1. NON-TREATY STORAGE AGREEMENT “Introduction to Operations and the Non Treaty Storage Scenarios” Presenter: Jim Gaspard

2. Content: Overview of Treaty/Non-Treaty Modifications to Operation –Supplemental Agreements –Non-Treaty Storage Operations Non-Treaty Scenarios System Modeling Modeling Output Climate Change

3. Definitions - Flow Flow: –cfs: cubic feet per second –kcfs:1000’s of cubic feet per second. Mica Unit discharge: 11 kcfs. Revelstoke Unit discharge: 15 kcfs.

4. Definitions - Volume Reservoir Storage Volume: –MAF: Million Acre Feet. Volume of water in 1 million acres, 1 foot thick. 504 kcfs flowing for a 24 hr period Top 10 feet at Kinbasket Top 8 feet at Arrow

5. WHAT IS THE NON-TREATY STORAGE AGREEMENT? A commercial agreement between BC Hydro and Bonneville Power Administration (BPA) that provides further coordination of Kinbasket and Arrow reservoir, beyond that which is provided by the Columbia River Treaty. Non-Treaty Storage Agreement

6. 6 Treaty vs. Non-Treaty Treaty: –International Treaty –Entities: BC Hydro (BCH), Bonneville Power Administration (BPA) and the US Army Corp of Engineers (COE) –15.5 million acre feet (MAF) of storage operated under a set of rules (at Mica, Arrow, and Duncan) Non-Treaty Storage Agreement: –Bilateral agreement between BCH and BPA –An enabling agreement that provides for up to 5 MAF of storage operated by mutual agreement (at Mica, but also impacts Arrow)

7. 7 Storage at Mica and Arrow Arrow Reservoir Kinbasket Reservoir 1 MAF = top 10 feet at Kinbasket 1 MAF = top 8 feet at Arrow Unusable Storage (8.0 MAF)

8. Treaty Operations (modeled): Kinbasket Reservoir Based on AOP 2012, with critical supplemental agreements, and Mica Flexibility. 2472 feet 2386 feet 2360 feet

9. Treaty Operations (modeled): Arrow Reservoir Flood Control Elevation 1413 feet 1437 feet 1403 feet Based on AOP 2012, with critical supplemental agreements, and Mica Flexibility.

10. Treaty Operations (modeled): Arrow Releases Based on AOP 2012, with critical supplemental agreements, and Mica Flexibility.

11. Modifications to Operations Supplemental Agreements

12. Supplemental Agreements A mutual agreement between BCH and BPA/COE to: –Adjust the level of storage in a reservoir, or –Adjust flows at Arrow Purpose: –To increase power benefits, and –Improve the non-power outcome in Mica and/or Arrow.

13. Summer Storage Agreement (2006)

14. Modifications to Operations Non-Treaty Storage Operations

15. Storage Operation - Initial - Summer: Treaty storage typically filled to at/near full Mica Discharge Arrow Discharge Non-Treaty Storage – Fall/Winter Draft

16. Storage Operation - Winter Draft - Late Winter Treaty storage drafted to near empty. Mica Discharge Arrow Discharge Still significant water at Kinbasket. Non-Treaty Storage – Fall/Winter Draft

17. Storage Operation - Utilize Flex - BCH can draft more than Specified Treaty Q from Mica (Flex). Mica Discharge Arrow Discharge Flood Control Elevation Non-Treaty Storage Seasonal Operation Still significant water at Kinbasket.

18. Storage Operation - NTSA Release - NTSA release facilitates greater draft at Mica Mica Discharge +NT Discharge Arrow Discharge + NT Discharge Flood Control Elevation Draft benefit of NTSA Non-Treaty Storage Seasonal Operation

19. Non-Treaty Scenarios

20. Modeling Process

21. 21 Non-Treaty Storage Utilization Scenarios Four different strategies for utilizing Non- Treaty Storage: Scenario A:High Potential Utilization (4.5 MAF Max) Scenario B:Mod Potential Utilization (3.0 MAF Max) Scenario C: Low Potential Utilization (2.0 MAF Max) Scenario D: No Utilization

22. 22 Non-Treaty Storage Utilization Scenarios Scenario A: (4.5 MAF max utilization) –Approximates operation of Non-Treaty Storage under the 1990 Agreement –Provides similar flexibility to that which was modeled in the Columbia Water Use Plan

23. 23 Non-Treaty Storage Utilization Scenarios Scenario B: (3.0 MAF max utilization) –BPA proposed operation –Flexibility for release of additional water in summer to aid salmon out-migration in the US Columbia 0.5 MAF release in May/June during dry years Return of storage in upcoming year (if above average inflows)

24. 24 Non-Treaty Storage Utilization Scenarios Scenario C: (2.0 MAF max utilization) –Restrictive operation of Non-Treaty Storage –Considered to be low end volume that will: Facilitate fall/winter draft at Kinbasket to serve system load. Facilitate key fisheries/power benefit in spring/summer, and Provide flexibility to manage Kinbasket Reservoir, in exceptionally high inflow years.

