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Columbia River Basin 2011 Long-Term Supply and Demand Forecast

The Forecast provides a generalized, system-wide assessment of how future environmental and economic conditions are likely to change water supply and demand by 2030. Understanding where additional water supply is most critically needed will assist OCR in making smarter investments that help improve water supply for eastern Washington’s instream and out-of-stream users.

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Water Supply and Demand Forecast 2016

As described in our letter of transmittal (attached), Washington State University (WSU)
would be pleased to partner with the Office of Columbia River (OCR) for the 2016 Long‐
Term Water Supply and Demand Forecast. We propose to focus the 2016 Forecast around
six key issues as described in detail below.

1. Update and expand the 2011 water forecast (3‐tier analysis)

This project comprises three types of updates to the 2011. WSU will 1) update the existing
forecast estimates for the Columbia River Basin using improved modeling capabilities (see
description below), 2) extend the forecast window forward 5 years while using future
climate projections from the most recent Coupled Model Inter‐comparison Project
(CMIP5); and 3) begin the preliminary work to eventually extend the forecast to Western
Washington WRIAs. With the third option, this effort includes coordination with west side
watershed planning, Puget Sound Partnership, King County demand projections, etc. This
work will provide a (nearly) geographically complete summary of water forecasts in the
State of Washington and could form a foundation for a geographically complete
Washington State Water Plan.

The update to the 2011 report will focus on the WRIA specific forecasts of the discrepancy
between water availability and water demand. This analysis combines hydrological and
economic modeling and was done for approximately 20 WRIAs in Eastern Washington.
Changes in the crop mix were based on forecasts of economic drivers of food demand.
Downscaled climate models were incorporated into VIC‐CropSyst to simulate physical
water supply throughout the year on a daily time step. The impact of water shortages
were incorporated based on the curtailment of interruptible rights holders in a spatially
explicit way based on available water rights data. The integrated hydrology/crop
growth/economic modeling framework has developed significantly since the previous
forecast under the BioEarth and WISDM projects funded by the USDA
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updated forecast will benefit substantially from this.

Full Proposal