 500 550 600 650 700 750 800 850 900 950 1000 1050 1100 1150 .boulderwall Channel Distance (ft) Figure 3. Longitudinal profile of the upstream and project reach of the South Toe River, surveyed lune 13, 2016. Note the likely influence of the boulder wall, including deposition of substrate and simplification of habitat diversity. Project Purpose & Need The purpose of this project is to increase the angle in the river bend and move the channel away from the road fill slope. By doing so, it is anticipated that there will be less erosive forces against the road fill slope, streamflow would be restored from the boulder fill to the open channel, and habitat diversity would improve in this reach. There is a need to stabilize the road fill before there is a catastrophic loss of the road. Proposed Action The following work is proposed: • Construct temporary access to the river by excavating an area of bank about 15 feet wide; a total disturbance of —400 square feet. The area would be sloped back to a 2:1 slope and graveled with railroad ballast rock. • Construct a temporary channel to move streamflow away from the boulder wall where the bankfull bench will be constructed. • Construct a bankfull bench from the toe of the road fill for a length of 250 feet over an area of about 1,800 sq.ft. or 0.04 acres. Place large boulders into the existing channel to construct the foundation of a flat bench surface (2-20 feet wide) from the fill slope. • Excavate river substrate to establish a new channel location & fill voids between placed boulders and in the boulders of the lower road fill. • Excavate transplants from the nearby floodplain area along a 450 feet section, approximately 0.25 acres (Figure 4). Transplants would be placed on the bench at the final bankfull elevation. Use Coir matting to stabilize bare soil. • Complete excavation and grading of the new channel location; 250 feet long over an area of about 0.14 acres. • Construct a Boulder Vane (see Appendix B for detail) at the top of the reach to help turn flow in the river bend, and excavate a pool downstream of the structure. 31 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION A river high-flow channel and perennial tributary enter the S. Toe River at the proposed vane location. The increase in constructed elevation would alter the hydrology of these channels where they outlet together into the river. Final elevations would enhance the existing wetland/bog environment at this location. • Exit the project reach by way of the constructed temporary access route. Recontour the disturbance and apply erosion control measures, including seed, mulch and coir matting. All disturbed soil would be seeded and mulched (Tables 1 & 2). These actions would minimize the erosion and sedimentation impacts on the river. Table 1 - Grass and grass -like species seeding list. Community Type: Riparian Common Name Percent of plantings Scientific Name Common Name Planting Density Elymus virginicus Virginia wild rye 22 lbs/acre Festuca rubra Creeping red fescue 5 lbs/acre Dichanthelium clandestinum Deertongue 2 lbs/acre Aster sagittifolius Arrow Leaved Aster 2 lbs/acre Rudbeckia hirta Black Eyed Susan 2 lbs/acre Eupatorium fistulosom Joe Pye Weed 1 lbs/acre Eupatorium perfoliatum Boneset 1 lbs/acre Asclepias syriaca Common Milkweed 1 lbs/acre Table 2 - Tree and shrub planting list, container/bare root and live stake species. Scientific Name Common Name Percent of plantings Spacing (feet) Container & Bare Root Species: Alnus serrulata Tag Alder 20% 3 Calycanthus floridus Sweetshrub 10% 3 Clethra acuminata Cinnamon Bark Clethra 10% 4 Hamamelis virginiana Witch Hazel 10% 4 Hypericum densiflorum Bushy St. Johns 10% 4 Itea virginica 10% 4 Xanthorhiza simplicissima Yellowroot 10% 2.5 Platanus occidentalis Sycamore 20% 6 Live Stake Species: Cornus ammonum silky dogwood 10 3 Salix nigra black willow 20 3 Salix sericea silky willow 20 3 Salix humilis prairie willow 10 3 Sambucus canadensis common elderberry 30 3 Physocarpus opulifolius ninebark 10 3 41 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION South Toe Rimer Stream bank Stabilization Project 2016 PLAN VIEW SKETCH— PROPOSED ACTION s� i?biettive; � t' t f Red ucetherisk ofroad fill erosianarid improve aquatic and Stream - side habitat. 