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HomeMy WebLinkAboutWPO202000006 Plan - VSMP 2020-10-29Erosion and Sediment Control Narrative For: 2946 Monacan Trail Rd. TM 87 Parcel 26 Albemarle County, VA HUC: NORTH FORK HARDWARE RIVER 020802031201 LAT: 37.968000N LONG: 78.63180OW Project Description: The proposed work involves the construction of a new 1 P P P parking area and travelway at an existing store. The project area is on the west side of Monacan Trail Rd, just north of Taylor's Gap Rd. The total area of the parcel is 1.989 acres. The total on -site disturbed area is approximately 0.47 acre. Work will be completed Spring of 2020. Erosion control measures shown will protect the stream and property below from receiving silt -laden runoff. Existing Site Conditions: The project site area is in an open yard and field and generally slopes to the southeast at 5 to 8%. The overall pre and post drainage patterns will be the same. Adjacent Property: The property is surrounded by small residential lots and large acreage farms and wooded areas. Off -site Areas: No off -site areas will be involved in this project. Soils: 19C-Minnieville loam, 0.24 K-Factor, Group B soil 416-Yadkin loam, 0.28 K-Factor, Group B soil Critical Erosion Areas: There are no critical erosion areas in the project area Soil Stockpiles: A temporary soil stockpile will be utilized during the excavation of the parking area, then distributed over the drainfield area with final grading. 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 specifications of the Virginia Erosion and Sediment Control Handbook. Additional measures may be required during construction by the Erosion Control Inspector, as needed. Structural Practices: Construction Frntraace: (CE) 3.02 (To be installed where construction site traffic exits the project area, to remove soil from tires prior to travel on public roads. The contractor shall clean and maintain the travelway as required to keep soil from washing into unprotected areas and to provide a safe surface for pedestrian and vehicular access. The Construction Entrance will be located within the footprint of the existing building to protect the adjacent paved travelways. Once the building is erected, all adjacent areas will be stabilized and the construction entrance will no longer be necessary.) Silt Fence: (SF) 3.05 Silt fence (wire -supported) shall be constructed along the lower limit of graded areas. (To be installed as shown on the plan, down -gradient of disturbed areas created by the proposed work, and above the proposed excavation to prevent up -gradient runofffrom crossing disturbed areas. ) Level Spreader (LS) 3.21 An outlet for dikes and diversions consisting of an excavated depression constructed at zero grade across a slope to convert concentrated, sediment free runoff to sheet flow and release it into areas of undisturbed soil which is stabilized by existing vegetation. (To be installed at the end of the roof drains to disperse concentrated runoff.) Peramient Seeding (PS) 3.32 Establishment of perennial vegetative cover by planting seed where pernmient, long-lived vegetative cover is needed on fine -graded areas. (Permanent seeding will be provided on all disturbed areas designated to be landscaped on the site plan within 7 days of final grading.) Mulching (MU) 3.35 Application of plant residues to disturbed surfaces to prevent erosion and reduce overland flow. Apply to all seeded areas. Refer to Table 