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Home My WebLink About20080427 Ver 1_More Info Received_20080916Friq September 12, 2008 BLUE RIDGE ENGINEERING PLLC 529 Main Street North Wilkesboro, NC 28059 Ian McMillan NCDENR - Division of Water Quality 1650 Mail Service Center Wetlands/401 Certification Unit Raleigh, NC 27699 Reference: 0.32 Acres Isolated Wetlands Near U.S. Hwy 421 Wilkesboro, NC Dear Ian, Phone: (33G) 838-2500 Fax: (33G) 838-4179 df-,? Alle7 R[R@[R0W900 SEP 1 6 2008 DENR -'MATER QUA:lfly WETLANDS AND STORMWATER BRANCH As requested by Steve Tedder of the NCDENR Division of Water Quality, enclosed is the revised Stormwater Management Plan (SMP) and supporting calculations for the 1.94 acre Gateway Avenue property located west of Wilkesboro, NC. Including: 1. Required Items Checklist 2. Operation and Maintenance Agreement 3. Revised cross sectional view of the BMP 4. Vegetative shelf planting plan 5. Construction sequence The SMP is designed to remove 90 percent TSS from the stormwater generated by this project. All BMPs were designed in accordance with the most recent version of the NC Division of Water Quality BMP manual. Please review at your earliest convenience and let me know if any additional information is required. You can reach me on my mobile phone anytime at 336-927-7666. Sincerely, d,0,5,- JC. Swaim Biologist, Blue Ridge Engineering copy: Roger Smithey, Member Neil Shepherd, Blue Ridge Engineering Permit Number: (to be provided by DWQ) Drainage Area Number: Wet Detention Basin Operation and Maintenance Agreement I will keep a maintenance record on this BMP. This maintenance record will be kept in a log in a known set location. Any deficient BMP elements noted in the inspection will be corrected, repaired or replaced immediately. These deficiencies can affect the integrity of structures, safety of the public, and the removal efficiency of the BMP. The wet detention basin system is defined as the wet detention basin, pretreatment including forebays and the vegetated filter if one is provided. This system (check one): ? does ® does not incorporate a vegetated filter at the outlet. This system (check one): ? does ® does not incorporate pretreatment other than a forebay. Important maintenance procedures: - Immediately after the wet detention basin is established, the plants on the vegetated shelf and perimeter of the basin should be watered twice weekly if needed, until the plants become established (commonly six weeks). - No portion of the wet detention pond should be fertilized after the first initial fertilization that is required to establish the plants on the vegetated shelf. - Stable groundcover should be maintained in the drainage area to reduce the sediment load to the wet detention basin. - If the basin must be drained for an emergency or to perform maintenance, the flushing of sediment through the emergency drain should be minimized to the maximum extent practical. - Once a year, a dam safety expert should inspect the embankment. After the wet detention pond is established, it should be inspected once a month and within 24 hours after every storm event greater than 1.0 inches (or 1.5 inches if in a Coastal County). Records of operation and maintenance should be kept in a known set location and must be available upon request. Inspection activities shall be performed as follows. Any problems that are found shall be repaired immediately. BMP element: Potential problem: How I will remediate the problem: The entire BMP Trash/debris is resent. Remove the trash/ debris. The perimeter of the wet Areas of bare soil and/or Regrade the soil if necessary to detention basin erosive gullies have formed. remove the gully, and then plant a ground cover and water until it is established. Provide lime and a one-time fertilizer application. Vegetation is too short or too Maintain vegetation at a height of long. approximately six inches. Form SW401-Wet Detention Basin O&M-Rev.3 Page 1 of 4 Permit Number: (to be provided by DWQ) Drainage Area Number: BMP element: Potential problem: How I will remediate the problem: The inlet device: pipe or The pipe is clogged. Unclog the pipe. Dispose of the swale sediment off-site. The pipe is cracked or Replace the pipe. otherwise damaged. Erosion is occurring in the Regrade the swale if necessary to swale. smooth it over and provide erosion control devices such as reinforced turf matting or riprap to avoid future problems with erosion. The forebay Sediment has accumulated to Search for the source of the a depth greater than the sediment and remedy the problem if original design depth for possible. Remove the sediment and sediment storage. dispose of it in a location where it will not cause impacts to streams or the BMP. Erosion has occurred. Provide additional erosion protection such as reinforced turf matting or riprap if needed to prevent future erosion problems. Weeds are present. Remove the weeds, preferably by hand. If pesticide is used, wipe it on the plants rather than spraying. The vegetated shelf Best professional practices Prune according to best professional show that pruning is needed practices to maintain optimal plant health. Plants are dead, diseased or Determine the source of the dying. problem: soils, hydrology, disease, etc. Remedy the problem and replace plants. Provide a one-time fertilizer application to establish the ground cover if a soil test indicates it is necessary. Weeds are present. Remove the weeds, preferably by hand. If pesticide is used, wipe it on the plants rather than spraying. The main treatment area Sediment has accumulated to Search for the source of the a depth greater than the sediment and remedy the problem if original design sediment possible. Remove the sediment and storage depth. dispose of it in a location where it will not cause impacts to streams or the BMP. Algal growth covers over Consult a professional to remove 50% of the area. and control the algal growth. Cattails, phragmites or other Remove the plants by wiping them invasive plants cover 50% of with pesticide (do not spray). the basin surface. Form SW401-Wet Detention Basin O&M-Rev.3 Page 2 of 4 Permit Number: (to be provided by DWQ) Drainage Area Number: BMP element: Potential problem: How I will remediate the problem: The embankment Shrubs have started to grow Remove shrubs immediately. on the embankment. Evidence of muskrat or Use traps to remove muskrats and beaver activity is present. consult a professional to remove beavers. A tree has started to grow on Consult a dam safety specialist to the embankment. remove the tree. An annual inspection by an Make all needed repairs. appropriate professional shows that the embankment needs repair. The outlet device Clogging has occurred. Clean out the outlet device. Dispose of the sediment off-site. The outlet device is damaged Repair or replace the outlet device. The receiving water Erosion or other signs of Contact the local NC Division of damage have occurred at the Water Quality Regional Office, or outlet. the 401 Oversight Unit at 919-733- 1786. The measuring device used to determine the sediment elevation shall be such that it will give an accurate depth reading and not readily penetrate into accumulated sediments. When the permanent pool depth reads 7 feet in the main pond, the sediment shall be removed. When the permanent pool depth reads 4 feet in the forebay, the sediment shall be removed. BASIN DIAGRAM (fill in the blanks) 0 Permanent Pool Elevation 1110 Sediment Removal . 1106 APeanen Pool - - - - - - - - - - - - - - - ume Sediment Removal Elevation 1103 lume -- Bottom Elevatio 1105 in. -------------------------------------------- L-vili, ement Bottom Elevation 1102 Storage Sedimer Storage FOREBAY MAIN POND Form SW401-Wet Detention Basin O&M-Rev.3 Page 3 of 4 Permit Number: (to be provided by DWQ) I acknowledge and agree by my signature below that I am responsible for the performance of the maintenance procedures listed above. I agree to notify DWQ of any problems with the system or prior to any changes to the system or responsible party. Project name:Wilkes Development Company-Proposed Retail Facility on 1.94 Acre Lot BMP drainage area number: Print name:Roger Smithey Title:Member Address:356 Smitheys Country Lane, Millers Creek, NC 28651 Phone: Signature:f6 'J?