1. Proposed Action; a increasetheangle intheriverbend and movethechannelawayfrom Imo' theroadfillslope. Specific Actions_ A. ThetrackhoewouldaccesstheprojectsitefromFSR 472and crass r the river downstream of thework site. Theriver bed and banks at th' s s to are ccml.csed c`ccl,b a and boulder. B. r;crk n_ n:he. e:.17i17-I ,e . ngwate— rdayfrom j T CKHOE i the areac`e:ca,? Ci) 7:r I .cCr,-- -ic :l,% �Lnk`u11 G1 CCESSTO 25C =ce: _==.I,v!,: _._ . =:1.=:. :l 4 r ►1 ROJECT acres..- aj the - _ c pe. jjj r b] Exca• -.-. •ersubstratetcetal. d7 re%, u jfs 4 Lhari 15e c: 2R on ti,- aC CI_I]EC:=EEn rce.Il;3u de s and in the bouldersof .l the e cj Exca.a e rsl.antsfromthenearby ccdl. -n. p -.. n�-h emcnthebenchat a 1 he na Isank`u E E. a: CC,. U_ec r mattingtostabilize baresoil. C. Completeexcavation and grading ofthe new channel location; 250 feet long over ¢' anareaofabout 0.14acres, : p D. Construct a Boulder Va ne at th eto p ofth e l reach to, helpturnflow intheriverbend,o f and excavate a pool downstreanofthe �ffle i structure. A river high-flow channel and d; f perennialtributary entertheS. ToeRiver ¢ atthepro posed vane location. The increaseincor.structed elevationwould aIter thehydro lop ofthesechannels y i wheretheyoutlet togetherintotheriver. fl' Final elevations w ou Id enhancethe f existingwetland/bogenvironment atth s '2' location. Fel."P v� KEY TO ACTIVITIES: LOCA- ON OF CONSTRUCTED 1 LOW -FLOUR CHANNEL r' -J (Area of Excavation =0-14 acres) riffle IL CONSTRUCTED BANKFULL3i //II/J BENCH (Area of FilI= 004 acres) /ffff� r P CONSTRUCTED BOULDER ."rice, �f '4 VANE scale: '"2Sfeet p. FL 00PPLAim Figure 4 - Plan view sketch of proposed action. See also Appendix A. 5l Page South Toe River Stream bank Stabilization Project - PROJECT DESCRIPTION The following are measures taken to avoid or minimize the proposed impacts through construction techniques: A. Minimize the area and degree of soil disturbance that reduces infiltration capacity and permeability, and destroys protective forest floor and ground cover. B. All hazardous materials will be stored outside of flood -prone areas and surrounded with sediment fence to reduce the risk of materials reaching the river. C. Work activities would not be scheduled on rainy days. D. Heavy Equipment Operation. 1. All equipment shall be cleaned before entering the project area and stream, so as to reduce the risk of fine grained sediment and oils and grease from entering the stream. This would also reduce the risk of invasive weed spread onto the Forest. 2. Do not operate on wet soils when they are most susceptible to damage and erosion. 3. Operate heavy equipment on slopes less than 12 percent so as to reduce the risk of soil erosion. Avoid operating heavy equipment on over -hanging stream banks. 4. Move large woody debris in a manner that minimizes disturbance of the forest floor, exposure of mineral soil, or degradation of stream bank stability. E. Install sediment fence to trap potential sediment (Figure 5) at the end of each workday. F. Re -vegetate exposed soils as soon as possible to take advantage of the loose soil conditions for seeding. 1. Exposed soil will be covered with mulch or erosion control matting (Figure 6) at the end of the project or before predicted rainfall. Matting will be secured in place with stakes and live stakes where conditions allow. 2. Seeding will occur on all bare soil within five days of ground disturbing activities or sooner in conjunction with mulch and matting placement to provide long-term erosion control. 3. Stabilize channel banks with a native seed mix and mulch or matting as work is completed. G. Do not move sediment trap devices until the vegetation in the disturbed areas has been established. H. Temporary access routes will be covered with clean railroad ballast size rock during use and recontoured after the project work is complete (Figure 7). Disturbed soil will be stabilized with seed and cover (mulch and/or coir matting). I. During on-going operations inspect the site frequently; inspect occasionally during inactive periods. 1. Check for potentially damaging or failing situations that may cause unacceptable water quality impacts. 