News Release
| Release Number: | 08-013 |
| Dated: | 8/6/2008 |
| Contact: | Paul T Johnston, 402-697-2552 |
OMAHA – The water levels of the three biggest Missouri River reservoirs rose from nearly 11 feet to almost 18 feet since April 1 due to the combination of a normal mountain snowpack, rain over much of the upper basin and flood-producing rain in the lower basin.
“The big reservoirs have been hit hard by eight consecutive years of drought in the upper basin. The near normal runoff along with the low releases for downstream flood control this spring and early summer provided significant recovery this year,” said Larry Murphy of the Water Management office here. “The reservoir system has recovered about a third of the storage lost during this prolonged drought. We will continue to conserve water to provide a full recovery for all authorized purposes.”
Runoff for 2008 is forecast to total 26.3million acre feet (MAF), an increase of 1.3 MAF from last month’s forecast. The storage in the reservoirs increased nearly 2 MAF in July, ending at 45.8 MAF.
Because reservoir storage remains lower than normal, only minimum service flows are being provided this year for navigation and other downstream uses. Based on the storage on July 1, the commercial navigation season will be shortened by 30 days. The last day of navigation flow support will be Oct. 31 at the mouth of the river; just north of St. Louis. The normal navigation season ends Dec.1.
Last year, the average release from the system of reservoirs set an all-time record low due to drought conservation measures and high downstream tributary inflow. Corps officials expect that releases will continue to be much-below average this year as efforts continue to help reduce downstream flooding and conserve water during this extended drought.
Gavins Point releases in August are expected to average 20,000 cfs, compared to the average 34,900 cfs. Releases will be adjusted as necessary if high downstream flows pose risks of lowland flooding.
Fort Randall releases averaged 15,600 cfs in July. They will be adjusted in August as necessary to maintain Gavins Point reservoir near its desired elevation.
Big Bend reservoir will remain in its normal range of 1420 to 1421 feet. Releases will be adjusted to meet hydropower needs.
Oahe reservoir rose 1.4 feet in July and 10.8 feet since April 1, ending at elevation 1594 feet msl. Releases in August will average 9,800 cfs, compared to the long-term average of 32,700 cfs. The reservoir begins its normal mid-summer decline this month, falling less than a foot to end August at elevation 1593.4 feet msl. That is 8.4 feet below its normal elevation. The reservoir is currently nearly 13 feet higher than it was last year at this time.
Garrison reservoir rose 5.8 feet in July and 17.8 feet since April 1, ending at elevation 1825.4 feet. Releases averaged 13,600 cfs during July compared to the long-term average of 24,500 cfs. They will average 14,000 cfs during August, compared to the average of 24,300 cfs. The reservoir is expected to remain essentially level this month, ending at 1825.6 feet, 12.3 feet below normal. The reservoir is currently 11 feet higher than last year at this time.
Fort Peck reservoir rose 1.7 feet in July and 10.8 feet since April 1, ending at elevation 2210 feet msl. Releases averaged 6,800 cfs, compared to the long-term average of 10,200 cfs. They will average 7,000 cfs this month, compared to the long-term average of 10,100 cfs. The reservoir will rise nearly a foot, ending the month at elevation 2209.2 feet, 23.6 feet below normal. It is currently 6.6 feet higher than last year at this time.
The six main stem power plants generated a record low 446 million kilowatt hours (kWh) of electricity in July, only 46 percent of normal because of lower pool levels and reduced releases from the dams. Total energy production for 2008 is forecasted to be 5 billion kWh, compared to the average of 10 billion kWh.