1. WECC System Schedulers Meeting Las Vegas, Nevada, May 10 – 11, 2010

2. NW Hydro Operations Francis Halpin – Bonneville Power Administration

3. Hydrology 101

4. Climatological zones range from high deserts to mountain ranges Elevation ranges from 300ft to over 10,000ft Impacted by Pacific Ocean as well as continental influences Adiabatic Lift The Columbia River Basin

5. Hydrology 101 Hydrographs A hydrograph is a representation of flow for a particular stream and is used to evaluate the watershed runoff volumes and the peak flow rates from a single storm or set of storms. This information is then used in the design of flood control facilities. Watershed runoff is a function of several things, including: rainfall intensity storm duration type of vegetation in the watershed area size and shape of the watershed

6. Hydrology 101 Hydrographs Unit Hydrograph The unit hydrograph depicts the response of the watershed from a unit (typically 1 inch) of excess rainfall uniformly distributed over the watershed at a uniform rate during a given period of time Unit hydrograph can be used to predict the response of the watershed for any given rainfall distribution. Unit hydrograph can be used to predict flood peaks within 25% of observed values (i.e. sufficient for planning)

7. Hydrology 101 Hydrographs

8. Storm or Flood Hydrograph Based on actual rainfall distribution and actual streamflow response Plots actual runoff from a particular storm Can be used to fine tune unit hydrograph.

9. Hydrology 101 Storm or Flood Hydrograph

11. Hydrology 101 ANNUAL HYDROGRAPH Annual streamflow hydrograph is a plot of streamflow versus time over a year or more Annual hydrographs show the long-term balance of precipitation, evaporation, and streamflow in a watershed In addition, annual hydrographs depict the temporal variability of streamflow

12. Hydrology 101 Annual Hydrograph

13. Hydrology 101 Annual Hydrograph – Multi Year

14. Hydrology 101 SUMMARY HYDROGRAPH Summary hydrographs are a family of graphs which show, for each day of the calendar year, the maximum, minimum, various percentiles, etc. for the basin of interest over some period of record. Any point can come from any of the years of record. Easier to read than 50 traces of 50 different water years.

15. Hydrology Natural versus Actual flow hydrographs Natural Flow – The flow which the basin would experience IF there were no dams. Actual or Regulated Flow – the flow actually observed in the basin. In a watershed with storage dams there is opportunity to store water from year to year or to release water stored from prior years. The change in storage is the major difference between natural flow and regulated flow.

16. Hydrology Summary Hydrograph – Willamette River

17. Hydrology Summary Hydrograph – Snake River

18. Hydrology Summary Hydrograph – Columbia River

19. Hydrology Columbia River Basin 61% 27% 12% Where does the water come from? (as a percent of the annual runoff at The Dalles)

21. Columbia River Annual Runoff Variability

23. OK We have all this water – what are we going to do with it all? Lets Build some dams. Rock Island Dam – 1932 1930s – 1 st of two federal dam building eras. Bonneville – 1938, Grand Coulee – 1941

24. Vanport Flood – 1948 Need more Storage

25. OK We have all this water – what are we going to do with it all? Lets Build some dams. Vanport Flood - 1948 1950s and 1960s – 2nd of two federal dam building eras. Canadian Treaty Large Storage Projects California Intertie

29. The Need for Coordination in the PNW Agreements Columbia River Treaty Yearly / Monthly regulation Yearly / Monthly regulation Pacific Northwest Coordination Agreement (PNCA) Yearly / Monthly regulation Yearly / Monthly regulation Mid Columbia Hourly Coordination Agreement (MCHC) Daily / Hourly regulation Daily / Hourly regulation Northwest Power Pool (NWPP) Reserve Sharing Program Reserve Sharing Program Hourly / within-hour Hourly / within-hour

30. The Need for Coordination in the PNW Agreements One utility principle – determine the optimum power operation within the bounds of non-power constraints as if operated by a single entity; a MW is a MW regardless of location. One utility principle – determine the optimum power operation within the bounds of non-power constraints as if operated by a single entity; a MW is a MW regardless of location. Power optimized on a monthly basis by directing the amount and timing of storage releases at specific reservoirs. Power optimized on a monthly basis by directing the amount and timing of storage releases at specific reservoirs. Coordination will be safe for all parties Coordination will be safe for all parties Recognize autonomy of owners to operate their resources for their own needs while providing certainty to other coordinated parties (using obligations for energy exchanges based on theoretical optimum hydro operation). Recognize autonomy of owners to operate their resources for their own needs while providing certainty to other coordinated parties (using obligations for energy exchanges based on theoretical optimum hydro operation). Since power benefits are independent of location, requirement for sufficient transmission capacity to make coordination work. Since power benefits are independent of location, requirement for sufficient transmission capacity to make coordination work.

