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Little Monocacy Subwatershed


Image of Little MonocacyThese tributaries of the Potomac River are located in the far western area of the County and consist primarily of agricultural and wooded areas. The Little Monocacy subwatershed is almost entirely within Montgomery County and does not flow into the Monocacy River as the name suggests (and many people believe). The Little Monocacy enters the Potomac River just downstream of where the Monocacy River joins the Potomac River in Frederick County. 

 Little Monocacy Subwatershed Study (PDF, 445KB)


A Journey Through the Little Monocacy Subwatershed

The headwaters of the Little Monocacy subwatershed begin in the rural countryside along Comus Road southwest of the town of Comus. This subwatershed is one of the most scenic, rural subwatersheds in Montgomery County. Numerous farms maintain the rural nature of this subwatershed for the full length of the stream system. The small towns of Barnesville, Sellman, and Dickerson represent the only concentrated areas of imperviousness. Portions of the Little Monocacy subwatershed drain Sugarloaf Mountain in Frederick County, with many of the headwater tributaries well forested.

By the time the Little Monocacy River passes under Route 28 near the town of Dickerson, it has grown into a wide, rapidly flowing cool-water stream. Deep pools and high-velocity riffles help to maintain a diverse cool-water fish community here. Most recently, nineteen fish species were found here.

  • Three species of darters: tessellated, greenside darter and fantail darter;

  • Rock bass and bluegills were found in the pools;

  • Silverjaw minnows swam along sandy bottom runs; and

  • Large central stonerollers and longnose dace were found in water flowing so fast that the monitoring crew had trouble remaining standing.

Because of the favorable conditions found here, DEP staff has explored this subwatershed to look for least-impaired stream reaches to add to the reference stream inventory.

Scenic view of the Little Monocacy