Despite moisture, drought maintains grip on Missouri basin

Despite moisture, drought maintains grip on Missouri basin Despite some welcome rain and snow, drought refuses to loosen its grip on most of the upper Missouri River basin. The disappointing runoff means continuing problems for people along the full length of the river.

"Normally, the mountain snowpack peaks around mid-April," said Larry Cieslik, chief of the Water Management office in Omaha. It topped out in the reach above Fort Peck at 76 percent of the normal peak accumulation and 72 percent of normal in the reach from Fort Peck to Garrison.

With below normal mountain snow and normal rainfall the rest of the year, the forecasted annual runoff is 16.5 million acre feet (MAF). Normal runoff is 25.2 MAF. "Under the basic computer simulation, the navigation season will be shortened 61 days, the greatest shortening since the dams was built," said Cieslik. A final determination of the navigation season length will be made after the water-in-storage check on July 1.

Releases from Gavins Point Dam averaged 19,200 cubic feet per second (cfs) in April, compared to a long-term average of 26,400 cfs.

"The Corps will continue to pursue ways to conserve water and mitigate the impacts of the drought throughout the basin," said Brig. Gen. William Grisoli, Northwestern Division engineer. "We will continue to work with our tribal, state, federal and local partners to mitigate impacts to domestic water intakes, cultural resource sites, boat ramps and noxious weeds in the upper basin while continuing to provide water for other authorized purposes."

A "steady release � flow to target" plan will be implemented at Gavins Point this summer to protect endangered species nesting below the dam, meet downstream flow needs and conserve additional water in the reservoirs. A release rate of 23,000 cfs was set May 2. Releases will be reduced on a two-out-of-three day cycle, provided those below 23,000 cfs will meet downstream flow targets. Cycling continued through the third week of May when the first eggs were expected to hatch. The 23,000 cfs release will be maintained until an increase is required to meet downstream purposes.

Compared with last year's regulation, this effort is expected to conserve an additional 500,000 acre feet of water in the three upstream reservoirs. This amounts to about 1 foot of elevation.

Because the reservoirs are low and the navigation industry has indicated it will not be using the reach from Omaha to Sioux City, the two days of reduced releases in the cycle will be set to meet only the minimum service flow target at Omaha and Nebraska City, NE, and Kansas City. While there will not be enough flow above Omaha to support navigation, there will be enough for all the drinking water and powerplant intakes and most river recreation facilities. However, some marinas and boat ramps may experience problems with access to the river until the cycling operation ends in late May.

System storage ended April at 35.3 MAF, down 300,000 acre feet during the month. Last year at this time it was 39.3 MAF. The amount of water in the reservoirs is more than 22 MAF below normal for this time of year.

Gavins Point reservoir will remain level during May at elevation 1206 feet msl.

Fort Randall releases averaged 16,100 cfs in April. They will range from 18,000 cfs to 23,000 cfs in May as needed to maintain the level of Gavins Point reservoir. Fort Randall reservoir ended April at 1356.9 feet msl. It will fall about a foot to elevation 1356 feet msl during May.

Oahe reservoir declined in early April and then rose steadily to benefit the forage fish spawn, ending the month at elevation 1574.7 feet msl. It will remain essentially level in May to continue supporting the fish spawn. The reservoir will end the month 31 feet below average. It is 7 feet lower than last year at this time.

Garrison releases averaged 17,400 cfs during April compared to the long term average of 19,500 cfs. They will remain at about 16,000 to 18,000 cfs in May to maintain the level of Oahe reservoir. When the interior least tern and piping plover nesting season begins in mid-month, a daily peaking pattern will be set to encourage the birds to nest on higher elevation habitat. Garrison reservoir fell two feet in April, ending the month at elevation of 1806.6 feet msl. It will fall a foot in May, ending the month 31 feet below average. The reservoir is 8 feet lower than last year at this time.

Fort Peck releases average 5,200 cfs in April, compared with the long term average of 7,700 cfs. They will remain at 5,500 cfs in May and June to help conserve water during the fish spawn and then will be increased in July to provide additional water for irrigation below the dam. The reservoir was essentially steady during April, ending the month at elevation of 2198.6 feet msl. It will remain essentially level in May, ending the month 35 feet below average. Last year at this time it was 6 feet higher.

The six main stem powerplants generated 508 million kilowatt hours (kWh) of electricity in April, 70 percent of normal. The forecast for 2005 energy production in 5.7 billion kWh, compared to a normal of 10 billion kWh.

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