a longtime member of middlesex county council where he served as an alderman and vice-chairman, he represented the authority on the metropolitan water board (mwb). he was chairman of the mwb from 1928 to 1940, and two massive steam-driven pumping engines at kempton park pumping station were named "william" and "bessie" after prescott and his wife. he co-founded the tottenham war services institute in 1920. he was appointed in 1924 as a deputy lieutenant of middlesex, and in 1929 served as high sheriff of the county. he was also a member of a number of other committees connected with middlesex, a member of the worshipful company of paviors and the worshipful company of glaziers and painters of glass and a freeman of the city of london.