• Date: c{ ?? C Note: The legally responsible party should not be a homeowners association unless more than 50% of the lots have been sold and a resident of the subdivision has been named the president. I, o-m-erc.. C a Notary Public for the State of I?orb?, C-o-v,oV-\c,-- , County of do hereby certify that owe r 17 `r,e.? personally appeared before me this day of ?,k rr? , and acknowledge the due execution of the forgoing wet detention basin maintenance requirements. Witness my hand and official seal, ............. c Notary public -W y SEAL My commission expires ,?O a I ?o \ 3 Form SW401-Wet Detention Basin O&M-Rev.3 Page 4 of 4 STORMWATER SYSTEM ANALYSIS AND REPORT Project: 1.94 Acres Gateway Avenue Reddies River Township, Wilkes County, NC Prepared for: Wilkes Development Company, LLC 529 Main Street North Wilkesboro, NC 28659 Date Revised: September 12, 2008 Prepared by: , F" BLUE RIDGE ENGINEERING PLLC 529 Main Street North Wilkesboro, NC 28659 (336) 838-2500 (336) 838-4179 fax s p P 1 6 2008 GENR -10) Ek QUALfI"Y 111, LANDS AND S70RM,ATER BRANCH 1 1 1 1 1 s i 1 1 1 1 1 Introduction The proposed commercial retail project is situated north of U.S. Highway 421 west of Wilkesboro, in Wilkes County, NC. Access to the site is provided by Gateway Avenue, a private street. The site includes approximately 1.94 acres. The property is currently vacant. The property is zoned for commercial development. The project is located in a Class IV watershed. The project involves the proposed disturbance of 0.32 acres of wetlands. There are currently no local stormwater detention ordinances applicable to this site. The site drains to an un-named tributary to the Yadkin River which is classified as a Class WS-IV water by NCDENR with Stream Index #12-(34). To mitigate impacts to water quality, a stormwater detention pond is proposed and has been designed in accordance with the NCDWQ Stormwater BMP Manual. Rainfall data was taken from Point Precipitation Frequency Estimates from NOAA Atlas 14. Stormwater run-off was calculated utilizing Hydraflow Hydrographs 2009 software and the SCS Standard storm. 1 Pre-Developed Conditions The current use of the property within the project limits is vacant land. The last use was agricultural grazing. Scattered wooded areas are also present on the site. The prevalent soils on site are Pacolet-Rion according to the Wilkes County Soil Survey. These soil types have a Hydrologic Soil Group (HSG) classification of "B". The site drains to the southeast corner of the property where stormwater enters an existing drainage pipe. Stormwater run-off from the north also flows into the existing drainage pipe. Existing conditions are summarized below. Pre-Developed Conditions Drainage Area #: #1 Subject Area, (acres): 1.94 Impervious Area, (acres): 0 HSG Soil Group: B SCS Curve Number: 69 Time of Concentration, (min): 2.8 1-yr Peak Flow, (cfs): 2.365 2-yr Peak Flow, (cfs): 3.793 5-yr Peak Flow, (cfs): 6.242 Post-Developed Conditions ' The post-developed conditions will consist of a commercial retail building, and associated streets, drives, ' parking, landscaping, and detention pond. In the post-developed condition studied in this report, impervious surface areas are equal to 70% of the land area. The off-site run-off is considered to be maintained in existing storm drainage piping and not allowed to flow onto the subject site. Post-developed conditions are summarized ' below using the same methodology as for the pre-developed conditions. k Post-Developed Conditions Drainage Area #: #1 Subject Area, (acres): 1.94 Impervious Area, (acres): 1.35 SCS Curve Number: 87 Time of Concentration, (min): 2.3 1-yr Peak Flow, (cfs): 6.27 2-yr Peak Flow, (cfs): 8.22 5-yr Peak Flow, (cfs): 11.24 1 Post-Developed Storm Water Release Rates As previously stated, development of this type increases the volume and rate of runoff from the pre-developed conditions. This increase must be mitigated so as not to cause a negative impact to the downstream conditions. The detention system was designed utilizing orifices to control and reduce the post-developed 1-yr, 2-yr, and 5-yr flows to below pre-developed rates. Drainage Area #1 A new detention pond with outlet control structure will be installed in the southeastern portion of the site and utilized to store and release stormwater such that the rate of release does not exceed pre-developed conditions. Drainage Area #1 1-yr 2-yr 5-yr Detention Storage, (cf): 8,827 9,630 10,443 Pre-developed Peak Flow, (cfs): 2.365 3.793 6.242 Post-Developed Peak Release, (cfs): 0.055 0.349 4.035 The resulting release rates for the 1-yr, 2-yr, and 5-yr storm events, shown above, are lower than the pre- developed rates. Storm Drainage Piping Storm drainage piping has been designed utilizing HyrdaFlow Storm Sewers 2009 software which computes peak flows using the Rational Method. Hydraulic capacity of storm drain piping is designed to convey the flow from a calculated 10-yr storm event. Less frequent, higher volume storms may surcharge the piping system, but should recede quickly due to the capacity of the detention systems and corresponding lower hydraulic elevation at the pond and underground storage. Conclusions This drainage report examines all known and reasonable conditions for this site. Based on this design, a net reduction in storm water run-off release rates will occur for the 1-yr, 2-yr and 5-yr calculated storm events. No detention will occur on any paved areas for the 1-yr, 2-yr and 5-yr calculated storm events. The detention pond has been designed to remove 90% total suspended solids in accordance with the NCDWQ Stormwater BMP Manual, instead of the 85% TSS removal requirement. This additional storage was added to compensate for the lack of a filter strip due to the outflow discharging to a watercourse. Therefore, it is our opinion that this plan provides sufficient mitigation to address the impacts to stormwater run-off for development of this property. AR' I NCDENR STORMWATER MANAGEMENT PERMIT APPLICATION FORM 401 CERTIFICATION APPLICATION FORM WET DETENTION BASIN SUPPLEMENT This form must be filled out, printed and submitted. The Required Items Checklist (Part III) must be printed, filled out and submitted along with all of the required information. O?OF WATF9pG o 1. PROJECT INFORMATION Project name Wilkes Development Company-Proposed Retail Facility on 1.94 Acre Lot Contact person Jon C. Swaim Phone number 336-838-2500 Date 9/12/2008 Drainage area number 1 II. DESIGN INFORMATION Site Characteristics Drainage area 84,506.00 ftz Impervious area 59,154.00 ftz % impervious 70.00 % Design rainfall depth 1.00 in Storage Volume: Non-SR Waters Minimum volume required Volume provided Storage Volume: SR Waters 1-yr, 24-hr runoff depth Pre-development 1-yr, 24-hr runoff Post-development 1-yr, 24-hr runoff Minimum volume required Volume provided Peak Flow Calculations 1-yr, 24-hr rainfall depth Rational C, pre-development Rational C, post-development Rainfall intensity:)-yr, 24-hr storm Pre-development 1-yr, 24-hr peak flow Post-development 1-yr, 24-hr peak flow Pre/Post 1-yr, 24-hr peak flow control Basin Elevations Basin bottom elevation Sediment cleanout elevation Bottom of shelf elevation Permanent pool elevation SHWT elevation Top of shelf elevation Temporary pool elevation Form SW401-Wet Detention Basin-Rev.4 5,328.00 ft3 11,730.00 ft3 in ft3 ft3 ft3 ft3 16.56 in 69.00 (unitless) 87.00 (unitless) 2.96 in/hr 2.37 ft3/sec 6.27 ft3/sec 3.90 ft3/sec 1,102.00 ft 1,103.00 ft 1,109.50 ft 1,110.00 ft 1,106.00 ft 1,110.50 ft 1,111.15 ft Permit No. (to be provided by DWQ) Parts i. & II. Design Summary, Page 1 of 2 ' Permit No. (to be provided by DWQ) L I E 0 IIL_DESIGN INFORMATION Volume and Surface Area Calculations SA/DA ratio 3.70 (unitless) Surface area at the bottom of shelf 1,305.00 ft2 Volume at the bottom of shelf 8,483.00 ft3 Permanent pool, surface area required 3,126.00 ft2 Permanent pool, surface area provided 3,220.00 ft2 OK Permanent pool volume 11,730.00 ft3 Average depth for SA/DA tables 3.64 ft OK Surface area at the top of shelf 4,188.00 ft2 Volume at the top of shelf 13,824.00 ft3 Forebay volume 2,392.00 ft3 Forebay % of permanent pool volume 20.39 % OK Temporary pool, surface area provided 5,016.00 -ft' Drawdown Calculations Treatment volume drawdown time 2.51 days OK Treatment volume discharge rate 0.03 ft3/s Pre-development 1-yr, 24-hr discharge 2.37 ft3/s OK Post-development 1-yr, 24-hr discharge 0.34 ft3/s OK Additional Information Diameter of orifice 1.25 in Design TSS removal 90 % Basin side slopes 3.00 :1 OK Vegetated shelf slope 10.00 :1 OK Vegetated shelf width 10.00 ft OK Length of flowpath to width ratio 3.00 :1 OK Length to width ratio 3.00 :1 OK Trash rack for overflow & orifice? Y (Y or N) OK Freeboard provided 1.30 ft OK Vegetated filter provided? N (Y or N) Design must be based on 90% TSS removal Recorded drainage easement provided? Y (Y or N) OK Capures all runoff at ultimate build-out? Y (Y or N) OK Drain mechanism for maintenance or emergencies PUMP OUT Form SW401-Wet Detention Basin-Rev.4 Parts I. & II. Design Summary, Page 2 of 2 Permit No. (to be provided by DWQ) III. REQUIRED ITEMS CHECKLIST ' Please indicate the page or plan sheet numbers where the supporting documentation can be found. An incomplete submittal package will tli ' CS 8. A copy of the signed and notarized operation and maintenance (0&M) agreement. 