The vegetated stormwater-detention basin at a small residential development in Monroe County, N.Y. has been shown to be effective in reducing loads of certain chemical constituents to receiving waters. Loads of suspended solids, nitrogen, and phosphorus have been reduced by an average of 14 to 62 percent. The basin has little effect on the temperature of runoff between the inflow and the outflow; water temperatures at the outflow during summer storms averaged 0.5 degrees Celsius higher than those at the inflow.