25. 25 Non-Treaty Storage Utilization Scenarios Scenario D: (no utilization of NTS) –Approximates operation that would be dictated by the Treaty

26. 26 Scenario A (4.5 MAF Maximum Utilized) BCH Non-Treaty Storage (Additional draft at Mica + Arrow due to release of Non-Treaty Storage) Average: 14 feet Outlier: 30 feet Additional Draft (MAF) 0 1.0 2.0 3.0 4.0 5.0

27. 27 Scenario C (2.0 MAF Maximum Utilized) BCH Non-Treaty Storage (Additional draft at Mica + Arrow due to release of Non-Treaty Storage) Outlier: 20 feet Average: 10 feet Additional Draft (MAF) 0 1.0 2.0 3.0 4.0 5.0

28. System Modeling

29. Modeling Process

30. 30 System Modeling Overview System modeling: –Using standard computer models used in BC Hydro long term planning. HYSIM (60 year, monthly time-step simulation) GOM (10 year, bi-hourly simulation) –Outputs: Revelstoke Release and Reservoir

31. 31 System Modeling Overview Modeling provides: –Economic optimal operation of BC Hydro system, given constraints. Modeling does not provide: –Wind integration impacts to operations –Operational adjustments that may be made to manage non-power issues, including: Managing flood control events. Enhancing Arrow Soft Constraints or other system objectives Managing non-power issues in other basins. Implementing discretionary supplemental agreements, for power or non-power benefit.

32. Modeling Output

33. Modeling Process

34. Kinbasket Reservoir: Scenario D (No NTS usage) Based on AOP 2012, with critical supplemental agreements. 2472 feet 2386 feet 2360 feet

35. Kinbasket Reservoir: Scenario A (4.5 MAF NTS use possible) Based on AOP 2012, with critical supplemental agreements. 2467 feet 2369 feet 2336 feet

36. Kinbasket Reservoir: Key Differences Non-Treaty usage will draft more in the Fall/Winter Non-Treaty usage will allow reduced full pool levels at Kinbasket No Usage 4.5 MAF Scenario

37. Arrow Reservoir: Scenario D (No NTS usage) Flood Control Elevation Based on AOP 2012, with critical supplemental agreements. 1413 feet 1437 feet 1403 feet

38. Arrow Reservoir: Scenario A (4.5 MAF NTS use possible) Flood Control Elevation Based on AOP 2012, with critical supplemental agreements. 1407 feet 1437 feet 1397 feet

39. Arrow Reservoir: Key Differences Non-Treaty usage will draft more in the fall Non-Treaty usage will result in lower elevation in March, with more rapid rise across the freshet No Usage 4.5 MAF Scenario

40. Arrow Releases No NTS Usage 4.5 MAF Usage

41. Climate Change

42. 42 Impacts of Climate Change on Hydro Systems Changes the annual volume of inflows. Shifts in timing of the runoff Changes in Electricity Demand Greater potential for extreme events (drought, floods, dam safety design) Biodiversity

43. BC Hydro Climate Change Work: BCH is a founding partner in the Pacific Climate Impacts Consortium (PCIC) –Mission: To quantify the impacts of climate change and variability on the physical environment in Pacific North America. –4 year research plan

44. 44 PCIC early general findings +4 ° +3 ° +5 ° +3 ° -10% +10% +25% Precipitation (for 2050’s from 2007 Overview Study) Mean temperature (for 2050’s from 2007 Overview Study) S U M M E R W I N T E R

45. 45 Columbia Mountains - Mica Potential Impacts on Hydrology Inflows (cubic meters per second) 1984 - 2007 2008 Inflow year Historical median Legend Freshet peak flows potentially increased Summer low flows likely decreased Spring runoff (freshet) starts earlier 1:10 A 1:10 indicates the annual peak flow that can be expected to occur once on average, every 10 years Inflow years 1984 - 2007 2008 Inflow year Historical median Return period frequency for annual peak flows For example: Legend 1:2 1:10 1:100 1:50