Review of the 2009 Snowmelt and Rain Streamflow Forecasts & Snow Survey Advisory Team Ron Abramovich, Hydrologist Water Supply Specialist USDA Natural Resources Conservation Service NRCS Snow Survey Office Boise Idaho Sponsored by: The Climatic Impacts Group at the University of Washington, the Idaho EPSoR Climate and Water Project and Idaho Department of Water Resources October 22,2009 Idaho Climate and Water Resource Forecast for the 2010 Water Year

2009 April 1 NRCS Predicted Flows 2009 Observed April-July Flows

Few fires Vegetation

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Unlike in 2007 when normal precipitation changed to below normal precipitation after Jan 15

Salmon River Canal Company Reservoir Reading September 30, 2009 Water was shut off at 5:00 pm Sunday evening. Results from the April 1 Water Forecast Meeting at 50% Efficiency: 90% Chance for.471; 70% Chance for.478; 50% Chance for.658; 30% Chance for.744; 10% Chance for The Board of Directors set a ninth Allotment totaling 1.00 acre feet per share.

KAF

Full Analysis :

Snowpack and Streamflow Needed for 2010 Season Analysis is based on September 30, 2009 reservoir storage Current storage is projected for March 31, 2009 based on near average changes Required streamflow needed to meet surface water irrigation demand is based on known demand levels from the Surface Water Supply Index (SWSI) Snowpack needed for 2010 is determined by looking at years when there was a good snowpack and ‘Worst Case Scenario’ for runoff. Some were: in middle of consecutive dry years low soil moisture, and / or groundwater levels dry spring 1989 is Good Example of Poor Runoff Year – snowpack was near average, but runoff was below to much below average due to dry spring and cumulative drought effects.

Secech Summit SNOTEL March 2009

Our mission to monitor and inventory mountain snow to produce streamflow forecasts has NOT changed. However, use of our data and products has increased with need to manage and use water efficiently for numerous and often competing uses. Challenges and Opportunities Facing the Idaho NRCS Snow Survey Program

Configuration of Advisory Team 45 on contact list includes: hydropower, recreation, Ground and Surface Water Users, Universities, USF&W, Risk Management, FSA, FS, BLM, USBR, IDWR, INL, ID Homeland Security, Soil Commission, Conservation District, WRCC, Water Council, Staffers and NRCS Data Collection Issues Automation of Sites – Need to Coordinate Inform Others of Request for New Sites Manual Snow Course Network Utilize Universities to Assist with Research and Implementation. If they don’t know our needs, they cant help. Meta Data Snowmelt Timing Runoff Products Watershed Assessment Past and Current Work / Research Needs

Snowmelt Runoff Model (SRM) Work with University of Idaho since 2002 to enhance the SRM, Will run Little Lost River basin this year Other calibrated basins, challenge is how to implement: NF Clearwater, SF Boise and Big Wood rivers, Analysis of Time Lag in Days from Onset of Snowmelt to Peak Streamflow Working with NRCS Spokane Engineering Team Water Supply – Analysis, Research and Implementation Snowmelt Timing Runoff Products

Prediction of Recession Flows Simpler to run than models Tools that have worked in past include: Number of Days or Volume Above Certain CFS Level Chance of Future Peak Flows Low Flow Forecasts Recession Forecasts Number of Days for Flow to Reach Certain Level Key Indicators Water Supply – Analysis, Research and Implementation Snowmelt Timing Runoff Products

Analysis and Product Development of Soil Moisture / Temperature Data - 50 RAWS and 40 SNOTEL sites. Collaboration with Others 50-Year Water Plan for Treasure Valley Lower Boise Comprehensive Plan Snow Survey Advisory Team Meeting EPSCoR – Water Resources in Changing Climate Water Supply – Analysis, Research and Implementation