Drought, endangered species cut Missouri River flows

Drought, endangered species cut Missouri River flows Continuing drought conditions combined with endangered and threatened species constraints have led to low flows on the Missouri River.

"Releases from Gavins Point Dam have been curtailed to no more than 25,500 cubic feet per second (cfs) since July 3. This is due to concerns that higher releases may negatively impact the nests and unfledged chicks of the interior least terns and piping plovers that exist below Fort Randall and Gavins Point Dams. Because of lower-than-normal tributary flow, the 25,500 cfs release from Gavins Point is not sufficient to meet service flow targets from Nebraska City to the mouth," said Larry Cieslik, chief of the Missouri River Basin Water Management Division in Omaha.

The corps had planned to move tern and plover nests to higher elevations, and/or collect tern and plover eggs and chicks for captive rearing, as necessary to allow increased releases from Gavins Point to meet downstream water needs. In early July, the Fish and Wildlife Service notified the corps that collecting tern and plover eggs and chicks for captive rearing was not acceptable, given the constraints of the November 2000 Missouri River Biological Opinion.

"As soon as the remaining eggs and chicks with the potential to produce fledged birds have fledged, or are no longer at-risk below Fort Randall and Gavins Point, and after coordination with the U.S. Fish and Wildlife Service, we will increase flows to meet minimum service levels." said Cieslik. "Current projections are that releases may be increased some time this week." The closing date for navigation will remain Dec. 1.

July's runoff was 2 million acre feet (MAF), 62 percent of normal. "Our runoff forecast above Sioux City for 2002 has been reduced to 1705 MAF due to the persistent dry conditions," said Cieslik. Annual runoff is normally 2502 MAF.

System storage ended the month at 48.3 MAF. Last year at this time it was 54.7 MAF. The amount of water in the reserviors is more than 13 MAF lower than average, putting the three largest main stem lakes 12-19 feet below normal.

Gavins Point releases averaged 25,500 cfs during July, compared to a normal of 34,100 cfs. Lewis and Clark Lake, which is near elevation1205.2 feet above mean sea level (msl), will gradually rise to elevation 1206 feet msl during August.

Fort Randall releases averaged 26,300 cfs in July. They will range from 26,000 to 30,000 cfs in August as needed to maintain Lewis and Clark near its desired elevation. Lake Francis Case rose one foot during July ending the month at elevation 1355.4 feet msl. The lake will remain near its current elevation through the summer.

Lake Oahe dropped nearly two feet during July, ending the month at elevation 1590.8 feet msl. It will drop more than two feet during August, ending the month almost 18 feet below normal. The lake is 18 feet lower than last year at this time.

Garrison releases averaged 20,800 cfs during June. They will remain at 21,000 cfs during August, before dropping to 14,000 cfs in September. Lake Sakakawea ended July at 1831.4 feet msl. It will drop less than two feet in August, ending the month 12 feet below normal. The lake is 3 feet lower than last year at this time.

Fort Peck releases averaged 8,600 cfs during July. They were reduced to 7,000 cfs early in July due to runoff on the Milk River. They returned to 9,000 cfs on July 8, and will remain at that rate during August. Releases will be reduced to 5,000 cfs in September. The lake ended the month at elevation 2219.8 feet msl. It will fall more than one foot during August, ending the month 19 feet below normal. Last year at this time it was 3.5 feet higher.

The six main stem power plants generated 828 million kilowatt hours (kWh) of electricity in July, 93 percent of normal. Given the forecasted inflow this year, energy production should be 7.4 billion kWh compared to a normal of 10.2 billion kWh.

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