Natural Resources Conservation Service Idaho Water Supply Outlook Report April 1, 2019 Owyhee Reservoir in Eastern Oregon near the Idaho Border, March 30, 2019 In 1932, the U.S. Bureau of Reclamation completed the Owyhee Dam and the Owyhee Reservoir started filling for the first time. At the time of completion, the Owyhee Dam was the tallest of its kind in the world (417 feet) and served as a prototype for the Colorado River’s Hoover Dam. In the otherwise arid climate of Eastern Oregon and Southwestern Idaho, the reservoir provides critical irrigation water to approximately 118,000 acres of farmland across both states and four separate irrigation districts. The Owyhee River basin is huge, covering ~7,690 square miles in Oregon, Idaho, and Nevada. To put this in perspective, the entire Boise River basin is ~2,200 square miles! April 1 snowpack in the expansive Owyhee River basin is 130% of normal, and the reservoir is 61% full (88% of average), inflows began to increase in March and will continue in April as we transition into Spring. Please see the full report for details on current snowpack and expected water supplies. Water Supply Outlook Report Federal - State – Private Cooperative Snow Surveys For more water supply and resource management information: Contact: Your local county Natural Resources Conservation Service Office Internet Web Address: http://www.id.nrcs.usda.gov/snow/ Natural Resources Conservation Service Snow Surveys 9173 West Barnes Drive, Suite C Boise, Idaho 83709-1574 (208) 378-5700 ext. 5 To join a free email subscription list contact us by email at:
[email protected] How forecasts are made Most of the annual streamflow in the western United States originates as snowfall that has accumulated in the mountains during the winter and early spring.