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HomeMy WebLinkAboutSDP202200046 Correspondence 2023-01-17TIMMONS GROUP January 17, 2023 Andy Reitelbach On behalf of John Anderson County of Albemarle Community Development 401 McIntire Rd, North Wing Charlottesville, VA 22902 608 Preston Avenue P 434.295.5624 Suite 200 F 434.295.1800 Charlottesville, VA 22903 www.timmons.com RE: SDP2022-00019 TJACH Premier Circle — Final Site Plan Review - Comment Response Letter Dear Mr. Reitelbach & Mr. Anderson: We have reviewed all of your comments from (Rev. 1) — December 2, 2022, and made the necessary revisions. Please find our responses to the comments below in bold lettering. 1. General: a. WP0202200013 approval is required prior to FSP approval. Comment Acknowledged Rev. 1): FSP Persists. b. An easement plat must be recorded prior to WPO plan approval: SWIM facility/ public drainage. Comment Acknowledged Rev. 1): FSP Persists. Acknowledged. Plat should be in review. c. A SWIM facility maintenance agreement must be recorded prior to easement plat recordation. Comment Acknowledged. Rev. 1): FSP Persists. Acknowledged will be updated with next plat submission. d. New: i. Remove C3.0, C3.1, C3.2, C3.3, C6.0 from plans; include with W P0202200013. Rev. 1): Not addressed. ENGINEERING I DESIGN I TECHNOLOGY The erosion and sediment control sheets have been removed from this plan set. 2. C2.2: a. Overall Demolition and C4.0 Overall Site Plan appear inconsistent in that nearly all existing hardscape requires partial / complete demolition to construct proposed improvements. Please revise demolition plan for consistency. Phase 1 demo plan has now replaced the overall demolition plan as the plans will be re -submitted as a final site plan submission. Rev. 1 : FSP: Addressed. b. Ensure that pre -developed site condition reflects discharge at parcel boundary that includes effect of existing SWM facility labeled to be abandoned. That is: pre -developed condition includes controlled storm runoff condition. Labels for Phase 1 demo plan have been updated. SWM facility will remain unchanged through phase 1 and impervious area to SWM facility and on entire site will be reduced meeting stormwater requirements at discharge at the parcel boundary. Rev. 1 : FSP: Withdrawn as FSP review comment; applicable to WPO. c. Identify existing SWM easement, if any. If easements exist, provide easement vacation plat. Ensure post -developed SWM provides requisite SWM control compared with a pre -developed condition that includes attenuating effect or treatment of storm runoff by existing SWM facility. After researching, no existing storm easement could be found for the existing stormwater management facility on site. Pre and Post conditions have been evaluated to ensure that the existing facility is still functioning as intended. Rev. 1 : FSP: Withdrawn as FSP review comment; applicable to WPO plan review. 3. C5.0: Provide, show, label SWM facility easement for proposed 125 LF detention system. See ACDSM Easement diagram, p. 15, for Min. width, which increases with detention system diameter and depth. The detention system is not required until Phase 2 of the site. An easement will be added for the future Phase 2 final site plan submission. Rev. 1 : FSP: NA 4. C4.0: If development is phased, an approved WPO plan must correspond with all phases shown on the final site plan. A final site plan may not be approved that does not provide SWM control for any phase depicted. This is, a comprehensive SWM plan (WPO Plan) is required prior to FSP approval. C4.0 indicates Phase 2 and Phase 3 potential locations of future building by others, but unless VSMP/WPO for TJACH Premier Circle accounts for approximate impervious area/s of future development, the FSP does nothing more than indicate potential locations, while deferring to a future date a WPO plan amendment or separate WPO required to construct potential buildings or establish impervious areas not previously accounted for. Comment acknowledged. Per comments with County, Phase 1 precondition will be used for all future phase WPO preconditions. Each phase's post condition will have adequate SWM measures to meet regulations. Rev. 1): FSP: NA i. C4.1 (Phase 1 site layout) shows no underground detention. Underground detention for the site is not required until phase 2 of the project begins. Phase 1 removes a large portion of the site's existing impervious area and converts that area to grass reducing flow and meeting energy balance without detention for phase 1. Underground detention will be added in future