EC2 Reservoir Storage
| Gigawatt-hours | F2005 | F2006 | F2007 | F2008 | F2009 | F2010 Plan | F1986-F2008 Avg |
| Total storage at year end (excluding Net Non-treaty) | 15,320 | 15,550 | 13,043 | 13,476 | 14,673 | 11,686.4 | 12,746.0 |
Generation from BC Hydro’s predominantly hydroelectric system is dependent upon precipitation and reservoir storage operations. The water supply into our reservoirs was 96 per cent of average for fiscal 2009.
During April 2008, record-breaking cold temperatures were experienced across British Columbia and the Pacific Northwest. These cold conditions resulted in a long delay in the start of the freshet. The storage flexibility in our largest reservoirs was fully utilized across this period to support system energy requirements. Residual energy requirements were made up through significant imports of energy. By end of April, the system had imported about 745 GWh of energy compared to the 230 GWh estimated for the period a month earlier. By mid-May, with the onset of the freshet, market energy prices at Mid-Columbia dropped to very low levels. During the freshet, significant amounts of highly economic energy were imported to allow the recharge of large reservoirs. By late summer, both Williston and Kinbasket reservoirs refilled to above average levels, with system storage about 2,500 GWh more than average. Across the third and fourth quarter, Columbia River Treaty constraints restricted the seasonal volume available for release at Mica, resulting in BC Hydro purchasing about 3,000 GWh of energy to meet domestic load requirements.
Overall, across fiscal 2009, BC Hydro was a net buyer of about 4,600 GWh of energy, resulting in a year-over-year increase in reservoir storage even though inflows were below average. Total reservoir storage on March 31, 2009, was about 1,900 GWh above average and 1,200 GWh above the previous year’s storage level. Based on the observed April snow pack conditions, system inflows for fiscal 2010 are expected to be 95 per cent of average. Despite the low forecasted inflows, system storage is forecast to refill to an above-average level during the summer, due to a combination of higher than average initial storage and economic imports.
Last Modified: Mar 25, 2010