05 ? 9. A copy of the deed restrictions (if required). result in a request for additional information. This will delay final review and approval of the project. Initial in the space provided to indicate the fol lowing design requirements have been met. If the applicant has designated an agent, the agent may initial below. If a ' requirement has not been met, attach justification. Pagel Plan ' I itial ? Sheet No. ? 1. Plans (1" - 50' or larger) of the entire site showing: -Design at ultimate build-out, -Off-site drainage (if applicable), ' - Delineated drainage basins (include Rational C coefficient per basin), -Basin dimensions, ' -Pretreatment system, -High flow bypass system, - Maintenance access, - Proposed drainage easement and public right of way (ROW), -Overflow device, and ' Boundaries of drainage easement. ti 2 P l l 1" = 30' l d d il f th ti t t d t b i h i ar . a p an ( or arger) an e a or e we s e en on as n s ow ng: ' -Outlet structure with trash rack or similar, -Maintenance access, - Permanent pool dimensions, -Forebay and main pond with hardened emergency spillway, ' - Basin cross-section, -Vegetation specification for planting shelf, and - Filter strip. " ' 3. Section view of the dry detention basin (1 = 20 or larger) shoving: -Side slopes, 3;1 or lower, -Pretreatment and treatment areas, and ' -Inlet and outlet structures. d ?5 4. If the basin is used for sediment and erosion control during construction, clean out of the basin is specified on the plans prior to use as a wet detention basin. C? 5. A table of elevations, areas, incremental volumes & accumulated volumes for overall pond and for Forebay, to verify volume provided. ' 6. A construction sequence that shows how the wet detention basin will be protected from sediment until the entire drainage area is stabilized. JCS 1-6? 7. The supporting calculations. 1 0. A soils report that is based upon an actual field investigation, soil borings, and infiltration tests. County ' soil maps are not an acceptable source of soils information. ' Form SW411-Wet Detention Basin-Rev.4 Part III. Required Items Checklist, Page 1 of 1 n u O/v D Avtva ?rG Dt pfti lj,1 .22, Avwaoe I??n-fZI??s'vc j?v(4,vo e. Avca 14 Ac) lmptvv,om5 Ave4 6q lo) ?? . 7 fvo mA T41e 10- ? DA o.o?i SA = 0,07[ Awc5 21v s4) -7 ?Eavo I.0iMC. ELLE ROM eVGNEIRM Pl1C 629 ARAN STREET NORTH WUa!SDM, NC 286N BLUE RIDGE COMM a 8 245MOOF= ENGINEERING CA&4vt A- IONS I Wit ,S Dive- o^C" - COMPAtJy 3 OF 1 1 1 1 I FOVC6 V ka nm P e va41ao = 1105-1001 RvmAk1&vLk Pool Uew = 1110,00' AV to - 12 0 " AvuA= V qty Arcs = I,tos r'fI- ?Y" Volctmt = h T, ?-)(q f?) + (I,c05 ;FL- °I/ ' 2,312,.+3 Ma(h Pool le,Am PcVAfi6M - 1102,00( Area= li3oS 4' Se?Q?w,f,,,, C,(c,?hv?uf EIN= (Io3o?c Arm ; 3n5? Z pIty % l1 0q. 5o r AvtA 7205 ?f Z POOL ON= /((0,00( ArtA Mal,, Pod Va(umt 2?r' ) (i ? L 1,3 " t)( ) ? ? = x,33 TorAi, Vol,(Imr-, Z, 3 1 Z lo 3 0 T13 3 r rc? 4/ 2,312- ale ONE O GNEERM P= W9 MAN STIMT NOM'W MOSS= W 2809 BLUE RIDGE OMMO Fm ENGINEERING UVILI?FS Vey"PMEK COMPA" 2 OF 3 1 L? 1 Pori,. 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Precipitation Frequency Data Server Page 1 of 4 POINT PRECIPITATION `" FREQUENCY ESTIMATES Q 0 FROM NOAA ATLAS 14 1 1 1 1 North Carolina 36.1511 N 81.1983 W 1197 feet from "Precipitation-Frequency Atlas of the United States" NOAA Atlas 14, Volume 2, Version 3 G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley NOAA, National Weather Service, Silver Spring, Maryland, 2004 Extracted: Mon Jul 7 2008 nce Limits Location Maps Other Info. GIS data Maps Help Docs U.S. n Intensity Estimates AEP* (1-in- Y) 5 min 10 min 15 mtn 30 min 60 min 120 min 3_hr 6 hr 12 hr 24 hr 48 hr 4 day day 7 10 day 20 day 30 day 45 day 60 day 4.64 3.71 3.11 2.15 1.35 1 -1 0.79 0.57 0.36 0.22 0.14 0.08 0.05 0.03 0.02 0.02 0.01 0.01 0.01 0 5.83 4.67 3.94 2.80 1.79 1.06 0.76 0.48 0.30 0.19 0.11 0.06 0.04 0.03 0.02 -1 -1 0.02 0.01 0.01 10 6.63 5.30 4.47 3.24 2.11 1.26 0.91 0.56 0.35 0.22 0.13 0.07 0.05 0.04 0.02 0.02 0.01 0.01 25 7.61 6.06 5.12 3.79 2.53 1.53 1.10 0.68 0.41 0.27 0.16 0.09 0.05 0.04 0.03 0.02 0.02 0.01 5 8.32 6.62 5.59 4.21 2.85 1.74 1.26 0.78 0.47 0.30 0.18 0.10 0.06 0.05 0.03 0.02 0.02 0.02 100 9.04 7.18 6.05 4.63 3.19 1.97 1.43 0.88 0.52 0.34 0.20 0.11 0.07 0.05 0.03 0.02 0.02 1 0.02 200 9.76 7.74 6.51 5.07 3.55 2.22 1.62 0.99 0.58 0.38 0.22 0.12 0.07 0.05 0.03 0.03 0.02 0.02 500 10.73 8.49 7.12 5.67 4.06 2.58 1.89 1.14 0.65 0.43 0.25 0.13 0.08 0.06 0.04 0.03 0.02 0.02 1000 11.51 9.06 7.58 6.14 4.48 2.88 2.11 1.27 0.72 7 0.27 0.14 0.09 0.06 0.04 0.4 0.03 0.02 0.02 * Upper bound of the 90% confidence interval Precipitation Intensity Estimates (in/hr) 0 AEP** 5 10 15 30 60 120 3 6 12 24 48 4 7 10 20 30 :da y :da y (1-in- min min min min min min hr hr hr hr hr day day day day day Y) 0 5.06 4.05 3.39 2.34 1.47 0.86 0.62 0.39 0.24 0.15 0.09 0.05 0.03 0.03 0.02 0.01 0.01 0.01 0 6.36 5.09 4.30 3.05 1.96 1.16 0.84 0.52 0.32 0.20 0.12 0.07 0.04 0.03 0.02 0.02 0.01 0.01 5.7 10 7.24 9 4.88 3.53 2.30 1.37 0.99 0.62 0.38 0.24 0.14 0.08 0.05 0.04 0.02 0.02 0.02 0.01 25 8.33 6.64 5.61 4.16 2.77 1.67 1.21 0.75 0.45 0.29 0.17 0.09 0.06 0.04 0.03 0.02 0.02 0.02 50 9.16 7.29 6.15 4.63 3.14 1.92 1.40 0.86 0.51 0.33 0.19 0.10 0.06 0.05 0.03 0.02 0.02 0.02 100 10.03 7.97 6.72 5.14 3.54 2.19 1.60 0.97 0.57 0.37 0.21 0.12 0.07 0.05 0.03 0.02 0.02 0.02 200 10.96 8.68 7.30 5.69 3.99 2.49 1.83 1.11 0.64 0.41 0.1 0.24 3 0.08 0.06 0.04 0.03 0.02 0.02 500 12.23 9.67 E16 .45 4.63 2.94 2.17 1.30 0.73 0.47 0.27 0.15 0.09 0.06 0.04 0.03 0.02 0.02 1000 13.28 10.46 8.75 7.09 5.17 3.33 2.47 1.47 0.81 0.52 0.30 0.16 0.09 0.07 0.04 0.03 0.02 0.02 http://dipper.nws.noaa.gov/cgi-bin/hdsc/buildout.perl?type=idf&units=us&series=am&state... 7/7/2008 ' These precipitation frequency estimates are based on an annual maxima series. AEP is the Annual Exceedance Probability. Please refer to the documentation for more information. NOTE: Formatting forces estimates near zero to appear as zero. i fie upper bound or ine confidence interval at au% confidence level is the value which 5% of the simulated quantile values for a given frequency are greater than. " These precipitation frequency estimates are based on an annual maxima series. AEP is the Annual Exceedance Probability. Please refer to the documentation for more information. NOTE: Formatting prevents estimates near zero to appear as zero. Precipitation Frequency Data Server Page 2 of 4 L? 5.35 114 3.61 2.57 1.65 0.97 0.70 0.44 0.27 0.17 0.10 0.06 110 110 110 0.02 0.01 0.01 10 6.06 4.84 4.08 2.96 1.93 1.14 70821E] 0.32 0.20 0.07 0.12 0.04 0.03 0.02 0.02 0.01 0.01 25 6.87 5.47 4.63 3.43 2.28 1.37 0.99 0.62 0.38 0.24 0.14 0.08 0.05 0.04 0.02 0.02 0.02 0.01 50 7.42 5.91 4.99 3.76 2.55 1.54 1.12 0.70 0.42 0.27 0.16 0.09 0.05 0.04 0.03 100 7.96 6.32 5.33 4.08 2.81 1.72 1.25 0.77 0.46 0.30 0.18 0.10 0.06 0.05 0.03 200 8.46 6.71 5.64 4.39 3.08 1.90 1.38 0.85 0.51 0.34 0.19 0.11 0.07 0.05 0.03 500 9.06 7.17 6.01 4.78 3.43 2.15 1.57 0.96 0.56 0.38 0.22 0.12 0.07 0.05 0.03 1000 9.51 7.49 6.27 5.07 3.70 2.35 1.72 1.05 0.61 0.42 0.24 0.13 0.08 0.06 0.04 The lower bound of the confidence interval at 90% confidence level is the value which 5% of the simulated quantile values for a given frequency are less than. "These precipitation frequency estimates are based on an annual maxima series. AEP is the Annual Exceedance Probability. Please refer to the documentation for more information. NOTE: Formatting prevents estimates near zero to appear as zero. L Text version of tables J Annual Maxima based Point IDF Curves - Version: 3 36.1511 N 81.1983 W 1197 ft 10 7 L 3 £ 2 `. 1 000.575 0. 3 y 0. 2 .o. . 1 07 p .05 .03 M .02 .01 U m L a 02 .001 ' 1 1 ' 1 1 1 1 I 1 f 1 i I 1 1 1 i1 i i i i t i { { I 1 1 1 i 1 !` C C C C C E L L L L L L L L L T a T T a ? a a T T E E E E 1 £ £ £ £ £ £ £ £ £ A A M /0 E N N M Ip Ip I 1 E E @ 1 1 I I I I I I 1 'a 'D 73 'a 10 I I 0 i G I N Cl V CS) .D OD N OD V •D OD 1 I I I I 1 1 1 I 1 Cl) Mon Jul 07 15:55:05 2008 Duration -+ N M V W Maps - Annual Exceedance Probability (1-in-Y? -gear-. _? 