Sycamore Creek
From District 4 -- Montgomery County, Maryland
Sycamore Creek is a tributary of Rock Creek and is also the name of a neighborhood in Aspen Hill which lies mostly in the vicinity of that tributary.
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Geography
Sycamore Creek has one major headwater located on the grounds of the golf course in Manor Country Club.
Sycamore Creek runs mostly southwest through Manor Country Club, where it is piped underground below Bel Pre Road to emerge just south of Dabney Drive into a semi-natural streambed running between Arctic Avenue and Briarwood Terrace. From there it meanders mostly south-southwest through back yards until it passes under a bridge at Bauer Drive. At this point it takes more of a westerly direction, paralleling Briarwood Terrace, again approaching Bauer Drive and running right behind the grounds of the Manor Woods Swim Club before again turning southwest. It runs in a deepening ravine before it enters Rock Creek Park before crossing under Russett Road, to join with the main branch of Rock Creek. A hiker-biker trail roughly parallels it from Russett Road to the main Rock Creek Hiker-Biker Trail, a distance of about a mile.
Flooding
Sycamore Creek is not regarded as much of a flooding problem because of the depth of the ravine it has carved itself south and west of Bauer Drive. However, during and after heavy rainfalls, significant amounts of water flow through Sycamore Creek. The entire drainage of the Manor Club Golf Course and most of the surrounding terrain can emerge with great force from the underground pipe carrying that drainage under Bel Pre Road.
Stream Restoration
From about 2001 to 2004, the Montgomery County Department of Environmental Protection was actively reconditioning and restoring the stream and stream bed.
Pre-Restoration Conditions
Much of the lower Rock Creek Watershed, including the Sycamore Creek subwatershed, was developed prior to regulations requiring stormwater management control and contains a high percentage of impervious surface.
Uncontrolled stormwater runoff from highly impervious areas creates erosive, high velocity or “flashy” stormwater flows that cause damage to receiving streams.
The Rock Creek Watershed Feasibility Study identified several impaired condtions in Sycamore Creek. Uncontrolled stormwater created severe stream bank erosion and unstable banks, undercut trees, and damaged private property.
Undercut trees fell into the stream and created debris jams that blocked the stream and caused further bank erosion.
Over time, the stream channel down-cut and became overwidened, which limited stream flow access to the original floodplain, exposed sewer lines to potential damage, and destroyed habitat necessary for diverse aquatic life.
Sediment from eroded banks and road grit accumulated in the stream, further degrading stream habitat conditions. The lower end of the project area, located on parkland, had better conditions, with numerous vernal pools, and a riparian buffer providing habitat and shade to help reduce stream water temperatures
Restoration Actions
The Sycamore Creek Project used construction restoration techniques and reforestation to help stabilize stream banks and enhance riparian habitat.
Newly built instream structures included rock and log vanes, which direct water away from unstable stream banks, and form downstream scour pools, providing good habitat for fish. Rock cross vanes also function as grade control, which slow the erosive process of stream down-cutting.
Root wad revetments are instream structures added to help stabilize stream banks, and create scour holes, and overhead cover for fish.
Boulder rock installed at the toe of stream bank slopes stabilized the area of the stream channel subject to the greatest erosive, or “shear”, stress. The slopes above the reinforced toes were graded back to create new floodplain terraces, and planted with native trees and shrubs to further stabilize the stream banks.
The project attempted to save undercut trees with supportive "rock packing." More seriously damaged trees were cut flush with the stream bank, allowing the root systems to remain in the bank for stabilization.
More than 1700 native trees and shrubs were planted along the project length to enhance the riparian buffer.
Two shallow wetlands were created to treat water quality of stormwater discharges from two local storm drains. These wetlands quickly establish balanced aquatic communities, which add additional aesthetic and habitat benefits, including natural mosquito control.
(Source: Montgomery County Department of Environmental Protection Sycamore Creek Factsheet[1], retrieved on May 20, 2008)
