Drought maintains grip on region Drought maintains its grip on most of the Upper Missouri River basin, increasing expectations for lower reservoir levels and reduced river flows again this year as snow accumulation on the plains and in the mountains remains sparse.
"As of March 1, the mountain snowpack was only 61 percent of normal in the reach above Fort Peck, and 69 percent of normal in the reach from Fort Peck to Garrison," said Larry Cieslik, chief of the Water Management office in Omaha. Normally, 80 percent of the peak snow in the mountains is accumulated by early March.
"With below normal mountain snow and near normal precipitation the rest of the year, we are forecasting annual runoff to be 16.7 million acred feet (MAF), about 66 percent of normal" said Cieslik. "It's likely that dry soil conditions due to persistent drought will absorb a good deal of the runoff before it reaches the reservoirs." Normal runoff is 25.2 MAF.
The first of each month the Corps conducts computer simulation studies for a range of possible annual runoff values centered on the "Basic" forecast, which is currently 16.7 MAF. This month the runoff simulations ranged from a high of 21.8 MAF to a low of 12 MAF. The basic study showed that it may be possible to keep Oahe reservoir levels steady and Fort Peck levels nearly steady during their respective forage fish spawn period if actual runoff occurs this spring at the magnitude and distribution assumed in the study.
However, under the lowest runoff simulation, proposed regulation would focus on keeping the water supply intakes at Oahe and Garrison reservoirs operational for as long as possible. As a result, Oahe and Fort Peck would likely decline during their fish spawn periods if low runoff continues. Detailed results of the upper basic (21.8 MAF of runoff), basic (16.7 MAF of runoff), and lower basic (12 MAF of runoff) studies are available in the Water Management Section of the Northwestern Division homepage at: www.nwd.usace.army.mil.
Six public meetings to review the 2005 Annual Operating Plan will be held next month. South Dakota's meeting will be held 7 p.m. April 12 at the Ramkota Best Western in Pierre.
These meetings are held each spring to review the plan for regulating the dams and reservoirs on the river based on current runoff and storage conditions. Meetings to describe the draft AOP and take comments were held last October in Glasgow, MT, Williston, ND, Pierre, Omaha, NE, Kansas City, MO, St. Louis, MO and New Orleans, LA.
Support for the 2005 navigation season will begin April 1 at the month near St. Louis. River flows will be at minimum service levels. Again this year, minimum navigation targets may not be supported in April in reaches where there is no traffic. The season length is anticipated to be shortened 50 to 61 days, depending on runoff in the coming months. The final decision will be based on the water-in storage check on July 1.
System storage ended February at 35.4 MAF. Last year at this time it was 38.3 MAF. "The amount of water in the reservoirs in nearly 19 MAF below normal for this time of year," said Cieslik.
Releases from Gavins Point averaged 9,900 cubic feet per second (cfs) in February, the lowest on record. They ranged from 12,000 cfs to 9,000 cfs in response to weather and river ice conditions. "We set release as low as possible this winter to meet drinking water and powerplant needs while conserving water in the reservoirs. Warmer temperatures and localized precipitation allowed us to cut releases to 9,000 cfs late last month," said Cieslik. The Corps is committed to conserving as much water as possible for the duration of this drought within the framework of the Master Water Control Manual.
Gavins Point reservoir is currently near elevation 1206 feet above mean sea level (msl), where it remain during March. Weather permitting; releases will remain at 9,000 cfs through mid-month before gradually increasing to the 18,000 cfs to 22,000 cfs range as the navigation season begins.
Fort Randall releases averaged 6,200 cfs in February. In early March, they will range from 6,000 to 7,000 cfs as needed to maintain Gavins Point reservoir near its desired elevation. Fort Randall reservoir ended February at 1351 feet msl. It will continue to refill, ending the month near 1355 feet msl.
Oahe reservoir rose one foot in February, ending the month at elevation 1576 feet msl. It will rise another foot in March, ending the month 28 feet below average. The reservoir is 3 feet lower than last year at this time.
Garrison releases averaged a record-low 13,000 cfs during February. In March, they will be maintained at 12,000 cfs as river ice conditions permit. Garrison reservoir fell less than half a foot in February, ending the month at ta record low elevation of 1808 feet msl. It will remain near that level in March, ending the month 27 feet below average. The reservoir is 6 feet lower than last year at this time.
Fort Peck releases averaged 5,400 cfs in February. They will be reduced to 4,500 cfs in early March. The reservoir declined less than half a foot during February, ending the month at a record low elevation of 2198 feet msl. It will remain near that level during March, ending the month 33 feet below average. Last year at this time it was 6 feet higher.
The six main stem powerplants generated a record-low 307 million kilowatt hours (kWh) of electricity in February, 47 percent of normal. The forecast for 2005 energy production is 5.7 billion kWh compared to a normal of 10 billion kWh.