100-year - -U='.yr-+- ::: it F?-,gear lEl-year 500-year -- c5-y ea r -«- 1000-year -? http://dipper.nws.noaa.gov/cgi-bin/hdsc/buildout.peri?type=idf&units=us&series=am&state... 7/7/2008 Precipitation Frequency Data Server Page 3 of 4 17 Other Maps/Photographs - _z z _z z _z 70 W These maps were produced using a direct map request from the U.S. Census Bureau Mapping and Cartographic Resources Tiger Map Server. Please read disclaimer for more information. LEGEND - State - Connector - County 8?! Stream C- Indian Resv Military Area LakelPond/Ocean National Park - Street 71,17, Other Park Expressway City - Highway 0 -- County 6 .8 mi Scale 1:228583 2 1 *average--true scale depends on monitor$ esolution View USGS digital orthophoto_quadrangle (DOQ) covering this location from TerraServer; USGS Aerial Photograph may also be available from this site. A DOQ is a computer-generated image of an aerial photograph in which image displacement caused by terrain relief and camera tilts has been removed. It combines the image characteristics of a photograph with the geometric qualities of a map. Visit the USGS for more information. Watershed/Stream Flow Information - Find the Watershed for this location using the U.S. Environmental Protection Agency's site. ' Climate Data Sources - Precipitation frequency results are based on data from a variety of sources, but largely NCDC. The following links provide general information about observing sites in the area, regardless of if their data was used in this study. For detailed information about the stations used in this study, please refer to our documentation. ' Using the National Climatic Data Center's (NCDC) station search engine, locate other climate stations within: http://dipper.nws.noaa.gov/cgi-bin/hdsc/buildout.perl?type=idf&units=us&series=am&state... 7/7/2008 1 1 1 1 1 1 1 1 1 1 1 III Precipitation Frequency Data Server Page 4 of 4 +/-30 minutes ...OR... +/-1 degree of this location (36.1511/-81.1983). Digital ASCII data can be obtained directly from NCDC. Hydrometeorological Design Studies Center DOC/NOAA/National Weather Service 1325 East-West Highway Silver Spring, MD 20910 (301) 713-1669 Questions?: HDSC.Questions@noaa.gov Disclaimer http://dipper.nws.noaa. gov/cgi-binlhdsc/buildout.perl?type=idf&units=us&series=am&state... 7/7/2008 I Precipitation Frequency Data Server Page 1 of 4 F 1 1 1 r I I 1 1 1 POINT PRECIPITATION FREQUENCY ESTIMATES 4 FROM NOAA ATLAS 14 %It 51 V North Carolina 36.15 N 81.2 W 1197 feet from "Precipitation-Frequency Atlas of the United States" NOAA Atlas 14, Volume 2, Version 3 G.M. Bonnin, D. Martin, B. Lin, T. Parzybok, M.Yekta, and D. Riley NOAA, National Weather Service, Silver Spring, Maryland, 2004 Extracted: Thu Jan 3 2008 Confidence Limits Seasonality Location Maps Other info. GIS data Maps Help Precipitation Frequency Estimates (inches) ARI* ?5 10 1- 30 60 120 F r 12 24 Nhr [day] 4 ?7 10 20 30 45 60 hr hr hr day day day day day day (years) mm mm mm m?n mm mm r F1 0.35 0.56 0.71 0.97 1.21 1.41 1.53 1.93 2.44 2.96 3.55 4.03 4.62 5.30 7.09 8.80 11.14 13.26 0 0.42 0.67 0.84 1.17 1.46 1.72 1.86 2.34 2.94 3.59 4.29 4.85 5.54 6.33 8.39 10.36 13.02 15.46 0 0.50 0.80 1.01 1.43 1.83 2.17 2.35 2.93 3.66 4.56 5.41 6.03 6.76 7.61 9.92 11.97 14.77 17.39 10 0.56 0.89 1.13 1.64 2.13 2.54 2.75 3.42 4.23 5.33 6.28 6.95 7.71 8.59 11.11 13.17 16.08 18.85 0.64 1.29 1.91 2.54 3.07 3.324.105.016.39 7.49 8.21 8.99 9.88 12.69 14.71 17.74 20.70 25 1.01 -1 50 0.70 1.11 1.40 2.111F2 86 3.50 3.80 4.67 5.64 7.25 8.45 9.22 9.99 10.88 13.92 15.87 18.98 22.07 100 0.76 1.20 1.52 2.33 3.20 3.96 4.31 5.28 6.29 8.15 9.45 10.25 11.00 11.88 15.16 17.00 20.18 23.38 200 0.82 1.30 1.64 2.54 3.57 4.46 4.87 5.93 6.96 9.08 10.50 11.31 12.03 12.88 16.40 18.10 21.33 24.64 500 0.90 1.42 1.79 2.84 4.08 5.18 5.69 6.86 7.91 10.38 11.94 12.77 13.43 14.23 18.07 19.53 22.81 26.25 1000 0.96 1.52 1.90 3.08 4.50 5.78 6.38 7.64 8.69 11.41 13.08 13.92 14.52 15.30 19.34 20.60 23.91 27.44 Text version of table ` These precipitation frequency estimates are based on a partial duration series. ARI is the Average Recurrence Interval. Please refer to the documentation for more information. NOTE: Formatting forces estimates near zero to appear as zero. * Upper bound of the 90% confidence interval Precipitation Frequencv Estimates (inches) 11 ARI** Fl 10 15 - 10 60 120 F 6 12 24 [!r 8 4 7 10 20 30 45 60 F r hr hr day F ay day 11 day 11 day day day (years) in min min min min min r 0.39 0.62 0.77 1.05 T32 1.54 1.68 2.10 2.65 3.24 3.87 4.38 4.99 5.68 7.53 9.28 11.68 13.89 0 0.46 0.73 0.92 1.27 1.60 1.87 2.04 2.55 3.20 3.92 4.68 7 5.98 6.77 8.91 10.93 13.66 16.21 5.2 0 0.54 0.87 1.10 1.56 2.00 2.37 2.58 3.21 598 4.99 5.89 6.55 7.29 8.15 10.53 12.61 15.50 18.23 10 0.61 0.97 1.23 1.78 2.32 2.77 3.01 3.73 4.60 5.82 6.84 7.55 8.31 9.19 11.79 13.89 16.86 19.76 25 0.70 1.11 1.41 2.09 2.78 3.35 3.66 4.50 5.46 6.98 8.17 8.93 9.70 10.58 13.47 15.51 18.62 21.72 50 0.77 1.22 1.54 2.33 3.15 3.85 4.22 5.15 6.17 7.93 9.23 10.03 10.79 11.66 14.80 16.75 19.95 23.17 100 0.84 1.33 1.69 2.58 3.56 4.39 4.83 5.86 6.92 8.93 10.34 1717F1 89 12.75 16.15 17.96 21.22 24.58 200 0.92 1.45 1.83 2.85 4.00 5.00 5.51 6.64 7.71 9.97 11.51 12.36 13.04 13.85 17.51 19.16 22.47 25.94 500 1.02 1.62 2.04 3.24 4.65 5.90 6.56 Elk 8611.44 13.14 13.99 14.61 15.36 19.36 20.72 24.10 27.70 1000 1.11 1.75 2.20 3.56 5.19 6.69 7.46 8.82 9.81 12.63 14.47 15.30 15.86 16.58 20.80 21.92 25.32 29.01 The upper bound of the confidence interval at 90% confidence level is the value which 5% of the simulated quantile values for a given frequency are greater than. " I hese precipitation frequency estimates are based on a partial duration series. ARI is the Average Recurrence Interval. Please refer to the documentation for more information. NOTE: Formatting prevents estimates near zero to appear as zero. * Lower bound of the 90% confidence interval Precipitation Frequency Estimates (inches) - ]F ["], ARI** 5 10 15 30 60 120 3 [?F 2 24 48 10 20 30 45 60 11 (years) min min min min min min r hr [hr [?2Q day 11 day 11 day 11 day 11 day I D 1 http://hdsc.nws.noaa.gov/cgi-bin/hdsc/buildout.perl?type=pf&units=us&series=pd&statena... 1/3/2008 Precipitation Frequency Data Server Page 2 of 4 I? 0.33 0.52 0.65 0.89 L 1 1 1.29 1.41 1.78 2.25 2.72 3.27 3.72 4.32 4.98 6.69 8.35 10.62 12.65 0.39 0.62 0.78 1.07 1.35 1.57 1.71 2.15 2.72 3.29 3.95 4.48 5.17 5.93 7.92 9.83 12.41 14.76 0 0.46 0.73 0.92 1.31 1.68 1.99 2.15 2.69 3.37 4.17 4.96 5.56 6.30 7.13 9.35 11.35 14.07 16.60 10 0.51 0.81 1.03 1.50 1.95 2.31 2.49 3.12 3.88 4.86 5.74 6.39 7.17 8.04 10.44 12.47 15.30 17.98 25 0.57 0.92 1.16 1.72 2.29 2.75 2.98 3.71 4.56 5.80 6.82 7.53 8.33 9.22 F 1 13- 90 16.84 19.72 1 0.6 00 50 2 0.99 1.25 1.89 2.56 3.103.374.185.086.54 7.66 8.41 9.22 10.12 13.00 14.96 18.00 21. 100 0.67 L06 1.34 2.05 2.82 3.46 3.76 4.65F5 60 7.32 8.52 9.32 10.12 11.02 14.11 15.98 19.09 22.20 200 0.71 1.12 1.42 2.20 3.09 3.82 4.17 5.14 6.12 8.10 9.39 10.24 11.02 11.90 15.19 16.96 20.12F23 35 500 0.76 1.20 1.51 2.40 3.44 4.33 4.73 5.79 6.82 9.17 10.59 11.45 12.20 13.07 16.62 18.23 21.43 24.78 1000 0.80 1.25 1.57 2.55 3.72 4.72 5.19 6.31 7.36 10.03 11.51 12.40 13.11 13.98 17.70 19.16 22.39 25.85 The lower bound of the confidence interval at 90% confidence level is the value which 5% of the simulated quantile values for a given frequency are less than. " These precipitation frequency estimates are based on a partial duration _maxima _series. ARI is the Average Recurrence Interval. Please refer to the documentation for more information. NOTE: Formatting prevents estimates near zero to appear as zero. Partial duration based Point Precipitation Frequency Estimates Version: 3 36.15 H 81.2 W 1197 ft 28 27 ? i 26 = - - 25 - - 24 23 4- 1 _ 22 - ^ 21 c 20 19 - s 1$ i' 17 -- -I-?-, a ap 16 -- - - - -- - - j-..{.. a 15 I -I c 14 o - - - - - 13 r M 12 a 10 -- L 7 6 5 . __-?- - -- -- - 4 -- _ - y -- - - 1 f 3 -T 1 0 1 2 3 4 5 6 7 8 910 20 30 40 50 80 100 140 200 300 500 700 1000 Average Recurrence Interval (years) Thu Jan 03 16:19:43 2008 Duration 5-min 48-hr 30-dara - - t- a ii-min -? 12-hr --f-- .ta?a + h, I t, "-»- 24-hr --B- ?v, - dara -e- http://hdsc.nws.noaa.gov/cgi-bin/hdsc/buildout.perl?type=pf&units=us&series=pd&statena... 1/3/2008 Precipitation Frequency Data Server Page 3 of 4 Partial duration based Point Precipitation Frequency Estimates Version: 3 36.15 N 81.2 W 1197 ft 28 27 26 25 24 23 22 21 20 s 19 ++ 18 m 17 a 16 15 0 14 13 4. 12 i 11 g 10 9 0 8 L 7 a 6 5 4 3 2 1 0 C C C C C C E L L L L L L L L L a T T 7' T 7 7 DIN D? 7I 9 e i z z r. t s z t s s N M R M M M A N M W e s E m 1 1 1 1 1 1 1 1 1 . a . a . a a 0 . a .a a . 