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HomeMy WebLinkAboutSW8021201_COMPLIANCE_20100713STORMWATER DIVISION CODING SHEET POST -CONSTRUCTION PERMITS PERMIT NO. SW_F6:gII D DOC TYPE El CURRENT PERMIT ❑ APPROVED PLANS ❑ HISTORICAL FILE COMPLIANCE EVALUATION INSPECTION DOC DATE YYYYMMDD NC®ENR North Carolina Department of Environment and Natural Resources Division of Water Quality Beverly Eaves Perdue Coleen H. Sullins Governor Director July 13, 2010 Mr. William Dansey Quality Built Construction, Inc 8-H Merry Lane Greenville, NC 27858 Subject: NOTICE OF VIOLATION, NOV-2010-PC-0850 The Marshes at Rivers Edge Stormwater Permit No. SW8 021201 New Hanover County Dear Mr. Dansey: Dee Freeman Secretary On June 8, 2010, Wilmington Regional Office personnel performed a Compliance Inspection and file review of the subject project, located at Independence Blvd in Wilmington, New Hanover County, North Carolina. The inspection was performed to determine the status of compliance with Stormwater Permit Number SW8 021201, issued to you on May 5, 2003. The project has been found in violation of Stormwater Permit Number SW8 021201, issued pursuant to the requirements of 15A NCAC 2H.1000. The violations found are: Failure to certify the stormwatersystem. A file review revealed that this office has not received a Designers Certificate. Permit condition states that upon completion of construction, prior to issuance of a Certificate of Occupancy, and prior to operation of this permitted facility, a certification must be received from an appropriate designer for the system installed certifying that the permitted facility has been installed in accordance with this permit, the approved plans and specifications, and other supporting documentation. Any deviations from the approved plans and specifications must be noted on the Certification. To correct these violations you must: Provide a written "Plan of Action" which outlines the actions you will take to correct the violation(s) and a time frame for completion of those actions, on or before August 13, 2010. 2. Submit the required Designers Certificate. Failure to provide the "Plan of Action" by August 13, 2010, or to correct the violations by the date designated in the "Plan of Action", are considered violations of 15A NCAC 2H.1000, and may result in the initiation of enforcement action which may include recommendations for the assessment of civil penalties, pursuant to NCGS 143-215.6A. Wilmington Regional Office 127 Cardinal Drive Extension, Wilmington, North Carolina 28405 Phone: 910-796-7215 l FAX: 910-350-20041 Customer Service: 1-877-623-6748 Internet: www.ncwalergaality.org An Equal Opportunity 1Affirmative Action Employer Nort:hCarolina ;VattirrrllJ { July 13, 2010 The Marshes at Rivers Edge Stormwater Permit No. SW8 021201 By copy of this letter to the New Hanover County Building Inspector, this Office is requesting that the Building Inspector consider withholding building permits and Certificates of Occupancy for this project until this matter is satisfactorily resolved. If you have any questions concerning this matter, please call David Cox at (910) 796 7318. Sincgrely, Georgette Scott Stormwater Supervisor Division of Water Quality. GDSldwc: S:IWQSISTORMWATERINOTICEI.jul10 CC.' Jimmy Fentress New Hanover County Building Inspections John Hennessey David Cox Georgette Scott 'Central Files WiRO Page 2 of 4 4 ` July 13, 2010 The Marshes at Rivers Edge Stormwater Permit No. SW8 021201 The Marshes at Rivers Edge Hew Hanover County Stormwater Project No. SW8 021201 Designer's Certification Page 1 of 2 I, , as a duly registered in the State of North Carolina, having been authorized to observe (periodically 1 weekly 1 full time) the construction of the project, ject for (Project Owner) hereby state that, to the best of my abilities, due care and diligence was used in the observation of the project construction such that the construction was observed to be built within substantial compliance and intent of the approved plans and specifications. Required Items to be checked for this certification to be considered complete are on page 2 of this form. Noted deviations from approved plans and specifications: Signature Registration Number Date SEAL Page 3 of 4 July 13, 2010 The Marshes at Rivers Edge Stormwater Permit No. SW8 021201 Certification Requirements: Page 2 of 2 1. The drainage area to the system contains approximately the permitted acreage. 2. The drainage area to the system contains no more than the permitted amount of built -upon area. 3. All the built -upon area associated with the project is graded such that the runoff drains to the system. 4. The outlet/bypass structure elevations are per the approved plan. 5. The outlet structure is located per the approved plans. 6. Trash rack is provided on the outlet/bypass structure. 7. All slopes are grassed with permanent vegetation. 8. Vegetated slopes are no steeper than 3:1. 9, The inlets are located per the approved plans and do not cause short-circuiting of the system. 10. The permitted amounts of surface area and/or volume have been provided. 11. Required drawdown devices are correctly sized per the approved plans. 12. All required design depths are provided. 13. All required parts of the system are provided, such as a vegetated shelf, and a forebay. 