Montana, Idaho Drought to Continue…. Could Harvesting Rain Help?
by Doug Pushard

Bad News

Low snowpack levels currently being recorded through the end of January 2005 across North Central Idaho and western Montana could forecast water shortages later again this summer.

Information from the Missoula office of the National Weather Service show snow that has fallen from October through the last week in January is ranging between 52 and 71 percent of normal. Many of the snowpack monitoring sites operated by the Natural Resource Conservation Service are setting new record low values for the end of January.

Idaho hydrologists say the state's 2005 outlook for water is 'deteriorating.'

data for January 6- February 3, 2005

Ron Nova, general manager of Schweitzer Mountain Resort above Sandpoint in northern Idaho, said Wednesday that this winter is already one of the worst on record. Ron, the service's water-supply specialist, says the likelihood is growing that the February through April period will be warmer than average, making chances of a seventh year of drought greater in a state where lack of moisture has intensified the water drought situation.

If snowpack trends continue to remain the same or decline further, according to a NWS report, streamflows will be at very low flows in the summer of 2005. Low streamflows could lead to some possible water shortages across western Montana and North Central Idaho.

Could rain water harvesting help alleviate some of the short term effects of less snowpack? Since one inch of rain falling on a one square foot of surface equaling .623 gallons of water, an average 1,500 square foot area could collect up to 934 gallons per inch of rain. With average rainfalls in Idaho of 12 – 20 inches and averages of 10 – 16 inches in Montana that is nearly 10,000 gallons of water per average-sized house that is harvestable. Plus, a great advantage of rain water harvesting is that the water can be captured all year round for FREE and then used later (i.e. in the summer months when it is drier).

Local Info

Some area utilities and communities have set up programs to educate locals in using this old fashion approach to dealing with the ongoing drought. A few of these include:

Rainwater Harvesting for Montana – A primer published by Montana State University.
A Water Conservation Handbook – A comprehensive water conservation manual with a chapter on rainwater harvesting published by Pullman-Moscow Water Resource Committee.
Water Conservation Brochure - A short brochure discussing the need to conserve water and includes a photo of a local rain barrel system published by City of Moscow, Idaho.

USGS Data

This year the U.S. Geological Survey reported that the Colorado River, which supplies water to seven U.S. states and Mexico, may be in its worst drought in 500 years (http://water.usgs.gov/pubs/fs/2004/3062/). The federal Drought Monitor (http://www.drought.unl.edu/risk/us/usimpacts.htm) currently shows that every Western state remains in drought at varying levels of severity. At the same time, record population growth continues – Census Bureau figures revealed that arid Western states like Nevada and Arizona lead the nation in population growth, increasing 66 percent and 40 percent, respectively, between 1990 and 2000. Over the same period, the states of Washington, Oregon, Idaho, Utah, California, New Mexico and Texas experienced double-digit growth.

Although harvesting rainwater will not solve the growth or drought problem, it seems it could help lessen its impact.