We appreciate the opportunity to provide comments on the Department of Conservation and Recreation (DCR) impounding structure regulations. Fairfax County owns and operates 23 facilities regulated by DCR. The Department of Public Works and Environmental Services (DPWES) operates 19 of these facilities, with the remainder operated by the Fairfax County Park Authority (FCPA). Section 4VAC50-20-160 of the impounding structure regulations state that: In accordance with § 10.1-609.2 of the Code of Virginia, impounding structure owners shall not permit the growth of trees and other woody vegetation and shall remove any such vegetation from the slopes and crest of embankments and the emergency spillway area, and within a distance of 25 feet from the toe of the embankment and abutments of the dam. We have been advised by DCR Dam Safety staff there are no provisions for variances from this policy. We are requesting that DCR consider including provisions for variances from Section 4VAC50-20- 160 in the regulations for the following reasons: a. As a result of the 2008 changes to the impounding structure regulations, a number of impoundments that act as dry ponds formed by roadway embankments in Fairfax County were deemed to be regulated structures. b. These impoundments are generally quite wide (top width ranging from 40 to 80 feet), designed to temporarily detain water for the 10-year event. The detention time is typically less than 12 hours, and therefore precludes the development of a phreatic surface. c. The control structure creating the temporary impoundment was installed after construction of the roadway, and we generally do not have easements that allow us to keep the entire embankment free from woody vegetation. We request that tree-clearing limits for these facilities be established based on the unique characteristics of the facility, including a geotechnical evaluation/study when necessary. We also request that the regulations better define methods for establishing the limits of the embankment for these structures, as they may have considerable roadway embankment lengths. Please note that we had earlier provided several comments to DCR on the impounding structure regulations and associated guidance document in October 2018, which are attached for reference. We received a response in December 2018, indicating that one or more regulatory actions would be initiated starting in the spring of 2019 to consider the issues we raised. However, to our knowledge, these regulatory actions have not yet been initiated. We request that these previously submitted comments also be officially considered during this periodic review cycle. We look forward to receiving DCR’s response to our comment related to regulated dry impoundments created by roadway embankments, as well any notice of initiation of regulatory actions to consider issues raised by comments sent previously. Please contact Dipmani Kumar at (703) 324-4612 if you have any questions or need additional information. Note: Attachments transmitted separately by e-mail.