2. Correct failing situations as soon as practical. J. Conduct visual inspections of South Toe River while the work is being conducted to maintain acceptable turbidity levels. Use a skilled heavy equipment operator, trained in stream restoration and construction of in - stream structures. Instruct the operator to minimize disturbance to the streambed. 61 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION f,•TIU L:.[sJT. ItTGRIN RI ■al[D TEMPORARY1-1.1.0IT ," 911C:.1i P101T SEDIMENT/SILT FENCE CONSTRUCTION DETAIL nL, IOOT _*TML h;•`.'Th`,9 LO -0 �- vrR...! �J P:TIi.7 Step I Orrve steel posts at least 12 in into ground and excavate a 40. x 8in. trench uphill along the ine of posts. Step 2: Attach wire fence to posts and extend the bottom of the fence 8in into the excavated trench. Step 3 Attach the fitter fabric to the wire fence and extend the bottom of the fabric 8in. Into the trench. .� SIPPOAT I DIC! f 4.x. opAC Ago wRpvT f wMlNNO11T I"to I Pd�QtN. Ml IMLI MIRR TOOT /RTUI IA�Aq ATD16�p 1TIML PMT7.�lOW �.� 0WORgC/ToepwoM1 VATS P110J�CTD 11 �� MAOI POlT ALJ.,WT 1 ; Step 4 BaCIM11 the trench and compact the soil firmly to anchor the Ir tax �I r x! rAame " bottom of the Silt fence So that II l van C�*WACTO runoff is forced to go through the GAC 0 fence and cannot go around it. 10110CA w 10 NA WV1 M&Cf AI I Ir ocko/11G Mt, AN.yT +IrAXLoaxb) la Nt a►u>vusaacr► TOWN w 111 oAAYp NOTES: t. INSPECT AND REPAIR FENCE AFTER EACH STORM EVENT 4REMOVE SEDIMENT WHEN NECESSARY. 2. REIIpvE 0 ' EOIMENT SHALL BE DEPOSITED TO AN AREA THAT WILL NOT CONTRIBUTE SEDIMENT OFF•SiTE aC.QN 6E PERMANENTLY STABILIZED. 3 SILT FE14CE SHALL BE PLACED ON SLOPE CONTOURS TO MAXIMIZE PONDINOEFFICIENCY. Figure 5 - Temporary sediment/silt fence construction detail. 71 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION F�RQSiQN&4r_`1TR L_M1ATT1NC Q_FTAJ_L TOP OF BANK EROSION CONTROL BLANKET FROM BANKFVLL TO V ABOVE TOP OF BANK COVERING SEED 100 GRAM COIRMATTMIG BANIOULL —• V LONO FROM TOE OF BANK TO WOODEN BANKFVLL ELEVATION. NAIL IN STAKE COVERING SEED TOP OF 3' STAKES TOE Of X LONO v watortunsw SANK -1, WOODEN STAKE Figure 6 - Erosion control matting detail. 81 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION TE M PROARY ACCESS DETAIL x � •+` p • . CRDSS-SECTION A — W Mkt temporary access Large CvbNepoint bar , stream channelandbank ff or AREA OF EXCAVATION FOR TEMPORARY ACCESS TO PROJECT. • Excavate to a 2:1 slope and cover with clean railroad ballast gravel. • Place spoil on the Upper flat near the road and apply E&S control measures. • When work is complete restore soil to the bank, seed, MUICh, cover with Coir matting. P;acespoil on the upper flat near the road and apply E&S control measures.. Excavate bankto new slope & cover with clean railroad ballastgravel When work is complete restore soi I to the bank, seed, mulch,coverwith Coir matting. Figure 7. Plan view and cross section of proposed temporary access route. 91 Page South Toe River Streambank Stabilization Project— PROJECT DESCRIPTION *Goes*, p • . CRDSS-SECTION A — W Mkt temporary access Large CvbNepoint bar , stream channelandbank ff or AREA OF EXCAVATION FOR TEMPORARY ACCESS TO PROJECT. • Excavate to a 2:1 slope and cover with clean railroad ballast gravel. • Place spoil on the Upper flat near the road and apply E&S control measures. • When work is complete restore soil to the bank, seed, MUICh, cover with Coir matting. P;acespoil on the upper flat near the road and apply E&S control measures.. Excavate bankto new slope & cover with clean railroad ballastgravel When work is complete restore soi I to the bank, seed, mulch,coverwith Coir matting. Figure 7. Plan view and cross section of proposed temporary access route. 91 Page South Toe River Streambank Stabilization Project— PROJECT DESCRIPTION APPENDIX A - Project Area Plan -Views 101 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION South Toe River Streambank Stabilization Proiect 2O16 ►TM0.141LI IXCU9612:1ON931x416.119: I I I P a g e South Toe River Streambank Stabilization Project— PROJECT DESCRIPTION South Toe River Streambank Stabilization Proied 2015 PLAN VIEW SKETCH— CURRENT CONDITION Current Condition Description: In the hu - cane storms c= - �, rh s sa, a road i seaixvn- :a -S_ cdecl a::a, andrhe channel s re cca_vcl n.c 'Iheraadpt sm. Repair`c owing � the daira�E nc udedthe - ccat-cn c= -he r channe a a _.ci„ :h-- cacl l,. e ase = I construc.ed c- a Vie= .edl,cU clv =,phc.c The ne-, cca cn`-:a ccns--uc--da--he toe c:-17 = —11E :01, encl c=:17 = vachc=:ha South Toe River is oriented at a nea gv degree angleto the Forest uery ce rcad. Aa -u t, during high strea - : c.. e•.en:s, - ... energy is h'ghaga-nst'he cad' asstreair-owhitsthe ! .t matera and -u -ns -he Lend and = c: -s atthe J :ce ci:he = c: al,cu:,ESCTelt, O.e -he ,,ears ' highstream- c:v against the slope ha• e e clod mater a - ci~ skates Let:veen Lou de s and7l nc:al, a ar—,cun, c= c•s r_s des n:he I,cu der wall.Add . onaierosion c -:he cad - l and i continued ass of quality aqua-chabitatinthe I ,� reach are a concern_ r o 9 I 7 ro y.. m j . P Y l F r Lowflow r � L Ji c South Toe River Streambank Stabilization Project— PROJECT DESCRIPTION 12IPage � r P. KEY: BANKFULL ELEVATICFN Sale: �2sfeet �-3/'PtlY6 12IPage baLl r5so— uth Toe Rive r Streambank Stabilization Project 2016 AERIAL IMAGE WITH PROPOSED ACTION KEY TO ACTIVITIES: .?� . , LOCATION OF CONSTRUCTED LOW -FLOW CHANNEL (Area of excavation = 0.14 acres) • s' CONSTRUCTED BANKFULL // • • BENCH (Area of Fill =4.04 acres) CONSTRUCTED BOULDER VANE R 0 w TRACKHOE ACCESS TO PROJECT N 13IPage South Toe River Streambank Stabilization Project— PROJECT DESCRIPTION .?� . , o R 0 w TRACKHOE ACCESS TO PROJECT N 13IPage South Toe River Streambank Stabilization Project— PROJECT DESCRIPTION APPENDIX B -STREAM RESTORATION SPECIFICATIONS EQUIPMENT AND OPERATOR SPECIFICATIONS A) Manner of Construction - Excavation will be done in a manner which will minimize sedimentation in the stream channel. Silt fence will be installed downstream of the construction area to reduce the risk of sediment entering the stream. B) Equipment Operator Performance - Equipment operators shall be experienced and competent in the use of the equipment to which they are assigned. They shall be expected to demonstrate a level of proficiency with the equipment which enables them to be productive in all aspects of stream restoration work. Equipment operators shall be experienced in the construction of Rosgen designed structures; including the cross vane, J - hook vane, and Toe-wood/Sod mat. Operators will be instructed by the construction inspector as to the desired result of construction activities. Operators will be responsible for determining how best to use equipment to achieve the desired results. Chain saw operators will be required to cut trees, limbs and root masses as necessary to facilitate the removal and placement of debris in the stream. C) Environmental Considerations - Earth moving equipment will cross and operate in the stream flow only when necessary and only when directed to do so by the construction inspector. Equipment shall be new or of low hours and be maintained to prevent fuel, oil and lubricant spills in the vicinity of the stream. Refueling, repairs and lubrication will be performed at a safe distances from the stream and only at locations approved by the construction inspector where water is controlled by runoff control measures. D) Safety Considerations - At work sites, where equipment will be operated on Forest Roads, flagman shall be stationed to warn oncoming traffic of congestion. Construction road signs shall be in place and a means of removing sediment, mud or rocks from roadways shall be established. The contractor will be responsible for the implementation of these measures. E) Equipment Specifications Hydraulic Excavator: • Track mounted, hydraulic powered. • Excavator: o Min weight— 30,000 lbs o Min. Reach — 22 feet o Min Digging Depth — 20 feet o Min Bucket size —1.0 Cu Yd. o Min 115 HP o Equipped with hydraulic thumb, with experienced operator as described above. (More than 1 excavator may be required. Unit price bid should be for one excavator for one hour of running time). IN -STREAM STRUCTURES SPECIFICATIONS Structure Stone Description The work covered by this section consists of furnishing, stockpiling, placing and maintaining approved stone to be utilized to construct rock and log vanes, root wad structures, the step -pool structures, 141 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION stream crossings, sediment and erosion control measures for use in locations as directed by the Designer. The quantity