OMAHA, NE - The U.S. Army Corps of Engineers (Corps) Missouri River Basin Water Management Division will hold five public meetings next week to update stakeholders on the planned operation of the Missouri River Mainstem Reservoir System. The public meetings will include a presentation from the Corps regarding current basin conditions and plans for operating the reservoir system in 2017, followed by a question and answer session. There will also be an opportunity for members of the public to speak one-on-one with Corps officials before and after the meetings.
The reservoir system began the 2017 runoff season at the base of the annual flood control pool, providing the full 16.3 million acre-feet (MAF) of flood control storage. The total volume of water stored in the reservoir system is currently 58.5 MAF. “System storage currently occupies 2.4 MAF of the 16.3 MAF flood control zone,” said Jody Farhat, chief of the Corps of Engineers’ (Corps) Missouri River Basin Water Management Division. “Approximately 85 percent of the flood control storage remains available to capture runoff from the spring rainfall and mountain snowmelt.” All significant plains snowpack has melted.
The 2017 runoff forecast in the Missouri River Basin above Sioux City, Iowa, is 29.4 MAF, 116 percent of normal. Runoff in March was 3.2 MAF, 111 percent of normal. As of April 3, the mountain snowpack was 92 percent of average in the reach above Fort Peck and 135 percent of average in the reach from Fort Peck to Garrison. Normally the mountain snowpack peaks in mid-April. View the mountain snowpack graphic here: http://www.nwd-mr.usace.army.mil/rcc/reports/snow.pdf.
In mid-March, Gavins Point releases were increased from 17,000 cfs to 26,000 cfs in support of the Missouri River navigation season which began Apr. 1 near St. Louis, Mo. Navigation flow support for the start of the navigation season was at full service levels, which is designed to provide a 9-feet deep navigation channel. “Because of the higher than normal runoff forecast, releases from Gavins Point will be increased in mid-April to a level slightly above full service to provide beneficial use of the excess runoff while reducing flood risk,” said Farhat.
“Flood risk reduction remains a primary consideration as we progress through 2017. While the risk of widespread flooding from upper basin runoff is low this year, floods can and will occur as a result of spring and summer thunderstorms, particularly along the lower Missouri River,” Farhat added. When possible, the Corps will utilize the available flood control space in the reservoirs to limit downstream river levels; however, the ability to significantly reduce flood risk along the lower Missouri River diminishes at locations further downstream due to the large uncontrolled drainage area and the travel time from Gavins Point Dam.
Weekly updates on plains and mountain snowpack conditions, reservoir levels and other topics of interest can be viewed here: http://www.nwd-mr.usace.army.mil/rcc/reports/pdfs/weeklyupdate.pdf.
Steady to rising reservoir levels during the forage fish spawn at the three large upper reservoirs, Fort Peck, Garrison and Oahe, are preferred, but may be difficult to accomplish this spring depending on the timing and distribution of runoff in the Missouri River basin during the coming weeks. If the runoff is not sufficient to keep all three reservoirs rising, the Corps will adjust releases to result in a steady to rising pool at Fort Peck and Oahe this year. The forage fish spawn generally occurs from early April through mid-June.
Spring Public Meetings
Times and locations for next week’s five public meetings are listed below.
Tuesday, April 11 – Smithville, MO
- Start time: 11 a.m. (CDT)
- Jerry Litton Visitor Center
- 16311 DD Hwy
Tuesday, April 11 – Council Bluffs, IA
- Start time: 5 p.m. (CDT)
- Western Historic Trails Center
- 3434 Richard Downing Ave.
Wednesday, April 12 – Fort Peck, MT
- Start time: 11 a.m. (MDT)
- Fort Peck State Fish Hatchery
- 277 Montana Highway 117
Wednesday, April 12 – Bismarck, ND
- Start time: 6 p.m. (CDT)
- Bismarck State College, National Energy Center of Excellence (NECE), Bldg. 15, Rm 431
- 1200 Schafer Street
Thursday, April 13 – Pierre, SD
- Start time: 10 a.m. (CDT)
- Ramkota Hotel
- 920 W Sioux Ave.
