United States Department of Agriculture
Natural Resources Conservation Service		 Montana Go to Accessibility Information
Skip to Page Content





Summer Streamflows Forecast to Be Well Below Average

June 6, 2007

For More Information:
Roy Kaiser, 406-587-6991

Bozeman-- Remaining mountain snowpack statewide as measured by the Natural Resources Conservation Service (NRCS) on June 1 was 40 percent of average and 60 percent of snowpack measured on that date last year.

Snowpack west of the Continental Divide was 56 percent of average and 72 percent of last year. Snowpack east of the Divide was 32 percent of average and 64 percent of last year. Mountain precipitation received during May in the Columbia River Basin was 98 percent of average; Missouri River Basin was 90 percent of average; and Yellowstone River Basin was 89 percent of average.

“Most rivers and streams have reached their primary snowmelt peaks for this year and will not crest higher without additional precipitation,” said Roy Kaiser, NRCS water supply specialist.

Streamflow forecasts statewide average 43 to 57 percent and are generally near or below those of last year. West of the Continental Divide, streamflow forecasts average 57 to 68 percent and east of the Divide average 33 to 48 percent.

“June and July rain will be the key to late spring and summer flows,” said Kaiser. “Unregulated streams will have the most adverse affects without good rainfall.”

Below are averaged river basin streamflow forecast summaries for the period June 1 through July 31. These forecasts do not account for well below average (70 percent or less) or well above average (130 percent of more) snowmelt or rain.

Streamflow Forecasts
River Basin June-July This Year Percent of Average June-July Last Year Percent of Average
Columbia 57 to 68 63 to 73
--Kootenai 74 to 86 64 to 76
--Flathead 67 to 75 66 to 76
--Upper Clark Fork 54 to 68 54 to 66
--Bitterroot 37 to 47 69 to 79
--Lower Clark Fork 48 to 57 67 to 76
Missouri 30 to 47 50 to 71
--Jefferson 16 to 35 48 to 68
--Madison 45 to 53 77 to 86
--Gallatin 42 to 53 69 to 82
--Missouri Mainstem 28 to 39 73 to 82
--Smith-Judith-Musselshell 25 to 44 39 to 66
--Sun-Teton-Marias 41 to 57 35 to 53
St. Mary 69 to 86 67 to 84
Yellowstone 40 to 54 57 to 70
--Upper Yellowstone 38 to 53 66 to 79
--Lower Yellowstone 44 to 57 44 to 57
Statewide 43 to 57 56 to 72

NOTE: The May-July Last Year Percent of Average column above is what was forecast last year on June 1, not what actually occurred.

The NRCS snow survey and water supply forecast program provides detailed snow water content, streamflow forecast, and climate information for Montana by evaluating data collected by a series of manual and automated snow survey sites located in the mountains of the state. Visit the NRCS website at http://www.mt.nrcs.usda.gov/snow/ for more information.

--end--

"The U.S. Department of Agriculture (USDA) prohibits discrimination in all its programs and activities on the basis of race, color, national origin, age, disability, and where applicable, sex, marital status, familial status, parental status, religion, sexual orientation, genetic information, political beliefs, reprisal, or because all or a part of an individual's income is derived from any public assistance program. (Not all prohibited bases apply to all programs.) Persons with disabilities who require alternative means for communication of program information (Braille, large print, audiotape, etc.) should contact USDA's TARGET Center at (202) 720-2600 (voice and TDD). To file a complaint of discrimination write to USDA, Director, Office of Civil Rights, 1400 Independence Avenue, S.W., Washington, D.C. 20250-9410 or call (800) 795-3272 (voice) or (202) 720-6382 (TDD). USDA is an equal opportunity provider and employer."