of stone may be increased, decreased, or eliminated entirely at the direction of the Designer. Such variations in quantity will not be considered as alterations in the details of construction or a change in the character of the work. Materials Stone for "Railroad Ballast" and "Boulder" shall consist of blasted stone or other stone approved by the Designer. The stone shall be sound, tough, dense, resistant to the action of air and water, and suitable in all other respects for the purpose intended. All stone shall meet the approval of the Designer. While no specific gradation is required, the various sizes of the stone shall be equally distributed within the required size range. The size of an individual stone particle will be determined by measuring its long dimension. Acceptance Criteria for Stone: CLASS REQUIRED STONE SIZES (INCHES) Minimum Average Maximum Railroad Ballast 2 3 6 Boulder 60 72 84 72"x36"x24" No more than 5 percent of the material furnished can be less than the minimum size specified, more than 10 percent of the material can exceed the maximum size specified. Boulders shall be relatively flat on either side in the same dimension, preferably the long dimension. Construction The Contractor shall place stone, in locations shown on the construction plans to the thickness, widths, and lengths as shown on the construction plans or directed by the Designer. All stone shall be placed neatly and uniformly with an even surface to form an in -stream structure or a sediment and erosion control device or in accordance with the construction plans and special provisions, and shall meet the approval of the Designer. Method of Measurement The quantity of stone required to construct the structures or sediment and erosion control measures detailed in these special provisions will be incidental to those bid items. However, field conditions may warrant the need for additional stone greater than the quantity specified or detailed for each bid item. The quantity of stone that has been incorporated into the project, as directed or approved by the Designer, which exceeds 110% of the quantity required for each bid item will be measured by weight. Measured by weight will require the quantity to be weighed in trucks on certified platform scales. Stone that was previously stockpiled for other bid items will not be measured a second time for this provision. 151 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION Basis of Payment When field conditions dictate the need for additional quantity greater than 10% of the bid item, the quantity of stone measured as provided above, will be paid for at the contract unit price per ton for "Misc. Coarse Aggregate, No. 57 Stone", "Misc. Rip Rap -Class B", and "Misc. Boulder". Such price and payment will be full compensation for all work covered by this section, including but not limited to furnishing, weighing, stockpiling, re -handling, placing, and maintaining the stone and disposal of any materials not incorporated into the project if directed by the Designer. Payment will be made under: RailroadBallast..................................................................................................................................TON Misc. Boulder..........................................................................................................................TON Rock Vane Description Rock Vanes are primarily used for turning flow energies and secondarily holding grade. These structures serve to maintain the integrity of the upstream riffle while promoting scouring in the downstream pool. The design shape is roughly an arm with the apex located on the upstream side at the foot of the riffle. Footer boulders are placed in the channel bottom for stability. Header boulders are then placed on top of these footer boulders. Header boulders in the middle of the channel are at approximately the same depth as the riffle. The vane is on one side of the channel; boulders are placed at an angle to the stream bank, gradually inclining in elevation until they are located near the bankfull surface directly adjacent to the stream bank. Water flowing downstream is forced over these boulders towards the middle and opposite side of the channel, effectively turning flow and scouring out a pool