Bonneville Dam & Lake on Columbia River

October 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	7241	302	96	84.70	74.70	60.00	2.30	75.40	74.90	7.70	67.20	7.70	6883	57.00
2	7762	323	96	81.50	78.50	63.80	2.30	75.60	75.50	7.90	67.60	7.90	7646	62.90
3	7499	312	96	69.40	76.40	61.70	2.30	75.00	75.30	7.70	67.60	7.60	7399	60.90
4	8058	336	96	84.50	81.50	66.80	2.30	75.40	75.00	8.00	67.00	7.90	7754	64.40
5	8357	348	96	84.60	84.60	69.90	2.30	75.30	75.00	8.30	66.70	8.30	7725	64.70
6	9166	382	96	91.20	92.20	77.50	2.30	75.20	74.90	8.90	66.00	8.90	7869	66.50
7	10084	420	96	99.80	100.80	86.10	2.30	75.10	74.90	9.60	65.30	9.60	7717	65.80
8	10302	429	96	105.90	102.90	88.10	2.40	75.40	75.00	9.90	65.10	10.10	8136	69.80
9	8784	366	96	88.60	88.60	73.80	2.40	75.60	75.40	9.10	66.30	9.30	7791	65.60
10	8387	349	96	84.00	85.00	70.20	2.40	75.40	75.30	8.80	66.50	8.90	7777	65.20
11	7759	323	96	81.40	79.40	64.60	2.40	75.50	75.30	8.60	66.70	8.50	7759	64.60
12				77.90	76.90	62.10	2.40	75.60	75.40	8.20	67.20	8.10		62.10
13				83.90	84.90	70.10	2.40	75.40	75.50	8.60	66.90	8.60		63.10
14				83.10	79.10	64.30	2.40	75.80	75.50	8.00	67.50	8.00		62.20
15				78.30	83.30	68.50	2.40	75.40	75.50	7.80	67.70	7.80		64.50
16				78.60	74.60	59.80	2.40	75.70	75.70	7.10	68.60	7.00		58.90
17				68.70	71.70	56.90	2.40	75.50	75.80	7.20	68.60	7.10		56.90
18				69.50	71.50	56.70	2.40	75.30	75.40	6.90	68.50	6.80		56.70
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TOT	93399		1056
AVG	8491	354	96	83.09	82.59	67.83	2.36	75.42	75.29	8.24	67.06	8.23	7678	62.88

MAX	10302			105.90	102.90	88.10	2.40	75.80	75.80	9.90	68.60	10.10	8136	69.80
MIN	7241			68.70	71.50	56.70	2.30	75.00	74.90	6.90	65.10	6.80	6883	56.70