1. 2007 Water Supply Summary Idaho Department of Water Resources

2. Atmospheric Sources and Sinks Streamflow River Basin Review: –Salmon –Big Wood –Snake –Boise –Bear and other Basins County Drought Declarations

3. UNIQUE APSECTS OF 2007 Below average snowpack followed by melting and runoff a month earlier than normal. Irrigation demand about the same as 2006 with similar above average temperatures in July and August, and below normal summer precipitation.

19. Precipitation was 66% of average in 2007

21. 2007 Streamflow

23. 2007 April-July Runoff Snake R. nr Heise* 1923 kaf 58 % of avg 6 th / 97 years Big Wood at Hailey 102 45 % 12 / 92 Boise R. nr Boise* 668 48 % 11 / 112 Payette at HSB* 921 57 % 13 / 88 Weiser nr Weiser 150 36 % 5 / 65 Snake at Weiser 2485 45 % 10 / 97 Salmon at Whitebird 3664 64 % 16 / 95 St. Joe at Calder 816 71 % 19 / 88 Bear at Stewart Dam 22 11 % 9 / 47 * Unregulated or natural flow

24. 2006 April-July Runoff Snake R. nr Heise* 3621 kaf 109 % of avg 61 st / 96 years Big Wood at Hailey 432 191 % 85 / 91 Boise R. nr Boise* 2062 145 % 96 / 111 Payette at HSB* 2238 139 % 74 / 87 Weiser nr Weiser 718 172 % 62 / 64 Snake at Weiser 8061 144 % 78 / 96 Salmon at Whitebird 6440 113 % 58 / 94 St. Joe at Calder 1191 103 % 45 / 88 Bear at Stewart Dam 250 125 % 11 / 46 * Unregulated or natural flow

25. Salmon

27. 2007 APR-SEP VOLUME 4058 KAF 63 % OF AVERAGE

28. Big Wood

32. Upper Snake 2007 APR-SEP NATURAL FLOW SNAKE R NR HEISE 2371 KAF 57% AVG

39. Boise

42. Bear and Other River Basins

49. 2007 County Drought Declarations

50. Precipitation at Winchester, Idaho

55. Summary Snow fall and runoff were below average in 2007. Record high summer temperatures and below average precipitation led to increase demands from irrigation storage A “normal” winter is needed to replenish reservoir storage to obtain sustainable water supplies for 2008