Construction began Aug. 8 on a restoration project for the stream running through Mount Vernon Park, beginning behind the intersection of Dartmouth Drive and Swarthmore Drive in Alexandria.

With increasing amounts of water running off the road and out of the community above, trees were coming down around the stream and sediment runoff was making its way down to Dyke Marsh. Sediment and nutrients have then been getting out to the Potomac River and Chesapeake Bay.

Wetlands Studies and Solutions, Inc. designed the stream reconstruction and Angler Environmental is carrying it out. At an update meeting on Oct. 13 for interested citizens, representatives from WSSI and Fairfax County said everything is still on track for completion by April 2017.

The construction cost of the project is $760,000 for the project. Including design and other fees, the total cost is $1,340,000.

Where soil has eroded at the top of the stream, coastal plain soil has been filled in, coming from Prince William County and Fort Belvoir projects also being worked on by Angler.

Also on the upper part of the 920-foot project, workers are beginning to install plunge pools to slow the water coming out of the community. Having it hit the lower stream with less speed will keep the original problem from returning.

Downstream, several rock structures were added to preserve the integrity of the existing bed while the project is underway and protect it from rainstorms. They also tiled layers of plastic to integrate flow from a smaller side tributary into the main stream.

Marshall Willis with WSSI, a senior ecosystem specialist, said when the Mount Vernon area recently received around an inch-and-a-half of rain in a short period of time, the preservation plan “worked beautifully.”

Once the stream has been reconstructed, the team will do restoration planning. They’ve consulted with Huntley Meadows to come up with a plant list. After the planting, there will be 10 years of active monitoring.

Kathy Ledec, president of Friends of Huntley Meadows Park and chair of the Mount Vernon Council of Civic Associations Environment and Recreation Committee, said she’s impressed with the work so far.

“They’ve been working pretty darn hard, for sure,” she said. “You see the progress, imagine how great it will look when finished.”

Ledec thinks the plunge pool structures will be a great attraction for community members and other nature-explorers. Though while the project is underway, she and the other officials urged the public to stay out of the construction area, where hard hats and visibility vests are required at all times.

The project website can be found here.