Water rights negotiation session focuses on technical aspects

By B.L. Azure

POLSON — Last Wednesday’s federal reserved water rights compact negotiation session was dominated by technical presentations.

Dr. Richard Allen of the University of Idaho and Dr. Jeppe Kjaersgaard a Dutch visiting professor at UI gave a power point presentation on the METRIC system. It is a system devised to measure evapotranspiration, or the water loss from soil and vegetation through evaporation. It is one of ways the water compact negotiation parties can use to get a better picture water use on the Flathead Indian Reservation.

The Confederated Salish and Kootenai Tribes, the State of Montana and the United States are currently negotiating a federally reserved water rights compact for the Flathead Reservation and quantification is key to that effort.

The METRIC system uses satellite imagery and data in an equation to measure evapotranspiration. Allen said the system is quite accurate but cloud cover does at times hinder the gathering of soil and vegetation water consumption. However, he said they used the system over a three-year period and were able to get information applicable to a typical 12-month period in that time. Consequently they have a decent snapshot of annual water use and loss through evapotranspiration in the area.

“We can’t see actual evaporation as it occurs,” Kjaersgaard said. However they use a METRIC energy balance formula along with satellite and weather data to calculate soil and vegetable water consumption. “Because the satellite is 400 miles above earth we need to calibrate the evapotranspiration.”

They calibrate by using a reference crop, in this case alfalfa, on a fully vegetated field and come up with a formula of its water consumption. They plug the calibrated numbers into the formula and come up with the amount of water used through evapotranspiration.

“It tells the actual rate of evaporation,” Allen said, adding that the evapotranspiration occurs in this area from April 1 to October 31. “July is the peak month for evapotranspiration. We add all the months together then come up with an average.”

Allen said several states including New Mexico, Colorado, Nebraska, Oregon, Washington and Idaho are using the METRIC system to measure evapotranspiration.

“The system can be used by farmers as a management tool,” Allen said. “You can’t manage what you can’t quantify.”

CSKT wetlands hydrologist Mary Price discussed the wetlands ecosystem on the Flathead Reservation. She said there were various types of wetlands on the reservation some created naturally and others man caused.

Some of the 35,000 acres of wetlands ecosystem on the reservation have been damaged and some of it has been restored, some is currently being restored and some will be restored in the future.

The Tribes receive mitigation funds from various sources to restore damaged wetlands ecosystems.

ARCO Mitigation funds are used to restore, replace, or acquire the equivalent of tribal resources injured by the release of hazardous substances from industrial mining in the Upper Clark Fork Basin.

The CSKT under their Wetland/Riparian and Bull Trout Restoration Plan will restore 800 acres of wetland and riparian habitat and restore Bull Trout populations and habitat.

Kerr Mitigation funds are used to mitigate damage done fisheries and wildlife by the operation of Kerr Dam

Under the FERC Kerr Dam operation license, the CSKT will acquire and manage 3,089 acres of habitat for reservation fisheries and wildlife resources.

The BPA/Hungry Horse Mitigation plan will mitigate impacts to 125.8 kilometers of Flathead River mainstreams and tributary streams caused by the operation of Hungry Horse Dam. The Tribes will acquire residential fish habitat on the reservation in exchange for credit against BPA’s mitigation obligation.

The Tribes also receive mitigation funds from the Montana Department of Transportation to mitigate the impacts of highway construction on the reservation.

Price said the Tribes coordinate mitigation efforts by using the various mitigation plans together in some instances “to get a better bang for the buck.”

Duane Mecham, federal negotiator said the Bureau of Reclamation is preparing water use models for Hungry Horse Dam and reservoir. The Tribes are looking to use excess water stored in the reservoir to supplant water use on the reservation.

They should be ready to present their findings at the next negotiation session, tentatively set for July 29.