Streamflow Evaluation for Water Right Claims for Wild and Scenic Rivers, Owyhee Canyonlands Wilderness

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Several river segments in the Owyhee Canyonlands Wilderness have been designated as “Wild and Scenic” under the Omnibus Public Lands Management Act of 2009. This designation is intended to protect the “outstanding remarkable values” (ORVs) in this area—specifically fish and wildlife habitat, scenic and geological features, and recreational opportunities.

The Bureau of Land Management (BLM) is applying for water right claims to ensure adequate streamflow to protect the ORVs unique to each segment. To develop the claims, the BLM needs adequate streamflow data. However, the rugged terrain, limited access, and budget constraints make it difficult to collect the streamflow data using standard methods. The BLM turned to the USGS to find a more cost-effective, statistically-based solution.

In 2012, we analyzed streamflow records from three available streamgages in the region. We then identified new sites where collecting additional streamflow data would help us compute streamflow statistics for the individual Wild and Scenic segments. Streamflow monitoring sites were within the Big and Little Jacks Creeks, Bruneau River, Jarbidge River, and Owyhee River basins.

We measured streamflow periodically from February to September 2012 at 14 sites. These data are available from the USGS National Water Information System.

Where long-term data were available, we used the actual streamflow record to compute streamflow statistics. Where data were sparse, we used a variety of techniques to develop “synthetic” streamflow records to compute streamflow statistics.

We continue to work with the BLM to develop a long-term streamflow monitoring plan for the Owyhee Canyonlands Wilderness.

We developed techniques for computing streamflow statistics where the available streamflow data were insufficient for precise statistical analysis. These techniques are particularly useful for areas where streamflow monitoring is limited and difficult. As we make more frequent streamflow measurements over a wider range of hydrologic and climatic conditions, the accuracy of these streamflow statistics will improve.