3.35-A on Sheet C3.3 for application rates. (To be installed along with Permanent Seeding) Dust Control (DC) 3.39 Reducing surface and air movement of dust during land disturbance, demolition or construction activities in areas subject to dust problemvs in order to prevent soil loss and reduce the presence of potentially airborne substances. (To be installed, if required by the County, where disturbed soil is to remain unprotected for an extended period. ) Vegetative Practices: Temporary Seeding 3.31: All areas disturbed by construction that will not be brought to final grade for a period of more than 14 days, will be stabilized by establishing a good stand of grass. Lime 3.31: Unless it is known that the site will remain undisturbed for many months, lime is not necessary. If necessary, the amount will be determined by Soil Test, or 3 tons per acre of pulverized agricultural limestone, uniformly applied to surface to be seeded during seedbed preparation and incorporated into the top 2-4 inches of soil. Fertilizer 3.31: 600 pounds per acre of 10-20-10 or equivalent, uniformly applied to the surface to be seeded during seedbed preparation and incorporated into the top 2-4 inches of soil. Surface roughening 3.31: Where disturbed soils have been compacted, loosen soils by discing, raking, or whatever acceptable means available to receive seed. Seed 3.31: Seed shall be broadcast evenly and planted from % to t/z inch deep. Seasonal seed selection shall be as follows: • Sept. 1 - Feb. 15: 50/50 Mix of Annual Rye and Winter Rye, 50-100 Ib/ac. • Feb. 16 - April 30: use Annual Rye, 60-100 Ib/ac. • May 1 - Aug. 31: use German Millet, 50 Ib/ac. Areas which fail to establish vegetative cover adequate to prevent rill erosion will be reseeded as soon as such areas are identified. Polly's Folly W PO2020-00006 Management Strategies: Construction should be sequenced so that grading operations can begin and end as quickly as possible. Areas that are not to P 9 q Y be disturbed shall be clearly marked by the placement of the erosion control measures prior to construction. The job superintendent shall be responsible for the installation and maintenance of all erosion and sediment measures. 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. Stabilization of Denuded Areas and Soil Stockpiles: Permanent or temporary soil stabilization must be applied to denuded areas within 7 days after final grade is reached on any portion of the site. Temporary soil stabilization shall be applied within 7 days to denuded areas which may not be at final grade but will remain dormant (undisturbed) for longer than 14 days. Permanent stabilization shall be applied to areas that are to be left dormant for more than one year. Soil stabilization refers to measures that protect soil from the erosive forces of raindrop impact and flowing water. Applicable practices include vegetative establishment, 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. Timing and Stabilization of Sediment Trapping Measures: Sediment barriers and traps, perimeter dikes, sediment barriers and other measures intended to trap sediment shall be constructed as a first step in an land disturbing activity and shall be made functional before u slo a land Y 9 Y P P disturbance takes place. Stabilization measures shall be applied to earthen structures such as dams, dikes, and diversions immediately after installation. Disposal of Temporary Measures: All temporary erosion and sediment