The purposes of Idaho's Water Supply Bank are to encourage the highest beneficial use of water, to provide a source of adequate water supplies to benefit new and supplemental water uses, and to provide a source of funding for improving water user facilities and efficiencies. The history of the Idaho Water Bank system began in the 1930s.
In its most simplistic sense, the Bank is a water exchange market operated by the Idaho Water Resource Board to facilitate the use of water rights to natural flow water or water stored in Idaho reservoirs. Water right holders can offer unused water rights to the Bank. From there, the water can be rented to people who do not have adequate water rights to meet their needs.
Categories of Water in the Bank
Idaho's Water Supply Bank is separated into two distinct categories—the Board's water supply bank and local rental pools.
The Board's water supply bank includes water rights from surface water and groundwater sources throughout Idaho. Water rights may be leased to the Bank, if not currently in use, and rights may be rented from the Bank for beneficial uses such as commercial, industrial, irrigation, or mining. The Idaho Department of Water Resources manages the Board's water supply bank for the Idaho Water Resource Board in accordance with Idaho Code §§ 42-1761 through 42-1766 and the Water Supply Bank Rules (IDAPA 37.02.03).
Local rental pools are generally for reservoir storage water, except in the Lemhi River basin where the rental pool utilizes natural flow water. Rental pools are established under the same authority as the Board's water supply bank but only pertain to specific watersheds in Idaho. Rental pools are managed by committees appointed by the Idaho Water Resource Board in accordance with local rental pool procedures, Idaho Code §§ 42-1761 through 42-1766, and the Water Supply Bank Rules (IDAPA 37.02.03). See the Local Rental Pools tab for local rental pool procedures and committee appointments.