Dry conditions persist in Missouri basin

Dry conditions persist in Missouri basin Accumulation of mountain snow continues to be disappointing and dry conditions persist across much of the Missouri River basin. Lower reservoir levels and reduced flows are expected again this year.

"Runoff above Sioux City, IA, in March was 2.7 million acre feet (MAF), 92 percent of normal," said Brig. Gen. William Grisoli, Northwestern Division engineer. "As of April 1, the mountain snowpack was 82 percent of normal in the reach above Fort Peck, and 72 percent of normal in the reach from Fort Peck to Garrison." Normally, the mountain snowpack peaks around mid-April.

With below normal mountain snow and normal rainfall the rest of the year, the forecasted annual runoff is 19.5 MAF. "It's likely that the low mountain snowpack along with dry soil conditions and low groundwater levels will reduce the runoff this year," said Grisoli. Normal runoff is 25.2 MAF.

Releases from Gavins Point gradually increased to 21,500 cubic feet per second (cfs) during March as support for the navigation season began. Because the reservoirs are low and the navigation industry has indicated it will not be using the upper reaches of the river, releases will be set to meet only the Nebraska City, NE, and Kansas, City, MO, flow targets during April. While there will not be enough flow above Nebraska City to support navigation, there will be enough water for other purposes including water supply.

Releases will be increased to 28,000 cfs in May as the least terns and piping plovers arrive to begin their nesting season.

"Under the most likely runoff scenario, the navigation season will be shortened 36 days," said Grisoli. A final determination of the navigation season length will be made after the water-in-storage check on July 1.

System storage ended March at 39.7 MAF, up 1.4 MAF during the month. Last year at this time it was 43.9 MAF. The amount of water in the reservoirs is more than 17 MAF below normal for this time of year.

Releases from Gavins Point averaged 13,100 cfs in March, compared to a long-term average of 20,900 cfs. Lewis and Clark Lake will remain near its current elevation of 1206 feet msl during April.

Fort Randall releases averaged 10,400 cfs in March. They will range from 15,000 cfs to 19,000 cfs in April as needed to maintain the level of Lewis and Clark Lake. Lake Francis Case ended March at 1354.6 feet msl and will remain near that level during April.

Lake Oahe rose nearly three feet in March, ending the month at elevation 1582.1 feet msl. It will rise nearly one foot in April, ending the month 24 feet below average. The reservoir is 6 feet lower than last year at this time.

Garrison releases averaged 16,700 cfs during March, gradually reduced from 23,000 to 14,000 cfs during the month. In early April, they will be increased to 16,000 cfs. Lake Sakakawea rose more than one foot in March ending the month at elevation of 1815.6 feet msl. It will rise nearly two feet in April, ending the month 19 feet below average. The reservoir is seven feet lower than last year at this time.

Fort Peck releases averaged 5,700 cfs in March, ranging from 7,000 to 5,000 cfs. They will remain at 5,000 cfs in April. The reservoir climbed more than one foot during March, ending the month at elevation of 2205.5 feet msl. It will rise another foot during April, ending the month 26 feet below average. Last year at this time it was seven feet higher.

The six main stem powerplants generated 456 million kilowatt hours (kWh) of electricity in March, 67 percent of normal.

The forecast for 2004 energy production is 7 billion kWh compared to a normal of 10 billion kWh.

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