Mean discharge of the Bow River at the Calgary gauge (ECCC station 05BH004), 1912–2024. Thin lines are individual years; thick lines are 10-year rolling means. Summer (Jul/Aug/Sep) is when the river runs lowest and demand runs highest — that’s the stress window the operational cap is designed for. Recent years like 2023 (summer mean 72 m³/s) have been notably low.