McNary Dam & Lake Wallula

May 2026

Day of Month	Inflow kcfs	Total Outflow kcfs	Generation Flow kcfs	Spill kcfs	Midnight Reservoir Elevation	Average Forebay Elevation	Average Tailwater Elevation	Average Head feet
1	229.80	233.80	54.90	174.20	337.74	337.71	266.94	70.77
2	236.60	231.80	53.70	173.40	338.00	338.02	267.11	70.91
3	225.30	237.20	54.50	178.10	337.35	337.63	267.42	70.21
4	235.80	221.90	54.20	163.00	338.08	337.61	267.06	70.55
5	229.10	239.70	54.60	180.40	337.53	337.73	267.26	70.47
6	241.80	225.80	53.30	167.80	338.36	337.90	267.06	70.84
7	228.50	230.30	53.20	172.40	338.31	338.51	267.38	71.13
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TOT
AVG	232.41	231.50	54.06	172.76	337.91	337.87	267.18	70.70

MAX	241.80	239.70	54.90	180.40	338.36	338.51	267.42	71.13
MIN	225.30	221.90	53.20	163.00	337.35	337.61	266.94	70.21