0 1 1 1 I N Cl) y w I N ao v . ao V1 m V) m 0 m .. .-' N M 't M Y7 h m Vi m m 17 m -» - M D m Duration N M v `o Thu Jan 03 16:19:43 2008 Maps - z z _z a z _z c 1 70 W These maps were produced using a direct map request from the U.S. Census Bureau Mapping and Cartographic Resources Tiger Map Server. Average Recurrence Interval (wears) 1 -?- 100 - I C1 -`13-- 500 - 25 1000 -a- http://hdsc.nws.noaa.gov/cgi-bin/hdsclbuildout.perl?type=pf&units=us&series=pd&statena... 1/3/2008 Precipitation Frequency Data Server Other Maps/Photographs - Please read disclaimer for more information. LEGEND Page 4 of 4 - State - Connector - County ,. Stream F- Indian Resv Military Area Lake/Pond/Ocean National Park - Street Other Park Expressway City - Highway 0 = County 6 s mi Scale 1:228583 11 s u io e n ? *auerage--true scale d pen itor resol t n s o mon View USES digital orthophoto quadrangl_e_( OQ) covering this location from TerraServer; USGS Aerial Photograph may also be available from this site. A DOQ is a computer-generated image of an aerial photograph in which image displacement caused by terrain relief and camera tilts has been removed. It combines the image characteristics of a photograph with the geometric qualities of a map. Visit the USGS for more information. Watershed/Stream Flow Information - Find the Watershed for this location using the U.S. Environmental Protection Agency's site. Climate Data Sources - Precipitation frequency results are based on data from a variety of sources, but largely NCDC. The following links provide general information about observing sites in the area, regardless of if their data was used in this study. For detailed information about the stations used in this study, please refer to our documentation. Using the National Climatic Data Center's_(NCDC) station search engine, locate other climate stations within: +/-30 minutes OR +/-1 degree of this location (36.15/-81.2). Digital ASCII data can be obtained directly from NCDC. Hydrometeorological Design Studies Center DOC/NOAA/National Weather Service 1325 East-West Highway ' Silver Spring, MD 20910 (301) 713-1669 Questions?: I1 DSC.Questions(a)noaa.go_v Disclaimer http://hdse.nws.noaa.gov/cgi-bin/hdsc/buildout.perl?type=pf&units=us&series=pd&statena. 1/3/2008 North Carolina Waterbodies Listed by County Note: Waterbodies are listed in more than one county if they cross county lines. Report Date: 07/05/08 Records Found: 195 Search Parameters: County: Wilkes Class: % SpDes: % Name: % Index#: % Name of Stream Description Curr. Class Date Basin Stream Index # Wilkes Count y YADKIN RIVER From source to mouth C;Tr 04/15/63 Yadkin 12-(1) in W. Kerr Scott Reservoir at Elevation 1030 YADKIN RIVER (W. From a point 3.2 mile WS-IV,B;Tr 04/01/99 Yadkin 12-(27.5) Kerr Scott downstream of Stony Reservoir below Fork to W. Kerr Scott Elevation 1030) Dam YADKIN RIVER (W. From mouth in W. Kerr B;Tr 04/01/99 Yadkin 12-(27) Kerr Scott Scott Reservoir at Reservoir below Elevation 1030 (1.4 Elevation 1030) mile downstream of Stony Fork) to a point 3.2 mile downstream of Stony Fork YADKIN RIVER From W. Kerr Scott Dam WS-IV 08/03/92 Yadkin 12-(34) to a point 0.4 mile upstream of Tucker Hole Creek YADKIN RIVER From a point 0.4 mile WS-IV;CA 08/03/92 Yadkin 12-(36.5) upstream of Tucker Hole Creek to Moravian Creek (Town of Wilkesboro water supply intake) YADKIN RIVER From Moravian Creek to C 04/06/55 Yadkin 12-(38) a point 1.0 mile upstream of Roaring River YADKIN RIVER From a point 1.0 mile WS-V 08/01/98 Yadkin 12-(45) upstream of Roaring River to a point 0.2 mile upstream of the mouth of Big Bugaboo Creek YADKIN RIVER From a point 0.2 mile WS-IV 08/01/98 Yadkin 12-(47.5) upstream of Big Bugaboo Creek to a point 0.9 mile upstream of mouth of Elkin Creek (River) South Yadkin From source to a point WS-II;HQW 08/03/92 Yadkin 12-108-(1) River 0.6 mile upstream of Alexander County SR 1456 Page I of 10 &2 ; a o m L ? «'E ? « r .wc «wu °a m w J n N N 1%1 y w x N q U an d m N [? m w m°«« 3 a ojLjmmo3E ?;m@?m3m?,33 ?u 33 ¢ E W N .w 7 w L w c m y y ?„ E¢ 6m?U1 ? m• m y m°jo ' A c.o F 3rN?On°333 nnQ?Nq 3w- La m omm3mwt o ° °°' ww m 6N`O"u`w uo' m 'u m ° m r i A o m 3 n n °w E E 30 % u m x u u 8 s a a a` z z ?n 3 3 3u'!'a f i=3 n O O Q N Z Q J m }U _H Hfr in 0 ZZ w} J z Fa- ? z0 wU 2(f) ZW OY EC J Z W O YY Al ?? fif@@aflih IMP i i ! a WYYYS'N YY 955YYV Y Y y2f e{ aFnt ?iS?3?Fff6b?sf????ASl?1 E g!llll?y6 Fi =11 L u ' Chapter 2 Estimating Runoff Teclydcal Release fib Urban 1(ydrolosy for small watesbsds ' Table 2-2a Runoff curve numbers for urban areas V Curve numbers for Cover description --hydrologic soil group Average percent ' Cover type and hydrologic condition impervious area V A B Fully developed urban areas (regetstton established) C D Open space (lawns, part, golf courses, c ometeri s, etc.) a': Poor condition (grass cover < 5096) _ ..............»........................ 68 79 Fair condition (grass cover 50% to 769 .................................. 49 69 Good condition (graze cover > 7596) ......................................... 39 61 Impervious areas: 86 79 74 89 84 .80 Paved parking lots, roofs, driveways, etc. ' (excluding right-of-way) ............................................................. 98 98 Streets and roads: 96 98 Paved; curbs and storm sewers (excluding ' rightof-way) ................................................................................ 98 98 Paved; open ditches (including right-of-way) .......................... 83 89 Gravel (including righWf way) ................................................. 76 86 Dirt (including de"f--way) ...................................................... 72 82 Western desert urban areas: 98 92 89 87 98 93 91 89 ?• Natural desert landscaping (pervious areas only) N ..................... 63 77 Artificial desert landscaping (impervious weed barrier, desert shrub with 1- to 24nch sand or gravel mulch and basin borders) ...................................................................... 98 98 Urban districts: 86 8 88 6 ' Commercial and business ................................................................. 86 89 92 Industrial ............................................................................................. 72 81 88 Residential districts by average lot size: 94 91 95 93 U8 acre or less (town houses) .......................................................... 66 77 85 1/4 acre ................................................................................................ 38 61 75 U3 acre ................................................................................................ 30 57 72 U2 acre ................................................................................................ 26 54 70 1 acre ................................................................................................... 20 51 68 2 acres .................................................................................................. 12 46 66 90 83 81 80 79 77 92 87 86 85 84 82 ' Devrkping urban area Newly graded areas (pervious areas only, no vegetation) W....._ 77 86 91 94 ' Idle lands (CWs are determined using cover types slmilar to those in table 2-2c). I Average runoff condition, and 4.0.25. n The average percent bnpeevbuu areashown wa used to develop the enrnpos to CMs. Other amuw4Aims we a foaoww brpavious nos are directly connected to the drainage system, bnpervious areas have a CN o(9% and pervious near we considered equivalent to open space in sood hydrolosic condition. CWs for other combinations of conditions may be computed using figure 2-3 or 2.4. n CWs shown an equivalent to those of pasture. Composite CN's may be computed for other combinations of open space cover type. ' c Composite CMs for nauard desert lamdscopbng should be computed usl% figures 2-3 or 2-4 booed on the Impervious area pereerdoge (CN . W and the pervious area CN. The pervious urea CNY are assumed egndvalent to desert shrub In poor hydrologic condition. n Composite CWs to we for" de sip of temporary nneasnaes dmitns sridbngand construction should be competed wing figs e"or band on the degree of development (Impervious area percentage) and the Ofs for the newly graded pervious area. M (210•Yl-TM,second Ed.,June 1986) 2 6 1 NCDENR Stormwater BMF Manual Chapter Revised 09LU-07 Table 3-4 Hydrologic soil groups for soil types found in North Carolina (Malcom, 1989) Alasa A Dragoon D/C Louisa B Ridgeland C Alamance B Dunbar D/B Louisburg B Rimini C Albany C/A Duplin C/B Lucy A Roanoke D Altavista C/B Durham B Lumbee D/C Rosman B