ron abramovich, hydrologist, water supply specialist usda natural resources conservation service...
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• Ron Abramovich, Hydrologist, Water Supply Specialist• USDA Natural Resources Conservation Service (NRCS)• Snow Survey Office Boise Idaho • http://www.id.nrcs.usda.gov/snow/
Idaho's Climate and Water Resource Forecast for the 2008 Water Year
Sponsored by: The Climatic Impacts Group at the University of Washington and the Idaho
Department of Water Resources
The Good, The Bad, The Ugly…. What Happened?????
News Releases - 2007
Date News Release Title
January 8, 2007 Idaho Water Supply Outlook is Promising
February 6, 2007 Dry Conditions Put Damper on Idaho’s Water Supply Outlook
March 8, 2007 Recent Precipitation Rejuvenates Idaho's Water Supply
April 6, 2007 Idaho's Water Supply Outlook is Disappointing
June 5, 2007 Winter Too Short, Summer Too Early
The Good, The Bad, The Ugly…. What Happened?????
News Releases - 2007
Date News Release Title
January 8, 2007 Idaho Water Supply Outlook is Promising
February 6, 2007 Dry Conditions Put Damper on Idaho’s Water Supply Outlook
March 8, 2007 Recent Precipitation Rejuvenates Idaho's Water Supply
April 6, 2007 Idaho's Water Supply Outlook is Disappointing
June 5, 2007 Winter Too Short, Summer Too Early
The Good, The Bad, The Ugly…. What Happened?????
News Releases - 2007
Date News Release Title
January 8, 2007 Idaho Water Supply Outlook is Promising
February 6, 2007 Dry Conditions Put Damper on Idaho’s Water Supply Outlook
March 8, 2007 Recent Precipitation Rejuvenates Idaho's Water Supply
April 6, 2007 Idaho's Water Supply Outlook is Disappointing
June 5, 2007 Winter Too Short, Summer Too Early
The Good, The Bad, The Ugly…. What Happened?????
News Releases - 2007
Date News Release Title
January 8, 2007 Idaho Water Supply Outlook is Promising
February 6, 2007 Dry Conditions Put Damper on Idaho’s Water Supply Outlook
March 8, 2007 Recent Precipitation Rejuvenates Idaho's Water Supply
April 6, 2007 Idaho's Water Supply Outlook is Disappointing
May 6, 2007 Idaho's Ever Changing Water Supply
June 5, 2007 Winter Too Short, Summer Too Early
The Good, The Bad, The Ugly…. What Happened?????
Bear Mountain SNOTEL Site, elevation 5,400 feet, 24-hour precipitation Nov 6-7, 2006 8am to 8am was 9.4 inches. Amount received midnight to midnight on Nov 6 was 8.4 inches. In addition, the snow pillow had 2.9 inches of snow water on Nov 4 of which all melted by Nov 8. Snow water melt on Nov 6 was 1.4 inches for a combined snow and rain runoff total of 10.8 inches. Previous 24-hour precipitation record was 6.9 inches on Nov 10, 1990 with 2.6 inches of melt occurring over several days.
2007 Snow and Precipitation
2007 Snow and Precipitation
2007 Snow and Precipitation
2007 Snow and Precipitation
May – September 2007 Idaho SNOTEL Precipitation
Mud Flat, Owyhee Basin2nd driest May-Sep in 26 years2.0” of Precipitation, 44% Avg
Garfield, Little Wood Basin4th driest May-Sep in 26 years3.7” of Precipitation, 50% Avg
Atlanta, Boise Basin3rd driest May-Sep in 26 years3.7” of Precipitation, 45% Avg
Secesh, Payette/Salmon Basin4th driest May-Sep in 26 years6.8” of Precipitation, 67% Avg
Island Park, Henrys Fork Basin2nd driest May-Sep in 26 years4.2” of Precipitation, 44% Avg
Shanghi, N.F. Clearwater Basin2nd driest May-Sep in 26 years6.9” of Precipitation, 51% Avg
Mosquito, Couer D’ Alene BasinDRIEST May-Sep in 26 years4.5” of Precipitation, 39% Avg
Schweitzer Basin, Pend Oreille Basin2nd driest May-Sep in 26 years7.5” of Precipitation, 61% Avg
March – July 2007 SNOTEL Precipitation Exceedances
Black Bear, MTPrecipitation = 8.5”> 99% exceedance
Meadow Lake, IDPrecipitation = 11.9”80-90% exceedance
Island Park, IDPrecipitation = 4.1”99% exceedance
Schweitzer Saddle, IDPrecipitation = 13.3”90-95% exceedance
Big Creek Summit, IDPrecipitation = 7.3”
95-99% exceedance
Hilts Creek, IDPrecipitation = 5.7”
80-90% exceedance
Hot March
2007 Streamflow Forecasts
What Happened?????