control measures shall be removed within 30 days after final site stabilization or after the temporary measures are no longer needed, unless otherwise authorized by the local program administrator. Trapped sediment and the disturbed soil areas resulting from the disposition of temporary measures shall be removed and replaced with suitably compacted soils, or, where applicable, permanently stabilized to prevent further erosion and sedimentation. Maintenance: All erosion and sediment control structures and systems shall be maintained, inspected, and repaired weekly and after each significant rainfall or as needed to insure continued performance of their intended function. Any damage to structural measures shall be repaired immediately. Silt fence shall be inspected after every rainfall event and at least daily during prolonged rainfall, as well as at the end of every working day, with any necessary repairs made immediately. Accumulated sediment shall be removed and disposed of as it becomes necessary, or when deposits have accumulated to one-half of the above ground fence height. All undercutting or erosion shall be repaired immediately. the contractor shall follow all manufacturers recommendations for installation, maintenance, replacement, and repair. damages caused by construction traffic or other activity must be repaired before the end of each working day. All seeded areas are to be checked to insure a good stand is maintained. General construction notes for Erosion and Sediment Control plans 1. 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. 2. All erosion and sediment control measures will be constructed and maintained accordingto minimum standards and specifications of the Virginia P 9 Erosion and Sediment Control Handbook and Virginia Regulations VR 625-02-00 Erosion and Sediment Control Regulations. 3. All erosion and sediment control measures are to be placed prior to or as the first step in clearing. 4. A copy of the approved erosion and sediment control plan shall be maintained on the site at all times. 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. 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. 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. 8. During dewatering operations, water will be pumped into an approved filtering device. 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. 10. All fill material to be taken from an approved, designated borrow area. 11. All waste materials shall be taken to an approved waste area. Earth fill shall be inert materials only, free of roots, stumps, wood, rubbish, and other debris. 12. Borrow, fill or waste activity involving industrial -type power equipment shall be limited to the hours of 7:00am to 9:00pm. 13. Borrow, fill or waste activity shall be conducted in a safe manner than maintains lateral support, or order to minimize any hazard to persons, physical damage to adjacent land and improvements, and damage to any public street because o slides, sinking, or collapse. 14. Temporary stabilization shall be temporary seeding and mulching. Seeding is to be at 75lbs/acre, and in the months of September to February to consist a 50/50 mix of Annual Ryegrass and Cereal Winter Rye, or in March and April to consist of Annual Rye, or May through August to consist of German Millet. Straw mulch is to be applied at 80lbs/100sf. Alternatives are subject to approved by the erosion control inspector. 