EN3(2) Reservoir Storage
Gigawatt hours (GWh)
1984-2006 average | F2003 | F2004 | F2005 | F2006 | F2007 | |
| Total storage at year end (excluding net non-treaty) | 13,050 | 11,460 | 11,718 | 15,320 | 15,550 | 13,043 |
The graph shows the energy stored in BC Hydro reservoirs excluding Non-Treaty Storage. System runoff conditions in fiscal 2007 were well below normal (88 per cent) due to below-average precipitation. This was down 10 per cent from the previous fiscal year. System Storage was equal to average at year-end and 2,500 GWh lower than the previous year. During the early part of fiscal 2007, the Peace River plants were run in preference to the Upper Columbia plants due to the higher probability of spill at Williston Reservoir. In the summer months, this generation preference switched to the Upper Columbia plants in order to support the level of Arrow Lakes Reservoir for recreation and fisheries reasons.
During the winter period there was above-average snowfall accumulation throughout the province, and system storage was drafted aggressively during the latter part of fiscal 2007 in anticipation of high runoff during fiscal 2008. Through much of this period, the Peace River plants were again run in preference due to the higher probability of spill, although operation of these plants was constrained for three weeks during the period of downstream ice cover formation.
During fiscal 2007, both BC Hydro and Bonneville Power Administration (BPA) partly refilled storage under the Non-Treaty Storage Agreement, and this will help to support the levels of Kinbasket and Arrow Lakes reservoirs in the summer months. In addition, three supplemental operating agreements (Summer and Fall storage agreements, and the Non-Power Uses Agreement) with the U.S. were implemented to improve Columbia system reservoir levels, provide power benefits and provide protection for Canadian fish.
Last Modified: Jul 11, 2007