Water Year Precip is Avg
0
50
100
150
200
250
Per
cen
t o
f A
vera
ge
Oct Dec Feb Apr Jun Aug
Mountain PrecipitationCLEARWATER RIVER BASIN
Monthly Year-to-date
Mountain Snowpack (inches)CLEARWATER RIVER BASIN
0
10
20
30
40
50
60
70
Jan Feb Mar Apr May Jun
Wat
er C
on
ten
t In
ches
.
Current Average
Maximum Minimum
<>
Buffalo Creek is usually one of the streams that peaks the latest from snowmelt in the upper Snake River headwaters. Streamflow record starts in 1966.
Date and CFS Peak Flow in 2007:
May 14 1860 cfs peak
May 20 1850 cfs peak
June 6 1860 cfs peak
Peak flow of 1860 cfs in 2007 nearly tied the previous lowest peak of 1850 cfs in 1992 AND earliest peak recorded was May 14, 1994, 2920 cfs.
2007 had two peak of 1860 on May 20 and 3rd peak of 1860 on June 6.
Highest cfs peak --- 6540 cfs on June 9, 1981
Latest cfs peak --- July 10 1983, 3940 cfs
The 2nd peak flow in 2007 had less volume associated with it when compared to first peak. Third peak of 1650 cfs occurred on June 17. All are based on provisional data.
Snowpack Needed for 2008 Season
Analysis is Based on September 30, 2007 Reservoir Storage
•Current Storage is Projected for March 31, 2008 Estimated Levels
•Required Streamflow Needed to Meet Irrigation Agriculture Demand Based on SWSIs (Surface Water Supply Index)
•Snowpack Needed for 2008 is Determined by Looking at Years When We had a Good Snowpack and Worst Case Scenarios Leading into or during the Snowmelt Runoff Season:
• Low Soil Moisture
• Low Groundwater Levels
• Dry Spring
• Cumulative Drought Effects
• 1989 is Good Example of Bad Runoff Year – snowpack was about average, but runoff was below to much below average due to dry spring and consecutive of drought years.
2007 Castle RockFire Location
SNOTEL site
Miles
0 2 4 8
Level
North
East
South
West
ASPECT
2007 Castle Rock FireBurned Area by Aspect
Acres Burned
Level:North:East: South:West:
62957,56864,82245,60141,880
Miles
0 1 2 4
2007 Castle Rock FireBurned Area by Elevation
ELEVATION
Acres Burned
5859 - 6000
6000 - 7000
7000 - 8000
8000 – 9000
9000 - 9189
5859 – 6000:
6000 – 7000:
7000 – 8000:
8000 – 9000:
9000 – 9189:
1,012
53,110
108,431
48,545
521
Miles
0 1 2 4
Elevation (feet)
Low = 5859
High = 9189
2007 Castle Rock FireTopography
view looking north
2007 Runoff based increased Runoff Coefficients in the Streamflow Model after the 2007 Castle Rock Fire
2006 Runoff based increased Runoff Coefficients in the Streamflow Model after the 2007 Castle Rock Fire
Questions – Comments – CorrectionsThis presentation and Snowpack Needed for 2008 for Other Basins is available on
the Idaho Snow Survey Web Page at: http://www.id.nrcs.usda.gov/snow/
• Ron Abramovich, Water Supply Specialist
• USDA NRCS Snow Survey, Boise Idaho • [email protected]