14. The dimensions of the system, as shown on the approved plans, are provided. cc: NCDENR-DWQ New Hanover County Building Inspections Page 4 of 4 Compliance Inspection Report Permit: SW8021201 Effective: 05/05/03 Expiration: 05/05/13 Owner: Quality Built Construction Inc Project: Echo Farms- The Marshes at River's Edge County: New Hanover Indepdence Blvd At River Rd Region: Wilmington Wilmington NC 28405 Contact Person: William Dansey Title: President Phone: 252-756-8702 Directions to Project: US 421 N from US 421/NC132 intersection to Independence Blvd. Left on Independence to River Road, property on NE corner. Type of Project: State Stormwater - HD - Detention Pond Drain Areas: 1 - (Barnards Creek) (03-06-17 } { C;Sw) 2 - (Barnards Creek) (03-06-17) ( C;Sw) 3 - (Barnards Creek) (03-06-17) ( C;Sw) 4 - (Barnards Creek) (03-06-17) ( C;Sw) 5 - (Barnards Creek) (03-06-17) { C;Sw) On -Site Representative(s): Related Permits: Inspection Date: 06/08/2010 Entry Time: 01:30 PM Primary Inspector: David W Cox Secondary Inspector(s): Reason for Inspection: Routine Permit Inspection Type: State Stormwater Facility Status: ❑ Compliant ■ Not Compliant Question Areas: ® State Stormwater (See attachment summary) Exit Time: 02:00 PM Phone: 910-796-7215 Inspection Type: Compliance Evaluation Page: 1 Permit: SW8021201 Owner - Project: Quality Built Construction Inc Inspection Date: 06/08/2010 Inspection Type: Compliance Evaluation Reason for Visit: Routine Inspection Summary: In order to bring this system into compliance File Review Yes No NA NE Is the permit active? ■ ❑ ❑ ❑ Signed copy of the Engineer's certification is in the file? ❑ ■ ❑ ❑ Signed copy of the Operation & Maintenance Agreement is in the file? Ri ❑ ❑ ❑ Copy of the recorded deed restrictions is in the file? ❑ ❑ ■ ❑ Comment: 1. No Engineer's Certification in File SW Measures Yes No NA NE Are the SW measures constructed as per the approved plans? ■ ❑ ❑ ❑ Are the inlets located per the approved plans? ®❑ ❑ Cl Are the outlet structures located per the approved plans? ® Cl ❑ 0 Comment: Operation and Maintenance Yes No NA NE Are the SW measures being maintained and operated as per the permit requirements? ■ ❑ ❑ ❑ Are the SW BMP inspection and maintenance records complete and available for review or provided to DWQ ❑ ❑ L 0 upon request? Comment: Page: 2 Compliance Inspection Report Permit: SW8021201 Effective:05105/03 Expiration 05105I17 Project: Echo Farms- The Marshes at Rivers Edge Owner: Quality Built Construction Inc County: New Hanover Adress: Indepdence Blvd At River Rd Region: Wilmington CitylStatelZip: Wilmington NC 28405 Contact Person: William Dansey Title: President Phone: 252-756-8702 Directions to Project: US 421 N from US 4211NC132 intersection to Independence Blvd. Left on Independence to River Road, property on NE corner. Type of Project: State Stormwater -fit) - Detention Pond Drain Areas: 1 - (Barnards Creek) (03-06-17) ( C;Sw) 2 - (Barnards Creek) (03-06-17) ( C;Sw) 3 - (Barnards Creek) (03-06-17) ( C;Sw) 4 - (Barnards Creek) (03-06-17) { C;Sw) 5 - (Barnards Creek) (03-06-17) ( C;Sw) On -Site Representative(s): Related Permits: Inspection Date: 03/20/2015 Entry Time: 01:OOPM Primary Inspector: Alida R Lewis Secondary lnspector(s): Reason for Inspection: Other Permit Inspection Type; State Stormwater Facility Status: ❑ Compliant 0 Not Compliant Question Areas: 0 State Stormwater (See attachment summary) Exit Time: 01:30PM Phone: 910-796-7215 Inspection Type: Transfer Renewal page: 1 Permit: SWO021201 Owner - Project: Quality Built Construction Inc >M Inspection Date: 0312=015 Inspection Type Transfer Renewal Reason for Visit: Other Inspection Summary: The inspection revealed the following deficiencies that must be addressed: 1. Pond #3 needs to be maintained to restore that pond to design condition. 2, The outlet stucture in Pond #1 needs to be maintainedfrepaired in order to restore orifice flow. 3. The added PVC pipe through the curbing at Building #5 needs to be plugged, or piped over to Pond #1 for treatment or piped into a catch basin that ultimately drains to Pond #1. 4. A partial designer's certification to cover the parts of the project and the BMP's that are built must be submitted. 5. Verification must be provided that the roof drainage from the backs of the buildings is being collected and directed into the appropriate permitted BMP. 6. Due to the dissolution of the original permittee LLC in 2008, and the passing of the permittee in 2013, ownership of the permit needs to be settled. The permit should probably be transferred to the next developer of the project because it may not meet the requirements to be transferred to the COA under SL 2011-256 at this time. page: 2 e—) Permit: SW8021201 Owner - Project: Quality Built Construction Inc Inspectlon Date: 03/20/2015 Inspection Type Transfer Renewal Reason for Visit: Other File Review Yes No NA NE Is the permit active? 0 ❑ ❑ ❑ Signed copy of the Engineer's certification is in the file? ❑ 0 ❑ ❑ Signed copy of the Operation & Maintenance Agreement is in the file? ❑ ❑ ❑ Copy of the recorded deed restrictions is in the file? ❑ ❑ E ❑ Comment: 1. The Designers Certification has not been received. The consultant provided a letter on August 12 2010 indicating that due to a lack of routine maintenance and due to the fact that not all of the buildings were completed, he was not able to certify the project. The consultant also indicated that he_expected to be able to certify the_oroiect by September 13, 2010. Built Upon Area Is the site BUA constructed as per the permit and approval plans? Is the drainage area as per the permit and approved plans? Yes No NA NE ■ ❑❑❑ ■❑❑❑ Is the BUA (as permitted) graded such that the runoff drains to the system? ❑ E 110 Comment: 2. In the PaNng lot in front of Building #5 someone has added a small PVC pipe through the curbing which allows runoff from some of that paved area to enter the wetland anCbypass treatment in the pond. 3. The consultant will need to verify that the roof drainage from the rear of those buildings that are already built is being collected and sent to the appropriate pond for treatment. SW Measures Are the SW measures constructed as per the approved plans? Are the inlets located per the approved plans? Yes No NA NE ❑ ■❑❑ ❑ ❑ ❑ Are the outlet structures located per the approved plans? 