Bonneville Dam & Lake on Columbia River

April 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	21220	884	96	239.20	238.20	214.70	11.10	75.30	75.30	19.70	55.60	19.50	12921	132.80
2	20301	846	96	222.70	219.70	202.00	5.40	75.40	75.30	18.90	56.40	18.80	12502	126.00
3				212.40	211.40	197.50	1.50	75.60	75.40	18.10	57.30	18.00		117.10
4				212.00	218.00	204.00	1.50	75.00	75.40	18.30	57.10	18.20		123.30
5				216.90	217.90	204.00	1.50	75.10	74.90	18.20	56.70	18.10		123.80
6				214.50	214.50	200.50	1.60	74.80	75.10	18.00	57.10	17.90		120.10
7				205.50	210.50	196.60	1.50	74.40	74.60	17.80	56.80	17.60		116.10
8				188.50	193.50	179.60	1.50	74.00	74.00	16.70	57.30	16.50		105.80
9				186.50	178.50	164.60	1.50	74.80	74.10	15.50	58.60	15.30		100.20
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TOT	41521		192
AVG	20760	865	96	210.91	211.36	195.94	3.01	74.93	74.90	17.91	56.99	17.77	12712	118.36

MAX	21220			239.20	238.20	214.70	11.10	75.60	75.40	19.70	58.60	19.50	12921	132.80
MIN	20301			186.50	178.50	164.60	1.50	74.00	74.00	15.50	55.60	15.30	12502	100.20