phases when needed. Rev. 1): FSP: Ref. item La., above. ii. C5.0 shows 125 LF of underground detention, an intentional level of SWM design detail, yet WPO202200013 design intent is unclear: 1. If UG detention is required for Phase 1, please revise FSP to clarify when UG detention is to be installed, and which phase or phases it is to treat. Underground detention is not required for phase 1 and will no longer be shown for phase 1 final site plan. Rev. 1): FSP: NA 2. Engineering recommends TJACH Premier Circle WPO provide comprehensive SWM quality/quantity control for a// phases: Quality requirements may be met with letter of nutrient credit availability without purchasing credits until a Grading Permit is requested for a particular phase. Expense of credit purchase may be timed to development. A drawback of a less comprehensive WPO plan is that physical space may not be assigned to on -site detention or on -site water quantity control may prove problematic if not integrated into initial WPO plan design to account for reasonably anticipated final build -out imperviousness (i.e., walks, parking, patios, buildings, etc.). An overall stormwater management plan will be submitted along with a stormwater management plan for phase 1. An updated narrative shall be provided in the calc book to help clarify quantity for the site. Rev. 1): FSP: Item La., above. b. Engineering recommends early coordination with APCO/VEPCO re. potential location of phase 3 future building which may encroach within existing OHP easement. Recommend show existing APCO/VEPCO utility easement on Existing Conditions plan sheet. Comment acknowledged. The easement can be found on the existing condition sheet and will be further coordinated during the phase 3 final site plan. Rev. 1): FSP c. Engineering cautions it is unclear this development may construct improvements within recorded access easement (Premier Circle). Instrument at deed bk. -pg. 797-242 was recorded May 2, 1984. Provide evidence of coordination, as needed, with access easement holder at bk. -pg. 797-242, or if this 1984 instrument benefits TMP 061M0-00-00-00600. Engineering recommends FSP title sheet clarify access easement benefits development parcel. Letters have been sent to all property owners on the road and owners have no objection to the installation of sidewalk along Premier Circle. Rev. 1): FSP: Addressed. d. Location of existing sanitary manhole in proposed sidewalk is questionable since sanitary MHs may be noxious or repellant, and separation from pedestrian facilities is typically recommended. Storm MHs/utility vaults do not pose equivalent concern, but sanitary sewer is a separate class. Comment Acknowledged. Rev. 1 : FSP e. ISP proposes to replace existing 21" RCP in certain locations with 18" DIA pipe. Provide calculations to support diminished pipe capacity (18" DIA has 73.5% capacity of 21" pipe). 18" DIA is more susceptible to obstruction than ex. 21" RCP. Engineering is unlikely to approve design that reduces existing storm conveyance given potential downstream effects, and comparable existing site to proposed full build -out impervious area, should all phases develop. Acknowledged. Pipe calcs shall be provided to ensure that smaller pipe is adequate for the site and can handle any future development on the site. Rev. 1): FSP: Addressed. f. Label Premier Circle Lane width at its narrowest at centerline stripe near U.S. 29 SBL. Ensure not less than 12' lane width in both directions along Premier Circle length wherever this site plan proposes improvements immediately adjacent to Premier Circle. 12' lane width does not appear to exist at all locations where project proposes improvements. Premier Circle Road widths have been added to the site plan. It has been ensured that all lane widths are 12' minimum or greater. Rev. 1): FSP: Addressed. Also, please see item 4.k., below. Noted. See response to comment 4k below. g. Revise Premier Circle curbing to CG-6, as exists on opposite side of Premier Circle. CG-2 is not approved for Premier Circle. CG-6 has now been provided as required on premier circle. (Rev. 1): FSP: Addressed. New (FSP) (Rev. 1) Items h -k do not appear to be addressed; appear to persist. h. Entrance radii to parking at 1-Level Motel must meet VDOT Access Management Standards (Appendix F) low -volume commercial entrance Min. radii =25-ft. Please revise 10' R. The entrance radius to parking at 1-Level Motel has been updated to have a minimum radius of 25'. Refer to Sheet C4.0 i. Dimension 1-Level Motel entrance width (Min. =18' Appendix F, Access