0 ❑ ❑ ❑ Comment: 4_Pond #_3 is not built per the approved plans. The slopes are very steep, bare and eroding. There is a lot of trash and construction debris littering the site. 5. Theequalizer pipe between Pond 2 and 2A was not visible. The consultant will need to verify its presence. Operation and Maintenance Yes No NA NE Are the SW measures being maintained and operated as per the permit requirements? ❑ , ❑ Are the SW BMP inspection and maintenance records complete and available for review or provided to ❑ ❑ ❑ DWQ upon request? Comment: 6. Ponds 1 and 2 are being maintained, but Pond 3 is not. 7. The outlet_ structure in Pond 1 may be blocked because there was no runoff leaving the pond, but the water level appeared to be up over the temporaryool outlet Other Permit Conditions Is the site compliant with other conditions of the permit? Yes No NA NE ❑ ■❑❑ page: 3 Permit: SW8021201 Owner - Project: Quality Built Construction Inc inspection Date: 03120/2015 Inspection Type Transfer Renewal Reason for visit: Other Comment: 8. The permittee of record_ dissolved their coporate_entity on February _1.2,-2008 and the permit holder Passed away in 2013. The permit will need to be transferred to the next developer, as it's likely the project will not meet the SL 2011-256 requirments for transfer to the Condominimum Owners Association at this time. page: 4 Compliance Inspection Report Permit: SW8021201 Effective: 05/05/03 Expiration: 05/05/17 Owner: Quality Built Construction Inc Project: Echo Farms- The Marshes at River's Edge County: New Hanover Indepdence Blvd At River Rd Region: Wilmington Wilmington NC 28405 Contact Person: William Dansey Title: President Phone: 252-756-8702 Directions to Project: US 421 N from US 421/NC132 intersection to Independence Blvd. Left on Independence to River Road, property on NE corner. Type of Project: State Stormwater - HD - Detention Pond Drain Areas: 1 - (Barnards Creek) (03-06-17) ( C;Sw) 2 - (Barnards Creels) (03-06-17 ) ( C;Sw) 3 - (Barnards Creek) (03-06-17 ) ( C;Sw) 4 - (Barnards Creek) (03-06-17 ) ( C;Sw) 5 - (Barnards Creek) (03-06-17 ) ( C;Sw) On -Site Representative(s): Related Permits: Inspection Date: 11/08/2012 Entry Time: 03:35 PM Primary Inspector: David W Cox Secondary Inspector(s): Reason for Inspection: Follow-up Permit Inspection Type: State Stormwater Facility Status: ❑ Compliant ■ Not Compliant Question Areas: E State Stormwater (See attachment summary) Exit Time: 04:00 PM Phone: 910-796-7215 Inspection Type: Compliance Evaluation Page: 1 f ti Permit: SW8021201 Owner - Project: Quality Built Construction Inc Inspection Date: 11/08/2012 Inspection Type: Compliance Evaluation Reason for Visit: Follow-up Inspection Summary: In order for this project to be in compliance with the terms and conditions please provide the required Engineer's Certificate within 30 days of receipt of this report. File Review Yes No NA NE Is the permit active? ■ ❑ ❑ ❑ Signed copy of the Engineer's certification is in the file? ❑ ■ ❑ ❑ Signed copy of the Operation & Maintenance Agreement is in the file? ■ ❑ ❑ ❑ Copy of the recorded deed restrictions is in the file? ❑ ❑ ■ ❑ Comment: This office has not received a copy of the engineer's certification Operation and Maintenance Yes No NA NE Are the SW measures being maintained and operated as per the permit requirements? ❑ ❑ ❑ ❑ Are the SW BMP inspection and maintenance records complete and available for review or provided to DWO ❑ ❑ ❑ ❑ upon request? Comment: Page: 2 Cox, David From: Cox, David Sent: Thursday, November 15, 2012 1:41 PM To: 'Jimmy Fentress' Cc: Scott, Georgette Subject: RE: SW8021021 Attachments: 2012 10 cei_bims 021201.pdf Jimmy, Here is the official inspection report. Look its attached aren't you proud? From: Jimmy Fentress [mailto:jfentressCabstroudenglneer.com] Sent: Tuesday, November 13, 2012 9:22 AM To: Cox, David Cc: Scott, Georgette Subject: RE: SW8021021 No attachment???? From: Cox, David[mailto:david.w.cox@ncdenr.aov] Sent: Tuesday, November 13, 2012 9:18 AM To: Jimmy Fentress Cc: Scott, Georgette Subject: RE: SW8021021 Here is the 2010 NOV. From: Jimmy Fentress [mailto:'fentress strouden ineer.com] Sent: Friday, November 09, 2012 11:14 AM To: Cox, David Subject: RE: SW8021021 Please and thanks. jimmy From: Cox, David [mailto:david.w.cox@ncdenr.gov] Sent: Friday, November 09, 2012 8:20 AM To: Jimmy Fentress Cc: Scott, Georgette Subject: RE: SW8021021 I'll send it Tuesday. I have a lot of inspection/meetings today. From: Jimmy Fentress [ma !Ito: jfentressCalstroudengineer.com] Sent: Thursday, November 08, 2012 11:19 AM To: Cox, David Cc: Scott, Georgette Subject: RE: SW8021021 Please send me the NOV. i can't find where we have certified it but we do have adequate survey data to consider it for