1. April Runoff Forecasts for the Columbia Basin and Power Supply Implications Jim Ruff and John Fazio Council Meeting April 14, 2010 Boise, ID

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4. 4 April 1 Snowpack for Columbia Basin above The Dalles, OR

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6. 6 2010 January-July Runoff Forecast 69.7 Million Acre Feet (April Forecast for The Dalles Dam) Hydroelectric Fuel Gauge 69.7 Maf is 65% of Average 95% Confidence Range is from 56 to 83 Maf

7. 7 Recent Runoff Volumes (January-July Volume at The Dalles)

8. 8 Lower Granite Flow Forecast

9. 9 McNary Flow Forecast

10. 10 Hydro System Generation

11. 11 2010 Power Supply Outlook (Approximate) Annual Load/Resource Balance Summer Sustained- Peak Reserve Margin Minimum Required0 MWa24% Critical Hydro and Firm Resources Only 300 MWa26% With this Year’s Hydro 1,400 MWa32% With Available Non- firm Resources 5,300 MWa35%

12. 12 Power Supply Conclusions  Very low chance of power outage  Revenues will be lower than average  Less non-firm hydro to sell  Need to purchase more from the market  BPA is using some of its financial reserves to get through this year  Reservoir elevations at BiOp levels

13. 13 NW Power Pool Analysis (March 5)  NW Power Pool area (larger than the Council region) has adequate generation  Low flows will decrease hydro flexibility  Emergency measures may need to be implemented in the event of a significant resource loss and/or extreme temperature event (standard caveat)

14. 14 Additional Slides

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16. 16 2010 Add’l. Court-Ordered Spill

17. 17 Generation Loss due to Court-Ordered Spill

18. 18 Runoff Distribution Used

19. 19 Annual Hydro Generation (relative to the driest year)

20. 20 Lower Granite Flow Forecast (in Kcfs)2010 Avg70-Yr Avg Apr 1-155878 Apr 16-305790 May73107 Jun61102 Jul2852 Aug 1-152430 Aug 16-312428

21. 21 McNary Flow Forecast (in Kcfs)2010 Avg70-Yr Avg Apr 1-15125189 Apr 16-30134228 May140275 Jun165298 Jul124204 Aug 1-15124162 Aug 16-31104126

22. 22 System Generation (in GW-mo)2010 Avg70 Yr-AvgDiff Apr 1-159.714.24.5 Apr 16-309.715.15.4 May9.417.27.8 Jun11.518.77.2 Jul9.415.46.0 Aug 1-159.512.22.7 Aug 16-318.310.11.8

23. 23 Hydro System Generation with and without Court-ordered spill

24. 24 Energy Value of Court-Ordered Spill MW-period Apr 1-15176 Apr 16-30304 May580 Jun318 Jul216 Aug 1-15373 Aug 16-31347 Season Avg350 MW-seas Annual Avg150 MWa

25. 25 Court-Ordered Spill (Columbia R.)  BONNEVILLE  Apr10-Jun20: 100 kcfs all hours  Jun21-Jul20: 85 kcfs day/ gas cap night (113 kcfs)  Jul21-Aug31: 75 kcfs day/ gas cap night  THE DALLES  40% of flow all hours  JOHN DAY  Apr 10-19: 0/60% of flow, all hours  Apr 20 - Jul 20: 35% of flow, all hours (testing 30% vs 40%)  Jul 21 - Aug 31: 30% of flow, all hours  MCNARY  Apr10-Jun14: 40% of flow  Jun15-Aug31: 50% of flow (testing 40% vs. 60%)

26. 26 Court-Ordered Spill (Snake R.)  ICE HARBOR  Apr3 - May1: 45 kcfs/gas cap (88 kcfs)  May2 - Jul16: 30% vs. 45 kcfs/gas cap  Jul17 - Aug31: 45 kcfs/88 kcfs of flow  LOWER MONUMENTAL  Apr3-June 20 : Gas Cap (~24-27 kcfs) all hours  Jun21- Aug 31: 17 kcfs all hours  LITTLE GOOSE  Apr3-Aug31: 30% of flow all hours  Apr24 - May7: 30% day/gas cap night (38 kcfs)  LOWER GRANITE  Apr3-Jun20: 20 kcfs all hours  Jun21-Aug31: 18 kcfs all hours