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HomeMy WebLinkAboutSUB200300108 Plan - Approved Stormwater Management Plan 2004-01-12SECTION A -A USE SIDE SLOPE OF EXISTING CHANNEL MODIFIED EC-1 CLASS 1 DETAIL SECTION B-B 2I I I I �2' DEPTH USEOTEXTILE FABRIC Equivalent Forest Protection BMP Protected area must be 1.5 times the Impervious surface area being "treated" If the pollutant removal rate is below 504. Area 1: 6774 sf x 1.5 = 10161 sf required Area 2: 5533 sf x 1.5 = 8330 sf required Riparian Protection Handbook for the James River 3.4 plants/1000 sf (2-3 shrubs for each tre(,) Plant List 16 Red Maple 16 Willow Oak 32 Bayberry Concentrated drainage shall be conveyed down slopes in non -erosive channels or storm sewers designed to carry the 10-year storm. The acceptance of approval implies that the applicant has agreed to use the materials as indicated on the erosion control plan, attachments and samples submitted. Any change in approved design or materials will require an amendment to the plan and must be reviewed and approved by the County of Albemarle Engineering Department. The developer shall reserve the right to install, maintain, remove and/or convert to permanent structure all erosion and sediment control measures required by this plan regardless of the sale of any lot. GENERAL EROSION AND SEDIMENT CONTROL NOTES ES-1: Unless otherwise Indicated, all vegetative and structural erosion and sediment control Practices will be constructed and maintained according to minimum standards and specifications of the Virginia Erosion and Sediment Control Handbook and Virginia Regulations VP 625-02-00 Erosion and Sediment Control Regulations. ES-2: The plan approving authority must be notified one week prior to the pre - construction conference, one week prior to the commencement of land disturbing activity, and one week prior to the final inspection. ES-3: All erosion and sediment control measures are to be placed prior to or as the first step in clearing. ES-4: A copy of the approved erosion and sediment control plan shall be maintained on the site at all times. ES-5: Prior to commencing land disturbing activities in areas other than indicated on these plans (including, but not limited to, off -site borrow or waste areas), the contractor shall submit a supplementary erosion control plan to the owner for review and approval by the plan approving authority. ES-6: The contractor is responsible for installation of any additional erosion control measures necessary to prevent erosion and sedimentation as determined by the plan approving authority. ES-7: All disturbed areas are to drain to approved sediment control measures at all times during land disturbing activities and during site development until final stabilization is achieved. ES-8: During dewatering operations, water will be, pumped into an approved filtering device. ES-9: The contractor shall inspect all erosion control measures periodically and after each runoff -producing rainfall event. Any necessary repairs or cleanup to maintain the effectiveness of the erosion control devices shall be made immediately. Existing vegetation: mostly wooded No off -site borrow or waste areas will be required for this plan. o / - O \ BENCHMARK: PKINAIL IN BASE\ OF 12" LOCUST ELEVATION=679.00 - 10280sf i � / equivalent Forest i Protection Area BMP - = - I / / / / treating area 18 1 " cal I trees /--�- - _-,- /_ / 17 18` shrubs / \ %---T--'`_ - - - 7- �- - 1 (plant list above) aLo I DRAINAGE \ o 0 DIVIDE \ WEIR LENGTH: 9. 5' C)Cc WEIR HEIGHT: 2. 