Grant: Engage Grants Program

Across the southern Northwest Territories, water levels and stream flows declined significantly in 2014 and 2015. These declines in flow impaired hydroelectric power generation across the region, especially in the Snare and Yellowknife river basins that supply electricity to the City of Yellowknife. The lost hydroelectric power generation led to substantial over expenditures of nearly $50 million by the Territorial Government to purchase diesel fuel to supplement the lost hydroelectric power generation. Planning for extreme low flows such as those during the past two years is difficult since instrumental climate records for this region only extend back in time to 1943. Records of stream flow and lake levels are equally short, and some records are very discontinuous. Therefore, it is difficult to determine the natural range of variability in these power generating systems using the short instrumental records of climate and hydrology. We propose to develop proxy data sources to extendthese short instrumental records. In particular, we will reconstruct past flows in these systems using precipitation sensitive jack pine trees. Previous research in the region has shown jack pine can be relatively long lived (200 yrs old; sometimes >300 yrs of age) and sensitive to the year-to-year variability in precipitation. Therefore, we should be able to reconstruct past stream flows/precipitation during the past 2-3 centuries. We will also examine atmospheric drivers of past climatic conditions as part of this study. In particular, large scale atmospheric patterns such as the Pacific Decadal Oscillation (PDO), the Pacific North American Pattern (PNA), El Nino-Southern Oscillation (ENSO) and others will be examined during the 20th century todetermine their importance in driving long- and short-term variability in precipitation and stream flow in this region. Results from this research will be incorporated into modelling experiments being conducted by researchers from Environment Canada to produce robust predictions of future flows in this region that will better inform Northwest Territories Power Corporation.