15. Permanent stabilization shall be lime and fertilizer, permanent seeding, and mulch. Agricultural grade limestone shall be applied at 90lbs/1000sf, incorporated into the top 4-6 inches of soil. Fertilizer shall be applied at 1000lbs/acre and consist of a 10-20-10 nutrient mix. Permanent seeding shall be applied at 180lbs/acre and consist of 95% Kentucky 31 or Tall Fescue and 0-5% Perennial Ryegrass or Kentucky Bluegrass. Straw mulch is to be applied at 80lbs/100sf. Alternatives are subject to approved by the County erosion control inspector. 16. Maintenance: All measures are to be inspected weekly and after each rainfall. An damage or clogging to structural measures is to be repair Y 9 99 9 P immediately. Silt traps are to be cleaned when 50% of the wet storage volume is filled with sediment. All seeded areas are to be reseeded when necessary to achieve a good stand of grass. Silt fence and diversion dykes which are collecting sediment to half their height must be cleaned and repaired immediately. 17. All temporary erosion and sediment control measures are to be removed within 15 daysof final site stabilization when measures are no longer needed 9 , subject to approval by the County erosion control inspector. 18. Permanent vegetation shall be installed on all denuded areas within nine (9) months after the date the land disturbing activity commenced. MINIMUM STANDARDS MS-1 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 15 days. Permanent stabilization shall be applied to areas that are to be left dormant for more than one year. Soil stabilization refers to measures which protect soil from the erosive forces of raindrop impact and flowing water. Applicable practices include vegetative establishment, 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-2 Duringconstruction of the project, soil stockpiles and borrow areas shall P 1 � P be stabilized or protected with sediment trapping measures. The applicant is responsible for the temporary protection and permanent stabilization of all soil stockpiles on site as well as borrow areas and soil intentionally transported from the project site. MS-3 A permanent vegetative cover shall be established on denuded areas not otherwise permanently stabilized. Permanent vegetation shall not be considered established until a ground cover is achieved that, is uniform, mature enough to survive and will inhibit erosion. MS-4 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 upslope land disturbance takes place. MS-5 Stabilization measures shall be applied to earthen structures such as dams, dikes, traps, basins and diversions immediately after installation. MS-6 Surface runoff from disturbed areas that is comprised of flow from drainage areas greater than or equal to three acres shall be controlled by a sediment basin. The sediment basin shall be designed and constructed to accommodate the anticipated sediment loading from the land disturbing activity. The outfall device or system design shall take into account the total drainage area flowing through the disturbed area to be served by the basin. MS-7 Cut and fill slopes shall be constructed in a manner that will minimize erosion. Slopes that are found to be eroding excessively within one year of permanent stabilization shall be provided with additional slope stabilizing measures until the problem is corrected. MS-8 Concentrated runoff shall not flow down cut or fill slopes unless contained within an adequate temporary or permanent channel, flume, or slope drain structure. MS-9 