The Pequea Creek and Mill Creek Basins within Lancaster and Chester Counties in Pennsylvania have been identified as areas needing control of nonpoint-source (NFS) pollution to improve water quality. The two basins are a total of approximately 200 square miles and are primarily underlain by carbonate bedrock. Land use is predominantly agriculture. The most common agricultural NFS pollution-control practices implemented in the Pequea Creek and Mill Creek Basins are barnyard-runoff control and Streambank fencing. To provide land managers information on the effectiveness of Streambank fencing in controlling NFS pollution, a study is being conducted in two small paired watersheds within the Mill Creek Basin.