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HomeMy WebLinkAboutWPO202100010 Correspondence 2021-02-17® ROUDABUSH, GALE & ASSOCIATES, INC.1 February 17, 2021 Mr. Frank Pohl ATTN: David James Albemarle County Department of Community Development 401 McIntire Road Charlottesville, VA 22902 Project title: Belvedere Phase 3 Block 10 Water Quality Requirements Dear Frank, Please find attached, an overview of the proposed Belvedere Block 10 Phase 3 development. It is our intention to satisfy the Offsite Compliance Options list of: § 62.1-44.15:35.D.3- Sections Hv. It is our understanding that the VSMP authority may allow the use of offsite compliance options when, after consideration of all practicable onsite treatment options and the specific elements of the statute, the proposed project is still unable to comply with treatment requirements. This describes the situation here with Belvedere Phase 3 Block 10. This letter analyzes the specific requirements of the statute mentioned above, explains how Block 10 meets these requirements, and requests authorization to use offsite compliance options. (iJ alternative site designs have been considered that may accommodate onsite best management practices," In our design protocols, we have balanced the development requirements of the Neighborhood Model District in accordance with ZMA200400007, with those of Virginia Department of Transportation (VDOT), as well as Albemarle County Design Standard in an effort to meet site requirements while honoring highest/best use of the parcel. Site features driven by these requirements, severely limit useable land area available for BMPs due to the presence of Albemarle County Preserved Steep Slopes, and Conservation and Preservation areas as illustrated in the rezoning Exhibits of the ZMA. Furthermore, our ability to alter the site layout is hampered by the existing ZMA and in order to limit the disturbance to the critical slopes as much as reasonably attainable, multiple retaining walls are utilized around the bluff. Therefore, the plan represents the maximum buildable envelope allowed by the code and it is not within our ability to alter the site layout since it is hampered by the existing ZMA. 9 � Awe B�,R �i°LLu1l// ��1i11llll WWIIV VI� q � ew Q BI.00k• BVXxn -: Belvedere ' General Development Plan Exhibit2A sroNEFIAus ® - "/ V o� r, ,-r�i• BUM 00 onsite best management practices have been considered in alternative site designs to the maximum extent practicable." This parcel is located at the outermost division of the Belvedere Neighborhood and located on a ridgetop overlooking the Rivanna River. As mentioned, the Block is surrounded by critical slopes which limits the area of development and grading. The design layout incorporates the design standards required, not only by VDOT, but also largely incorporates the Grading Standards set forth by Albemarle County Zoning Ordinance. Due to the increase in the requirements of road design radii; the development has expanded into the previously designated Conservation and Preservation areas stipulated in the ZMA. Attempts have been made to constrict our water quality improvements to areas atop the development, however, facilities large enough to treat the water are of such a footprint that safety and stability becomes a concern. We have altered our design multiple times to address the issue using onsite BMPs, but have found no such feasible option that cooperates with the topography of the parcel and offer a financially feasible solution. In the effort to incorporate water quality requirements for this site, multiple BMP strategies have been considered, including using propriety filtering devices by manufacturers. The use of these strategies would require stormwater to be collected and dammed to be treated with open ponds discharging atop critical slopes. Due to this strategy being problematic, our focus turned to underground detention. However, cavernous 96" underground storage tanks that may be subject to collapse if a vehicle traverses the peak, and a price tag of over $400,000 makes this solution impracticable. Given the topography of the site, no practical location exists to store stormwater at the top of critical slopes that is not already designated as residential lots per the ZMA, nor is there an area remaining on the site that is not within >25% slopes. (M) appropriate onsite best management practices will be implemented." The postconstruction phosphorous control requirement for Block 10 is 13.31 pounds per year. The evaluation of using onsite best management practices in open space have been exhausted. Furthermore, using areas dedicated for residential lots for the implementation of BMPs is not practical. It will have the adverse impact of losing lots which will make the project financially nonviable for development; and the incremental increase in onsite treatment will not capture enough to meet the 75% onsite threshold. Besides it still does not solve the issue of having large BMPs at the top of critical slopes as a function of practical engineering design practices. It should be noted that any facilities atop these slopes will still likely require a pipe network to discharge below these slopes. We will of course implement features such as large disconnected Park areas and yards as specified in the ZMA. Further, we will properly handle water collected atop the critical slopes for safe passage to the discharge point. It should be noted that large portions of this project have been dedicated or deeded to the benefit of preservation and 31.47 acres of the parcel has been deeded to Albemarle County in the Greenway Parcel DB-5294-417. (iv) "full compliance with post -development nonpoint nutrient runoff compliance requirements cannot Practicably be met onsite." Law Insider Dictionary defined "Practicable" as follows: "Practicable means available and capable of being done after taking into consideration cost, existing technology and logistics in light of overall project purposes." The incremental gains discussed in items above cannot alleviate the need for offsite credits without irreparably altering the nature and the financial viability of the development. Therefore, the development needs to use offsite solutions, to meet the required treatment compliance. It is important to understand that we are not asking for a variance or relief from the quantity of Phosphorus to be addressed by the development. We are merely seeking your concurrence that we have met the practicability threshold, which then enables offsite compliance for this project. Considering the above we ask that you concur with our findings and allow offsite nutrient credit purchase to be utilized for the entire 13.31 pounds for treatment. We trust this meets the Code requirements and we very much look forward to moving this project forward. As usual, we thank you for your help here and look forward to working with you to get this to fruition. Respectfully, Riki van-Niekerk, EIT Roudabush, Gale, and Associates Inc.