certification. I think that the ponds in areas that were not finished probably have not been maintained. The ponds in areas that are complete are in great shape. Let me revisit the site on the way home today and I will report back as to my ability to certify or partially certify. jimmy From: Cox, David [mailto:david.w.cox(a)ncdenr.gov] Sent: Thursday, November 08, 2012 10:26 AM To: Jimmy Fentress Cc: Scott, Georgette Subject: SW8021021 Jimmy, Did the Marshes at Rivers Edge ever get certified? It is coming up for renewal soon and I have an Notice of Violation on it. It is a clearing house day. David From: Jimmy Fentress [ma ilto:jfentress@stroudenginee r.com] Sent: Thursday, November 08, 2012 9:40 AM To: Cox, David; Scott, Georgette Cc: 'Murray, Anne W (GE Power & Water)' Subject: RE: Airlie Forest Got it and thanks From: Cox, David [pailto:david.w.cox@ncdenr.gov] Sent: Thursday, November 08, 2012 9:38 AM To: Scott, Georgette; Jimmy Fentress Cc: 'Murray, Anne W (GE Power & Water)' Subject: RE: Airlie Forest Jimmy, Don't forget the transfer documents before the modification. David From: Scott, Georgette Sent: Thursday, November 08, 2012 8:09 AM To: Jimmy Fentress Cc: Cox, David; 'Murray, Anne W (GE Power & Water)' Subject: RE: Airlie Forest Thank you for your plan. It sounds reasonable. Let us know when you will move forward. Ccorgelte Scott. Storiir►vater Progmun Supervisor Stale Stor[nwater Progn':uii NC Division of Water Quality 127 Cardinal Drive Ext. Wilminglon, NC 2840.5 Phone (910) 796-7335 Fax (910) ; 3 50-2004 1'�ntai] a�rrespundcnec lu and front Ibis address nra}' be Sobjcct to the North Caroh m 1'ub k Rceurds W mid nmy he VMS m [bird parties. From: Jimmy Fentress[mailto:]fentress(&stroudengineer.com] Sent: Wednesday, November 07, 2012 3:58 PM To: Scott, Georgette Cc: Cox, David; 'Murray, Anne W (GE Power & Water)' Subject: Airlie Forest All, The attached Plan of Action went out in the mail today. I am now engaged by the Airlie Forest Homeowner's Association to make application in this regard. Thanks, Jimmy Fentress WET DETENTION POND ANALYSIS FILE NAME: G:IDATAIWPDATAIWQSIPOND1021201-2.WK1 PROJECT #: SW8 021201-2 REVIEWER: L. Lewis PROJECT NAME: Barnards Landing @Echo Farms DATE: 14-Apr-03 Receiving Stream: Barnards Creek Class: C Sw Drainage Basin: Cape Fear Index No. CPF17 18-8C Site Area 53.40 acres Drainage Area >-374.180 00 ;square feet Area in Acres 8.59 IMPERVIOUS AREAS Rational C Buildings 93489.00 square feet Parking 74779.00 square feet Sidewalks 14566.00 square feet Street 29007.00 square feet square feet square feet TOTAL 21f1 00 square feet Rational Cc= 0.09 SURFACE AREA CALCULATION % IMPERVIOUS 56.61% Des. Depth 5.5 TSS: 90 SA/DA Ratio 3,63% Req. SA 13580 sf Prov. SA VOLUME CALCULATION * place a "1" in the box if Rational is used Req. Volume .. °I44 Vol. Prov. at DP :........179.31 cf ORIFICE CALCULATION Perm. Pool Volume= 38212 Req. Forebay Volume= 7642.4 Provided Volume= 8234.00 Percent= 21 5°fo Elevation 7.00 8.00 Area 15604.00 17728.00 Inc. Vol. 14597.50 16666.00 Acc. Vol. 14597.50 31263,50 Avg. Head = 0.56 ft Q2 Area = 4.04 sq. inches Flow Q2, cfs 0.101 cfs 05 Area = 1.62 sq. inches Flow Q5, cfs 0.040 cfs Orifice Area 3.14 sq. inches No. of Orifices :.;:::<; Q- 0.078 cfs Diameter, inches weir H x W in x in Drawdown = im days Surface Area @DP = 16293.5 sq. ft. Falling Head Drawdown = 3.6 days COMMENTS Surface Area, Volume and Orifice are within Design Guidelines. WET DETENTION POND ANALYSIS FILE NAME: G:IDATAIWPDATAIWQSIPOND1021201-3.WK1 PROJECT #: SW8 021201-3 REVIEWER: L. Lewis PROJECT NAME: Barnards Landing @Echo Farms DATE: 14-Apr-03 Receiving Stream: Barnards Creek Class: C SW Drainage Basin: Cape Fear Index No, CPF17 18-8C Site Area 53.40 acres Drainage Area f,4244! 00 square feet Area in Acres 3.27 IMPERVIOUS AREAS Buildings Parking Sidewalks TOTAL 36943.00 square feet 46353.00 square feet 5554.00 square feet 4� square feet square feet square feet 888�6 0> square feet SURFACE AREA CALCULATION % IMPERVIOUS 62.40% Des. Depth 6 TSS: 85 Rational C Rational Cc= 0.08 SA/DA Ratio 2.67% Req. SA 3806 sf Prov. SA ..........4t}33'€ sf VOLUME CALCULATION * place a "1" in the box if Rational is used Req. Volume ..... ;Z6t} cf Vol. Prov. at DP 7416 cf ORIFICE CALCULATION Avg. Head = Flow Q2, cfs Flow Q5, cfs No. of Orifices Diameter, inches Drawdown = Perm. Pool Volume= 9836 Req. Forebay Volume= 1967.2 Provided Volume= 2222.00 Percent= Elevation Area Inc. Vol. Acc. Vol. 7.00 5073.00 4553.00 8.00 6377.00 5725.00 10278.00 COMMENTS Surface Area, Volume and Orifice are within Design Guidelines. WET DETENTION POND ANALYSIS FILE NAME: G:IDATAIWPDATAIWQSIPOND1021201-5.WK1 PROJECT #: SW8 021201-5 REVIEWER: L. Lewis PROJECT NAME: Barnards Landing @Echo Farms DATE: 14-Apr-03 Receiving Stream: Barnards Creek Class: C Sw Drainage Basin: Cape Fear Index No. CPF17 18-8C Site Area 53.40 acres Drainage Area 45738 00 square feet Area in Acres 1.05 IMPERVIOUS AREAS Buildings Parking Sidewalks TOTAL SURFACE AREA CALCULATION % IMPERVIOUS 68.81% Des. Depth 4 TSS: 90 Rational C 13402,00 square feet 16770.00 square feet 1300.00 square feet square feet square feet square feet 3172 a0.> square feet Rational Cc= 0.06 SA/DA Ratio 5,92% Req. SA 2706 sf Prov. SA ........3..5 sf VOLUME CALCULATION * place a "1" in the box if Rational is used Rational ?