Lower Granite Dam & Lake

September 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	Midnight Lewiston Gage ft
1	2840	118	51	22.00	21.40	16.30	4.50	735.58	735.71	636.47	99.24	735.92
2	2656	111	51	21.90	20.10	15.20	4.40	736.00	735.87	636.67	99.20	736.44
3	2844	119	51	22.00	21.40	16.30	4.70	736.14	736.21	636.75	99.46	736.54
4	2983	124	51	23.40	22.30	17.00		736.46	736.48	636.74	99.74	736.78
5	3362	140	51	24.70	24.50	19.10	4.90	736.51	736.64	636.70	99.94	736.77
6	2957	123	51	23.20	22.00	16.70	4.90	736.85	736.85	636.10	100.75	737.12
7	3202	133	51	23.80	23.50	18.20	4.90	736.94	736.80	636.20	100.60	737.20
8	3181	133	51	24.30	23.70	18.60	4.70	737.21	736.88	636.32	100.56	737.52
9	3081	128	51	25.60	25.30	17.90	6.90	737.30	737.25	635.98	101.27	737.62
10	2829	118	51	26.60	26.60	15.80	10.30	736.57	737.10	636.06	101.04	737.07
11	2461	103	51	24.90	24.90	13.80	10.40	736.37	736.45	636.21	100.24	736.77
12	2549	106	51	19.80	19.80	14.40	4.90	736.79	736.63	636.34	100.29	737.46
13	2525	105	51	19.50	19.50	14.30	4.70	737.36	737.17	636.32	100.85	737.71
14	2904	121	51	23.40	22.80	17.00	5.20	736.96	737.08	636.45	100.63	737.37
15				22.30	21.20	16.00	4.80	736.78	736.97	636.57	100.40	737.19
16				20.50	19.90	14.30	4.90	736.77	736.74	636.53	100.21	737.07
17				18.90	18.70	13.40	4.90	736.83	736.75	636.58	100.17	737.28
18				18.30	18.40	16.10	1.60	736.81	736.88	636.65	100.23	737.24
19				17.30	18.10	15.90	1.60	736.59	736.60	636.41	100.19	736.97
20				16.90	16.30	14.30	1.60	736.77	736.64	636.17	100.47	737.10
21				16.90	16.40	14.20	1.70	736.96	736.83	636.32	100.51	737.28
22
23
24
25
26
27
28
29
30

TOT	40375		714
AVG	2884	120	51	21.72	21.28	15.94	4.83	736.69	736.69	636.41	100.29	737.07

MAX	3362			26.60	26.60	19.10	10.40	737.36	737.25	636.75	101.27	737.71
MIN	2461			16.90	16.30	13.40	1.60	735.58	735.71	635.98	99.20	735.92