3' , 3 TOP OF BERM: 679.3 v a / \ - TOP OF WEIR: 678.3' cn r cu \ LOT 9 \ BOTTOM OF WEIR: 676' 31x3l' o LOT 8 c� \ \ LOW POINT: 672' 23x23' wo / \ BERM WIDTH: 2.5' I q I I E uivolent` Forest \ \ +' DRAINA 11 1 1 1 1 i I `� \ \ \ H �r / \ AREA= 1 I I I \ rotection Are BMP c�`y / PERMANENTS 7�G.1 I I I I \ \ \ \ \ \ treating area 2 _ 20 D AINAAbEENT \ , m / \ DR�AI�NAGE \14 1` cal trees EASEMENT\ \ / \ EASEMENT ST11 I 15 18` shrubs ALONG SWALE\ 1 MODI�IED \ (plar" list above) 'TO STREAM EC-11 -I \ E I I I \ \ \ \ \ I \ (to be establ-ished after \ \DRAINAGE CLAS 1 _ , / \ \ I I \ \ I \ \ site is stablliz�d_ and \ I AREA= / / LANDMARK DRIVE (50\) U \ county allows silt 13 AG. I trap rbmoval) A. EA 2 AREA t \ UP/ I \ I \ I \ I \ I \ I , \ I \ I � \ 1 � i \ o O k, \ i \ i o PP66o Ppv� \ \ \ 77 CU Limits of \ \ \ \ \ \ \ \ \ \ \ t I DRAINAGE / I / Disturbance AR \ \ \ \ \ \ \ \ 0.117AC. qI \ \ Protopted Forest Sign I 1 I O�L�41gC 70 x 15 " \ CM PIPE \ \ \ \ \ \ \ I I \ LOT 7 I / \ \ \ \ \ \ I WEIR LENGTH: 3. 0' (2) STD. \ ES-2 \ \ ` I l 1 \ \ \ \ \ \ WEIR HEIGHT: 2.0' / (2) EC-1 CLASS 1 \ \ 1\OP OF BERM: I 683 ' Z TQP OF WEIR: 682' g \ \ \ \ \ \ \ \ \ \ \ I I I I BOTTOM QMMF WEI�: 680' 18x19' LOW PWIDT: \ 676; 10x11'BER \ \ \ \ \ \ I I I \ \ � \ REVISED \ o SOT 6 \ \ \ cJ "1\` w I \ \ t / / / / / / / / I / \ PERMANENT 1 \ \: / i I ( / / \ DRASNAGE \ 1 EASEMENT T I I I I I I I \ \ \ O o� rn m M I o� I I m I I \ I I ( \ \ \ I CD o f I o I o I CD I CDI o I o I o I \ I I CD I IITO1 Silt Trap #1 Silt Trap #2 Drainage Area (ac): 1.58 Drainage Area (ac): Wet Storage Req (cy): 0.50 33.5 Wet Storage Req (cy): Dry Storage Req (cy): 105.86 105.86 Dry Storage Req (cy): 33.5 Total Storage Req (cy): 211.72 Total Storage Req (cy): 67 Elev Side 1 Side 2 Area Vol Vol Elev Side 1 Side 2 Area Vol Vol (sf) (Cf) (Cy) (sf) (Cf) (cy) Low Point 672.0 23 23 529.0 Low Point 676.0 10 11 110.0 1: 1 side slope Bottom of Weir: 676.0 31 31 961.0 2980.0 110.4 wet 1: i side slope Bottom of Weir: 660.0 18 19 342.0 904.0 33.5 wet 2: 1 side slope 2: 1 side slope Top of Weir 678.3 40.2 40.2 1616.0 2963.6 109.8 dry Top of Weir 682.0 26.0 27.0 702.0 1024.0 38.7 dry Weir Length (ft): 9.5 Weir Length (ft): 3.0 Weir Height (ft): 2.3 Weir Height (ft): 2.0 Top of Berm: 679.30 Top of Berm: 683.0 Top of Weir: 678.30 Top of Weir: 682.0 Berm Width (ft) : 2.5 Berm Width (ft) : 2.5 Red or White Waterproof Exterior Grade z Exterior (araae background color Black Lettering Metal Sign Screws (typ)\ \ ftyP) 1/ 4 PROTECTED FOREST This area is protected against vegetation disturbance. No cutting, logging, bush or brush cutting. E Contact Albemarle County Department of Engineering and Public Works for further details. Project: Ivy Fields 0 11" (min) o Typical Forest Protection Sign (nts) Sign to be mounted 72' to 46' from ground level and shall be ppermanently afixed facing outward from the Protection area. Sign shall be fixed to exisking trees or exterior arade costs and boards. DRAINAGE -- ' AREA= / - 1.45 C. 1 /DRAINAGE / DIVIDE / / I I 1 I \ I \ I \ \ \ O FOREST PROTECTION NOTES: 1. Forest protection signs will be supplied and installed by the owner. 2. Trees must be 1.5' to 2' caliper and must be installed during the first planting season after issue of the grading permit. (Planting seasons are March 15 through June 30 and September 15 through November 15) 3. The developer shall maintain a one year 607 care and replacement warranty for all plants. The period of the warranty will begin after inspection and approval of the complete installation of all plants. 4. All reestablishment of forest area plantings shall be performed by hand and without mass grading equipment. Contact the Water Resource Personnel prior to planing for information on proper area preparation (434-296-5661). Temporary construction entrance is required for this site. Standard 9 Specification 3.02 is adequate due to the lack of available water to the site. Should the temporary construction entrance not be maintained properly or an excessive amount of soil found tracked onto the public roadway, then a paved construction entrance, water tanker truck with 2 pressure washers and a settling area may be required by the erosion and sediment control program administrator. The site will be permanently stailized after construction is completed as specified in the narrative. Ivy Fields Erosion/Sediment Control Narrative October 23, 2003 PROJECT DESCRIPTION