* Des. Storm ::;:'.1..O.Q: inches Rv= 0.669 Bottom 2 msl Perm. Pool 6 OCh:: msl Design Pool 6.8 msl Storage met @elev 6.70 msl Req. Volume 2a1-,' cf Vol. Prov.'at DP :::::;:294.': cf ORIFICE CALCULATION FOREBAY Perm. Pool Volume= 4149 Req. Forebay Volume= 829.8 Provided Volume= 909.00 Percent= 21#o Elevation Area Inc. Vol. Acc. Vol. 6.00 3105.00 0.00 7.00 4181,00 3643.00 3643.00 Avg. Head = 0.38 ft Q2 Area = 0.71 sq. inches Flow Q2, cfs 0.015 cfs Q5 Area = 0.28 sq, inches Flow Q5, cfs 0.006 cfs Orifice Area 0.44 sq. inches No. of orifices <;iA Q= 0.009 cfs Diameter, inches D 75.; weir H x W :.....> m x ;.; i n Drawdown = 3 days Surface Area @DP = 4181 sq. ft. Falling Head Drawdown = 5.1 days COMMENTS Surface Area, Volume and Orifice are within Design Guidelines. WET DETENTION POND ANALYSIS FILE NAME: G:IDATAIWPDATAIWQSIPOND1021201-4.WK1 PROJECT #: SW8 021201-4 REVIEWER: L. Lewis PROJECT NAME: Barnards Landing @Echo Farms DATE: 05-May-03 Receiving Stream: Barnards Creek Class: C Sw Drainage Basin: Cape Fear Index No. CPF17 18-BC Site Area 53.40 acres Drainage Area 84ii7 CR0 :< square feet Area in Acres 1.93 IMPERVIOUS AREAS Buildings Parking Sidewalks TOTAL SURFACE AREA CALCULATION 20359,00 square feet 25906.00 square feet 2235.00 square feet square feet square feet square feet 4$f30 04` square feet Rational C Rational Cc= 0.08 % IMPERVIOUS 57.69% SAIDA Ratio 4.59% Design Depth 4.5 Req. SA 3861 sf TSS: 90 Prov. SA :,,;::> 233. sf VOLUME CALCULATION Rational ?* Des. Storm _. ._ inches Rv= 0.569 Bottom 2.5 msl Perm. Pool ? 00:'; msl Design Pool 8 msl Storage met @elev 7.81 msl Req. Volume I..........;;9$8:' cf Vol. Prov. at DP 4912 ` cf ORIFICE CALCULATION place a "1" in the box if Rational is used FOREBAY Perm. Pool Volume= 7053 Req. Forebay Volume= 1410.6 Provided Volume= 1391.00 Percent= .1 7o/u Elevation Area Inc. Vol. 7.00 4233.00 8.00 5591.00 4912.00 Acc. Vol. 0.00 4912.00 Avg. Head = 0.48 ft Q2 Area = 1.00 sq. inches Flow Q2, cfs 0.023 cfs Q5 Area = 0.40 sq. inches Flow Q5, cfs 0.009 cfs Orifice Area 0.79 sq. inches No. of Orifices :::: Q= 0.018 cfs Diameter, inches 1 04:, weir H x W . Drawdown = :: 2 5 days Surface Area @DP = 5591 sq. ft. Falling Head Drawdown = 4.3 days COMMENTS Surface Area, Volume and Orifice are within Design Guidelines. WET DETENTION POND ANALYSIS FILE NAME: G:IDATAIWPDATAIWQSIPOND1021201-4.WK1 PROJECT #: SW8 021201-4 REVIEWER: L. Lewis PROJECT NAME: Barnards Landing @Echo Farms DATE: 05-M2y-03 Receiving Stream: Barnards Creek Class: C Sw Drainage Basin: Cape Fear Index No. CPF17 18-8C Site Area 53.40 acres Drainage Area 8407 Oa `square feet Area in Acres 1.93 IMPERVIOUS AREAS Buildings Parking Sidewalks TOTAL SURFACE AREA CALCULATION 20359,00 square feet 25906.00 square feet 2235.00 square feet square feet square feet square feet 48SQ 00 .' square feet Rational C Rational Cc= • 0.08 % IMPERVIOUS 57.69% SA/DA Ratio 4.59% Design Depth 4.5 Req. SA 3861 sf TSS: 90 Prov. SA 423'' sf VOLUME CALCULATION * place a "1" in the box if Rational is used Rational ?* Des. Storm €?`: inches Rv= 0.569 Bottom 2.5 msl Perm. Pool ?OQ.. msl _.......... Design Pool 8 msl Storage met @elev 7.81 msl Req. Volume :.:.:3988::< cf Vol. Prov. at DP _ - .; 4912'' cf ORIFICE CALCULATION Perm. Pool Volume= 7053 Req. Forebay Volume= 1410.6 Provided Volume= 1391.00 Percent= Elevation Area Inc. Vol. Acc. Vol. 7.00 4233.00 0.00 8.00 5591.00 4912.00 4912.00 Avg. Head = 0.48 ft Q2 Area = 1.00 sq. inches Flow Q2, cfs 0.023 cfs Q5 Area = 0.40 sq. inches Flow Q5, cfs 0.009 cfs Orifice Area 0.79 sq. inches No. of Orifices <; Q= 0.018 cfs Diameter, inches 1i0 >, weir H x W i :: in x in Drawdown W 5 € days Surface Area @DP = 5591 sq. ft. Failing Head Drawdown = 4.3 days COMMENTS Surface Area, Volume and Orifice are within Design Guidelines. WET DETENTION POND ANALYSIS FILE NAME: G:\DATA\WPDATA\WQS\POND1021201-5.WK1 PROJECT#: SW8 021201-5 REVIEWER: L. Lewis PROJECT NAME: Barnards Landing @Echo Farms DATE: 14-Apr-03 Receiving Stream- Barnards Creek Class: C Sw Drainage Basin: Cape Fear Index No. CPF17 18-8C Site Area 53.40 acres Drainage Area 5738Isquare feet Area in Acres 1.05 IMPERVIOUS AREAS Rational C Buildings 13402.00 square feet Parking 16770,00 square feet Sidewalks 1300.00 square feet square feet square feet square feet TOTAL square feet Rational Cc= 0,06 SURFACE AREA CALCULATION % IMPERVIOUS 68.81% Des. Depth 4 TSS: 90 SA/DA Ratio 5.92% Req. SA 2706 sf Prov, SA VOLUME CALCULATION * place a "ll" in the box if Rational is used Rational ?* Des. Storm inches Rv= 0.669 Bottom 2 msl Perm. Pool FTFU7W msl Design Pool 6.8 msl Storage met @elev 6.70 msl Req. Volume cf Vol. Prov. *at DP cf ORIFICE CALCULATION Avg. Head = Flow Q2, cfs Flow Q5, cfs No. of Orifices Diameter, inches Drawdown = FOREBAY Perm. Pool Volume= 4149 Req. Forebay Volume= 829.8 Provided Volume= 909.00 Percent= Elevation Area Inc. Vol. 6.00 3105.00 7.00 4181.00 3643.00 0,38 ft Q2 Area = 0.71 0.015 cfs Q5 Area = 0.28 0.006 cfs Orifice Area 0.44 Q= 0,009 4.7weir H x W in x days Surface Area @DP Falling Head Drawdown COMMENTS Surface Area, Volume and Orifice are within Design Guidelines. Acc. Vol. 0.00 3643.00 WET DETENTION POND ANALYSIS FILE NAME: G:IDATAIWPDATAIWQSIPOND1021201-2.WK1 PROJECT #: SW8 021201-2 REVIEWER: L. Lewis PROJECT NAME: Barnards Landing @Echo Farms DATE: 14-Apr-03 Receiving Stream: Barnards Creek Class: C Sw Drainage Basin: Cape Fear Index No. CPF17 18-8C Site Area 53.40 acres Drainage Area 7418q f�0 ' square feet Area in Acres 8.59 IMPERVIOUS AREAS Rational C Buildings 93489.00 square feet Parking 74779.00 square feet Sidewalks 14566.00 square feet Street 29007.00 square feet square feet square feet TOTAL 21 i.M 'WO."I square feet Rational Cc= 0.09 SURFACE AREA CALCULATION % IMPERVIOUS 56.61% SAIDA Ratio 3.63% Des. Depth 5.5 Req. SA 13580 sf TSS: 90 Prov. SA�13591 fl sf VOLUME CALCULATION * place a "1" in the box if Rational is used Rational ?