Letter from 4CA Stormwater task force to Arlington County and Arlington Public Schools, July 14 2020
Dear Chairpersons Garvey and O’Grady,
Six months ago, our four civic associations wrote to the Arlington County Board and the Arlington Public School Board about the severe flood that occurred in the Westover area on July 8, 2019, seeking leadership and cooperation between your organizations to undertake stormwater management measures that could mitigate against a repeat of that devastating event. In particular, the letter urged the County to consider measures at the Reed School site, which is uniquely situated in the Torreyson Run watershed to provide protection to Westover.
It has now been a year since the 2019 flood. We are pleased to see Torreyson Run included in the proposed Capital Improvement Plan for 2021, and we urge the County Board to support this recommendation from the County Manager. At the same time, our community is frustrated that the County has not yet initiated specific remedial steps to prevent future flooding in the Westover area.
We believe that building detention vaults under the large tract of the Reed School playing fields offers a reasonable, effective approach to save the Westover business district, and thus should be the centerpiece of the stormwater strategy for Torreyson Run.
Why a detention vault? A detention vault captures water during the peak period of a storm and then releases the captured water back to the regular pipe system after the storm. This approach would allow the County to even out the flow of water through its system (similar to “flattening the curve” of Covid19 hospitalizations) to prevent excess water from overloading the pipes and causing localized flooding as well as flooding throughout the 4 Mile Run corridor, down to south Arlington.
Why the Reed School playing fields?
> There are very few parcels of public land in Torreyson Run; the Reed School site is one of the largest.
> This parcel of land is immediately upstream of Westover.
> In fact, the major pipe that carried the bulk of the stormwater into Westover on July 8, and caused the devastating flooding, runs through the Reed site adjacent to the planned playing fields.
> An underground detention vault can be designed and constructed to be fully compatible with the intended recreational uses on the playing fields.
> The site is currently flat, easily accessible and does not contain other features (e.g., mature trees) that complicate its use for this purpose, suggesting that it offers a particularly cost-effective option.
> The underground gradient of the major stormwater pipe at the site would facilitate efficient return of water stored in the detention system to the main stormwater system.
We have been in discussions with staff from both the County and APS. As we understand the current situation, the County has asked APS to study three options for stormwater relief at the site. Once there is an agreement on an option, the County will pay APS’s contractor to construct the detention structures.
We think it is critical that the options for analysis include a full range of choices so that the community can appreciate the relative strengths and weaknesses of the choices. In particular, the study should include an option that fully utilizes the large fields adjacent to the storm pipe.
We understand that APS staff oppose a “whole field” option out of concern that detention vaults could preclude future building on the playing fields and could create contractual issues that might delay completion of the project. While we recognize APS’s concern, we believe that the “whole field” option still warrants analysis so there is full transparency about how Arlington’s final choice reflects public values. We also urge the County to consider ways to alleviate APS’s concerns.
We appreciate the opportunity to discuss this critical issue with staff and look forward to continued work. We know that stormwater management is one of the most complicated and pressing challenges for Arlington and hope that the County and APS can continue to identify and collaborate on solutions.
Mark Greenwood, Chair Torreyson Run Task Force
Lilith Christansen, Pres. Westover Village Civic Association
John Ford, Pres. Tara Leeway Heights Civic Association
Kathleen Trainor, Pres. Highland Park Overlee Knolls Civic Association
Mike Weinstein, Pres. Leeway Overlee Civic Association