Mgmt. Std). A dimension has been added to the 1-Level Motel entrance. The entrance width is greater than 18'. j. Inset detail label 'portion of sidewalk and curb to be asphalt' is unclear. Clarify design intent with curb type label, and sidewalk /Premier Circle EP spot elevations (C5.0). Please refer to the hatch legend in the top right corner of Sheet C4.0. The area with the dot hatch is to be asphalt while the southern portion hatched with the concrete hatch shall be concrete. k. Revise pavement striping to delineate 2-12' travel lane widths at NW end of striping. Lane width may exceed 12' at Int. Rt. 29, but CL striping should allocate lane space such that >_12' w exists to either side of CL striping for its entire length. Avoid driver confusion that may occur if striped lane width <12' on Premier Circle, outbound /eastbound. The lanes are noted to be a minimum of 12' in width. A dimension has been added to the inset on sheet C4.0. S. C4.1: a. No portion of parking lots maybe without curbing; 4 spaces along west edge of Phase 1, for example. The 4 parking spaces along the western edge of phase 1 is a temporary condition. 1' gravel shoulder has been added to allow water to sheet flow off the asphalt to a proposed ditch. This will help save cost to the owners and developers and prevent them from having to remove new curb for future phases of development. Curb is proposed in the overall final buildout of the site and will be called out as necessary in future site plan phase 2 submissions. Rev. 1 : FSP: Persists. Engineering defers to Planning. Rev. 2 : May persist. If planning Div. reviews coordinator does not object, comment will be withdrawn. Per conversations with Planning and Engineering, the gravel edge along the pavement is acceptable as a temporary condition. b. Provide/label safety railing at retaining wall. Rev. 1 : FSP Addressed. c. Provide TW/BW elevations for all retaining walls. FSP May persist. Please advise which sheet includes TW/BW elevations. Rev. 1 : Addressed. d. Note: Retaining wall ht. >3' requires a building permit; retaining wall ht. >4' requires sealed retaining wall design (not generic typ. Sections, Diamond Pro TM, for example). Submit sealed retaining wall plans for Engineering review prior to / as condition of FSP approval. Comment Acknowledged. Structural design of retaining walls by others have been included in this resubmission. Building permit will be submitted before construction. FSP e. While possible to construct proposed retaining wall south of Phase 1 Virginia Supportive Housing during site work phase, prior to building erection, once phase 1 building is constructed, any future maintenance / replacement of this wall necessitates off -site easement/s. Obtain temporary off -site construction easements to operate intermittently in the future during any period of routine or emergency retaining wall maintenance or replacement. Comment Acknowledged. A temporary off -site construction easement will be considered for construction and wall maintenance. (FSP) f. Recommend stop sign or stop bar at site exit/s. Acknowledged. FSP 6. C5.0: a. Provide CG-6 wherever proposed grade concentrates runoff against curb, rather than CG-2. FSP : Addressed. b. Provide VDOT LD-204 (stormwater inlet computations), LD-229 design tables (storm drain design computations). The above calculations shall be provided in the calc book. FSP : Review ed with WPO Plan. c. Provide pipe profiles. (FSP): Addressed. d. Provide spot elevations to ensure no nuisance ponding on parking surfaces. FSP : Addressed. e. Avoid SAN — Storm conflict near contour label 475 NE of phase 1 building, near Premier Circle. Relocate one or the other to ensure adequate SAN-Storm separation. FSP : Addressed. New (FSP) (Rev. 1) Items f. e. I. i. do not aooear to be addressed: aooear to persist f. Indicate direction of flow in proposed and existing storm pipes. Flow in existing pipes is shown on C2.1, but should be included with Grading and Drainage Plan, as well. Flow arrows have been added to proposed and existing storm pipes. g. Label structure 142. A label for structure 142 has been added. h. (On WPO Plan) provide IP at Str. 142. Rev. 1): Addressed. w/ 11/09/22 CSMP / WPO plan, C3.3. Revise swale perpendicular to swale. Swale-swale connection (90-deg) is unstable at point of intersection. 