Pimmit Hills stormwater issues come to forefront in revised Leesburg Pike development plan

The Fairfax County Planning Commission gave its support to a proposed comprehensive plan amendment last week that will let a developer replace an aging Pimmit Hills office building at 7700 Leesburg Pike with townhomes.

The vote to recommend approval of the amendment came only after two commissioners and county staff worked with EYA Development to secure stronger language regarding the prospective developer’s obligations to address existing stormwater management and flooding issues.

“I think we’re at a place where we need to be in terms of strengthening that language and beefing it up,” Dranesville District Planning Commissioner John Ulfelder said during the Oct. 6 meeting. “So, as the rezoning proceeds, we have some clear guidance based on the particular issues and problems that this site and sub-water shed present.”

Initiated by the Fairfax County Board of Supervisors on Sept. 15, 2020, the 7700 Leesburg Pike plan amendment process is unfolding in conjunction with a rezoning application that EYA submitted in December.

The developer has proposed building 104 single-family, attached townhouses — nine of which will be priced as affordable dwelling units — in place of the 150,000 square-foot office complex that currently occupies on the site.

The property is right on the edge of Pimmit Hills, which has encountered drainage and flooding challenges since construction began on the neighborhood in the 1950s, according to Ulfelder.

“People had muddy yards and so on,” he said. “Today, people — with some of the extraordinary rain events we’ve had — have had real problems with their basements and with their yards.”

Flood Factor, a tool developed by the nonprofit First Street Foundation, characterizes the overall risk of flooding in Pimmit Hills over the next 30 years as minor, but it says 174 properties, or 8% of all properties in the neighborhood, face a 26% or greater chance of being severely affected by flooding in that time frame.

In addition, the risk to residential properties and roads is increasing, with the latter already deemed at moderate risk of flooding, according to the database.

Fairfax County staff recommended in a report that the plan amendment include a provision requiring “stormwater management controls for the new development above the minimum standards are provided to the extent possible.”

However, Ulfelder and Braddock District Commissioner Mary Cortina raised concerns about what exactly that will entail at a Sept. 29 public hearing on the amendment. The commission decided to defer making a decision at that meeting.

“The feeling was, maybe the language that was being initially proposed didn’t go far enough in spelling out how we should proceed in order to try to reduce runoff,” Ulfelder said on Oct. 6.

The revised amendment includes a more specific explanation of the stormwater requirements that EYA will need to meet in order to get its proposed development approved:

Provide stormwater management controls above the minimum standards to the greatest extent possible to reduce runoff to good forested conditions; provide for an adequate outfall as informed by the Middle Potomac Watershed Plan; and to help mitigate downstream flooding.

EYA’s legal representative said at the public hearing that the developer plans to provide two facilities designed to capture water before releasing it at a slower rate, along with filters throughout the property that will improve the water quality.

The planning commission voted 10-0-1 to recommend that the Board of Supervisors adopt the revised amendment, with At-Large Commissioner Timothy Sargeant abstaining and Commissioner Candice Bennett not present.

The commission is scheduled to hold a public hearing on EYA’s rezoning application on Nov. 3.

Photo via Google Maps