Bonneville Dam & Lake on Columbia River

May 2026

Day of Month	Total Generation MWh	Average Generation MW	Station Use MWh	Inflow kcfs	Total Outflow kcfs	Generation Flow kcfs	Spill kcfs	Midnight Reservoir Elevation	Average Forebay Elevation	Average Tailwater Elevation	Average Head feet	Project Average Tailwater	2nd Powerhouse Total MWh	2nd Powerhouse Flow kcfs
1	7834	326	96	247.50	244.50	82.50	149.60	73.90	73.40	19.90	53.50	19.90	7518	79.20
2	4893	204	96	225.20	213.20	48.90	151.90	75.00	74.20	18.20	56.00	18.20	4893	48.90
3	7215	301	96	229.80	235.80	73.40	150.00	74.40	74.70	19.20	55.50	19.20	6928	70.40
4				227.30	235.30	73.80	149.10	73.60	74.00	19.40	54.60	19.40		66.60
5				243.20	240.20	78.50	149.30	74.20	74.20	19.60	54.60	19.60		69.50
6				225.50	219.50	57.60	149.60	74.40	74.40	18.60	55.80	18.70		57.50
7				217.50	214.50	52.50	149.60	74.90	74.40	18.10	56.30	18.10		52.50
8				226.00	226.00	63.60	150.00	74.80	74.70	18.60	56.10	18.60		63.60
9				225.40	229.40	67.00	150.00	74.40	74.70	18.80	55.90	18.80		67.00
10				243.40	235.40	72.60	150.50	75.20	75.00	19.20	55.80	19.20		72.60
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TOT	19942		288
AVG	6647	277	96	231.08	229.38	67.04	149.96	74.48	74.37	18.96	55.41	18.97	6446	64.78

MAX	7834			247.50	244.50	82.50	151.90	75.20	75.00	19.90	56.30	19.90	7518	79.20
MIN	4893			217.50	213.20	48.90	149.10	73.60	73.40	18.10	53.50	18.10	4893	48.90