The project consists of construction of a road for a four lot subdivision. This will require the disturbance of 1 acre. EXISTING SITE CONDITIONS The site is currently mostly pasture. ADJACENT PROPERTY This subdivision fronts on Dick Woods Road, Route 637, to the south. A tributary to Ivy Creek and Interstate 64 are off site to the north. Rural properties are to the east and west. OFFSITE AREAS No off -site areas will be disturbed. Earthwork balances on site according to road designer. SOILS 361�- Hayesville Loam, 2 to 7 percent slopes; 36C-Haysville Loam 7 to 15 percent slopes: and 36D- Hayesville Loam 15 to 25 percent slopes CRITICAL EROSION AREAS There are no critical erosion areas. EROSION AND SEDIMENT CONTROL MEASURES Unless otherwise indicated, all vegetative and structural erosion and sediment control practices will be constructed and maintained according to minimum standards and soecifications of the Virginia Erosion and Sediment Control Handbook (VESCH). STRUCTURAL PRACTICES 1. Construction Entrance- 3.02 A temporary construction entrance will be provided upon field determination by the County and the contractor. 2. Temporary Sediment Trap - 3.13 A small ponding area, formed by construction an earthen embankment with a stone outlet across a drainage swale. 3. Silt Fence- 3.05 A temporary sedtment barrier consisting of a synthetic filter fabric stretched across and attached to supporting posts and entrenched. 4. Temporary iversion Dike - 3.03 A ridge of compacted soil constructed at the top or base of a sloping disturbed area which diverts sediment -laden runoff to a sediment trapping structure. 5. Outlet Protection - 3.16 Riprop channel and/or stilling basins below storm drain outlets. VEGETATIVE PRACTICES 1. Temporary Seeding - 3.31 Establishment of temporary vegetative cover on disturbed areas by seeding with appropriate rapidly growing plants on sites that will not be brought to final grade for pperiods of 30 days to one year. German Millet at 60 lb./ac., Weeping Lovegrass at 3 )b./ac.. Korean L.espedeza at 20 lb./ac. Temporary seeding shall be fertilized. Fertilizer shall be applied at a rate of 600 It:s/acre of 10-20-10 according to the handbook. The builder may save considerable funds by h.,ving the soil tested by VA TECH (kits are available at the extension office and the test casts Z7.00). 2.. Mulch - 3.35 Organic mulch shall be used in conjunction with seeding operations and sball be applied at the rate of 2 tons/acre. 3. Dust Control- 3.39 Dust control Measures shall be utilized throughout this site when necessary. Typical temporary measures include but are not limited to, irrigation, temporary seeding barriers. These measures will aid in the prevention of harmful airborne substances as well the effects of wind erosion. MANAGEMENT STRATEGIES 1. Construction should be sequenced so that grading operations can begin and end as quickly as possible. 2. Sediment trapping measures shall be installed as a first step in grading and shall be seeded and mulched immediately following installation. 3. The job superintendent shall be responsible for the installation and matntenonce of all erosion and sediment control practices. 4. Temporary seeding or other stabilization will follow immediately after grading. 5 Areas which are not to be disturbed will be clearly marked by flags, signs, etc. 6. After achieving adequate stabilization, the temporary EgS controls will be cleaned out and converted to permanent stormwater management basins. PERMANENT STABILIZATION All areas disturbed by construction will be stabilized with permanent seeding immediately following finish grading. Seeding will be done with Kentucky 31 Tall Fescue according to Std. 9 Spec. 3.32 of The Virginia Erosion #- Sediment Control Handbook. 