below. Boulders placed at the apex hold back streambed material and prevent it from washing downstream. The quantity of Rock Vanes may be increased, decreased, or eliminated entirely at the direction of the Designer. Such variations in quantity will not be considered as alterations in the details of construction or a change in the character of the work. Materials All materials shall meet the requirements of boulder as outlined in Special Provision "Structure Stone". Back fill material shall be obtained from the stream channel bed, likely from the constructed pool. Large woody debris may be incorporated into the structure as directed by the Designer. Installation A trench shall be dug in such a manner that the footer boulders, the hook header boulders and at least 1/3 of the wing boulders are buried beneath the bed surface elevation. Refer to the construction plans for exact installation guide and locations of vane to be installed. An excavator, with a bucket that includes a hydraulic thumb, shall be used to place boulders under the supervision of Designer. Footer boulders shall be placed first with header boulders placed on top prior to any back filling of the trench. Boulders shall be selected and positioned such that they butt tightly together and there are multiple contact points between all boulders (flat smooth surfaces that fit together). Gaps between boulders shall be filled (chinked) with a combination of class A and No. 57 size stone found on site until plugged. 161 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION In the center portion of the channel (vane invert), the header boulder shall be placed with gaps between the rock with the top of the header boulder at an elevation designated by the Designer. The header boulders in the side, or wing, portion shall be placed in such a manner as they slope up from bed elevation to bankfull or below at a 2 to 7 percent slope or as shown in detail. Header and footer boulders at both banks shall be tied in securely to the bank in such a way that eliminates the possibility of water diverting around them. A rock sill shall be utilized to further prevent water from cutting around the structure. The area between the stream bank and vane on the upstream side of the structure will be backfilled with stream bed material. Structures shall be built to the approval of the Designer. The Designer may adjust the number and placement of structures in the field. Basis of Payment Payment for installation of Rock J -hook Vane shall be as outlined. This payment shall be considered full compensation for all labor, equipment, hauling, placing, handling, sorting, fitting, materials, and incidentals necessary to construct the rock vane. Payment will be made under: Equipment& Labor...................................................................... Materials: Boulders...................................................................... EROSION CONTROL SPECIFICATIONS Seed (Native) ........................................................... HOURS ................................................................ TON Description Seeding shall occur within 24 hours of ground disturbing activities. Seed shall be applied by hand or with a cyclone seeder and on steep slopes be immediately covered with leaf litter , raked in from the surrounding area. On stream banks, biodegradable matting/blanket shall be placed to keep seed and soil in place. Below are native grass species to be sown and their seeding density of pure live seed. Community Type: Riparian Scientific Name Common Name Planting Density Elymus virginicus Virginia wild rye 22 lbs/acre Festuca rubra Creeping red fescue 5 lbs/acre Dichanthelium clandestinum Deertongue 2 lbs/acre Aster sagittifolius Arrow Leaved Aster 2 lbs/acre Rudbeckia hirta Black Eyed Susan 2 lbs/acre Eupatorium fistulosom Joe Pye Weed 1 lbs/acre Eupatorium perfoliatum Boneset 1 lbs/acre Asclepias syriaca Common Milkweed 1 lbs/acre Materials All materials shall meet the approval of the Designer. 