Reservoir Forecasts
Gavins Point Dam releases averaged 20,500 cubic feet per second (cfs) during March. Releases are currently on 26,000 and will be increased to approximately 30,000 cfs in mid-April as flow support is increased above full-service. The Gavins Point reservoir ended March at elevation 1206.6 feet and will remain near 1206.0 feet during April.
Fort Randall Dam releases averaged 18,200 cfs in March. Releases will be adjusted as necessary to maintain the desired reservoir elevation at Gavins Point Dam. The reservoir ended March at elevation 1355.0 feet, rising 1.6 feet during the month.
Big Bend Dam releases averaged 18,200 cfs in March. Releases are expected to average 27,400 cfs this month. The reservoir will remain near its normal elevation of 1420.0 feet during April.
Oahe Dam releases averaged 19,000 cfs during March. Releases are expected to average 27,400 cfs in April. The reservoir ended March at elevation 1607.8 feet, falling 0.2 feet during the month. The reservoir level is expected to rise during April due to increases in Garrison releases and spring rains, ending the month near elevation 1608.7 feet.
Garrison Dam releases averaged 14,000 cfs during the month of March. Releases were increased from 14,000 cfs to 20,000 cfs at the end of March and will continue to be stepped up to 28,000 cfs during early April. Garrison reservoir ended March at elevation 1841.4 feet, rising 3.1 feet during the month. The reservoir level is expected remain near elevation 1841.5 during April.
Fort Peck Dam releases averaged 4,700 cfs during March. Releases are forecast to average 6,500 cfs during April. The reservoir ended March at elevation 2236.2 feet, rising 1.3 feet during the month. The reservoir is expected to rise during April ending the month near elevation 2237.3 feet.
The forecast reservoir releases and elevations discussed above are not definitive. Additional precipitation, lack of precipitation or other circumstances could cause adjustments to the reservoir release rates.
The six mainstem power plants generated 582 million kWh of electricity in March. Typical energy generation for March is 641 million kWh. The power plants are projected to generate 10.3 billion kWh of electricity this year, compared to the long-term average of 9.3 billion kWh.
To view the detailed three-week release forecast for the mainstem dams, go to http://www.nwd-mr.usace.army.mil/rcc/reports/twregfcast.pdf.
MISSOURI RIVER MAINSTEM RESERVOIR DATA
|
Pool Elevation
(feet above mean sea level)
|
Water in Storage
(1,000 acre-feet)
|
|
On March 31
|
Change in March
|
On March 31
|
% of 1967-2016 Average
|
Change in March
|
Fort Peck
|
2236.2
|
+1.3
|
15,252
|
109
|
+269
|
Garrison
|
1841.4
|
+3.1
|
18,999
|
112
|
+1,002
|
Oahe
|
1607.8
|
-0.2
|
18,753
|
105
|
-63
|
Big Bend
|
1420.0
|
-0.7
|
1,631
|
95
|
-44
|
Fort Randall
|
1355.0
|
+1.6
|
3,409
|
92
|
+137
|
Gavins Point
|
1206.6
|
+0.1
|
340
|
93
|
+2
|
|
|
Total
|
58,384
|
107
|
+1,303
|
WATER RELEASES AND ENERGY GENERATION FOR MARCH
|
Average Release
(1,000 cfs)
|
Releases
(1,000 acre-feet)
|
Generation
(Million kWh)
|
Fort Peck
|
4.7
|
291
|
43
|
Garrison
|
14.0
|
860
|
134
|
Oahe
|
19.0
|
1,169
|
177
|
Big Bend
|
18.2
|
1,120
|
69
|
Fort Randall
|
18.2
|
1,121
|
108
|
Gavins Point
|
20.5
|
1,262
|
50
|
|
|
Total
|
582
|