Americus A Dykes B Lynchburg C/B Rumford B Appling B Edneyville B Lynn Haven D/C Ruston B Ashe B Elbert D Madison B Ruttege D/B Augusta C Elioak B Magnolia B Saluda C/B Avery B Eainboro B Manadde C/B Scranton D/B Aycock B Enon C Manteo D Seneca C/B Barclay C Eustis A Marlboro B Starr B Barth C Exum C/B Masada B State B Bayboro D/C FacevWe B Maxton B Suncook A Berrie C/B Fannin B Mayodan B Surry B Bibb D/B Fletcher B McColl D/C Talladega C Bladen D/C Puquay B Mecklenburg C Tal epoosa C Blaney a Georgeville B Meggett D/C Tate B Banton A Gilmd C Molena A Tatum B Bowie B Goldsboro C/B Musella B Thurmont B Braddock B Goldston C Myatt D/C Toccom B Bradley B Granville B Nahum C/B Toiskwt C/B Nudywine B Grover B Nason C Torhuna C/A Brevard B Guin A Nixonton B Toxaway D Bucks B Gwirurett B Norfolk B Transylvania B Buncombe A HartseW B Ochiockonee B Troup A Burton B Hatboro D/C Ocilla C/B Tuckerman D/C Byars D Hayesville B Olustee D/C Tusquitee B Cahabs B Haywood B Onslow B Unison B Cape Fear D/B Helena C Orange D Vance C Caroline C Herndon B Orangeburg B Varina C Cartecay C Hiwasaee B Vaucluse C Caaula C Hoffman C B Wadesboro B Cecil B Hulett B us A Wagram A Chandler B Hyde D/C Pamlico D/C Wahee D/C Chastain D Invershiel C Pantego D/C Wake D Chester B Iredell D Pmquotank D/B Watauga B Chesterfield B luka C Pelham D/C Wedowee B Chew-ads C Izagora C Pander D hipe C/A Johnston D/B Pam C/B Clifton B John C/B P6rkston C Codurus C Kalma B Plummer D/B Colfax C Kenansville A Pocalla A Comus B Kershaw A Pocomwke D/B Congaree B Kinston D/C Pomello C/A Cowart C Lakeland A Ponxer D/C Coxville D/C Leaf D/C ftim B Craven C Lenoir D/B Portsmouth D/C Davidson B Iron C/B Rabun B Deanco C Liddell D/C Rains D/B Dorovan D Lloyd B Ramsey D Dothan B Lockhart B Ranger C Stormwater Management and Calculations 3.6 - July 2007 r 0 0 0 o n- O CL> Hw 0 0 ? N 3 U > 0 ? w w O Q O V >`. , E LO N _O a o a O O N o > 00 ° Q (D 6 o c(0 y N O c 0 0 o s o° 0 O n ° c LL ? o :3 (n I C) Q 0 o U Co m W C N O L n J °? D7 O O T O L 0 a) C w > - C C O - E c [D co U-) > N j U U) C O ? 3 °' ! Y > J 0 U) LL Z i °° ° o ° Q) (h N O m I I I I I I I U) Q O J LL O ry } 2 d' N O d' U O O ^L LL F' O -0 O O D_ r O ? fl_ ? O ? H W L N ? N U > Q? W "t ' O Q O •? O > ° 0 C! 0 0 0 Cl) N r a co 00 ao 0 E? 0 0 mW 1 0o a? O ? T T T E cu N c 0 3 .°' ? Y ' 0 y+ C 0 U) LL Z co O O (N r Q U) m a C 0 2 Q- 0 J LL O r' 0 2 d N O L) U N O L lWatershed Model Schematic 1 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 1 2 Fri 3® I Legend Hyd. Origin Description 1 SCS Runoff Pre-Developed Flow 2 SCS Runoff Post-Developed Storm 3 Reservoir Post-Developed Release 4 Reservoir Spillway Project: 4024 HYDROFLOW.gpw Monday, Sep 15, 2008 Hydraflow Table of Contents 4024 HYDROFLOW.gpw 1 Hydraflow Hydrographs Extension for AutoCAD® Civil 3DO 2009 by Autodesk, Inc. v6.066 Monday, Sep 15, 2008 Watershed Model Schematic ................................................................................... 1 ' HYdro9raph Return Period Recap ........................................................................... 2 ' 1 -Year Summary Report ....................................................................................................................... 3 ' Hydrograph Reports ................................................................................................................. 4 Hydrograph No. 1, SCS Runoff, Pre-Developed Flow ............................................................ 4 TR-55 Tc Worksheet ......................................................................................................... 5 ' Hydrograph No. 2, SCS Runoff, Post-Developed Storm ........................................................ 6 TR-55 Tc Worksheet ......................................................................................................... 7 Hydrograph No. 3, Reservoir, Post-Developed Release ........................................................ 8 ' Pond Report - POND #1 .................................................................................................... 9 Hydrograph No. 4, Reservoir, Spillway ................................................................................. 10 Pond Report - SPILLWAY ............................................................................................... 11 2 -Year Summary Report ..................................................................................................................... 12 ' Hydrograph Reports ............................................................................................................... 13 Hydrograph No. 1, SCS Runoff, Pre-Developed Flow .......................................................... 13 Hydrograph No. 2, SCS Runoff, Post-Developed Storm ...................................................... 14 ' Hydrograph No. 3, Reservoir, Post-Developed Release ...................................................... 15 Hydrograph No. 4, Reservoir, Spillway ................................................................................. 16 ' 5 - Year Summary Report ..................................................................................................................... 17 Hydrograph Reports ............................................................................................................... 18 ' Hydrograph No. 1, SCS Runoff, Pre-Developed Flow .......................................................... 18 Hydrograph No. 2, SCS Runoff, Post-Developed Storm ...................................................... 19 Hydrograph No. 3, Reservoir, Post-Developed Release ...................................................... 20 ' Hydrograph No. 4, Reservoir, Spillway ................................................................................. 21 OF Report ............................................................................................................... 22 r 1 1 Hydrograph Return Period R?,q y ra Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. Hydrograph Inflow Peak Outflow (cfs) Hydrograph No. type Hyd(s) description (origin) 1-Yr 2-Yr 3-Yr 5-Yr 10-Yr 25-Yr 50-Yr 100-Yr 1 SCS Runoff ------ 2.365 3.793 ------- 6.242 ------- ------- ------- ------- Pre-Developed Flow 2 SCS Runoff ------ 6.267 8.217 ------- 11.24 ------- ------- ------- ------- Post-Developed Storm 3 Reservoir 2 0.055 0.349 ------- 4.035 ------- ------- ------- ------- Post-Developed Release 4 Reservoir 2 0.056 0.230 ------- 2.328 ------- ------- ------- ------- Spillway Proj. file: 4024 HYDROFLOW.gpw Monday, Sep 15, 2008 Hyd rog ra p h Summary Re po rtydraflow Hydrographs Extension for AutoCAD@ Civil 3D® 2009 by Autodesk, Inc. v6.066 C C 1 C 11 Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to peak (min) Hyd. volume (cult) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) Hydrograph description 1 SCS Runoff 2.365 1 716 4,281 ------ ------ ------ Pre-Developed Flow 2 SCS Runoff 6.267 1 715 11,251 ------ ------ ------ Post-Developed Storm 3 Reservoir 0.055 1 1358 6,575 2 1111.86 8,827 Post-Developed Release 4 Reservoir 0.056 1 1338 400 2 1112.25 10,862 Spillway 4024 HYDROFLOW.gpw Return Period: 1 Year Monday, Sep 15, 2008 Hydrograph Report ' Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 1 Pre-Developed Flow Hydrograph type = SCS Runoff Storm frequency = 1 yrs Time interval = 1 min Drainage area = 1.940 ac Basin Slope = 4.5% ' Tc method = TR55 Total precip. = 2.96 in Storm duration = 24 hrs 4 Monday, Sep 15, 2008 Peak discharge = 2.365 cfs Time to peak = 11.93 hrs Hyd. volume = 4,281 cuft Curve number = 69* Hydraulic length = 0 ft Time of conc. (Tc) = 2.80 min Distribution = Type II Shape factor = 484 " Composite (Area/CN) _ [(1.910 x 69)] / 1.940 ' Pre-Developed Flow Q (cfs) Hyd. No. 1 -- 1 Year ' 3.00 2.00 ' 1.00 ' 0.00 Q (cfs) 3.00 2.00 1.00 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 ' Hyd No. 1 Time (hrs) TR55 Tc Worksheet 41 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 1 Pre-Developed Flow Description A B C Totals Sheet Flow Manning's n-value = 0.011 0.011 0.011 ' Flow length (ft) = 300.0 0.0 0.0 Two-year 24-hr precip. (in) = 3.59 0.00 0.00 Land slope (%) = 4.00 0.00 0.00 ' Travel Time (min) = 2.09 + 0.00 + 0.00 = 2.09 ' Shallow Concentrated Flow Flow length (ft) = 100.00 0.00 0.00 Watercourse slope (%) = 2.00 0.00 0.00 ' Surface description = Unpaved Paved Paved Average velocity (ft/s) = 2.28 0.00 0.00 ' Travel Time (min) = 0.73 + 0.00 + 0.00 = 0.73 Channel Flow ' X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 ' Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) = 0.00 0.00 0.00 Flow length (ft) = 0.0 0.0 0.0 ' Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 ' Total Travel Time, Tc ............................................................... ............... 