There is strictly only one reservoir on the canal. Water is, of course, absolutely essential to the performance of a canal. Earlswood reservoir was originally built in 1821 and now has three pools, named Windmill pool (30 acres), Engine pool (40 acres) and Terry’s pool (15 acres). The engine house to raise water originally had a steam pump from 1823 but this was replaced by two electric pumps in 1936.