Bonneville Dam & Lake on Columbia River

August 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	3526	147	96	120.70	122.70	31.10	79.20	76.00	75.70	11.60	64.10	11.60	3526	31.10
2	3583	149	96	122.20	123.20	31.50	79.30	76.00	75.80	11.60	64.20	11.60	3583	31.50
3	3577	149	96	119.00	117.00	31.10	73.50	76.10	76.00	11.10	64.90	11.00	3577	31.10
4	3530	147	96	122.00	125.00	31.10	81.50	75.80	75.60	11.50	64.10	11.40	3530	31.10
5	3508	146	96	124.00	124.00	30.80	80.80	75.70	75.50	11.40	64.10	11.40	3508	30.80
6	3730	155	96	129.90	129.90	33.10	84.40	75.70	75.20	11.90	63.30	11.90	2960	26.50
7	3853	161	96	127.50	125.50	33.80	79.30	76.00	75.60	11.60	64.00	11.70	2169	19.40
8	3511	146	96	123.80	123.80	31.00	80.40	75.80	75.60	11.70	63.90	11.70	3513	31.00
9	3521	147	96	123.00	122.00	31.10	78.50	76.10	75.60	11.70	63.90	11.60	3521	31.10
10	3551	148	96	114.20	119.20	31.20	75.60	75.60	75.60	11.50	64.10	11.40	3551	31.20
11	3506	146	96	116.70	118.70	31.10	75.20	75.30	75.20	11.40	63.80	11.40	3506	31.10
12	3633	151	96	117.00	109.00	31.80	64.80	76.20	75.40	10.90	64.50	10.80	3633	31.80
13	3652	152	96	113.10	113.10	31.80	68.90	76.20	76.00	11.10	64.90	11.10	3652	31.80
14	3617	151	96	111.10	114.10	31.60	70.10	75.90	75.90	11.30	64.60	11.30	3617	31.60
15	3611	150	96	119.20	114.20	31.60	70.20	76.50	75.70	11.30	64.40	11.20	3611	31.60
16	3639	152	96	111.60	118.60	31.90	74.30	75.70	75.80	11.50	64.30	11.50	3639	31.90
17	3570	149	96	113.80	110.80	31.10	67.30	76.00	75.80	10.80	65.00	10.70	3570	31.10
18	3551	148	96	111.00	111.00	30.90	67.70	76.00	75.80	10.70	65.10	10.60	3551	30.90
19	3579	149	96	114.10	112.10	31.10	68.60	76.30	75.90	10.60	65.30	10.50	3579	31.10
20	3552	148	96	115.40	116.40	31.00	73.00	76.10	75.90	10.90	65.00	10.80	3552	31.00
21	3593	150	96	116.10	118.10	31.40	74.30	75.90	75.70	11.10	64.60	11.00	3593	31.40
22	3571	149	96	113.30	114.30	31.30	70.60	75.80	75.40	10.80	64.60	10.70	3571	31.30
23	3587	149	96	97.00	104.00	30.90	60.70	75.20	75.50	10.00	65.50	9.80	3587	30.90
24				110.50	106.50	31.30	62.80	75.40	75.10	10.10	65.00	10.00		31.30
25				117.40	116.40	31.30	72.70	75.60	75.20	11.00	64.20	11.00		31.30
26				126.00	124.00	31.80	79.80	75.80	75.40	11.70	63.70	11.70		31.80
27				107.60	110.60	31.00	67.20	75.50	75.40	11.00	64.40	11.00		31.00
28				131.70	129.70	31.90	85.40	75.70	75.40	12.20	63.20	12.20		31.90
29				100.50	103.50	31.40	59.70	75.40	75.50	10.60	64.90	10.50		31.40
30				92.10	91.10	30.70	48.00	75.60	75.50	9.40	66.10	9.30		30.70
31

TOT	82551		2208
AVG	3589	150	96	116.05	116.28	31.42	72.46	75.83	75.59	11.13	64.46	11.08	3483	30.72

MAX	3853			131.70	129.90	33.80	85.40	76.50	76.00	12.20	66.10	12.20	3652	31.90
MIN	3506			92.10	91.10	30.70	48.00	75.20	75.10	9.40	63.20	9.30	2169	19.40