Of the five reservoirs authorised, only Kentmere Head was built. By the time it was completed, the railways had reached Kendal, and coal from the Wigan coalfields was readily available. Steam engines began to replace water power, with Castle Mill installing a engine in 1850. Wakefields, who operated the Sedgwick lower gunpowder mill on the east bank of the river moved their operations to Gatebeck on the Peasey Beck, which was supplied with compensation water from the Killington Reservoir, built to supply the Lancaster Canal. There was no enthusiasm to pay rates from the smaller mills, with even less to spend large amounts of money on new works, and so the Commissioners of the Kendal Reservoirs became the Commissioners of the Kentmere Reservoir.