system that discharges into the creek. Composed of 8- to 10-foot brick and concrete pipes, the Piney Branch Trunk Sewer is one of the city's major trunk sewers. Project design was slated to start in January 2014 and last one year. As of early 2016, work was to begin in 2017 and last until 2019. See also List of rivers of Washington, D.C. References External links Piney Branch watershed photos 2009 map of the combined sewer that empties into Piney Branch Rock Creek (Potomac River tributary) Rock Creek Park Rivers of Washington, D.C.