Watershed Drainage

Based on a 1981 U.S. Water Resources Council study current methods to predict peak flows for small drainage watersheds are grossly inaccurate. When current methods were compared to actual gauged ( true) flows errors ranging from 55% to 75% four underestimation and 105% to 310% overestimation were determined. Clearly this could lead to under- and over- sizing culverts. The costs associated with materials is significant. However the cost associated with flood event damage can be enormous. This study will gage 30 diverse watersheds geographically spread across the state. Peak flow data will be compared to current prediction methods and results analyzed. This three year study will provide an indication of the accuracy of the models.