Tuesday - U.S. Drought Monitor Forum

1. Drought in Managed Systems—Snake River Plain
Presented by David Hoekema
Water Supply Committee Meeting
Date: April 14th, 2015

2. Idaho Water Supply Committee
Idaho Department of Water Resources (IDWR) hosts meetings
• Meets every 2nd week of the month (Jan-April)
• April 1st marks the beginning of the Irrigation Season and Peak
Snowpack.
• Membership
- IDWR, Homeland Security, Idaho Department of
Agriculture, Idaho F&G, USBR, NWS, NRCS, USACE,
USGS, USFS, Farm Service Agency, IPCo
• Responsibilities
- Track drought, coordinate with agencies, provide public
information

3. Defining Drought in the West
• Climate (Rain, Temp, and SWE)
• Warm and Dry Winter
• Unusual August rains (PDSI, SPI, etc.)
• Storage Supplies vs. Irrigated Regions
• USBR Hydromet
• Supply vs. Demand
• Groundwater (responds to climate and management)
• Managed conjunctively
• Managed thru mitigation (rental pools)

7. 2011
2013

8. 2011
2013

11. Eastern Snake River BasinWestern Snake River Basin
Payette River
Boise River

12. Eastern Snake River Basin
Western Snake River Basin

13. 0
5
10
15
20
25
30
1-Oct 1-Nov 1-Dec 1-Jan 1-Feb1-Mar 1-Apr 1-May 1-Jun
SnowWaterEquivalent[SWE,in]
North Fork Composite
[Long Valley, Bear Basin, Squaw Flat,
Burndage Reservoir, Secesh Summit, Big
Creek]
Median 1981-2010 2013 2014 2015
0
5
10
15
20
25
30
SnowWaterEquivalent[SWE,
in]
Long Valley-Snotel
Elevation 4890 ft
Median 1981-2010 2013 2014 2015
60%
42%

17. 0
2,000,000
4,000,000
6,000,000
8,000,000
10,000,000
12,000,000
14,000,000
16,000,000
18,000,000
20,000,000
CumulativeStorageChange(acre-feet)
CumulativeVolume Change of Water Stored Within ESPA
Water Budget Volume Change ESPAM1.1 Simultaneous Volume Change
Declines in the eastern Snake Plain aquifer