Let the Water Flow

Let the Water Flow

Final public meeting about rehabilitating Watts Branch.

If Dan Harper has his way, the Watts Branch will be a revitalized stream in a few years. “Our goals are to create stable channels and create habitat,” said Harper of the Montgomery County Department of Environmental Protection.

The department held the third in a series of three meetings to discuss its plans to improve the health of the stream.

The Watts Branch is a stream which flows from the City of Rockville, through Potomac and into the Potomac River just upstream of the WSSC Water Filtration Plant. Its watershed covers 22 square miles.

“It used to be mostly agricultural, and now is mostly large-lot residential,” said Pam Parker of the Montgomery County Department of Environmental Protection.

As the area has become more developed, more of what used to be forest and meadow is now driveways, roads and buildings, impervious surface. An increasing percentage of impervious surface means in a storm, water races through streams, eroding the banks more rapidly and creating more sediment than there should be in the stream. In a less developed area the water would have time to be absorbed by the earth.

“You get more runoff. … It comes off in a greater amount, at a greater rate. It comes off with a greater velocity and force,” said Sally Hoyt of AMT, one of the consultants assisting with the project.

THE ADDITIONAL SEDIMENT creates a more hostile environment for wildlife, and since it goes in upstream of the WSSC plant, increases the amount that WSSC needs to filter out of the water (see sidebar).

Through the study, the Department of Environmental Protection and their consultants have identified the areas most in need of help, and prioritized by analyzing the need, and other factors like cost and accessibility.

“Some of these watersheds with the highest ranks have the most development on them,” said Vince Sortman of Biohabitats, another one of the consultants.

There are a variety of improvements proposed in the project. Five new stormwater management ponds will be created, and the channel will be adjusted and flattened out to allow the waters to reach the floodplain.

Some residents, however, question how the department is going about its restoration efforts.

“The Watts Branch is an extremely flashy [subject to flash floods] stream,” said Ginny Barnes. “You cannot possibly do any of these restoration projects until you control the flow of water.”

THE WATTS BRANCH flows through Barnes’ property. She wants to ensure that the Department works its way down the stream, reasoning that any downstream improvements will be washed away if the upstream area is not fixed first. “The volume of water that comes down the Watts Branch destroys anything,” she said.

Barnes advocates increasing the stormwater mitigation before doing any of the other projects.

Harper said that the department does plan to put in the five new ponds and intends to install them as it does other projects. “We try to get as much stormwater control as we can,” he said.

He agreed that the upstream areas should take priority, and will try to rehabilitate them first. He expects to apply for the first grants to fund the project in February 2005. He expects to hold local, site-specific public meetings with affected neighbors before any implementation begins. The earliest likely date for starting any rehabilitation is 2008, Harper said.


The Watts Branch, and its sediment, flows into the Potomac River not far from the water intake pipe for the WSSC filtration plant.

Sediment levels in the Watts Branch are so high that WSSC is studying moving its intake pipe about 500 feet out into the river, which they say will get them past the Watts Branch sediment plume.

This, in turn, will mean that they will have cleaner source water and therefore less filtering. They project this will result in a substantial cost savings.

Environmental groups argue that WSSC should instead invest in helping to rehabilitate the Watts Branch. They say this will reduce the sediment load and allow WSSC to act as a good neighbor.


The most recent study is expected to be released in the fall, said Dan Harper of the Montgomery County Department of Environmental Protection.

An earlier publication in the process was released in March 2003. It can be seen at www.askdep.com then follow the link for “Watershed restoration” and go to the bottom of that page.