The U.S. Army Corps of Engineers’ effort to open up storage space on upstream reservoirs to receive runoff this spring is going according to plan.
The Corps updated the media tonight and Water Management Division Chief Jody Farhat said already about 500,000-acre-feet more storage is open now than a year ago. “The total system storage in the main stem reservoir system is currently at 56.4-million-acre-feet. That’s 400,000-acre-feet below the base of annual flood control pool, thus providing an additional 400,000-acre-feet of additional flood control storage for the 2012 runoff season. Last year at this time system storage was at 56.9, about 100,000-acre-feet above the base of annual flood control zone.”
Farhat says that gives the Corps some wiggle room. “What this additional storage gives us is the opportunity perhaps in the spring to hold additional water back if we get rainfall events downstream. Having that additional storage provides just a little bit of additional flexibility.”
The extra space also allows more room for higher inflows upstream as well, but right now Farhat says the snowpack does not look threatening. Farhat says the snow-water equivalence on the plains reported by the National Weather Service remains less than one inch, with few exceptions. NWS shows a below-normal mountain snowpack throughout the Missouri River basin as well, though storms this week have increased that amount.
With the River and most of its reservoirs having frozen up this week, Farhat says the Corps will increase flows into the River beginning tomorrow. “We’ll step up our releases from Garrison at a rate of about 1,000-cubic-feet-per-second every other day until we reach 26- or 27,000 in early February.”