Snake River Adjudication Instream Flow Monitoring Program

Description

The Snake River Basin Adjudication (SRBA) was an administrative and legal process that began in 1987 to determine the water rights in the Snake River Basin drainage. The Final Unified Decree for the SRBA was signed on August 25, 2014. The Nez Perce Tribe (NPT) received "Partial Decrees" for state minimum stream flow water rights held by the Idaho Water Resources Board (IWRB). The minimum stream flow water rights were approved by resolution of the Idaho Water Resources Board dated February 8, 2005, and established by the Idaho Legislature in chapter 148 of the 2005 Idaho Session Laws. The Tribal Priority Streams are divided into "A" and "B" List groups based on the level of existing use. The "B" List streams include those streams where instream flows and other non-flow-related actions will be developed by the parties, in conjunction with local stakeholders and communities. The "A" List Tribal Priority Streams have instream flows and future non-DCMI use levels assigned based on land classification except in those cases specifically set forth where the parties have agreed to address certain special resource value areas, or areas of special concern relative to local uses. Land classification was established based upon the predominant land ownership and where appropriate, federal land classification, existing in particular stream's basins. There are 159 "A" List streams and 28 "B" List streams. The purpose of this proposed activity is to determine compliance with the adjudicated instream flow program, which is a condition of the 2004 Final Mediator's Term Sheet. Monitoring the flow in these streams is essential to establishing the current condition of these waters and to ensure that the terms of the SRBA agreement are fulfilled. Due to a lack of funding, the required monitoring has not yet been initiated. With this financial assistance, the NPT staff will initially create a GIS map identifying "A" and "B" Listed streams, active instream water rights, and current operating USGS stream gages. Initial analysis will include the potential to improve stream flows based on the amount of active instream water rights, cultural importance, and biological importance of the streams. Final determination for stream gage placement will be done in coordination with partners. NPT will purchase 12 Solinst Water Level Data Loggers and will place them in stilling wells that are installed at the mouths of six identified SRBA listed streams. Each site will have two loggers, one to measure water level and one to measure barometric pressure. Staff gages will also be installed at each site to provide reference reads to compare water level recordings against. NPT will measure instantaneous discharge at each site a minimum of 20 times throughout the calendar year, making sure to try and capture peak stormflow events and low flow periods. The instantaneous flow data will be used to develop a rating curve in order to derive streamflow estimates from water level elevations. The NPT will also work on developing the Tribal Water Code, in order to administer the on reservation use of the adjudicated water right. As the primary enforcement and management entity responsible for administering Tribal water rights on the Reservation, it is essential that the NPT complete the Tribal Water Code, which is currently in rough draft form. Anticipated Results: A final technical report will be developed for this project and will be disseminated to relevant Tribal staff, and the Idaho Department of Water Resources (IDWR). Creation of the GIS database will also occur and the data collected will be made available on the NPT websites. The proposed activity is anticipated to identify potential water exchange projects to help restore flows where minimum instream flows are not currently being met. NPT Watershed implements projects to protect and restore critical habitat for ESA listed salmonids. Cold water refugia in the summer is critical to the survival and recovery of these fish. Potential water exchange projects include but are not limited to irrigation improvement projects, instream water leases during critical low flow periods, and permanent retirement of instream water rights. Completion of the Tribal Water Code will allow the NPT staff to enforce regulations established pursuant to the Code, thereby expanding the Tribe's jurisdictional capacity to protect instream water rights. RECLAMATION INVOLVEMENT There is no anticipated involvement from Reclamation.

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