2.80 min 1 Hydrograph Report Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 2 ' Post-Developed Storm Hydrograph type = SCS Runoff Storm frequency = 1 yrs 1 Time interval = 1 min Drainage area = 1.940 ac Basin Slope = 0.0% ' Tc method = TR55 Total precip. = 2.96 in ' Storm duration = 24 hrs * Composite (Area/CN) = [(1.350 x 95) + (0.590 x 69)] / 1.940 ' Post-Developed Storm Q (cfs) Hyd. No. 2 -- 1 Year ' 7.00 ' 6.00 ' 5.00 4.00 3.00 ' 2.00 ' 1.00 ' 0.00 6 Monday, Sep 15, 2008 Peak discharge = 6.267 cfs Time to peak Hyd. volume Curve number Hydraulic length Time of conc. (Tc) Distribution Shape factor 11.92 hrs 11,251 cuft 87* 0 ft 2.30 min Type II 484 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 ' - Hyd No. 2 Q (cfs) 7.00 6.00 5.00 4.00 3.00 2.00 1.00 __' 0.00 20.0 Time (hrs) TR55 Tc Worksheet 7 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 2 ' Post-Developed Storm Description A B C Totals Sheet Flow Manning's n-value = 0.011 0.011 0.011 ' Flow length (ft) = 100.0 0.0 0.0 Two-year 24-hr precip. (in) = 3.59 0.00 0.00 Land slope (%) = 2.00 0.00 0.00 ' Travel Time (min) = 1.14 + 0.00 + 0.00 = 1.14 ' Shallow Concentrated Flow Flow length (ft) = 200.00 0.00 0.00 Watercourse slope (%) = 2.00 0.00 0.00 Surface description = Paved Paved Paved Average velocity (ft/s) = 2.87 0.00 0.00 ' Travel Time (min) = 1.16 + 0.00 + 0.00 = 1.16 Channel Flow X sectional flow area (sqft) = 0.00 0.00 0.00 Wetted perimeter (ft) = 0.00 0.00 0.00 Channel slope (%) = 0.00 0.00 0.00 ' Manning's n-value = 0.015 0.015 0.015 Velocity (ft/s) = 0.00 0.00 0.00 Flow length (ft) = 0.0 0.0 0.0 Travel Time (min) = 0.00 + 0.00 + 0.00 = 0.00 Total Travel Time, Tc ............... ................................................ ............... 2.30 min Hydrograph Report 8 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Monday, Sep 15, 2008 Hyd. No. 3 Post-Developed Release Hydrograph type = Reservoir Peak discharge = 0.055 cfs Storm frequency = 1 yrs Time to peak = 22.63 hrs Time interval = 1 min Hyd. volume = 6,575 cuft Inflow hyd. No. = 2 - Post-Developed Storm Max. Elevation = 1111.86 ft ' Reservoir name = POND #1 Max. Storage = 8,827 cuft Storage Indication method used. Post-Developed Release Q (cfs) Hyd. No. 3 -- 1 Year Q (cfs -7 nf% --- 0 5 10 15 20 25 30 35 40 45 50 v Vv ' Time (hr: Hyd No. 3 Hyd No. 2 L' Total storage used = 8,827 tuft ' Pond Report 9 Hydraflow Hydrographs Extension for AutoCAD@ Civil 3DO 2009 by Autodesk, Inc. v6.066 Monday, Sep 15, 2008 Pond No. 1 - POND #1 Pond Data Contours - User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 1110.00 ft ' St / St T bl age orage a e Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cult) Total storage (cuft) ' 0.00 1110.00 3,22 0 0 0 0.50 1110.50 4,18 8 1,852 1,852 3.00 1113.00 6,09 7 12,856 14,708 ' Culvert / Orifice Structures Weir Structures [A] [B] [C] [PrfRsr] [A] [B] [C] [D] ' Rise (in) = 18.00 1.25 Inacti ve 0.00 Crest Len (ft) = 14.00 0.00 0.00 0.00 Span (in) = 18.00 1.25 0.00 0.00 Crest El. (ft) = 1112.00 0.00 0.00 0.00 No. Barrels = 1 1 1 0 Weir Coeff. = 3.33 3.33 3.33 3.33 Invert El. (ft) = 1106.00 1110.00 0.00 0.00 Weir Type = Rect --- --- --- ' Length (ft) = 10.00 0.25 0.00 0.00 Multi-Stage = Yes No No No Slope (%) = 5.00 1.00 0.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000 (by Wet area) Multi-Stage = n/a Yes Yes No TW Elev. (ft) = 0.00 Note: Culvert/Orifice outflows are analyzed under inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table ' Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfil User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 1110.00 0.00 0.00 ___ ___ ___ 0.00 _ _-_ 0.000 ' 0.05 185 1110.05 15.34 is 0.00 is __ 0.00 ___ ___ 0.003 0.10 370 1110.10 15.34 is 0.01 is --- --- 0.00 --- --- --- --- --- 0.009 0.15 556 1110.15 15.34 is 0.01 is --- --- 0.00 --- --- --- --- --- 0.013 ' 0.20 741 1110.20 0.25 926 1110.25 15.34 is 15.34 is 0.02 is -__ 0.02 is - 0.00 --- -- 0.00 ___ --- 0.016 0.018 0.30 1,111 1110.30 15.34 is 0.02 is -- 0.00 - --- 0.020 0.35 1,296 1110.35 15.34 is 0.02 is --- --- 0.00 --- --- --- --- --- 0.022 0.40 1,482 1110.40 15.34 is 0.02 is --- --- 0.00 --- --- --- --- --- 0.024 0.45 1,667 1110.45 15.34 is 0.03 is __ ___ ___ 0.00 ___ ___ _-_ 0.026 ' 0.50 1,852 1110.50 15.34 is _ 0.03 is __ 0.00 0.027 0.75 3,138 1110.75 15.34 is 0.03 is --- --- 0.00 --- --- --- --- --- 0.034 1.00 4,423 1111.00 15.34 is 0.04 is --- --- 0.00 --- --- --- --- --- 0.040 ' 1.25 5,709 1111.25 1.50 6,995 1111.50 15.34 is 15.34 is 0.04 is --- 0.05 is --- 0.00 -_- __- 0.00 ___ --- _-- 0.045 0.049 1.75 8,280 1111.75 15.34 is 0.05 is 0.00 0.053 2.00 9,566 1112.00 15.34 is 0.06 is --- --- 0.00 --- --- --- --- --- 0.057 2.25 10,851 1112.25 15.34 is 0.06 is --- --- 5.83 --- --- --- --- --- 5.888 2.50 12,137 1112.50 16.54 is 0.06 is __ _ ___ 16.48 ___ ___ ___ 16.54 ' 2.75 13,423 1112.75 20.50 is _ 0.02 is __ 20.48s - _ 20.50 3.00 14,708 1113.00 21.12 is 0.01 is --- --- 21.10s --- --- --- --- --- 21.12 1 1 1 Hydrograph Report 10 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 4 ' Spillway Hydrograph type = Reservoir Storm frequency = 1 yrs ' Time interval = 1 min Inflow hyd. No. = 2 - Post-Developed Storm ' Reservoir name = SPILLWAY Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage Monday, Sep 15, 2008 = 0.056 cfs = 22.30 hrs = 400 cuft = 1112.25 ft = 10,862 cuft Storage Indication method used. Spillway Q (cfs) Hyd. No. 4 -- 1 Year 6 00 . 5 00 . 4 00 . 3.00 2.00 ' 1.00 ' 0.00 Q (cfs) 7.00 6.00 5.00 4.00 3.00 2.00 1.00 0 00 U 2 4 6 8 10 12 14 16 18 20 22 ' Hyd No. 4 - Hyd No. 2 Total storage used = 10,862 cuft 24 26 Time (hrs) ' Pond Report 11 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 200 9 by Autodesk, Inc. v6.066 Monday, Sep 15, 2008 Pond No. 2 - SPILLWAY Pond Data Contours - User-defined contour areas. Average end area method used for volume calculation. Begining Elevation = 1110.00 ft ' St / St T l age orage ab e Stage (ft) Elevation (ft) Contour area (sqft) Incr. Storage (cuft) Total storage (cuft) ' 0.00 1110.00 3,220 0 0 0.50 1110.50 4,188 1,852 1,852 3.00 1113.00 6,097 12,856 14,708 Culvert / Orifice Structures Weir Structures [A] [Bl [C] [PrfRsr] [A] [B] [C] [D] Rise (in) Inactive Inactive Inactive 0.00 Crest Len (ft) = 16.00 0.00 0.00 0.00 ' Span (in) = 18.00 1.25 16.00 0.00 Crest El. (ft) = 1112.25 0.00 0.00 0.00 No. Barrels = 1 1 1 0 Weir Coeff. = 3.33 3.33 3.33 3.33 Invert El. (ft) = 1110.00 Length (ft) = 30.00 1110.00 0.25 1111.25 0.00 0.25 0.00 Weir Type Multi-Stage = Rect --- = No No --- --- No No Slope (%) = 3.00 1.00 1.00 n/a N-Value = .013 .013 .013 n/a Orifice Coeff. = 0.60 0.60 0.60 0.60 Exfil.(in/hr) = 0.000 (by Wet area) Multi-Stage = n/a No No No TW Elev. (ft) = 0.00 Note: Culve rt/Orifice outflows are analyzed u nder inlet (ic) and outlet (oc) control. Weir risers checked for orifice conditions (ic) and submergence (s). Stage / Storage / Discharge Table ' Stage Storage Elevation Clv A Clv B Clv C PrfRsr Wr A Wr B Wr C Wr D Exfii User Total ft cuft ft cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs cfs 0.00 0 1110.00 0.00 0.00 0.00 ___ 0.00 ___ __ _ ___ -__ 0.000 ' 0.05 185 1110.05 0.00 0.00 0.00 0.00 _ __ 0.000 0.10 370 1110.10 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 0.15 556 1110.15 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 ' 0.20 741 1110.20 0.25 926 1110.25 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 - 0.000 0.000 0.30 1,111 1110.30 0.00 0.00 0.00 --- 0.00 --- --- --- --- -- 0.000 0.35 1,296 1110.35 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 0.40 1,482 1110.40 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 0.45 1,667 1110.45 0.00 0.00 0.00 ___ 0.00 __ ___ ___ -__ __ 0.000 ' 0.50 1,852 1110.50 0.00 0.00 0.00 0.00 = _ 0.000 0.75 3,138 1110.75 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 1.00 4,423 1111.00 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 ' 1.25 5,709 1111.25 1.50 6,995 1111.50 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 --- -_- _-_ --- 0.000 0 000 1.75 8,280 1111.75 0.00 0.00 0.00 --- 0.00 --- . 0.000 2.00 9,566 1112.00 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 2.25 10,851 1112.25 0.00 0.00 0.00 --- 0.00 --- --- --- --- --- 0.000 2.50 12,137 1112.50 0.00 0.00 0.00 --- 6.66 ___ __ _ - 6.660 ' 2.75 13,423 1112.75 0.00 0.00 0.00 18.84 _ __ ___ __ 18 84 3.00 14,708 1113.00 0.00 0.00 0.00 --- 34.61 --- --- --- --- --- . 