Urban watershed management using activity indicators to predict water quality

The first step in the management of small watersheds by local regulatory agencies is the establishment of priorities for implementing the dictates of the 1972 Federal Water Pollution Control Act amendments. Although data requirements for establishing priorities are extensive, typically, very little water quality and streamflow data exist for small urban watersheds. Local regulatory agencies do not possess the resources to generate these data. To solve this problem, the use of indirect indicators is developed to describe watershed activity, predict water quality, and forecast the status of several individual water quality parameters. Stream quality is then predicted for watersheds for which no previous direct measurements had been made. The methodology is applied to Allegheny County in Pennsylvania, a region composed of 52 small urban watersheds. Indicators of watershed activity are used here to determine which streams should be sampled to provide a representative measure of water quality conditions existing throughout the county. The information from the monitoring program is currently being used by the Allegheny County Health Department to define implementation priorities for the small urban streams in the region.