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	20341	848	96	212.40	211.40	197.50	1.50	75.60	75.40	18.10	57.30	18.00	11945	117.10
4	20831	868	96	212.00	218.00	204.00	1.50	75.00	75.40	18.30	57.10	18.20	12469	123.30
5	20639	860	96	216.90	217.90	204.00	1.50	75.10	74.90	18.20	56.70	18.10	12407	123.80
6	20472	853	96	214.50	214.50	200.50	1.60	74.80	75.10	18.00	57.10	17.90	12161	120.10
7	20021	834	96	205.50	210.50	196.60	1.50	74.40	74.60	17.80	56.80	17.60	11744	116.10
8	18531	772	96	188.50	193.50	179.60	1.50	74.00	74.00	16.70	57.30	16.50	10820	105.80
9	17418	726	96	186.50	178.50	164.60	1.50	74.80	74.10	15.50	58.60	15.30	10488	100.20
10	3391	141	96	179.20	189.20	33.00	143.70	73.90	74.20	16.30	57.90	16.30	3384	33.00
11	3602	150	96	189.80	193.80	35.90	145.50	73.50	73.40	16.70	56.70	16.70	3602	35.90
12				214.90	205.90	43.40	150.20	74.40	74.00	17.50	56.50	17.40		43.40
13				199.90	212.90	50.30	150.20	73.10	74.00	18.00	56.00	18.00		50.30
14				213.60	213.60	52.40	148.70	73.20	73.10	18.20	54.90	18.20		52.40
15				208.50	205.50	43.80	149.20	73.50	73.40	17.90	55.50	17.90		43.80
16				209.30	208.30	46.60	149.30	73.60	73.50	18.10	55.40	18.10		46.60
17				227.80	226.80	64.80	149.60	73.70	73.60	19.00	54.60	19.00		64.80
18				246.00	245.00	83.00	149.60	73.70	73.60	20.00	53.60	20.00		83.00
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TOT	186767		1056
AVG	16979	707	96	210.40	211.29	123.15	75.73	74.28	74.27	17.94	56.33	17.86	10404	84.36

MAX	21220			246.00	245.00	214.70	150.20	75.60	75.40	20.00	58.60	20.00	12921	132.80
MIN	3391			179.20	178.50	33.00	1.50	73.10	73.10	15.50	53.60	15.30	3384	33.00