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Home My WebLink AboutWPO200500012 Bond Reduction 2022-09-15�q oe nt 401 McIntire Road, North Wing Charlottesville,VA22902-4579 County of Albemarle Telephone: 434-296-5832 COMMUNITY DEVELOPMENT DEPARTMENT WWW.ALBEMARLE.ORG VSMP Bond Inspection Letter Project title: Charlottesville Self Storage at Crozet Project file number: WP0201500020 (WP02005-00012; WP0201500085) Owner or rep.: Jo Higgins [ musxit@aol.com ] Inspection date: 14-Sep 2022 (+ Additional dates) Date of reduction: 15-Sep 2022 Inspector/Compliance Mgr: Mark Hopkins, Dan Ratzlaff Bond Reduction Reviewer: John Anderson Dear Jo, We received your WPO bond inspection request for WP0201500020 (WP02005-00012). The bond can be reduced to $13,300 (ESC to $3,600; SWM to $9,700). Items 1., 2. must be completed before the WPO plan bond can be released: 1) Extended detention basin (current sediment basin serving TNC); convert to SWM. Please see Notes, below (item 3), for additional background information, or guidance. 2) As -built to confirm existing sediment pond is converted to extended detention basin, per WP0201300064 design details for'Permanent stormwater structure'. 3) Notes. a. While sediment basin (SB) is utilized by adjacent property (Three Notch'd Center /TNC) under approved WP0201300064, this SB requires conversion in the future to receive and detain runoff from Charlottesville Self Storage at Crozet (CSS), Drainage Shed B. WP0201500020 review memos (4/9/15; 4/22/15) and approved plan indicate prior - approved SWM is unaffected by WP0201500020; that is, approved SWM facilities shown on WP02005-00012, corresponding with SDP2004-00106, Charlottesville Self Storage at Crozet, include both surface detention and bioretention facilities located on CSS parcel, TMP 56A3-7. b. WP0201500085 replaces bioretention with underground detention to provide SW quantity control for Drainage Shed A, only. Stormwater quality is met with purchase of 0.59 lb. nutrient credits, purchased 3/22/16, to offset loss of phosphorus reduction provided by bioretention. c. Neither WP0201500020 nor WP0201500085 eliminate need for SWM detention shown on WP0200500012, south of storage building C, that also serves a SWM detention purpose for Three Notch'd Center (TNC /WP0201300064, WP0201700033). Conversion, when and by whom, is an important topic for another time, but it is apparent to Albemarle after extensive review that SWM Facility Maintenance Agreement with Princess Anne LLC (CSS owner, 6/15/2005; deed bk.-pg. 3000-392/395) establishes maintenance responsibility for CSS to construct and maintain "a combination surface facility [that] will provide both water quality control and extended detention." SDP2004- 00106, C-11 explains: "Drainage Shed B is comprised of 7.09 Acres, of which 3.66 acres are onsite [CSS], and 3.43 Acres are offsite [TNC]." d. Surface SWM detention facility is relied upon by both CSS and TNC. Engineering Review Comments Page 2 of 6 e. VAR10G818 may not be terminated until the surface facility (sediment basin) is converted to extended detention (SWM), consistent with design on C-11A, SDP2004-00106 (i.e., WPO2005-00012); also shown on sheet 23, WPO201300064, the last sheet of a 7-sheet WPO plan. f. Design details on WPO201300064 should be relied upon since elevations for certain structural features vary slightly from elevations depicted on SDP2004-00106, and WPO201300064 is more recent than WPO2005-00012 /SDP2004-00106. g. Also, see next pp. for supportive graphic /text information. Please contact me if you have any questions. Thank you. Sincerely, John Anderson, PE (434) 296-5832 ext 3069 Engineering Review Comments Page 3 of 6 TNC, WM201300064 sheet 20; 41h sheet of WPO plan FA ER05ION eInrrs / rac 6 / Foet�AWTf O V sraerbvarErzoFn N11 ewe A2554 'issM 1 lTP 56A-(3)-1 5�OR46E, ,fFer, 20. CSS, SDP2004-00106, sheet C-11A ( print plan Not scanned) P PXX AXMXTT O�nDM n.. 654 652 650 646 646 644 642 640 6JB 636 634 632 630 628 Engineering Review Comments Page 4 of 6 CSS, WP0201500020 (sheet 4: graphic /text images, below): Label is confusing and may be misleading. File documents indicate SWM is not an existing SWM facility, but a sediment basin and that it is associated with both CSS and TNC. Also, runoff from CSS paved /impervious areas is collected at grates and conveyed via pipe to the SWM Ex. detention facility to meet CSS state stormwater quantity requirements. i6nu - I I I I 1 I I� 1 EXISTING STORAGE BUILDING C 1 1 I I I 1 1 1 f STORMWATER MANAGEMENT FACILITY NO PART OF STORMWATER MANAGEMENT PUN AND E&S RAN ASSOCIATED WITH THREE NOTCH'D CENTER 9TE PUN s - _..a WPO 2m7 - .. 