* Des. Storm 1;';.QfJ inches Rv= 0.560 Bottom 0.5 msl Perm. Pool 6 00' , msl Design Pool 7.2 msl Storage met @elev 7.17 msl Req. Volume 17 47 ` cf Vol. Prov. at DP 17:33.1 cf ORIFICE CALCULATION FOREBAY Perm. Pool Volume= 38212 Req, Forebay Volume= 7642.4 Provided Volume= 8234.00 Percent= Elevation 7.00 8.00 Area 15604.00 17728.00 Inc. Vol. 14597.50 16666.00 Acc. Vol. 14597.50 31263.50 Avg. Head = 0.56 ft Q2 Area = 4.04 sq. inches Flow Q2, cfs 0.101 cfs Q5 Area = 1.62 sq. inches Flow 05, cfs 0.040 cfs Orifice Area 3.14 sq. inches No. of Orifices 1: Q= 0.078 cfs Diameter, inches „2 C3;; weir H x W in x to Drawdown = ;2 6:, days Surface Area @DP = 16293.5 sq. ft. Falling Head Drawdown = 3.6 days COMMENTS Surface Area, Volume and Orifice are within Design Guidelines. WET DETENTION POND ANALYSIS FILE NAME- G:kDATA\WPDATA\WQS\POND1021201-3.WK1 PROJECT#: SW8 021201-3 REVIEWER, L. Lewis PROJECT NAME- Barnards Landing @Echo Farms DATE.- 14-Apr-03 Receiving Stream- Barnards Creek class, C Sw Drainage Basin: Cape Fear Index' No. CPF17 18-8C Site Area 53.40 acres Drainage Area Qqsquare feet Area in Acres 3,27 IMPERVIOUS AREAS Buildings Parking Sidewalks TOTAL 36943.00 square feet 46353.00 square feet 55&4.00 square feet square feet square feet square feet $$�6 OQ,: square feet SURFACE AREA CALCULATION - % IMPERVIOUS 62.40% Des. Depth 6 TSS: 85 Rational C Rational Cc= 0.08 SA/DA Ratio 2,67% Req. SA 3806 sf Prov. SA VOLUME CALCULATION * place a "1" in the box if Rational is used Rational ?* FOREBAY Des. Storm inches Perm. Pool Volume= 9836 Rv= 0.612 Req. Forebay Volume= 1967.2 Bottom 0 ms1 Provided Volume= 2222.00 Perm. Pool MSI Percent= Design Pool 7.5 msl Storage met @elev 7.47 msi Elevation Area Inc. Vol. Acc. Vol. Req. Volume cf 7.00 5073.00 4553.00 Vol. Prov. at DP cf 8.00 6377.00 5725.00 10278.00 ORIFICE CALCULATION Avg. Head = 0,73 ft Q2 Area = 1,47 sq. inches Flow Q2, cfs 0.042 cfs Q5 Area = 0.59 sq. inches Flow Q5, cfs 0.017 cfs Orifice Area 0.79 sq. inches No. of Orifices 7,1 Q= 0.022 cfs Diameter, inches 6�il weir H x W in x 17777M in Drawdown Tj days Surface Area @DP 5854,33333 sq ft. Falling Head Drawdown = 5.3 days COMMENTS Surface Area, Volume and Orifice are within Design Guidelines. NCDENR STATE STORMWATER MANAGEMENT PLAN BA ARLDG @ O'FA�41S -T-y� MAnSHES V f�IVEUsE-vGE REVISED APRIL 2, 2003 NOVEMBER 19, 2002 Owner: Quality Built Construction, Inc. 8 Courtney Square, Apt. 8 Greenville, NC 27858 RECEIVF APR 0 2 2003 PROJ�GZ l 2a STROUD ENGINEERING, P.A. 102 SUITE D CINEMA DRIVE WILMINGTON, N.C. 28403 (910)815-0775 File fAmasterlpw-131gbd\wpd\DENRsw.wpd NARRATIVE Project Description The purpose of this development is to allow for the clearing and grading of the property for the proposed multifamily residential condominium development. The site consists of approximately 20 acres of upland soils located adjacent to Barnard's Crcek in the City of Wilmington, just east of the intersection of River Road and Independence Blvd. Extended (formerly Titanium Road). Approximately 18 acres will be disturbed during the construction period with the wetlands slated for protection. Storm water from the impervious portions of the project will be collected via a subterranean pipe system and conveyed to five wet storm water detention ponds. The ponds will provide treatment of the first inch of rainfall per North Carolina Department of Environment and Natural Resources, Water Quality Section regulations. The ponds will also provide detention to insure that the post development runoff from the site does not exceed the calculated pre development runoff rate. Site Description The site has a sloped topography with 10 feet of relief formed as peninsulas situated in and adjacent swamp and fresh marsh lands. The soils on the site are given by the New Hanover County Soil Survey to be Craven, Kureb, and Norfolk. The property was logged three years ago yet a number of trees are still evident within the uplands. The emergent vegetation subsequent the logging activities is primarily six to eight feet tail at this time and consists primarily of pine, privet, holly and oak. Storm water from the site flows overland as sheet flow and into the wetlands which drain to Barnard's Creek and then to the Cape Fear River approximately two thousand feet downstream of the project. Both waters are stream class C-SW. Adjacent Properties Land use in the vicinity is zoned Industrial, High Density, and Residential. The property is situated on the City jurisdictional line with New Hanover County to the east. Land to the north is being developed as single family residential. Land to the west is undeveloped. Land to the south is being developed as a commercial marina. The land in the county to the cast is undeveloped and buffered by the wide expanse of Barnard's Creek. Design Itinerary The following design is structured to address both the City of Wilmington storm water detention and also North Carolina Storm water Management requirements. The format is divided by pond areas and is repetitive. Initially calculations of the required storage and discharge rates for the latter mentioned criteria, then a summary of pond area and volume quantities, followed on the next page by pre