NEWS

April 6, 2007, BOISE, Idaho -- An unseasonably warm and dry March has decreased snowpack, precipitation, and streamflow forecast averages throughout most of the state.  According to Idaho’s Water Supply Outlook Report issued by the Natural Resources Conservation Service (NRCS), there is little possibility for a near normal runoff season unless April and May bring extremely wet and cold conditions.

“Usually, snow amounts peak on April 1 so it is extremely rare and discouraging to see snow water content decrease during this time.  Dry conditions removed almost all hopes for a near normal runoff season,” said NRCS Hydrologist Phil Morrisey.  “On the positive side, most water users can rely on above average reservoir storage to carry them through this water year.”  

Snowpacks are down 10 to 30 percent from March.  Snowpacks in most basins range from just 40-70 percent of average.  The highest snowpack in the northern Panhandle area is only 80 percent of normal overall.  The lowest areas are the Owyhee, Camas (Fairfield), and Little Wood, all less than 40 percent of average. Snowpack is about half of last year’s totals in most areas south of the Clearwater Basin.  

With earlier than normal runoff, summer streamflow forecasts have decreased significantly from last month, so expect earlier and shorter duration peak flows. Streamflow forecasts range from 50-80 percent of average in most parts of the state, except in the Panhandle and Snake River Basins. Forecasts are best in the Panhandle Region at 85-110 percent of average; they are the lowest in rivers south of the Snake River with forecasts at less than 40 percent.

Relief for many water users will come from carryover storage.  Most of Idaho’s reservoirs are storing above average water, due to last year’s runoff.  Reservoir storage in most basins ranges from 100-175 percent of average.     

The NRCS Snow Survey Program publishes the full report on Idaho’s water supply outlook, including conditions for specific basins, and daily updates. To access it, visit www.id.nrcs.usda.gov/snow/watersupply.  Please contact Ron Abramovich, 208/378-5741 or Phil Morrisey, 208/685-6983 for additional information.