Whenever water seeps from a slope face, adequate drainage or other protection shall be provided. MS-10 All storm sewer inlets that are made operable during construction shall be protected so that sediment -laden water cannot enter the conveyance system without first being filtered or otherwise treated to remove sediment. MS-11 Before newly constructed stormwater conveyance channels are made operational, adequate outlet protection and any required temporary or permanent channel lining shall be installed in both the conveyance channel and receiving channel. MS-12 through 15 - Not applicable, no live watercourses. MS-16 Underground utility lines shall be installed in accordance with the following standards in addition to other applicable criteria: a. No more than 500 linear feet of trench may be opened at one time. b. Excavated material shall be placed on the uphill side of trenches. c. Effluent from dewatering operations shall be filtered or passed through an approved sediment trapping device or both and discharged in a manner PP PP 9 � � 9 that does not adversely affect flowing streams or off -site property. d. Restabilization shall be accomplished in accordance with these regulations. e. Applicable safety regulations shall be complied with. MS-17 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 every four hours. 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. MS-18 All temporary erosion and sediment control measures shall be removed within 30 days after final site stabilization or after the temporary measures are no longer needed, unless otherwise authorized by the local program administrator. Trapped sediment and the disturbed soil areas resulting from the disposition of temporary measures shall be permanently stabilized to prevent further erosion and sedimentation. MS-19 Channel Protection - The site's peak flow rate from a one-year 24-hour storm is less than 1% of the existing peak flow rate from a one-year 24-hour storm prior to implementation of any stormwater water quantity control measures. (9VAC25-870-66 B-4-b). VICINITY MAP SCALE: 1 "=500' 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 VR 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. THE RLD IS RESPONSIBLE FOR ONGOING MAINTENANCE AND OPERATION OF THE E&SC PLAN. FOR THE PURPOSES OF PLAN SUBMITTAL, REVIEW AND APPROVAL, THE RLD IS B. CLARK GATHRIGHT, P.E. SEQUENCE OF CONSTRUCTION 1. Install Construction Entrance and silt fence where shown on the plan. 2. Excavate foundations and grade travelways as required. 3. If the site will remain dormant for more than 15 days, provide temporary seeding measures to stabilize the surface. 4. Install storm pipe and structures and provide inlet protection. 5. When building construction is complete, completely distribute the temporary stockpile as necessary to complete final grading. 6. Apply mulching and permanent seeding on all permanently stabilized areas. 7. Remove silt fence after all disturbed areas are stabilized. APPROVED by the Albemarle County Communittyy Development Department Date 4/8I20 IiyIC�h71�Y�tY�rUUUIQ:� DRAWING INDEX SITE DATA: OWNER/DEVELOPER: THREEDEE LLC 1429 BURCHS CREEK RD CHARLOTTESVILLE, VA 22903 LOCATION: 2946 MONACAN TRAIL RD. TM 87 PARCEL 26 ALBEMARLE COUNTY, VA PLAN PREPARED BY: B. CLARK GATHRIGHT, P.E. 100 10TH ST NE SUITE 200 CHARLOTTESVILLE, VA 22902 TOTAL SITE AREA: 1.989 Ac. ZONING: RA SOURCE OF TOPOGRAPHY: COUNTY GIS NEW BUILDING ADDITION & PARKING AREA