| The risk of fish entrainment is influenced by thermal dynamics within reservoir forebays. The study objective was to understand these dynamics at Kinbasket (Mica Dam), Revelstoke (Revelstoke Dam), and Arrow Lakes (Hugh Keenleyside Dam) reservoirs on the Columbia River. Temperature profiles measured in the forebay of Arrow Lake and Kinbasket portrayed two-layer and linear temperature profiles, respectively. A waveform analysis revealed most internal seiching periods were wind driven and multiple vertical modes at Kinbasket. In Kinbasket, 1 day mid-depth seiches had negative and positive correlations with low and high discharges, respectively. Calculations showed some Arrow Lake seiching was controlled by a boundary 100km upstream. Kinbasket seiching was controlled by 150km and 15km reaches. Calculations revealed selective withdrawal from the epiliminion in Arrow Lakes and withdrawal layer growth with discharge in Kinbasket. Revelstoke and Kinbasket historic temperature profiles were similar. Warmer local inflow at Revelstoke allowed development of an epiliminion layer. |
