ESTIMATING PEAK DISCHARGES OF SMALL, RURAL STREAMS IN MASSACHUSETTS.

Floodflows on natural-flow streams in Massachusetts with drainage areas between 0. 25 square miles and 260 square miles may be estimated from drainage area, main-channel slope, mean basin elevation, and the area of swamps, lakes, and ponds. Multiple-regression techniques were used to define the relationship between a suite of basin and climatic characteristics and flood peaks in three flood-frequency regions at a total of 95 sites. Regression equations for estimation of peak discharges for 0. 5, 0. 2, 0. 1, 0. 04, 0. 02, and 0. 01 exceedance probabilities are provided for ungaged sites. The equations are applicable to streams unaffected by regulation where the usable manmade storage is less than 4. 5 million cubic feet per square mile, or by diversions or urbanization. Refs.