Save Klingle Valley

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Stormwater Problems

Here is how the Federal Highway Administration described the problem in Klingle in 1991:

"The Klingle Road project began as a repair and resurfacing project in the early 1980's. The existing storm drainage system intercepted the roadway runoff and dumped the water into Klingle Valley (a natural stream bed). Failure of the surface drainage has resulted in severe deterioration of the roadway, headwalls and underlying drainage system and has adversely affected aquatic life in Klingle Valley. The project now being proposed is a total reconstruction project."

The problem in Klingle Valley is largely about stormwater runoff. Klingle Creek is a stream about 1/2 mile long which discharges into Rock Creek near Porter Street. The Klingle watershed is about 320 acres, much of it impervious surfaces. This means that when there are heavy rains, the water goes into the valley almost immediately, flash flooding the creek, causing massive erosion of the creek and the roadbed. Although this is a big deal for Klingle Stream - each time there are big rains it scours the stream - it is a far bigger deal for Rock Creek. This water is hotter than the natural stream water, and depleted of oxygen, and comes down way to fast, carrying all sorts of sediment and other junk with it.

The chief pollutants are dirt (which has an enormous impact on biological oxygen demand in streams, which causes eutrophication), pollen and other organic stuff (ditto), bird and other animal waste (ditto); heat (drives down the ability of water to carry dissoved oxygen), deposited air pollution (e.g., sulfates, acid rain, misc toxics), and then auto-related oils and gunk.

Klingle is different from other DC stream valleys in that it is too narrow to provide for a generous buffer area to filter and slow this road stormwater runoff. A typical city block generates 9 times more runoff than a woodland area of the same size. See more about the urban runoff problem from the EPA http://www.epa.gov/OWOW/NPS/facts/point7.htm

A 3'6" storm drain, which parallels Klingle creek and Macomb Street, joins a 4'6" drain from Porter Street just before the combined system empties into Rock Creek. This system is overwhelmed during heavy rains and has been deteriorated due to lack of upkeep prior to the road closure. This runoff is a major pollution problem for Rock Creek. Various stormwater management proposals have been worked on over the years,

The 1991 plan proposed that there should be "ten oil and particulate removal structures with a wet detention/release volume of 400 cubic feet each and they should have underdrains to slowly bleed (l-2gpm) the 4,000 cubic feet to the stream. In essence, this will capture and treat all of a 0.5 inch of a precipitation event which is about the ten day frequency storm."

The problem with this is that with the roadbed, guardrails and other road structures, as well as the sewer and gas pipes under the road, there is very little room within the right of way to put these measures in place, even if they were adequate to solve the problem. This would mean that federal parkland would be needed to fix the road.

Adrienne Coleman, Superintendent of Rock Creek Park described the problem this way at the Nov '00 meeting: "We are in a valley and we are literally dumped on constantly. Storm water runoff, leaky sewers, mystery discharges into the creek. The Klingle Valley is just a microcosm of some of the things that are happening in Rock Creek Park. Storm water and drainage problems have been an issue in the Klingle Valley for many, many years, and the park has been harmed for many, many years as a result of it. I think we all need to keep in mind that the reason that the road was closed because the drainage system failed. And at this point, we are not assured that any construction of paved surface is not going to cause harm to Rock Creek Park . So, at this point, we cannot support any paved roadway leading or feeding into Rock Creek Park.."