Bonneville Dam & Lake on Columbia River

June 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	7625	318	96	236.00	241.00	78.30	150.30	74.20	74.20	19.50	54.70	19.50	7491	76.80
2	7371	307	96	237.60	237.60	75.50	149.60	74.10	73.90	19.40	54.50	19.40	7012	72.00
3	7291	304	96	236.50	236.50	74.90	149.30	74.20	73.90	19.30	54.60	19.40	7291	74.90
4	5740	239	96	210.90	219.90	58.30	149.20	73.40	73.40	18.50	54.90	18.50	5740	58.30
5	6153	256	96	227.60	225.60	63.60	149.60	73.60	73.10	18.60	54.50	18.50	6153	63.60
6	4798	200	96	223.00	210.00	47.40	150.20	74.90	74.50	17.90	56.60	17.90	4798	47.40
7	4921	205	96	215.70	209.70	47.80	149.50	75.50	74.90	17.70	57.20	17.70	4921	47.80
8				227.30	238.30	77.00	148.90	74.40	74.50	19.20	55.30	19.20		73.30
9				205.70	198.70	37.60	148.70	75.10	74.40	17.50	56.90	17.50		37.60
10				194.90	192.90	31.00	149.60	75.30	75.00	16.80	58.20	16.80		31.00
11				194.60	193.60	31.60	149.60	75.30	75.00	16.80	58.20	16.80		30.80
12				189.60	193.60	31.90	149.30	74.90	74.80	16.80	58.00	16.80		31.90
13				181.40	181.40	31.50	137.40	74.90	74.50	16.00	58.50	16.00		31.50
14				174.30	183.30	33.60	137.30	74.20	74.30	15.90	58.40	16.00		33.60
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TOT	43899		672
AVG	6271	261	96	211.08	211.58	51.43	147.75	74.57	74.31	17.85	56.46	17.86	6201	50.75

MAX	7625			237.60	241.00	78.30	150.30	75.50	75.00	19.50	58.50	19.50	7491	76.80
MIN	4798			174.30	181.40	31.00	137.30	73.40	73.10	15.90	54.50	16.00	4798	30.80