DISTURBED AREA: 0.46 ACRE EXISTING IMPERVIOUS SURFACE: 0.1 ACRE NEW IMPERVIOUS SURFACE: 0.25 ACRE WATER QUANTITY: SITE CONTRIB. DRAINAGE AREA: 0.46 AC., IS LESS THAN 1% OF 159 AC. STREAM WATERSHED. LAND AREA IS LESS THAN 1% OF THE TOTAL WATERSHED (9VAC25-870-66 B-4-A) CHANNEL ADEQUACY: RUNOFF IN THE VDOT MEDIAN CHANNEL IS CALCULATED AT THREE POINTS AND IS ADEQUATELY CONTAINED WITH ALLOWABLE VELOCITIES AT EACH LOCATION. WATER QUALITY: 0.28 LB./YR NUTRIENT CREDIT PURCHASE REQUIRED CRITICAL SLOPES: NO CRITICAL SLOPES IN THE PROJECT AREA. TIMING OF CONSTRUCTION: SPRING 2020 1 T-1.0 TITLE SHEET & EROSION AND SEDIMENT CONTROL NARRATIVE 2 C-1.0 EXISTING CONDITIONS & EROSION AND SEDIMENT CONTROL PLAN 3 C-1.1 STORMWATER MANAGEMENT PLAN 4 C-1.2 EROSION AND SEDIMENT CONTROL DETAILS 5 C-1.3 CALCULATIONS 0 N U CD cn CV CV U Q M J z � J O (D . CD N L- J (� W _J w W C'� zwrn C/) O O O ~ U T_ � � (16o U00 �TH OF f f' OB. CLARK GATHRIGHT Z Lic. Pio. 3 3 �S$IONAL O1 U\-1 Q Q � Z O- J N 0 Z 0 70 L (B _c_- Z i ww Z 7Ci Q Q N ~ dS Z LML N (6 Q LuZ ` o =0 =_ (/) - 00 O CC J 0 G 0) a H N �:= LU REVISIONS: 03-19-2020 DATE: 02-10-2020 DRAWING NUMBER: T-1 00 SHEET 1 OF 6 I 1 I 71 I \ \ 0000 /000e r / 00000 � - �/ LIMIT OF DISTURBANCE0000 / 20,187 SF, 0.46 AC_ _ _ — — _ /R IMOVE PORCH EXISTING 2-STORY ' BUILDING / RET, WALL EXISTING PAVEMENT RT. 29' S.B. < EXISTING 15" CULVERT / EXISTING CONDITIONS/DEMOLITION PLAN TOPO SOURCE: COUNTY GIS C 1.o� SCALE: I"=30' LINETYPE & SYMBOL LEGEND EXISTING CONTOUR LINE PROPOSED CONTOUR LINE PROPERTY BOUNDARY — — — — — — — — — — DRAINAGE DIVIDE LIMIT OF GRADING 1� 1� 1� 1� 1♦ SOIL TYPE BOUNDARY = SOIL TYPE XXX SWPPP NOTE: THE USE OF CHEMICALS/SOLVENTS IS NOT ANTICIPATED. PAINTS, STAINS AND POLYURETHANE FINISH MATERIALS WILL BE STORED INSIDE THE BUILDING. / / / `"low / � 1 / I / ' I / I / / / / / / / 1 CONSTRUCTION ENTRANCE 3.02 Q SILT FENCE 3.05 S F X X STORM DRAIN INLET PROTECTION 3.07 I P TEMPORARY SEEDING 3.31 TS PERMANENT SEEDING3.32 PS MULCHING 3.35 SOIL BLANKETS & MATTING 3.36 TEMPORARY SOIL STOCKP4 1 2 EROSION & SEDIMENT CONTROL PLAN C-1 .0SCALE: 1 "=30' RT. 29 S.B.L. \ I I I I I I I � I U CV C:� m N c— N U Q co' J z � J o C7 .� J co c— J 0 uJ U) fCa Z W V U clq C:> i O 0 J _� U Q 00 m CD o 2 I:t m U t UB. CLARK CA RIGHT z 0 vs Iq-Zo2p SSIONALGS W ZZ Q Q u J CL rn ZCN 00 Q J ~ OZ 70 �O co W CD F.- (j Z CW L OLLJ Q v Lm ZC) N Oz (� U Q cn co m Z �a 0 ZO 00 p � -O a H CV X � W W REVISIONS: 03-19-2020 DATE: 02-10-2020 DRAWING NUMBER: C-1 00 SHEET 2 OF 6 I •. / � \ � \ \ \1 \ \ill I III I I l \\ \ \ \\ fy� I /� ; 0.15 AC. NEW IMP. AREA�'- \ If it III �, I � ` -�--- �'`��� \ \I I I ,/ i / � - � I / I I \ �\ \ \ \ \ � \ \ \ \ \ \�\ \ \ \ \\ \ \ \ \ I / �`•�� \ I / CONCRETE DITCH - _ - _ ` % \ _ 1 Af \ ' \1 •'Ps-L—� � � � � � STA 1 T �T - - _ v ----� STA 2 � _! \ � � �\� _ - \ �-�_\ � POINT OF ANALYSIS _ _ DA: 9.37 AC. I(�� - - - - EXISTING 15" CULVERT STA 3 _ - _ \ \ 7 , 0.79 AC. IMP. POINT OF ANALYSIS 1 \ \ \ /<� _-_--------- ---- - ���� _ \ / EXISTING 15" CULVERT I \---------- ---- ---- �� \ --- �y�= DA: 4.61 AC.' l I \ / --^ - CONCRETE DITCH _ - - - - - _ _ - _ - - _ PRE IMP AREA: 0.79 AC. \ \ i \ / / i i / r---�__- - - _- - - T �� - - - _ _ � _ POST IMP. AREA: 0.94 AC. \ \ I I / - / - - - - - _ _ _ - / / // ^ / — \ "'� - G / a BOX CONCRETE ---_ BOX CULVERT OVERALL DRAINAGE AREA TOPO SOURCE: COUNTY GIS C-17 77771717 Slormwater Summary The proposed improvements will disturb 0.47 acre of the total 1.989 