4—e-�r/r 1GE / )EXISTING ST GE L , BUILDING A DRAINAGE:HED:8�1 COISED OF 7.09 ACRES,OF WHICH3.66 ACRES ARE ONSrrE, AND 3.43 ACRES ARE OFFSRE. THE EXISTING S INSHED B CONSIST OFAN EXISTING PARKING LOT AND OPEN SPACE. THE OIN E AREA WILLBE REDEVELONEW SELF STORAGE BUILDINGS,ALONG WITH TRAVELWAYSAND PARKINGAREAS. APPROXIATELY0.40IONAL IMPERVIOUS SURFACE WILL BE GENERATED IN SHED B. SURFACE RUNOFF IN SHEDS WILL BE DIRECTED TO A BISECTING NATURAL DRAINAGE WAY THAT COLLECTS AND CONVEYS SURFACE RUNOFF SOUTHEAST AND EVENTUALLY OFFSTTE. A COMBINATION SURFACE FACILITY WILL PROVIDE BOTH WATER QUALITY CONTROL AND EXTENDED DETENTION. STORAGE FOR WATER QUANTITY WILL BE PROVIDED TO ATTENUATE THE 2-YEAR AND 10-YEAR POST -DEVELOPMENT EVENTS. UTILIZING THE MODIFIED DIRECT METHOD, THE ALLOWABLE RELEASE RATE FOR THE POST -DEVELOPED 2-YEAR STORM IS 21.8 CFS, AND 28.5 CFS FOR THE 10-YEAR STORM. ROUTED RELEASE RATES WERE 8.33 CFS FOR THE 2-YEAR STORM AND 14.19 CFS FOR THE 10-YEAR STORM. EXTENDED DETENTION VOLUME WILL BE PROVIDED FOR TWICE THE WATER QUALITY VOLUME, AS DETERMINED BY CAPTURING THE FIRST 34 INCH OF POST -DEVELOPED IMPERVIOUS SURFACE IN DRAINAGE SHED B. THE FACILITY IS DESIGNED WITH A MULTI -STAGE OUTFALL STRUCTURE CONTAINING A 3' NOTCHED WEIR TO CONTROL THE 2-YEAR STORM EVENT. THE FACILITY OUTFALL WILL BE PROVIDED BY DISSIPATING ENERGY AND RENDERING THE OUTFALL VELOCITY NON -EROSIVE PRIOR TO ENTERING THE NATURAL DRAINAGE WAY. WP0201500085 (CSS, biofilter removed; underground detention replaces bioretention; surface SWM from WP0200500012 remains (2'd sheet of 5-sheet plan; plan approved 6/13/16 by J. Anderson/Alb.): Engineering Review Comments Page 5 of 6 Ex. detention basin (Stormwater Management Facility, image below) is also associated with C. Self Storage WP02005-00012, WPO201500020, WP0201500085, and required for SW quantity control, drainage shed B. 3VNW-DI5ITGRB B fFER IT IT�1'I - r / w'rRBAMBI r/ 1 TORMWATE .� AGEMENT FACILITY 6 Sa \ \ I I A6 \ \ 1 i NNG STORAGE EXISTING S RACE �� l BUILDING D BUILDING C TING POND PA I \ \ STD TER MANAGEM T •\ ANDES PO /,Yi o EXISTIN STORAGE EI7TING ASPHALT _ - �•/ ING B RWEWArS( WP0201300064, Three Notch'd Center, approved 4/15/15, sheet C23 (71 sheet of plan) Permanent Storm Water Structure — rely on WPO201300064 design elevations PERMANENT STORM WATER STRUCTURE 654 652 650 648 646 644 642 640 638 636 634 632 630 628 626 624 SCALE 4.1 Engineering Review Comments Page 6 of 6 VSMP plan review Memo (J. Anderson /WPO201500020. Approved 22 Apr 2015) VSMP Permit plan review Approved Project: Charlottesville Self Storage at Crozet, VSMP Plan preparer: Scott Collins, Collins Engineering [200 Garrett St., Suite K, Charlottesville, VA 22902, scoff tAcollins-eneineerine.coml Owner or rep.: H.M. Walker, Jr./Albemarle Storage, LLC, P. O. Box 332, Charlottesville, VA 22902 Jo Higgins, Project Development LLC, 2564 Mt. Torrey Road, Lyndhurst, VA 22952 T: 434.326-0334 1 musxit(a.aol.com Plan received date: 6 Apr 2015 (Rev. 1) 16 Apr 2015 (.PDFs) (Rev-Irev) 22 Apr 2015 (Final) Date of comments: 9 Apr 2015 (Rev. 1) 21 Apr 2015 (e-review comments/email) (Rev-lrev) 22 Apr 2015-AAWroved Reviewer: John Anderson Notg/Current bond amounts: $4,500 remains on WPO/ESC (BND200500021 WP-SE); $62,000 (original) remains on WPO/SWM bond (BND200500022WP-SW). A. Stormwater Pollution Prevention Plan (SWPPP) —All comments addressed —CV/prior comments. The SWPPP content requirements can be found in County Code section 17-405. A SWPPP must contain (1) a PPP, (2) an ESCP, (3) a SWMP, and (4) any TMDL measures necessary. B. VSMP: SWPPP: Stormwater Management Plan (WPO201500020) VSMP Regulation 9VAC25-870-108 requires the VSMP authority to approve or disapprove a SWMP. The SWM Plan for post -developed site conditions associated with ESC Plan submitted with this VSMP Application was approved as WP02005-00012/SDP2004-00106. Prior approval and design are unaltered and unaffected under this VSMP Application, which proposes construction of remaining self -storage units, and converts sediment trap to SWM bioretention facility. Reference ACCD Files/SWPPP for prior -approved SWMP, or plan details.