The building of a reservoir to regulate the flow was a small part of a much bigger scheme to build a series of reservoirs in the parish of Kendal to regulate the River Sprint, otherwise known as the Sleddale Beck, the River Mint, known at the time as the Bannesdale Beck, and the River Kent. By 1844 there were 15 mills on the Kent, three on the Sprint and five on the Mint, processing wool, gunpowder, bobbins, logwood, dyewood, paper, marble and iron. Water power was important because there were no sources of coal nearby. A total of ten mill owners and the mayor of Kendal formed a provisional committee, which resolved to build reservoirs in Kentmere and elsewhere, to maintain flows on the rivers. The mayor was involved because Kendal Corporation owned the water rights and leasehold to Castle Mill.