31. The Need for Coordination in the PNW Pacific Northwest Coordination Agreement Methods of making Parties whole Methods of making Parties whole In Lieu Provisional Draft StorageInterchange Mid Columbia Hourly Coordination BPA BPA Grand Coulee (BoR) and Chief Joe (Corps) Grand Coulee (BoR) and Chief Joe (Corps) Wells (DOPUD) Wells (DOPUD) Rocky Reach and Rock Island (CHPUD) Rocky Reach and Rock Island (CHPUD) Wanapum and Priest Rapids (GCPUD) Wanapum and Priest Rapids (GCPUD) Many other utilities both public and private are also members Many other utilities both public and private are also members Northwest Power Pool Operating Committee Operating Committee Reserve Sharing Group Reserve Sharing Group 19 Balancing Authorities – Canada, PNW and California

32. Coordinating with Federal Partners Corps of Engineers Willamette River Plants Willamette River Plants Headwater Projects Headwater Projects Outages Outages Special Operations Special Operations Bureau of Reclamation Outages Outages Special Operations Special Operations Pumping Operations and Banks Lake Pumping Operations and Banks Lake

33. Coordinating with Other Parties Fishery Operations Technical Management Team (TMT) Technical Management Team (TMT) Weekly Operations Special Operations Hatchery release timing and required spill Seasonal use of available water Use of storage space versus flood control Conflicting constraints Conflicting constraints Flood Control below the fish VECC results in a flat operation with no ability to draft below FC.

34. Putting the Daily Plan Together Headwater Projects (storage) Libby, Dworshak, Hungry Horse Planned weeks to months ahead Drafting to FC – Refill rate End of month target elevation Actual Schedules depend on inflow Willamette Projects Flows determined by Corps Some shaping on the Storage project is available as long as the Re-Reg keeps enough flow to run at the required flow.

35. Putting the Daily Plan Together The Big Ten Mid Columbia Grand Coulee Chief Joseph Lower Snake Lower Granite Little Goose Lower Monumental Ice Harbor Lower Columbia McNary John Day The Dalles Bonneville

36. Scheduling the Big 10 BPA has optionality on the scheduling of these Big Ten projects. The majority of load following and dispatchable reserves are carried on these 10 projects. These are the focus of BPAs hydro generation scheduling group.

37. Scheduling the Big 10 The optionality is bounded by physical limitations and constraints at the projects and by mandated hydraulic objectives like flood control and fishery requirements. Much of the year the constraints and hydraulic requirements are so prescriptive that we have little optionality or flexibility.

38. Scheduling the Big 10 Planning and modeling is done days to weeks in advance in order to plan for marketing necessary to adjust load to meet hydraulic objectives. On the preschedule day, generation schedules are produced by the models. They are sent to the TOP for planning purposes. The actual scheduling of the Big 10 generation does not really occur until hour ahead; just prior to the WECC interchange ramp. We have over 2,000 MW of contractual uncertainty up until XX:30 each hour and normal load uncertainty beyond that. And once we get into the hour there is wind !

39. Scheduling the Big 10 Meeting load obligations requires not only capacity but having the fuel in the right place at the right time. Complex task. Load variability (Peaking contracts, SLICE, BPA marketing) Load variability (Peaking contracts, SLICE, BPA marketing) Final Load is not know until XX:40 (or later) Lag Times do not always verify No water = no generation (limited to inflow only) No water = no generation (limited to inflow only) Unplanned outages Wind – BPA has over 2,700 MWs of wind in BA Within hour disruption of scheduled gen = disruption of future hour fuel supply downstream Within hour disruption of scheduled gen = disruption of future hour fuel supply downstream Persistent Imbalance disrupts operation over longer periods. Persistent Imbalance disrupts operation over longer periods.