171 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION Basis of Payment Payment for installation of seed and mulch will be paid for as outlined. This payment shall be considered full compensation for all labor, equipment, furnishing materials, hauling, rehandling, sorting, materials, and incidentals necessary to seed and mulch. Payment will be made under: Seed.......................................................................................................................................................................................ACRE Matting Materials All materials shall meet the approval of the Designer and include Coir fiber mat 700, hardwood stakes, and live stakes (see "Planting" Specs). Installation Coir fiber mat 700 shall be used on upper and lower stream banks (above and below the bankfull elevation). The matting shall be fastened in place using hardwood stakes. During the following plant dormant season, live stakes shall be planted in the matting from water's edge to just above bankfull. Species include silky dogwood (Cornus ammonum), black willow (Salix nigra), silky willow (Salix sericea), ninebark (Physocarpus opulifolius) and common elderberry (Sambucus canadensis) from a local source. Provide stakes made of hardwood to anchor the matting. Stakes shall be installed to no less than 1 foot deep for use on side slopes and along the top edge of matting. Place the matting upon final grading, following seed and mulch application. Provide a smooth soil surface free from stones, clods, or debris which will prevent the contact of the matting with the soil. Unroll the matting on the contour, starting at the bottom of the slope and apply without stretching such that it will lie smoothly but loosely on the soil surface. Bury the top end of each piece of matting in a narrow trench at least 6 in. (150 mm) deep and tamp firmly after staking with evenly spaced stakes. Stake the matting according to the manufactures recommended pattern for specific product and slope. Where one roll of matting ends and a second roll begins, install matting end -over -end with approximately 6 inches of overlap. Stake through overlapped area. Install stakes across the matting at ends, junctions, and trenches approximately 1.3 feet apart. Basis of Payment Payment for installation of matting will be paid for as outlined. This payment shall be considered full compensation for all labor, equipment, furnishing materials, hauling, stockpiling, rehandling, sorting, fitting, materials, and incidentals necessary to install matting. Payment will be made under: Matting................................................................................................................................................................... LINEAR FOOT Plantings Description Plantings shall be specified in each contract as to type e.g., container, bare root, and live staking. Plantings from containers shall be from one gallon containers and can be planted throughout the year. Live staking and bare root planting shall occur during plant dormancy. Bare root seedlings shall be 6 to 12 inches tall. Below is a list of woody vegetation species to be planted on stream banks and floodplains. 181 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION Scientific Name Common Name Percent of plantings Spacing (feet) Container & Bare Root Species: Alnus serrulata Tag Alder 20% 3 Calycanthus floridus Sweetshrub 10% 3 Clethra acuminata Cinnamon Bark Clethra 10% 4 Hamamelis virginiana Witch Hazel 10% 4 Hypericum densiflorum Bushy St. Johns 10% 4 Itea virginica 10% 4 Xanthorhiza simplicissima Yellowroot 10% 2.5 Platanus occidentalis Sycamore 20% 6 Live Stake Species: Cornus ammonum silky dogwood 10 3 Salix nigra black willow 20 3 Salix sericea silky willow 20 3 Salix humilis prairie willow 10 3 Sambucus canadensis common elderberry 30 3 Physocarpus opulifolius ninebark 10 3 Materials All materials shall meet the approval of the Designer. Basis of Payment Payment for installation of plantings will be paid for as outlined. This payment shall be considered full compensation for all labor, equipment, furnishing materials, hauling, rehandling, sorting, materials, and incidentals necessary to plant. Payment will be made under: Plantings...............................................................................................................................................................................EACH Temporary Silt Fence Description Furnish material, construct, maintain, and remove temporary silt fence in locations shown on the plans or in locations that require surface drainage to be filtered. Materials Posts: Provide steel posts meeting the following requirements: • Minimum 5 feet (1.5 meters) long. • Minimum 13/8 inches (34.9 mm) wide measured parallel to the fence. • Minimum weight of 1.33 Ib/ft of length. • Equipped with an anchor plate with minimum area of 14.0 square inches (9,032.1 square mm). • Have a means of retaining wire and fabric in the desired position without displacement. Woven Wire Fence: Provide woven wire fence meeting the following requirements: • Minimum 32 inches (812.8 mm) high. • Minimum 5 horizontal wires. 