34.61 H drogra h Summary Re 12 or? y - Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 1 1 1 1 1 1 Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to peak (min) Hyd. volume (cuft) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) Hydrograph description 1 SCS Runoff 3.793 1 716 6,657 ------ ------ ------ Pre-Developed Flow 2 SCS Runoff 8.217 1 715 14,944 ------ ------ ------ Post-Developed Storm 3 Reservoir 0.349 1 781 9,707 2 1112.01 9,630 Post-Developed Release 4 i Reservoir 0.230 1 832 4,092 2 1112.26 10,896 Spillway 4024 HYDROFLOW.gpw Return Period: 2 Year ' ' ' Monday, Sep 15, 2008 Hydrograph Report 13 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 1 ' Pre-Developed Flow Hydrograph type = SCS Runoff Storm frequency = 2 yrs Time interval = 1 min Drainage area = 1.940 ac Basin Slope = 4.5% ' Tc method = TR55 Total precip. = 3.59 In ' Storm duration = 24 hrs Monday, Sep 15, 2008 Peak discharge = 3.793 cfs Time to peak = 11.93 hrs Hyd. volume = 6,657 cuft Curve number = 69* Hydraulic length = 0 ft Time of conc. (Tc) = 2.80 min Distribution = Type II Shape factor = 484 * Composite (Area/CN) = [(1.910 x 69)] / 1.940 ' Pre-Developed Flow Q (cfs) Hyd. No. 1 -- 2 Year ' 4.00 ' 3.00 ' 2.00 ' 1.00 ' 0.00 Q (cfs) 4.00 3.00 2.00 1.00 ?!!!IIII 0 2 4 6 8 10 12 14 16 18 20 22 24 ' - Hyd No. 1 1 -L- 0.00 26 Time (hrs) Hydrograph Report 14 ' Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 2 ' Post-Developed Storm Hydrograph type = SCS Runoff Storm frequency = 2 yrs ' Time interval = 1 min Drainage area = 1.940 ac Basin Slope = 0.0% ' Tc method = TR55 Total precip. = 3.59 in ' Storm duration = 24 hrs Monday, Sep 15, 2008 Peak discharge = 8.217 cfs Time to peak = 11.92 hrs Hyd. volume = 14,944 cuft Curve number = 87* Hydraulic length = 0 ft Time of conc. (Tc) = 2.30 min Distribution = Type II Shape factor = 484 * Composite (Area1CN) _ [(1.350 x 95) + (0.590 x 69)] / 1.940 ' Post-Developed Storm Q (cfs) Hyd. No. 2 -- 2 Year 10.00 8.00 ' 6.00 ' 4.00 2.00 t ' 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 ' Hyd No. 2 Q (cfs) 10.00 8.00 6.00 4.00 2.00 _ 0.00 20.0 Time (hrs) Hydrograph Report 15 Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 3 ' Post-Developed Re lease Hydrograph type = Reservoir Storm frequency = 2 yrs ' Time interval = 1 min Inflow hyd. No. = 2 - Post-Developed Storm Reservoir name = POND #1 Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage Monday, Sep 15, 2008 = 0.349 cfs = 13.02 hrs = 9,707 cuft = 1112.01 ft = 9,630 cuft Storage Indication method used. ' Post-Developed Release Q (cfs) Hyd. No. 3 -- 2 Year ? ? n nn 0 5 10 15 20 25 30 35 40 ' Hyd No. 3 - Hyd No. 2 "' ID 1 ; Il Total storage used = 9,630 cuft Q (cfs; 10.00 8.00 6.00 4.00 2.00 0.00 45 50 Time (hr! Hydrograph Report 16 ' Hydraflow Hydrographs Extension for AUtoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 4 ' Spillway Hydrograph type = Reservoir Storm frequency = 2 yrs Time interval = 1 min Inflow hyd. No. = 2 - Post-Developed Storm ' Reservoir name = SPILLWAY Peak discharge Time to peak Hyd. volume Max. Elevation Max. Storage Monday, Sep 15, 2008 = 0.230 cfs = 13.87 hrs = 4,092 tuft = 1112.26 ft = 10,896 cuft Storage Indication method used. Q (cfs) Spillway Hyd. No. 4 -- 2 Year ' I u.uu 8 00 . 6 00 . 1 4 00 ' . 2 00 . Q (cfs) 10.00 8.00 6.00 4.00 2.00 0.00 0 00 0 2 4 6 8 10 12 14 16 18 20 22 Hyd No. 4 - Hyd No. 2T'_rL l Total storage used = 10,896 cuft 24 26 Time (hrs) Hydrograph Summary Repo 17 rt ydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. Hydrograph type (origin) Peak flow (cfs) Time interval (min) Time to peak (min) Hyd. volume (cuft) Inflow hyd(s) Maximum elevation (ft) Total strge used (cuft) Hydrograph description 1 SCS Runoff 6.242 1 716 10,854 ------ ------ ------ Pre-Developed Flow 2 SCS Runoff 11.24 1 715 20,828 ------ ------ ------ Post-Developed Storm 3 Reservoir 4.035 1 720 15,589 2 1112.18 10,443 Post-Developed Release 4 Reservoir 2.328 1 722 9,977 2 1112.34 11,301 Spillway 4024 HYDROFLOW.gpw Return Period: 5 Year Monday, Sep 15, 2008 Hydrograph Report 18 ' Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 1 Pre-Developed Flow Hydrograph type = SCS Runoff Storm frequency = 5 yrs ' Time interval = 1 min Drainage area = 1.940 ac Basin Slope = 4.5% ' Tc method = TR55 Total precip. = 4.56 In Storm duration = 24 hrs Monday, Sep 15, 2008 Peak discharge = 6.242 cfs Time to peak = 11.93 hrs Hyd. volume = 10,854 cuft Curve number = 69* Hydraulic length = 0 ft Time of conc. (Tc) = 2.80 min Distribution = Type II Shape factor = 484 Composite (Area/CN) = [(1.910 x 69)] / 1.940 Pre-Developed Flow Q (cfs) Hyd. No. 1 -- 5 Year Q (cfs) 7.00 6.00 5.00 4.00 3.00 2.00 1.00 ¦ "."" 0.00 0 2 4 6 8 10 12 14 16 18 20 22 24 26 Hyd No. 1 Time (hrs) Hydrograph Report 19 ' Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 2 ' Post-Developed Storm Hydrograph type = SCS Runoff Storm frequency = 5 yrs Time interval = 1 min Drainage area = 1.940 ac ' Basin Slope Tc method = 0.0% = TR55 Total precip. = 4.56 in Storm duration = 24 hrs Monday, Sep 15, 2008 Peak discharge = 11.24 cfs Time to peak = 11.92 hrs Hyd. volume = 20,828 cuft Curve number = 87* Hydraulic length = 0 ft Time of conc. (Tc) = 2.30 min Distribution = Type II Shape factor = 484 Composite (Area/CN) = [(1.350 x 95) + (0.590 x 69)] / 1.940 ' Post-Developed Storm Q (cfs) Hyd. No. 2 -- 5 Year 4 n nn Q (cfs) 12.00 10.00 8.00 6.00 4.00 2.00 . U.uv ' _ 0.00 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 18.0 20.0 Hyd No. 2 Time (hrs) h R H t d 20 epor y rograp ' Hydraflow Hydrographs Extension for AutoCAD® Civil 3D@ 2009 by Autodesk, Inc. v6.066 Monday, Sep 15, 2008 HYd. No. 3 ' Post-Developed Release Hydrograph type = Reservoir Peak discharge = 4.035 cfs Storm frequency = 5 yrs Time to peak = 12.00 hrs ' Time interval = 1 min Hyd. volume = 15,589 cuft Inflow hyd. No. = 2 - Post-Developed Storm Max. Elevation = 1112.18 ft ' Reservoir name = POND #1 Max. Storage = 10,443 cuft Storage Indication method used. Post-Developed Release Q (cfs) Hyd. No. 3 5 Year Q (cfs: 0 5 10 15 20 25 30 35 40 45 50 ' Time (hr: Hyd No. 3 - Hyd No. 2 71 Total storage used = 10,443 cuft t Hydrograph Report ' Hydraflow Hydrographs Extension for AutoCAD® Civil 3D® 2009 by Autodesk, Inc. v6.066 Hyd. No. 4 ' Spillway Hydrograph type = Reservoir Peak discharge Storm frequency = 5 yrs Time to peak ' Time interval = 1 min Hyd. volume Inflow hyd. No. = 2 - Post-Developed Storm Max. Elevation Reservoir name = SPILLWAY Max. Storage 21 Monday, Sep 15, 2008 = 2.328 cfs = 12.03 hrs = 9,977 cuft = 1112.34 ft = 11,301 cuft Storage Indication method used. ' Spillway Q (cfs) Hyd. No. 4 -- 5 Year ' IL.VU 10 00 . 1 8.00 6 00 ' . ' 4 00 . 2.00 ' ' n nn Q (cfs) 12.00 10.00 8.00 6.00 4.00 2.00 n nn 0 2 4 6 8 10 12 14 16 18 20 22 ' Hyd No. 4 -Hyd No. 2 i.'.. T .1.' Total storage used = 11,301 cult 1 26 Time (hrs) 24 Hydraflow Rainfall Report 22 ' Hydraflow Hydrographs Extension for AutoCAD® Civil 3D@ 2009 by Autodesk, Inc. v6.066 Monday, Sep 15, 2008 1 1 1 1 1 Return Period Intensity-Duration-Frequency Equation Coefficients (FHA) (Yrs) B D E (N/A) 1 0.0000 0.0000 0.0000 -------- 2 69.8703 13.1000 0.8658 -------- 3 0.0000 0.0000 0.0000 -------- 5 79.2597 14.6000 0.8369 -------- 10 88.2351 15.5000 0.8279 -------- 25 102.6072 16.5000 0.8217 -------- 50 114.8193 17.2000 0.8199 -------- 100 127.1596 17.8000 0.8186 -------- File name: SampleFHA.idf Intensity = B / (Tc + D)^E Return Period Intensity Values (in/hr) (Yrs) 5 min 10 15 20 25 30 35 40 45 50 55 60 1 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 2 5.69 4.61 3.89 3.38 2.99 2.69 2.44 2.24 2.07 1.93 1.81 1.70 3 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 5 6.57 5.43 4.65 4.08 3.65 3.30 3.02 2.79 2.59 2.42 2.27 2.15 10 7.24 6.04 5.21 4.59 4.12 3.74 3.43 3.17 2.95 2.77 2.60 2.46 25 8.25 6.95 6.03 5.34 4.80 4.38 4.02 3.73 3.48 3.26 3.07 2.91 50 9.04 7.65 6.66 5.92 5.34 4.87 4.49 4.16 3.88 3.65 3.44 3.25 100 9.83 8.36 7.30 6.50 5.87 5.36 4.94 4.59 4.29 4.03 3.80 3.60 Tc = time in minutes. Values may exceed 60. D-in 81o n • nKIM IK!r' J CTnonA .. Rainfall Precipitation Table (in) Storm Distribution 1-yr 2-yr 3-yr 5-yr 10-yr 25-yr 50-yr 100-yr SCS 24-hour 2.96 3.59 1.00 4.56 5.33 6.39 6.80 8.15 SCS 6-Hr 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-1st 0.00 0.00 0.00 0.00 0.00 0.00 6.50 0.00 Huff-2nd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-3rd 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-4th 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Huff-indy 0.00 0.00 0.00 0.00 0.00 0.00 0.00 0.00 Custom 0.00 0.00 0.00 0.00 0.00 0.00 6.00 0.00