Idaho water law, like much of the water law in the western United States, is based on the prior appropriation doctrine. The doctrine states that the water right is authorized for beneficial use based on the priority date: “first in time, first in right.” In cases where there is not enough water to satisfy all the water rights, junior water-rights holders must curtail their water use until the senior water-rights holders receive their allocated amount. In some cases this means that the junior holders receive no water.
In the State of Idaho, most minimum stream-flow water rights are junior to the irrigation water rights. During drought years, when the flow in the river is low, there is typically not enough water to meet the needs of irrigators and fish. In some areas, irrigation can divert all of the flow in the stream (fig. 1 on the Science tab).
Idaho experienced drought conditions from 2000 to 2005. The long duration of the drought increased the probability of stream flows falling below desirable levels for fish populations listed under the Endangered Species Act (ESA). The State of Idaho took action to begin development of a conservation plan for the Lemhi River Basin with the National Marine Fisheries Service and U.S. Fish and Wildlife Service. One goal of the proposed plan was to identify stream flow targets for endangered fish in the long-term. In order to achieve this task, an accounting of the irrigation water use in the area was needed. Monthly METRIC- and Landsat-based evapotranspiration data was used to estimate basin-level consumptive use and to develop the area’s water budget (fig. 2). The data showed that irrigation in the year 2000 consumptively used 33,520 acre-feet (11 billion gallons) of water (Kramber and others, 2006).
The evapotranspiration data were then used to assess the consumptive use of water rights that may be leased under the Columbia Basin Water Transactions Program to improve stream flows. The Idaho Water Resource Board identified stream reaches that would benefit from flow enhancement and worked with willing irrigators through leases, agreements not to divert, and other transaction methods. The evapotranspiration data allowed negotiations with irrigators to be based on the consumptive use of the water rights instead of the maximum diversion allowed for the water rights (Kramber and others, 2012).
References:
Kramber, W., Morse, A., Case, M., Allen, R., Masahiro, T., and Trezza, R., 2006, Balancing water needs of crops and fish: GeoWorld, p. 24–27.
Kramber, W., Allen, R., Trezza, R., and Morse, A., 2012, Landsat-based ET data for water management in Idaho: poster presented to the Idaho Department of Water Resources.
Idaho water law, like much of the water law in the western United States, is based on the prior appropriation doctrine. The doctrine states that the water right is authorized for beneficial use based on the priority date: “first in time, first in right.” In cases where there is not enough water to satisfy all the water rights, junior water-rights holders must curtail their water use until the senior water-rights holders receive their allocated amount. In some cases this means that the junior holders receive no water.
In the State of Idaho, most minimum stream-flow water rights are junior to the irrigation water rights. During drought years, when the flow in the river is low, there is typically not enough water to meet the needs of irrigators and fish. In some areas, irrigation can divert all of the flow in the stream (fig. 1 on the Science tab).
Idaho experienced drought conditions from 2000 to 2005. The long duration of the drought increased the probability of stream flows falling below desirable levels for fish populations listed under the Endangered Species Act (ESA). The State of Idaho took action to begin development of a conservation plan for the Lemhi River Basin with the National Marine Fisheries Service and U.S. Fish and Wildlife Service. One goal of the proposed plan was to identify stream flow targets for endangered fish in the long-term. In order to achieve this task, an accounting of the irrigation water use in the area was needed. Monthly METRIC- and Landsat-based evapotranspiration data was used to estimate basin-level consumptive use and to develop the area’s water budget (fig. 2). The data showed that irrigation in the year 2000 consumptively used 33,520 acre-feet (11 billion gallons) of water (Kramber and others, 2006).
The evapotranspiration data were then used to assess the consumptive use of water rights that may be leased under the Columbia Basin Water Transactions Program to improve stream flows. The Idaho Water Resource Board identified stream reaches that would benefit from flow enhancement and worked with willing irrigators through leases, agreements not to divert, and other transaction methods. The evapotranspiration data allowed negotiations with irrigators to be based on the consumptive use of the water rights instead of the maximum diversion allowed for the water rights (Kramber and others, 2012).
References:
Kramber, W., Morse, A., Case, M., Allen, R., Masahiro, T., and Trezza, R., 2006, Balancing water needs of crops and fish: GeoWorld, p. 24–27.
Kramber, W., Allen, R., Trezza, R., and Morse, A., 2012, Landsat-based ET data for water management in Idaho: poster presented to the Idaho Department of Water Resources.