Montgomery County is rehabilitating the Watts Branch. “Urbanization has drastically increased the erosion and we’re trying to bring that back to natural levels,” said Scott Randall, Watershed Planner with the county Department of Environmental Protection (DEP).
Toward that end, the county started a study last March, which will cost approximately $246,000, to determine the best way of attacking the problem. The first stage of the study has been completed, and the DEP held a public meeting to explain their findings and gain public input before the next phase of the study begins.
Most of the group of about 15 at the hearing were representatives of other county agencies. “It’s really nice to get all the agencies in the room,” said Randall.
The study is expected to be completed in October of this year, with implementation set to begin in 2006. Implementation will depend largely on funding sources available. “We depend heavily on grants,” said Daniel Harper, senior engineer with the DEP.
The DEP broke the Watts Branch watershed into over 40 subwatersheds then studied these areas to determine which are most in need of help. The top few will receive treatment.
“We can only handle so many projects at a time. The idea is to prioritize,” said Harper. He explained that studies only have a limited time before they are rendered obsolete. “We want to work on those we can do in a reasonable amount of time,” Harper said.
As the subwatersheds were studied, they were grouped into tiers numbered one to six with one being the most in need of attention. Only two tier-one areas were identified.
The classification of each tier was based on factors concerning both the need for rehabilitation and the feasibility of working in that particular area, in addition to the proximity of other watersheds. “Fixing a poor [stream] that feeds into a good one helps to keep the good, good,” Harper said.
A minor consideration was the likelihood of getting volunteers to assist in an area. “Would it increase the probability?” said Mary Yakatis, a resident whose property is in a tier three area.
“It wouldn’t hurt,” replied Harper. He explained that potential for volunteers would have a relatively minor impact on the chances of having work done.
Now the county, with help from private consulting firms, will do a more in depth analysis of the various areas which need to be rehabilitated with an emphasis on stormwater management and stream restoration.
“We’ll be considering both retrofits [of existing facilities] ... and new sites,” said Sally Hoyt an engineer with A. Morton Thomas, the company dealing with stormwater management. Improving stormwater management will help to improve water quality, allow for better groundwater recharge and protect the stream channel.
Hoyt and her associates will use computer models to see how best to improve stormwater management. She explained that older standards had called for stream to be able to handle a major storm -- one that would only happen every five or ten years. “Now we’ll set it up for something that happens, maybe five times in one year,” Hoyt said. This will allow for water to be distributed along a wider area and help to control long term stream erosion. DEP will take into consideration the proximity of residences, and will keep them out of the 100-year floodplain of the newly designed stream. “If it’s in an area where it’s not going to effect anybody, it’s beneficial to do it,” Harper said.
Stream reconstruction can take a variety of forms, blockages could removed, the shape of the streambed could be modified, or the banks could be stabilized. “The more natural techniques you use, the more natural it’s going to look when you finish,” said Vince Sortman, a fluvial geomorphologist with Biohabitats.
Currently, the Washington Suburban Sanitary Commission’s water intake pipe is just downstream from where the Watts Branch hits the Potomac. WSSC is proposing to move their pipe further out into the stream in order to avoid the sediment created by the Watts Branch.
“We knew about each other’s work,” said Daniel Harper, senior engineer with the DEP.