to dismal start
Idaho snow facts
snow produces more than 75 percent of Idaho’s water. The other 25
percent comes from spring and summer rains.
National Resources Conservation Service, based in Boise, uses 78
automated SNOTEL stations and 100 manually measured snow courses to
collect information about the amount of snow and its water content.
oldest sites began monitoring in the 1990s in Yellowstone National Park
and northern Idaho.
amount of new snowfall it takes to equal 1 inch of water is about 10
deepest snow ever measured in Idaho was 23.5 feet at Lost Lake in
Shoshone County on April 1, 1974.
greatest amount of water ever measured in an Idaho snowpack was 9.75
feet at Bear Mountain in Bonner County on May 1, 1974.
two snowiest places, receiving more than 50 feet of snow each year,
are Bear Mountain in Bonner County and Lost Lake in Clearwater
least snowy place is Grand View in Owyhee County, recieving 7.2
inches of snow each year.
wettest winters on record in Idaho are 1997 in the Upper Snake River
Basin and 1965 and 1974 in Central and Northern Idaho.
driest winters on record in Idaho are 2001 in Northern Idaho and
1977 and 1992 in Southern Idaho.
Express Staff Writer
most of the Eastern United States has wallowed in rain and snow this
fall, Idaho and most of the Pacific Northwest are severely parched and
without a significant quenching in sight.
to the Natural Resources Conservation Service the lack of summer and
fall precipitation has taken its toll on Idaho’s water supply, and the
new water year is off to a poor start. October precipitation was far
below normal, with the lowest amount at 25 percent of average across
western and northern Idaho and 87 percent of average in Southeast Idaho’s
Bear River basin.
Idaho rivers are at or near record low flows for early November,
including the Weiser, Bruneau, South Fork Payette, Little Wood, Portneuf
and Lower Bear rivers.
the Big Wood River in Hailey was about 40 cubic feet per second higher
than average for this time of year.
the state’s reservoirs are also extremely low, and Magic, Mackay,
Salmon Falls and Oakley reservoirs are nearly empty.
news is that several wet years are needed to fill reservoirs and to
recharge soil moisture, springs and wetlands, said Ron Abramovich, NRCS
water supply specialist.
news is a weak to moderate El Nino is forecast to sear weather patterns
in the Northwest this winter.
took three years of below normal snowfall to get to this critical point
in the drought, and it may take several years to get us out," said
Abramovich. "Near normal or better snowpacks are needed by April 1
to provide adequate irrigation water next summer."
said that, because of groundwater deficiencies, a 113 percent of average
snowpack is needed above Palisades Reservoir on the Snake River just to
produce a 90 percent of average stream flow.
minimum snowpack percentage needed is based on observed runoff for other
years that followed droughts and the inefficiency of the snow to produce
streamflow," said Abramovich. "For example, a snowpack of 96
percent on April 1, 1989, in the Big Lost basin resulted in a summer
stream flow of only 40 percent of average."
El Nino patterns have favored wetter-than-normal winters in the
Southwest and drier than normal winters in the Pacific Northwest,
explained that El Nino represents a shift in the odds in obtaining
various amounts of winter precipitation in Idaho. For the Snake River
basin, El Nino events since 1934 have resulted in streamflows greater
than 90 percent of average 12 out of 21 years.