development and post development runoff calculations, inflow hydrograph parameters and a storage estimate to address City design parameters. The proceeding pages are the ten year and fifty year storm routings through the subject pond. After the fifth pond and on the last page is the piping design. Please find the plan and a reduced scale map showing the drainage areas in the pocket at the very rear of the report. famasterlpw 131 gbclwpolswnarra.wpd ,PROJECT: BARNARD'S LANDING, POND 1 PROJECT NO.: PW-13106C DATE: FEBRUARY 22, 2003 BASIN DATA TOTAL AREA (AC) = 1 1.84 PROPOSED IMPERV AREA (AC)= 1.210 r % IMPER AREA = 0.658 PROPOSED PERVIOUS AREA (AC)= 0.63 % PERVIOUS = 0.342 NCDENR STORMWATER MANAGEMENT CALCULATIONS SPATE REQUIRED STORAGE FOR 1ST IA IN OF RAINFALL RUNOFF = 0.05 + 0.009 X %IMPERV = RUNOFF = 0.642 REQUIRED VOLUME = 1.0 IN X RUNOFF X AREA X 43560 SF/AC/12 IN/FT VOLUME (CF) = 4287 STATE REQUIRED SURFACE AREA 90 % TSS REMOVAL 6.0 FT DEEP POND, 65.8% IMPERVIOUS SAIDA = 3.69 SURFACE AREA (SF) =SA/DA X AREA X 43560/100 12958 POND DIMESIONS AND VOLUMES ELEV. SA FOREBAY VOL FOREBAY SA POND VOL POND SUM VOL (FT) (SF) (CF) (SF) (CF) (CF) 0 0 93 1 0 0 233 163 163 2 100 50 436 334.5 547.5 3 207 153.5 704 570 1271 4 354 280.5 1039 871.5 2423 5 533 443.5 1442 1240.5 4107 5.8 678 484.4 2213 1462 6053A TOTAL 1411.9 TOTAL 4641.5 6053.4 %FORBAY 23.3 POND VOLUMES ABOVE PERMANENT POOL ELEV. SA POND VOL POND (FT) (SF) (CF) 5.8 3016 6 3306 632.2 7 4088 3697 8 4932 4510 9 5831 5381.5 10 6700 6265.5 STATE REQUIRED STORAGE (CF) = HEIGHT ABOVE PERM. POOL FOR STATE STORAGE (FT) _ STATE STORAGE ELEVATION (FT) = NCDENR OUTLET ORIFICE DESIGN TOTAL STORAGE = 2 DAY FLOW (CFS) = 4287/(2 X 24 X 60 X 60) = 5 DAY FLOW (CFS) = 4287/(5 X 24 X 60 X 60) = Q=AXCd(2XGXH)".5 2 DAY AREA A= Q/(Cd(2 X G X H)A.5 (SF) SUM VOL (CF) 0 632.2 4329.2 8839.2 14220.7 20486.2 4287 1.19 7.00 4287 A = AREA Cd = ORIFICE COEFF. = 0.6 G = GRAVITY = 32.2 F/SEC^2 H=HEIGHT(FT)= 1.19 0.0066837 USE H = 1.2 0.024809201 0.009923681 DIAMETER (IN) = 1.11 5 DAY AREA A = Q/(Cd(2 X G X H)^.5 (SF) 0.00267348 DIAMETER (IN) = 0.700301 DRAWDOWN ORIFICE TO BE 1.0 INCH IN DIAMETER DRAWDOWN RATE(CFS) = 0.020234991 DRAWDOWN TIME (DAY) 2.45 r PROJECT: BARNARD'S LANDING, POND 2 PROJECT NO.: PW-131QBC DATE: FEBRUARY 22, 2003 BASIN DA'I'A TOTAL AREA (AC) = 8.59 PROPOSED IMPERV AREA (AC)= 4,863 % IMPER AREA = 0,566 PROPOSED PERVIOUS AREA (AC)= 3.73 % PERVIOUS = 0.434 NCDENR STORMWATER MANAGEMENT CALCULATIONS STA'CE REQUIRED STORAGE FOR IST LO IN OF RAINFALL RUNOFF = 0.05 + {}.009 X %IMPERV = RUNOFF = 0.560 REQUIRED VOLUME = 1.0 IN X RUNOFF X AREA X 43560 SFIAC112 IN/FT VOLUME (CF) = 17447 STATE REQUIRED SURFACE AREA 90 % TSS REMOVAL ✓ 5.5 FT DEEP POND, 56.6% IMPERVIOUS SA/DA = 3.628 SURFACE AREA (SF) =SAlDA X AREA X 43560/100 = 113576 POND DIMESIONS AND VOLUMES 0AR0 =o.;ossro;� v :4 ��A►�4 'T. FeN f+!lfeu%+• ELEV. SA FOREBAY VOL FOREBAY SA POND VOL POND SUM VOL (FT) (SF) (CF) (SF) (CF) (CF) 0.5 0 0 1 0 0 2938 734.5 734.5 2 1115 557.5 3874 3406 4698 3 1478 1296.5 4971 4422.5 10417 4 1886 1682 6186 5578.5 17677.5 5 2338 2112 7504 BB45 26634.5 6 2833 2585.5 10480 8992 38212 TOTAL 8233.5 TOTAL 29978.5 38212 %FORBAY 21.5 POND VOLUMES ABOVE PERMANENT POOL ELEV. SA POND VOL POND SUM VOL (FT) (SF) (CF) (CF) 6 13591 0 7 15604 14597.5 14597.5 8 17728 16666 31263.5 9 19966 18847 50110.5 10 22200 21083 71193.5 STATE REQUIRED STORAGE (CF) = 17447 HEIGHT ABOVE PERM. POOL FOR STATE STORAGE (FT) = 1.17 USE H W 1.2 STATE STORAGE ELEVATION (FT) = 7,20 NCDENR OUTLET ORIFICE DESIGN TOTAL STORAGE = 17447 2 DAY FLOW (CFS) = 4287/(2 X 24 X 60 X 60) = 0.100967361 5 DAY FLOW (CFS) = 42871(5 X 24 X 60 X 60) = 0.040386944 0=AXCd(2XGXH)^.5 A=AREA Cd = ORIFICE COEFF. = 0.6 G = GRAVITY = 32.2 FISEC42 H=HEIGHT(FT)= 1.17 2 DAY AREA A = 0I(Cd(2 X G X H)-.5 (SF) 0.027404753 5 DAY AREA A = 0I(Cd(2 X G X H)^.5 (SF) 0,010961901 DRAWDOWN ORIFICE TO BE 2.0 INCH IN DIAMETER DRAWDOWN RATE(CFS) = 0,081327414 DRAWDOWN TIME (DAY) 2.48 DIAMETER (IN) = 2.24 DIAMETER (IN) = 1.418043 TOOT cv 72-1 %A I Is PL4 1, - a SS aq 0 w ss 31 IS 9 rb 4f 4f CN 4f 0 C) 04 C*4 4 Y. Ia C�l Ir �iyz %CO C!n L.A.J N O M 0 0 N O N N C Rl (d E C 3 U m 0 M r r PROJECT: BARNARD'S LANDING, POND 3 PROJECT NO.: PW-131QBC DATE: FEBRUARY 22, 2003 BASIN DATA TOTAL AREA (AC) = 1 3.27 PROPOSED IMPERV AREA (AC)= 2.040 % IMPER AREA = 0.624 PROPOSED PERVIOUS AREA (AC)= 1.23 % PERVIOUS = 0.376 NCDENR STORMWATER MANAGEMENT CALCULATIONS STATE RI,.QIJIREI) STORAGE FOR I ST I A IN OF RAINFALI. RUNOFF = 0.05 + 0.009 X %IMPERV = RUNOFF = 0.611 REQUIRED VOLUME = 1.0 IN X RUNOFF X AREA X 43560 SFIACII2 INIFT VOLUME (CF) = 72571 STATE REQUIRED SURFACE ARF,A 85 % TSS REMOVAL WILL PROVIDE VEGATATIVE FILTER -� 6 FT DEEP POND, 62.4% IMPERVIOUS SAlDA = 2.67 SURFACE AREA (SF) =SAIDA X AREA X 43560/100 = 13803 POND DIMESIONS AND VOLUMES ELEV. SA FOREBAY VOL FOREBAY SA POND VOL POND SUM VOL (FT) (SF) (CF) (SF) (CF) (CF) 0 45 420 1 110 77.5 603 511.5 589 2 203 156.5 828 715.5 1461 3 323 263 1134 981 2705 4 473 398 1479 1306.5 4409.5 5 654 563.5 1848 1663.5 6636.5 6 873 763.5 3023 2435.5 9835.5 TOTAL 2222 TOTAL 7613.5 9835.5 %FORBAY 22.6 POND VOLUMES ABOVE PERMANENT POOL ELEV. SA POND VOL POND (FT) (SF) (CF) 6 4033 7 5073 4553 8 6377 5725 9 7711 7044 10 9101 8406 STATE REQUIRED STORAGE (CF) HEIGHT ABOVE PERM. POOL FOR STATE STORAGE (FT) STATE STORAGE ELEVATION (FT) NCDENR OUTLET ORIFICE DESIGN TOTAL STORAGE = SUM VOL (CF) 0 4553 10278 17322 25728 7257 1.47 7.50 7257 