Techniques are developed for estimating 100-year flood depths in natural channels of unregulated Pennsylvania streams that drain less than 2,200 square miles. Equations and graphs are presented relating the depth of the 100-year flood above median stage and drainage area in five defined hydrologic areas in the State. Another graph defines the relation between drainage area and median depth of flow over the low point of riffles. Thus 100-year depths on riffles can be estimated by summing depth values derived from two simple relations.
Technique for estimating depths of 100-year floods in Pennsylvania