Figure 1. Location of Northwest Branch of the Anacostia River within Maryland Piedmont geographic province.

Figure 2. Observed and modelled flood frequency distributions for Northwest Branch watershed. Modelled distributions based on TR-55 simulations run within GIS environment.

Figure 3. The Northwest Branch watershed. Green dots represent parcels developed since 1950. Red squares represent anticipated parcel development over next 20 years. Heavy black stream trace is flow path traced in Figure 4.

Figure 4. (a) Simulated 1997 2-year peak discharge along trace shown in Figure 3; (b) 2-year discharge ratio for past (1951) and future (2020) conditions.