2 DAY FLOW (CFS) = 42871(2 X 24 X 60 X 60) = 5 DAY FLOW (CFS) = 4287I(5 X 24 X 60 X 60) = Q=AXCd(2XGXH)^.5 A=AREA Cd = ORIFICE COEFF. = 0.6 G = GRAVITY = 32.2 F/SEC^2 H=HEIGHT(FT)= 1.50 2 DAY AREA A = QI(Cd(2 X G X H)".5 (SF) 0.0100711 5 DAY AREA A = QI(Cd(2 X G X H)".5 (SF) 0.00402844 DRAWDOWN ORIFICE TO BE 1.0 INCH IN DIAMETER DRAWDOWN RATE(CFS) = 0.022731703 DRAWDOWN TIME (DAY) 3.69 USE H = 1.5 0.041995399 0.01679816 DIAMETER (IN) = 1.36 DIAMETER (IN) = 0.859637 \PW-131QBC1\dgnIBARNARD.DGN 2/23/2003 5:20:40 PM a--T ISTROUDIPW-131QBCIldgnlmeas.dgn 2/20/2003 9:58:53 PM PROJECT: BARNARD' S LANDING, POND 4 PROJECT NO.: PW-131QBC BASIN DATA DATE: FEBRUARY 22, 2003 REVISED: APRIL 24, 2003 TOTAL AREA (AC) = 1.93 PROPOSED IMPERV AREA (AC)= 1.113 % IMPER AREA = 1 0.577 PROPOSED PERVIOUS AREA (AC)= 0.82 °% PERVIOUS = 0.423 NCDENR STORMWATER MANAGEMENT CALCULATIONS STATE REQUIRED STORAGE FOR 1ST 1.0 IN OF RAINFALL RUNOFF = 0.05 + 0.009 X °%IMPERV = RUNOFF = 0.569 REQUIRED VOLUME = 1.0 IN X RUNOFF X AREA X 43560 SFIACII2 IN/FT VOLUME (CF) = 3988 STATE REQUIRED SURFACE AREA 90 °% TSS REMOVAL 4.5 FT DEEP POND, 57.7°% IMPERVIOUS SAIDA = 4.693 SURFACE AREA (SF) =SAIDA X AREA X 43560/100 = 13861 POND DIMESIONS AND VOLUMES ,`��rrrerrrrrr,�i C,A.1304 �10Q^s�SSfp�A.9 :� ELEV. SA FOREBAY VOL FOREBAY SA POND VOL POND (FT) (SF) (CF) (SF) (CF) 2.5 0 3 394 98.5 4 62 31 818 606 5 209 135.5 1309 1063.5 6 559 384 1844 1576.5 7 1122 840.5 2987 2415.5 TOTAL 1391 TOTAL 5661.5 POND VOLUMES ABOVE PERMANENT POOL ELEV. SA POND VOL POND (FT) (SF) (CF) 7 4233 0 8 5591 4912 9 7011 6301 10 8635 7823 STATE REQUIRED STORAGE (CF) = HEIGHT ABOVE PERM. POOL FOR STATE STORAGE (FT) _ STATE STORAGE ELEVATION (FT) = NCDENR OUTLET ORIFICE DESIGN TOTAL STORAGE = 2 DAY FLOW (CFS) = 42871(2 X 24 X 60 X 60) = 5 DAY FLOW (CFS) = 4287/(5 X 24 X 60 X 60) = Q=AXCd(2XGXH)^.5 A=AREA °%FORBAY SUM VOL (CF) 0 4912 11213 19036 3988 8.00 3988 Cd = ORIFICE COEFF. = 0.6 G = GRAVITY = 32.2 FISEC"2 H=HEIGHT(FT)= 1.00 2 DAY AREA A = QI(Cd(2 X G X H)^.5 (SF) : 0,00677813 5 DAY AREA A = Q1(Cd(2 X G X H)A.5 (SF) 0.0027111252 DRAWDOWN ORIFICE TO BE 1.0 INCH IN DIAMETER DRAWDOWN RATE(CFS) = 0.018560358 DRAWDOWN TIME (DAY) 2.49 0.81 USE H 0.023077517 0.009231007 QC� 1.� '10 y . SUM VOL (CF) 98.5 735.5 1934.5 3895 7151 7151 19.5 DIAMETER (IN) = 1.12 DIAMETER (IN) = 0.705231 m 0 N cr, CV o= LL- • - ,, w - 11 IF F i 5 � , l+� r4v k� ram, 6 10 N,,! J f f i ; { 4 ' M��� 4'N o"P d y p• 1 i • � i '' I 1 { � i • 1 � I t N f 1PW-131QBCI1dgn1BARNARD.DGN 2/23/2003 9:47:04 PM PROJECT: BARNARD'S LANDING, POND 5 PROJECT NO.: PW-131QBC BASIN DATA DATE: FEBRUARY 22, 2003 REVISED; APRIL 24,2003 TOTAL AREA (AC) = 1.05 PROPOSED IMPERV AREA (AC)= 0.722 % IMPER AREA = 1 0.686 PROPOSED PERVIOUS AREA (AC)= 0.33 % PERVIOUS = 0.312 NCDENR STORMWATER MANAGEMENT CALCULATIONS STATE REQUIRED STORAGE FOR 1ST 1.0 IN OF RAINFALL RUNOFF = 0.05 + 0.009 X %IMPERV = RUNOFF = 0.669 REQUIRED VOLUME = 1.0 IN X RUNOFF X AREA X 43560 SF/AC/12 IN/FT VOLUME (CF) = 2551 STATE REQUIRED SURFACE AREA 90 % TSS REMOVAL 4 FT DEEP POND, 68.8% IMPERVIOUS SA/DA = 5.916 SURFACE AREA (SF) =SA/DA X AREA X 43560/100 = 12706 POND DIMESIONS AND VOLUMES ELEV. SA FOREBAY VOL FOREBAY SA POND VOL POND (FT) ($F) (CF) (SF) (CF) 2.0 104 3 5 2.5 300 202 4 124 64.5 635 467.5 5 394 259 1111 873 6 771 582.5 2285 1698 TOTAL 908.5 TOTAL 3240.5 POND VOLUMES ABOVE PERMANENT POOL ELEV, SA POND VOL POND SUM VOL (FT) (SF) (CF) (CF) 6 3105 0 0 7 4181 3643 3643 8 5313 4747 8390 9 6503 5908 14298 STATE REQUIRED STORAGE (CF) = 2551 HEIGHT ABOVE PERM. POOL FOR STATE STORAGE (FT) = 0.70 STATE STORAGE ELEVATION (FT) = 6.80 NCDENR OUTLET ORIFICE DESIGN TOTAL STORAGE = 2551 2 DAY FLOW (CFS) = 4287/(2 X 24 X 60 X 60) = 5 DAY FLOW (CFS) = 4287/(5 X 24 X 60 X 60) = Q = A X Cd(2 X G X H)".5 A=AREA Cd = ORIFICE COEFF. = 0.6 G = GRAVITY = 32.2 F/SEC"2 H=HEIGHT(FT)= 0.80 2 DAY AREA A= Q/(Cd(2 X G X H)".5 (SF) 0.004847728 5 DAY AREA A = QI(Cd(2 X G X H)".5 (SF) 0.001939091 DRAWDOWN ORIFICE TO BE 0.75 INCH IN DIAMETER DRAWDOWN RATE(CFS) = 0.009338 DRAWDOWN TIME (DAY) 316 %FORBAY USE H = 0.014762587 0.005905035 SUM VOL (CF) 204.5 736.5 1868.5 4149 4149 21.9 0.8 c*� o I p--q NI cnCc N Cc cr �� CL Q O DIAMETER (IN) = 0.94 DIAMETER (IN) = 0.596411 r m C O C 2 U m in } _ O w a Y � w N U U cc*4 H n W O to r� CE z v O Z W a C7 A z_ W 2 J_ r C7 4 � z LL o a Q w w 0.1 U LL Q O l/1 Fy J N N W ,� O mr V� Q N&( r .N-- (O W O OO M 2 2 N O m (O uiMiMiMiM)MiMi 0vcp0LoM ry 7 gwnL 04 m uitriv v rv-: .. � ��7r ...� OtOOWOO6 M00w0tov�v�����v tf)t(itriv m r m N n m N r O O r r C7 (p l() r m O m m N m 0 0 M m O ppprn� ppCV 00vnn0 cr) M (D 1n N M M V n n N n m�nN N N Cf (V � O to M) 10 CO N 7 CO r d m CO N st N CO c0 T O O O)M)(im9 nNO O)m m C)M O)O W V ONO O)mmm NNNNMMMi'v(V NMMM�(V (V (V NstM(p [VMMM N N N O m m lA m N to m O V O N tt7 a0 N d N (+1 in tp ap cp r r r r rvnr-vmv vm(aniotntnMo(onv vr Or Ovvnvnnv �r CoM.— rr vr rr-_ aro (nm'jo r r N r�ivqmcooi N r r r r Mcl m Vn OONmvVmmmmmc (m"w MmmM 0000000 000000000000000 0000 (n0 a0 O OD an0 (� (O COO [D M h Uf N N N (V -OCV �M(D ao qW Ntf)c[i 0Mr.-(M CV t;M to 00 (ma(��cmo(Dw( cmp c�c�� c� a o 0 0 0 0 0 I(mo o o o o 0 o o d d d d o o 0 0 o o 0 fVNNCV(mVCYN NNNNNN(V cV NNNNNNN N(V (V nr-nr+r+r`r- tilhtinr-Af+f--r�Nr,Nr-nt- P- r— O M) O t l) r l] if) to O O O O O O O O O O O M7 O O O O O O O O ('� r `,' n r h ww v N cD N N C7 N � N m n M) M) In CD o o o o o r r pOp G rp pCp? 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