County Adopts Reduced Mowing Policy: Promote Natural Growth in Stormwater Management Ponds

Much of the rainwater flowing into storm drains and nearby streams is collected in dry ponds located in or near our neighborhoods. The pond may improve the water quality of collected stormwater by allowing sediments and attached nutrients, certain types of chemicals, yard debris, and litter to settle out gradually before flowing out of the pond. By detaining polluted stormwater runoff, cleaner water flows from the pond into local streams, the Potomac River, and the Chesapeake Bay.

If the bottom of a dry pond remains naturally vegetated, the water quality function of that pond is enhanced. Plants and their root systems filter sediments and absorb nutrients that otherwise would flow into the stream. To promote this natural vegetative growth in dry ponds and enhance the water quality function, the County’s Maintenance and Stormwater Management Division (MSMD) will minimize its yearly pond bottom mowing activities to just a narrow swath on each side of the ditches in the pond. The County will continue to mow the dam embankment and access ways. Look for signs in the ponds that show the areas to remain natural.

About a year ago, the County adopted a new policy to encourage tree preservation and replanting in areas in and around stormwater management ponds. Working with a County-approved plan, property owners and homeowner associations can plant on the banks of wet or dry ponds and in the bottom of a dry pond. Areas that cannot be planted include the dam embankment, emergency spillway, access easements, and areas closer than three meters to other structural elements.

To obtain a planting application form or get more information about the planting or mowing policies, call 703-934-2860.

Pictured is a stormwater management pond that has been left to grow naturally. The homeowner association has added to the vegetation by planting trees (covered with protectors) around the perimeter of the pond.