5-20-10 fertilizer shall be applied at the rate of 1000 lb/ac and lime at 2 tons/or. Permanently seeded areas shall be protected during establisbment with straw mulch (2 tons/ac). STORMWATER MANAGEMENT This is a rural subdivision with negligible change in stormwater. MAINTENANCE In general, all erosion and sediment control measures will be checked daily and after each significant rainfall. The following items will be checked in particular: 1) Should sediment basins and/or silt traps be required, they will be cleaned and maintained according to the Virginia Erosion E! Sediment Control Handbook. 2.) All gravel outlets will be checked regularly for sediment buildup that will prevent drainage. If the gravel is clogged by sediment, it shall be removed and cleaned or replaced. 3) All silt fence barriers will be checked regularly for undermining or deterioration of the fabric and repaired as required. Sediment shall be removed when the level of sediment deposition reaches half way to the top of the barrier. L') All seeded areas will be checked regularly to see that a good stand is maintained. Areas should be fertilized and reseeded as needed. MS-i Stabilization of Denuded Areas and Soil Stock lies Permanent or temporary soil stabilization must be applied to denuded areas within seven days after final grade is reached on any portion of the site. Temporary soil stabilization shall be applied within seven days to denuded areas that may not be at final grade, but will remain dormant (undisturbed) for longer than 30 days. Permanent stabilization shall be applied to areas that are to be left dormant for more than one year. Sod stabilization refers to measure which protect soil from the erosive forces of raindrop impact and flowing water. Applicable practices include vegetative establisbment, mulching, and the early application of gravel base on areas to be paved. Soil stabilization measures should be selected to be appropriate for the time of year, site conditions and estimated duration of use. MS-4 Timing and stabilization of Sediment Trapping Measures Sediment basins and traps, perimeter dikes, sediment barriers and other measures intended to trap sediment shall be constructed as a first step in any land -disturbing activity and shall be made functional before up -slope land disturbance takes place. NiS- 5 Stabilization Measures Stabilization measures shall be applied to earthen structures sucb as dams, dikes and diversions immediately after installation. MS- 17 Vehicle Access Where construction vehicle access routes intersect paved public roads, provisions shall be made to minimize the transport of sediment by (vehicular) tracking onto the paved surface. Where sediment is transported onto a public road surface, the road shall be cleaned thoroughly at the end of each day. Sediment shall be removed from the roads by shoveling or sweeping and transported to a sediment control disposal area. Street washing shall be allowed only after sediment is removed in this manner. This provision shall apply to individual subdivision lots as well to larger land disturbing activities. MS-15 Disposition of Temporary Measures A All temporary erosion and pediment control meosuresr1611\be removed within 30 Ndays after final site stabilization or after `the temporary measuf.es/aro no longer/neled�ed�,, un�e�ss otherwise authorized by the local progiram/ adm�nistra�tor. Trapped seOim,Pnh, and t� disturbed soil areas resulting from the disposition pf\temporary measures shall be permanently stabilized to prevent further ore 6sion and sedimentation. /f - __- s l in 1 (11)l Eilglnclering & Public ftrl ate,:. Jr/ GRAPHIC"t i 0 60 120 180 U -7 W. THOMAS MUNCASTER, JR. C-, CERT. NO. 16242 Q ti SSZ Z rn co 0 rn Q m V o rn a LU J cs CD 0 J Q a o a 0 Cc m zz- Q J o a 0 In m z 0 u� H J' 0 z m a o w M � H rn a ti ti o � � r H H m C m E E 0 m to 0 z z L o,-, W � � H C C > Lu m Cr w m 0 ti 0 C 00 17-1 LL Q ` J (� - z M m H CD � C- M LL] CD U --) 0 C 3 1 P Q LLJ 0- L H z 0 LL 0 U I-- r-1 W 0 IL L Q Q C � :�: 0 m x Q Q 0 U) 0 W DESIGNED BY DATE TM 10/23/03 DRAWN BY DATE TM 10/23/03 CHECKED BY DATE FILE EDIT Ivy Fields 2 - SCALE 1 " =60 DRAWING 1: 1 PLOT PROJECT 12721C ;0F 1 SHEET NO" i