90-deg. intersecting runoff may only occur at /in a structure (i.e., MH). Intersecting ditch flow requires 2-45' bends (or similar) to protect ditch walls. Label and provide ditch calculations for each ditch. Specify ditch lining. The swale has been updated to not intersect at a 90-degree angle. Include highlight C0.1 storm pipe /inlet elements with Phase 1 for integrity of pavement, curb, walks, etc. since these elements are required with Phase 1 and would require demo to install pipe /inlets, later. Utility marking, grading, etc. required with Phase 1 favors installation of Dls shown on C0.1 simultaneous with Phase 1 curb //entrrance installation. \ v� The existing pipe run along Premier Circle that leads to the existing BMP to the North of the site is fairly flat with a slope —0.3%. In order to install the proposed pipe under the entrance in this phase, the proposed pipes would either have to have the same slope, or the entire pipe to BMP would need to be replaced in order for the inverts to work. 7. C5.1: a. Shows no storm detention: WPO202200013 for TJACH Premier Circle (under review) must provide SWM to meet SWM requirements for each phase. Only phases meeting SWM requirements may be approved with FSP. WPO202200013 appears to provide comprehensive SWM control via 125 LF underground detention which appears required with Phase 1 development / Phase 1 building - parking, etc., but WPO is ambiguous. Concept of a Master Plan does not exist in state regulations per se (9VAC25-870-). Rather, proposed elements of development / site improvements are evaluated against requirements and SWM control provided to meet requirements for proposed improvements. WPO/FSP should clarify that SWM is provided for design elements shown on either plan. FSP title sheet should include reference to WPO202200013 (review pending). Underground detention for the site is no required until phase 2 of the project begins. Phase 1 removes a large portion of the site's existing impervious area and converts that area to grass reducing flow and meeting energy balance without detention for phase 1. Underground detention will be added in future phases when needed. FSP : Ref. item 1.a., above. 8. 1-1.0, L3.0: a. Labels do not discriminate between phase 1, 2, 3, buildings; all are labeled proposed buildings, whereas other plan sheets indicate phase 2, 3, potential future building locations. Also related comments elsewhere. Revise 'proposed building' labels for consistency across plan sheets. Labels have been updated on Sheet L1.1 to differentiate between phases. FSP : Addressed. 9. New: C7.0: a. Pipe 121 i. Recommend increase pipe diameter to 8". Rev. 1 : Addressed. ii. VDOT Subdivision Street Design Guide, Appx 13(1) Sec. 41.3.g. /Access Points: 'Generally, distance between points of access in storm sewer trunk lines shall be limited based on pipe diameter, ...' for 12" pipes, 50'. 8" pipe DIA would reasonably require a limit less than 50'. Provide at least one point of access to (revised) 8" DIA storm pipe #121, 195.71' L.. Rev. 1 : Not Addressed. Provide at least one point of access to storm pipe 121. VDOT requires point of access every 50' for 12" storm pipe. The existing pipe in question has an existing slope of -0.3%. In order to install the proposed pipe under the entrance in this phase, the proposed pipes would have to match the same slope of the existing pipe, or the entire pipe to stormwater system would need to be replaced to get the pipet to have more fall. Based on not wanting to change the stormwater system and not knowing the full details of future phase 3, we feel it is best to keep the existing pipes as they are. After discussions with engineering, this comment has been satisfied. b. Recommend revise all 6" PVC pipe to 8" DIA for ease of maintenance, reliable performance, additional capacity during less frequent events (becoming more frequent), and leeway during construction (installation errors may have less impact). Rev. 1 : Addressed. c. Revise storm profile caption, Ditch Strm, consistent with structures /pipe depicted. Rev. 1 : Not addressed. Storm profile caption has been updated to be consistent with the other storm profiles. d. Rev. 1 : New: Restore pipes and structures in profiles deleted with 11/09/22 submittal; for example, pipes and structures upstream of Str. 110. Recommend revise all 6" PVC pipe to 8" DIA. The main 12" storm line has been added to the profile on sheet C7.0. Please refer to the landscape plans for the storm yard drain and pipes in the courtyard area. All court yard pipes are 8". We have included PDF copies of the plans and calculations for your review. If you have any questions or comments, please feel free to give me a call at 434.295.5624 or email 6onathan.showalter@timmons.com. Sincerely, Jonathan Showalter, PE Project Manager