Poolesville High School Students called for creek protection in 2013 .
Land cover in the 3,046-acre
PHOTO : caroline taylor
Ten Mile Creek Watershed remains largely rural and covered by riverine and upland forests that have regrown since being cleared in the settlement period . John Parrish , a botanist and vice president of Friends of Ten Mile Creek , has documented over 450 native plant species , including 7 that are rare in Maryland , in the forests , wetlands and meadows of Ten Mile Creek Conservation Park and on properties owned by the County that are designated to become parkland . 1 Ten Mile Creek ’ s 11 subwatersheds include some of the most sensitive and high-quality tributaries in the County . These contribute to the watershed ’ s overall good health and Ten Mile Creek ’ s designation as a reference stream against which other streams are compared when monitoring water quality . In fact , Ten Mile Creek was one of the last streams in Montgomery County to support our native Brook trout .
Ten Mile Creek remains the cleanest of three major tributaries to the Little Seneca Reservoir , which submerged its lower stream valley . The reservoir was completed in 1984 as one of two backup reservoirs that augment the flow of the Potomac River during droughts . The Little Seneca Reservoir , jointly owned by utilities in Maryland , DC and Virginia , and cooperatively managed through the Interstate Commission on the Potomac River Basin ( ICPRB ), is part of the critical water supply infrastructure for the entire Washington Metropolitan Area . The other two tributaries to the Reservoir , Cabin Branch and Little Seneca Creek , drain areas where there has been significant development — in Germantown and in the vicinity of Clarksburg — and therefore bring high loads of polluting sediment to the Reservoir .
However , Ten Mile Creek is threatened by both ongoing developments in its watershed and by climate change . Development projects are increasing impervious surfaces and stormwater runoff and also impairing the watershed ’ s hydrology as a result of extensive bulldozing and regrading of slopes . Anticipated impacts on water quality are based on outdated rainfall data and do not factor in the climate change induced increases in heavy storms — a trend that is most pronounced in the northeastern US , as is consistently shown in US National Climate Assessments 2 . These will both lead to increases in runoff that will further erode the stream channels , leading to more flooding and greater transport of sediment and other pollutants to the reservoir unless we protect this critical natural infrastructure .
The largest current development plan , submitted by Pulte Homes Corporation and recently approved by the Planning Board , would build 326 homes in the Ten Mile Creek watershed , west of I-270 . The Pulte plan would concentrate development wholly within the two most sensitive subwatersheds , LSTM 110 and LSTM 111 , which were singled out for extraordinary protection in the Ten Mile Creek Area Limited Amendment to the Clarksburg Master Plan . The amended Master Plan was adopted in 2014 with the unanimous support of the Montgomery County Council , under the leadership of then Council member and current County Executive , Marc Elrich , as well as in response to advocacy initiated
1 A summary of John Parrish ’ s findings can be found at : https :// www . tenmilecreek . org / blog / overview-flora-of-ten-mile-creek )
2 Climate Change Science Special Report , Fourth National Climate Assessment ( NCA4 ), Volume I . 2017 , Chapter 7 , Precipitation Change in the United States . https :// science2017 . globalchange . gov / chapter / 7 / plenty I autumn harvest 2022 27