- Rock Creek and Piney Branch Trunk Sewers - Washington DCTo help alleviate pollution in Rock Creek, the Public Works Administration (PWA) granted approximately $3,500,000 for the creation of a massive new sewer system serving Crestwood, Petworth and surrounding areas in 1939-1941. The trunk sewer lines were constructed by private contractors, one of which was the Philadelphia construction company of Joseph Lombardi. Beginning near the intersection of 16th Street and Arkansas Avenue (northwest), the system runs southwest down Piney Branch Parkway, under the National Zoo, and then south. It splits into two lines, one along each side of Rock Creek: the western line to carry storm water runoff and the eastern to...