acre parcel. Runoff from the project area discharges and sheetflows into a culvert on Rt. 29 southbound ditch, which conveys runoff into a concrete v-ditch in the median. Ultimately, the median ditch discharges into a stream. At this point, the project site area is less than 1 % of the stream watershed. Channel adequacy of the VDOT median is checked at three locations. At each point, the channel is adequate for the increase in runoff from 2-year and 10-year storms generated by the new development. STA 1 Concrete 1:1 v-ditch 2-year peak flow: 8.27 cfs, Max. Velocity: 12.94 fps 10-year peak flow: 20.49 cfs, Max. Velocity: 15.23 fps STA 2 Grass 3:1 / 16:1 v-ditch 2-year peak flow: 8.77 cfs, Max. Velocity: 3.02 fps 10-year peak flow: 21.36 cfs, Max. Velocity: 3.77 fps STA 3 Concrete 1:1 v-ditch w/ riprap above 2-year peak flow: 6.21 cfs, Max. Velocity: 12.43 fps 10-year peak flow: 24.45 cfs, Max. Velocity: 177.52 fps 0.46 AC. STREAM DRAINAGE AREA SCALE: 1 "=509 STREAM WATERSHED: 159 AC. SITE CONTRIB. DRAINAGE AREA: 0.46 AC. LESS THAN 1% OF AREA. LAND AREA IS LESS THAN 1% OF THE TOTAL WATERSHED (9VAC25-870-66 B-4-A) N U rn N CV CV U Q -0 J z J o 0 - O 0:� C- L .� J U) J > (13 w U) z W `1 cn o Ca o OJ ti 00 cti m U H t UB. CLARK GATHRIGHT z uc. 0 3 3� 0 03 I q-2�2o v �SSIONAL �OS z N N Q a J > a Z 70 L LI__I V I U L V Z Z 70 \ L O N w LL N 1.-- O _ C G — 00 O �'4 O H N ~ REVISIONS: 03-19-2020 DATE: 02-10-2020 DRAWING NUMBER: C-1 1 9 SHEET 3 OF 6 STONE CONSTRUCTION ENTRANCE GROUND 70' MIN, EXISTING AI 3, PAVEMENT 5:1 Y FILTER CLDTH� 6" MIN. AI MOUNTABLE BERM (OPTIONAL) SIDE ELEVATION 12' MIN. V➢OT #1 COURSE AGGREGATE ' MUST EXTEND FULL WIDTH OF INGRESS AND EGRESS OPERATION RE6I u.iI uKNIN B 70' MIN. WASHRACK (OPTIONAL) i \ POSITIVE DRAINAGE B TO SEDIMENT TRAPPING DEVICE PLAN VIEW SECTION A -A SECTION B-B SOURCE: ADAPTED from 1983 Maryland Standards for Soil erosion and Sediment Control, and Va. DSWC Plate 3.02-1 CONSTRUCTION ENTRANCE DETAILS SCALE: NONE CONSTRUCTION OF A SILT FENCE (WITH WIRE SUPPORT) POSTS1. SET . THE POSTS. TRENCH UPOF POSTS. SLOPE ALONG THE LINE •..I� 1� I Jill IIIIl�I�► °�,,,,I _iill� I II�� 3. ATTACH THE FILTER FABRIC TO THE WIRE 4. BACKFILL AND COMPACT FENCE AND EXTEND IT INTO THE TRENCH. EXCAVATED SOIL. rfl IF'. Jill rll I/' I . _lillr= ll—FLOWFILTER FABRIC EXTENSION OF FABRIC AND WIRE INTO THE TRENCH. WIRE �I SOURCE: Adapted from Installation of Straw and Fabric Filter Barriers for Sediment Control, Sherwood & Xyant 4 SILT FENCE DETAIL \C-1.2 SCALE: NONE STONE 70' MIN. CONSTRUCTION ACCESS il�3" SM-2A ASPHALT TOP COURSE EXISTING 2% 2% PAVEMENT . \�b"VA. �21 A' AGGR_Oa7L BASE PROFIL STONE 70' MIN. CONSTRUCTION ASPHALT PAVED ACCESS - A WASHRACK EXISTING 2% 2% PAVEMENT I2% 12' MIN." "MUST EXTEND FULL WIDTH L� POSITIVE DRAINAGE OF INGRESS AND EGRESS TO SEDIMENT OPERATION TRAPPING DEVICE PLAN 12' MIN. POSITIVE DRAINAGE 2% TO SEDIMENT TRAPPING DEVICE FILTER CLOTH SECTION A -A A nnin mun water tap of 1 inch must be installed with a Inininitun 1 inch ballcock shutoff valve supplying a wash hose with a diameter of 1.5 inches for adequate constant pressure. Wash water must be carried away from the entrance to an approved settling area to remove sediment. All sediment shall be prevented from entering stomn drains, ditches or watercourses. PAVED WASH RACK NO SCALE ALT: PAVED WASH RACK, IF REQUIRED BY COUNTY E&SC INSPECTOR TYPICAL TREATMENT - (SOIL STABILIZATION BLANKET) INSTALLATION CRITERIA 2" TAMP FIRMLY ANCHOR SLOT 2" T- ANCHOR SLOT NOTES APPROXIMATELY 200 STAPLES REQUIRED PER 100 SQ. YDS. OF MATERIAL ROLL. y ANCHOR SLOTS, JUNCTION SLOTS & CHECK SLOTS TO BE BURIED 6" TO 12". 