OMAHA, Neb. – Runoff in the Missouri River Basin above Sioux City, Iowa, was 1.8 million acre feet (MAF) during March, only 60 percent of average, according to the U.S. Army Corps of Engineers (Corps). “Conditions in most of the upper basin during March were dry and warm. Additionally, runoff from the plains snowpack, which typically enters the system in March and April, occurred in January and February this year and contributed little to March runoff,” said Jody Farhat, chief of the Corps’ Missouri River Basin Water Management Division.

The 2016 runoff forecast is 21.7 MAF, 86 percent of average. “While the plains snow has melted, the mountain snowpack, which normally peaks in mid-April, continues to accumulate. As of April 1, the mountain snowpack was 95 percent of average in the reach above Fort Peck and 89 percent of average in the reach from Fort Peck to Garrison,” said Farhat.

View the mountain snowpack graphic at http://www.nwd-mr.usace.army.mil/rcc/reports/snow.pdf.

The total volume of water stored in the Missouri River Mainstem Reservoir System is currently 57.0 MAF, occupying 0.9 MAF of the 16.3 MAF flood control zone. “While below normal runoff is expected, the reservoirs are well positioned to meet all authorized purposes this year,” said Farhat.

In mid-March, releases from Gavins Point Dam were increased from 14,000 cfs to 20,000 cfs in support of the Missouri River navigation season that began April 1 near St. Louis, Mo. “Flow support for the first half of the navigation season will be full service,” said Farhat. Full-service navigation flow support is generally sufficient to provide a 9-feet-deep by 300-feet-wide channel. “Flow support for the second half of the navigation season and the season length will be determined based on the July 1 system storage check.”

Steady-to-rising reservoir levels during the forage fish spawn at the three large upper reservoirs, Fort Peck, Garrison and Oahe, are preferred, but may be difficult to accomplish without additional rainfall in the Missouri River basin during the coming weeks. If the runoff is insufficient to keep all three reservoirs rising, the Corps will adjust releases to result in a steady-to-rising pool at Garrison this year. The forage fish spawn generally occurs from early April through mid-June.

The Corps will continue to monitor basin conditions, including rainfall and mountain snow accumulation, and will fine tune the regulation of the reservoir system based on the most up-to-date information.

Spring Public Meetings

Five public meetings will be conducted throughout the basin April 12–14. The purpose of these meetings is to update the region on current hydrologic conditions and the planned operation of the reservoir system. Meeting times and locations are listed below.

Tuesday, April 12 – Smithville, Mo.

Start time:  11 a.m.

Jerry Litton Visitor Center

16311 DD Hwy

Tuesday, April 12 – Nebraska City, Iowa

Start time:  5 p.m.

Lewis and Clark Missouri River Visitor Center

100 Valmont Drive

Wednesday, April 13 – Fort Peck, Mont.

Start time:  11 a.m.

Fort Peck Interpretative Center

Lower Yellowstone Road

Wednesday, April 13 - Bismarck, N.D.

Start time:  6 p.m.

Bismarck Civic Center

315 South 5th Street

Thursday, April 14 – Pierre, S.D.

Start time:  11 a.m.

Capitol Lake Visitor Center

500 E Capitol Ave.

Reservoir Forecasts

Gavins Point Dam releases averaged 16,200 cfs in March. Releases are currently set at 20,000 cfs and will be adjusted in April to meet downstream navigation flow targets in reaches with commercial navigation. In the event of heavy rains downstream of the reservoir system, releases will be reduced to lessen flood risk along the lower river. The reservoir behind Gavins Point Dam ended March at elevation 1206.3 feet. The reservoir will remain near elevation 1206.0 feet during April.

Fort Randall Dam releases averaged 13,800 cfs in March. Fort Randall Dam releases will be adjusted as necessary to maintain the desired elevation at Gavins Point Dam. The reservoir ended March at elevation 1354.1 feet, up 2.9 feet during the month. The reservoir is expected to gradually rise to near elevation 1355 feet in April.

Big Bend Dam releases averaged 15,100 cfs during the month of March. Releases are expected to average 18,200 cfs this month. The reservoir will remain near its normal elevation of 1420.0 feet during April.

Oahe Dam releases averaged 16,200 cfs during the month of March. Releases are expected to average 18,000 cfs this month. The reservoir ended March at elevation 1609.0 feet, up 0.4 feet during the month. The reservoir level is expected to remain near its current elevation in April.

Garrison Dam releases were reduced from 18,000 cfs to 16,000 cfs in early March, averaging 16,100 cfs during the month. Releases will remain at 16,000 cfs during April. Garrison ended March at elevation 1837.6 feet, down 0.5 foot from the end of February. The reservoir is expected to remain near its current elevation during April.

Fort Peck Dam releases averaged 6,000 cfs in March. Releases will be increased from 6,000 cfs to 7,000 cfs around mid-April. The reservoir ended March at elevation 2233.9 feet, down 0.2 foot during the month. The reservoir level is forecast to lower slightly during April.

The forecast reservoir releases and elevations discussed above are not definitive. Additional precipitation, lack of precipitation or other circumstances could cause adjustments to the reservoir release rates.

The six mainstem power plants generated 556 million kilowatt hours of electricity in March. Typical energy generation for the month of March is 641 million kWh. The power plants are projected to generate 8.9 billion kWh of electricity this year, compared to the normal of 10 billion kWh.

To view the detailed three-week release forecast for the mainstem dams, go to http://www.nwd-mr.usace.army.mil/rcc/reports/twregfcast.pdf.

Missouri River Mainstem Reservoir Data

Water releases and energy generation for March