42. GermanyDenmark

44. Wind Ramping Event April 27, 2010

45. Dispatcher Standing Order 216 Public Rate Setting Process on Wind Balancing Rate R.O.D. set rate based on meeting 99.5% of events based on statistical study and methodology. In order to assure ramping events are covered, BPA holds 835 MW of INC (upward) reserves 1035 MW of DEC (downward) reserves Wind fleet pays for the service through the rate. When extreme events cause the wind balancing reserves to be depleted DSO 216 measures are enacted. Plants are sent signals to feather or otherwise reduce generation to schedule OR to curtail e-tags depending.

46. Scheduling Hydro Under Uncertainty ~3,500 MW of contractual and wind uncertainty, differing project constraints - characteristics - lag times - reservoir factors - H/K - TW limits, etc. make managing the fuel supply a complex problem.

47. The Current Water Year

51. Low Water One of the lowest on Record (Apr EB 68.8) One of the lowest on Record (Apr EB 68.8) Shape of runoff could make things worse Shape of runoff could make things worse Biop has provisions for Low Water Very prescriptive Very prescriptive If not enough for Biop Spill we must do minimum generation and spill the remainder If not enough for Biop Spill we must do minimum generation and spill the remainder No Flexibility on Snake and Lower Columbia No Flexibility on Snake and Lower Columbia

52. 78.64 MAF Jan – Jul @ TDA 76.40 MAF Jan – Jul @ TDA 75.54 MAF Jan – Jul @ TDA 73.55 MAF Jan – Jul @ TDA

53. Required Spill ProjectDuration QS 120% TDGMNQS MNQ T LWGAll Hours 20 k 41 k6.1 k 11.5 k LGSAll Hours QO Deadband @ 25 k – 35 k 30%** 32 k7.2 k Hi Crest* 11.5 k LMNAll Hours Gas Cap 24 k7.9 k 11.5 k IHR0500 – 1800 day 1800 – 0500 night Start 45k/TDG: 4/3 5/2 5/6 5/12 5/16 5/22 5/28 6/3 ----------------------------------------------------------- Start 30%/TDG beginning 0500 4/30: 4/30 5/4 5/8 5/14 5/20 5/24 6/1 6/5 45k day / Gas cap night ----------------- - 30% day / Gas cap night 95 k8.4 k 9.5 k MCN4/10-6/19 All Hours 40% 145 k 50 k JDA4/10-6/19 All Hours Alternate 30/40%. Changes at 0600: 30%: 4/28 5/4 5/8 5/16 5/20 5/24 5/30 6/5 ----------------------------------------------------------- 40%: 4/30 4/30 5/6 5/12 5/18 5/22 5/28 30% ------------------ 40% 120 k 50 k TDA4/10-6/30 All Hours 40% 125 k 50 k BON4/10-6/20 All Hours 100 k 75 k 30 k

54. The Current Water Year Extremely Challenging Ramifications of Min Gen Spill the rest Shape of scheduled generation Shape of scheduled generation Maintaining upward AND downward reserves Reserves ReservesQuantities Location – Fisheries constraints limit LCOL, LSN Wind Wind Location relative to reserves N of John Day – West of McNary – N of Hanford DSO 216 measures

55. The Current Water Year Extremely Challenging Coordination will be the key – both internally and externally. Spring freshet has begun and we are in better shape now than in April. Similar low flow conditions are likely to occur in mid to late August depending on how available water is requested by salmon managers.

56. BPA General Facts and Figures 7,588 - average annual MW hydro generation 31 - total hydro projects with varying modeling complexity 20,230 MW - total Nameplate hydro Capacity 18,139 - all time peak generation (2002) 45 - types of project/system constraints to be modeled 15,212 - circuit miles of transmission owned by BPA 300,000 - sq miles service area for BPA 147 - total wholesale customers 13 - federally recognized tribes and reservations in the basin Over $2 billion spent on fish and wildlife programs since1978

57. Questions ????? Francis Halpin fjhalpin@BPA.gov (503) 230-7545