This reservoir is owned/managed by Washington Suburban Sanitation Commission (WSSC). Since the Spring of 2006, Triadelphia has been closed to paddlers; the water level is low, with the work on the dam.
I checked recently (beginning August 2006) with the WSSC field office on Brighton Dam Rd., and it will be closed until further notice. Please call (see other report for desk phone) before making the trip.
The nearest destinations that are open are Rocky Gorge Reservoir. The day passes or a season pass can be obtained at the same location for Triadelphia Reservoir.
Another place to paddle near Germantown, is Black Hills Park.