12" MAX. 4:1 OR FLATTER 6" MAX. STEEPER THAN 4:1 _ JUNCTION SLOT EDGE AND END JOINTS CHECK SLOT { TO BE SNUGLY ABUTTED (JUTE MESH WILL HAVE TERMINAL FOLD STAPLED LAP JOINT IN LIEU OF EDGE JOINT) LAP JOINT 2" MIN. I (JUTE MESH ONLY) I 5' MAX. 4:1 OR FLATTER 3' MAX. STEEPER THAN 4:1 T 1 I I 6" TO 12" I I I I I I I I I I I I I I I I I CHECK SLOT Fr JE2'� JUNCTION SLOT TAMP FIRMLY �12" "CHECK SLOT I I � 1' , 0 2" I I I I I I I I I I VAR. VAR. TO a' MI PLAN VIEW STAPLING DIAGRAM CHECK SLOTS AT MIN. STAPLE FORMED FROM NO.11 STEEL WIRE. 50' C—C INTERVALS; 8" STAPLE MIN. LENGTH FOR SANDY SOIL. NOT REQ.'D WITH ALL 6" STAPLE MIN. LENGTH FOR OTHER SOIL. "�nI,ADiI,i An.,wDi Akio c ❑ 12, PLATE.3.05-1 SOURCE: VDOT ROAD AND BRIDGE STANDARDS _ 4 BIM DETAILS C-1.2 SCALE: NONE TERMINAL FOLD Y 2" PLATE: 3.36-2 SILT FENCE DROP INLET PROTECTION 2 X 4' WOOD FRAME DROP INLET NLNNIsoMIAMI=!hI IM; \ 7 AT CORNERS PERSPECTIVE VIEWS ELEVATION OF STAKE AND FABRIC ORIENTATION SPECIFIC APPLICATION �.1' MIN. IIIII V DETAIL A THIS METHOD OF INLET PROTECTION IS APPLICABLE WHERE THE INLET DRAINS A RELATIVELY FLAT AREA (SLOPE NO GREATER THAN 5%) WHERE THE INLET SHEET OR OVERLAND FLOWS (NOT EXCEEDING 1 C.F.S.) ARE TYPICAL. THE METHOD SHALL NOT APPLY TO INLETS RECEIVING CONCENTRATED FLOWS, SUCH AS IN STREET OR HIGHWAY MEDIANS. SOURCE: N.C. Erosion and Sediment Control Planning and Design Manual, 1988 2111111111111111INLET PROTECTION DETAIL -1.2j SCALE: NONE PLATE 3.07-1 TYPICAL ORIENTATION OF TREA TMENT - i (SOIL STABILIZATION BLANKET) sHAI I OW WHERE THERE IS A BERM AT THE TOP OF THE SLOPE, BRING THE MATERIAL OVER THE BERM AND ANCHOR R BEHIND THE BERM. ON SHAi I nw SLOPES, STRIPS OF NETTING PROTECTIVE COVERINGS MAY BE APPLIED ACROSS THE SLOPE. in=n=u III=R=1f 11=,. IL=71=7f.=71=71=.1, _ It=11=11=11=11=11=1n =.I I:=11:-11-11:=.11=11=11=11=11- -=.11=1I=11=11=II=11= - 1=11=11=11= ON CTCFP SLOPES, APPLY PROTECTIVE COVERING PARALLEL TO THE DIRECTION OF FLOW AND ANCHOR SECURELY. 4 BRING MATERIAL DOWN TO A LEVEL AREA BEFORE TERMINATING THE INSTALLATION. TURN THE END UNDER 4" AND STAPLE AT 12" INTERVALS. IN DITCHES, APPLY PROTECTIVE COVERING PARALLEL TO THE DIRECTION OF FLOW. USE CHECK SLOTS AS REQUIRED. AVOID JOINING MATERIAL IN THE CENTER OF THE DITCH IF AT ALL POSSIBLE. 0 CV 0 O N CV CV U U Q -0 J z J o (D CD 2Y 0) _- CV CD L . LLI Cz L J C- Cn J C-5 `> L-I--I V ) 1� z Ljj V � o O I` O 00 CDZ CD ' m U H f cD B. CLARK CA RIGHT oz � Lic. ��" a 0 03 Iq 2o2Dv SSIONAL�1 J Q Lu N C) N Q J > O 70 Z L �O U 0 ~ Z LZ 70 0 >_ N, Lu C//) CU 06 /wJ� —I ` 0 O C ; 00 ) IO O H RI) LJJ REVISIONS: 03-19-2020 DATE: 02-10-2020 DRAWING NUMBER: C-192 SHEET 4 OF 6 E 0 N 0 o m uj c- N U Q co' J z � N . co L J c- U) J 0 LJJ U) fCa z Lu "zj- V 4-1 U O co 0 ti U o � 00 m o U t OB. CLARoK CA RIGHT z � Lic. 3" a 0 03 Iq 2OZD v �SSIDNAL ��1 N N Q N 70 L r� V tf 0 z v II Z ONTO IL z L — co m Q ` a o J - U 00 0 Q a N U REVISIONS: 03-19-2020 DATE: 02-10-2020 DRAWING NUMBER: C-1 03 SHEET 5 OF 6 E 0 N 0 o m uj c- N U Q co' J z � N . co L J c- U) J 0 LJJ U) fCa z Lu "zj- V 4-1 U O co 0 ti U o � 00 m o U H OF t OB. CLARK GATHRIGHT � Lic. NO. 03" � 0�03-lq 2J2o�yry �SSIONAL�t N N Q N 70 L (� V tf 0 z V) 7 ONTO IL z L — co m Q ` a o J - U 0 t0 0 J Q a N U REVISIONS: 03-19-2020 DATE: 02-10-2020 DRAWING NUMBER: C-i 04 SHEET 6 OF 6