191 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION Vertical wires spaced 12 inches (304.8 mm) apart. Minimum 10 gage top and bottom wires. Minimum 12 % gage all other wires. Filter Fabric: Provide Type 3 engineering fabric, Class A or B meeting the requirements of Section 1056 of the NCDOT Specification book. Attachment Device: Provide an approved attachment device (e.g., plastic tie). Installation Install in locations as shown on the plans or as directed. Install wire and fabric as shown in the plans. Class B synthetic filter fabric may be used without the woven wire fence backing, subject to the following conditions: a maximum post spacing of 6 feet (1.8 m), fabric is approved by the Designer, and post spacing is inclined toward the runoff source, at an angle of not more than 20 degrees from vertical. Install posts at a 10 feet (3.0 m) maximum spacing with wire support, with not more than 4 feet (1.2 m) of the post appearing above ground. Attach filter fabric to the wire fence on the upslope side of the post with wire or other acceptable methods. Overlap filter fabric a minimum of 18 inches (457.2 mm) at splice joints. Install fabric that is free of defects, rips, holes, flaws, deterioration, or damage. See figure below for detail. Basis of Payment Payment for installation of silt fence will be paid for as outlined. This payment shall be considered full compensation for all labor, equipment, furnishing materials, hauling, weighing, stockpiling, rehandling, sorting, fitting, materials, and incidentals necessary to construct the silt fence. Payment will be made under: SiltFence...............................................................................................................................................................LINEAR FEET 201 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION TEMPORARY WETRO STRENGTH FILTE R MEE6E6 RXO IIT WMESHIRE ESX SNPPO PO RT RT SEDIMENT/SILT FENCE CONSTRUCTION DETAIL 133 L.ILI. EkR FDOT -- —"STEEL POSFS,@LO 110 WrrH PROJECTIONS Installation Step 1: Drive steel posts at least 12 in into ground and excavate a 4in. x Sin. trench uphill along the line of posts. Step 2: Attach wire fence to posts and extend the bottom of the fence Bin. into the excavated trench. Step 3: Attach the filter fabric to the wire fence and extend the bottom of the fabric Bin. Into the trench. Step 4: Backfill the trench and compact the soil firmlyto anchorthe bottom Ofthe siltfence so that runoff is forced t0 go through the fence and cannot go around it. ,1 �d --------------- NOTES: 1. INSPECTAND REPAIR FENCEAFTER EACH STORM EVENT &REMOVE SEDIMENTwHEN NECESSARY. 2. REMOVED SEDIMENT SHALL BE DEPOSITED TO AN AREATHATwILL NOTCONTRIBUTE SEDIMENT OFF-SITE & CAN BE PERMANENTLY STABILIZED. 3. SILT FENCE SHALL BE PLACED ON SLOPE CONTOURS TO MAXIMIZE PONDING EFFICIENCY. 211 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION F P WITH WIPE PO RT IA. NOE SU E SN P PO SPAC IW B MAX. 8PAC IN6 W RHO IIT I WIRE 811 PPO RT FENCE nNDIPVC I.T. PAfmpkC KT. 133 LR YLIN EkR FOOT STEEL P0=.q LONG II PICA rACHEP Y TO NPSTRBVA WITH PROJECTIONS OST LEADEOF F P A" �%. _ (RE Ew " T, r, STORAf.E -r, H OPC k eXSTRENCH LHRH COLFPACTEH t-1 L: HAOMILL STANDARD DETAIL TRENCH LM TH NATIVE EA1CK R L L ALTERNATE DETAIL TRENCH LM TH GRAVEL NOTES: 1. INSPECTAND REPAIR FENCEAFTER EACH STORM EVENT &REMOVE SEDIMENTwHEN NECESSARY. 2. REMOVED SEDIMENT SHALL BE DEPOSITED TO AN AREATHATwILL NOTCONTRIBUTE SEDIMENT OFF-SITE & CAN BE PERMANENTLY STABILIZED. 3. SILT FENCE SHALL BE PLACED ON SLOPE CONTOURS TO MAXIMIZE PONDING EFFICIENCY. 211 Page South Toe River Stream bank Stabilization Project — PROJECT DESCRIPTION