Effects of small dam removal on stream chemistry in southeastern Pennsylvania

We examined changes in stream chemistry following the removal of a 2-m-high dam on Manatawny Creek in southeastern Pennsylvania. Our primary objective was to determine the effect of small dam removal on the concentrations and forms of C, N, and P. Dissolved and particulate constituent concentrations were monitored at sites upstream and downstream of the dam and impoundment. Seasonal changes in alkalinity and N and P concentrations were observed before and after dam removal. However, the proportions of NO sub(3) super(-) + NO sub(2) super(-), NH sub(4) super(+), and dissolved organic N (DON), and soluble reactive P (SRP) and dissolved organic P (DOP) in the total dissolved pools of N and P did not change seasonally. The dam and dam removal did not influence C, N, or P concentrations and forms (except for NH sub(4) super(+)) in this stream. The lack of significant changes probably was a result of the short hydraulic residence time (