Bonneville Dam

Sunday June 21, 2026

Hour	Total Outflow kcfs	Generation Flow kcfs	Spill kcfs	PH 1 Forebay Elevation	Tailwater Elevation	Average Head	Project Forebay Elevation	Stevenson Gage Elevation	Project Tailwater Elevation
1	138.70	30.80	95.50	74.20	12.80	61.40	74.10	74.80	12.90
2	139.00	31.00	95.60	74.20	13.00	61.20	74.00	74.80	13.00
3	139.10	31.20	95.50	74.10	13.00	61.10	73.90	74.70	13.10
4	139.30	31.40	95.50	74.10	13.00	61.10	74.00	74.70	13.10
5	139.40	31.50	95.50	74.10	13.00	61.10	73.90	74.70	13.00
6	139.80	32.00	95.40	74.00	13.00	61.00	73.80	74.60	13.00
7	139.90	32.20	95.30	74.10	13.00	61.10	73.90	74.60	12.90
8	140.20	32.30	95.50	74.20	13.00	61.20	74.00	74.70	13.00
9	140.30	32.40	95.50	74.00	12.90	61.10	73.90	74.70	12.90
10	140.00	32.20	95.40	74.10	12.80	61.30	74.00	74.70	12.90
11	139.90	32.10	95.40	74.10	12.80	61.30	74.00	74.80	12.80
12	140.10	32.30	95.40	74.20	12.80	61.40	74.10	74.80	12.80
13	148.70	40.80	95.50	74.20	13.40	60.80	74.10	74.90	13.40
14	150.90	43.00	95.50	74.10	13.50	60.60	74.10	74.90	13.50
15	151.10	43.10	95.60	74.30	13.50	60.80	74.20	75.00	13.50
16	151.20	43.20	95.60	74.40	13.50	60.90	74.30	75.10	13.60
17	151.20	43.20	95.60	74.40	13.50	60.90	74.30	75.10	13.50
18	151.30	43.20	95.70	74.40	13.50	60.90	74.40	75.20	13.50
19	151.50	43.30	95.80	74.90	13.60	61.30	74.80	75.40	13.50
20	151.70	43.10	96.20	75.00	13.50	61.50	74.90	75.60	13.50
21	151.90	43.10	96.40	75.20	13.60	61.60	75.10	75.80	13.60
22	152.00	43.10	96.50	75.20	13.50	61.70	75.00	75.90	13.40
23	141.20	32.20	96.60	75.20	12.80	62.40	75.20	75.90	12.80
24	139.90	30.80	96.70	75.40	12.80	62.60	75.30	76.00	12.70

AVG	144.51	36.40	95.72	74.42	13.16	61.26	74.30	75.06	13.16

MAX	152.00	43.30	96.70	75.40	13.60	62.60	75.30	76.00	13.60
MIN	138.70	30.80	95.30	74.00	12.80	60.60	73.80	74.60	12.70

	Powerhouse 1		Powerhouse 2		Project
Hour	Generation Flow kcfs	Forebay Elevation	Forebay Elevation	Generation Flow kcfs	Spillway Gates in Use	Miscellaneous Flow kcfs*
1	0.00	74.2	74.1	30.80	18	12.4
2	0.00	74.2	74.0	31.00	18	12.4
3	0.00	74.1	73.9	31.20	18	12.4
4	0.00	74.1	74.0	31.40	18	12.4
5	0.00	74.1	73.9	31.50	18	12.4
6	0.00	74.0	73.8	32.00	18	12.4
7	0.00	74.1	73.9	32.20	18	12.4
8	0.00	74.2	74.0	32.30	18	12.4
9	0.00	74.0	73.9	32.40	18	12.4
10	0.00	74.1	74.0	32.20	18	12.4
11	0.00	74.1	74.0	32.10	18	12.4
12	0.00	74.2	74.1	32.30	18	12.4
13	0.00	74.2	74.1	40.80	18	12.4
14	0.00	74.1	74.1	43.00	18	12.4
15	0.00	74.3	74.2	43.10	18	12.4
16	0.00	74.4	74.3	43.20	18	12.4
17	0.00	74.4	74.3	43.20	18	12.4
18	0.00	74.4	74.4	43.20	18	12.4
19	0.00	74.9	74.8	43.30	18	12.4
20	0.00	75.0	74.9	43.10	18	12.4
21	0.00	75.2	75.1	43.10	18	12.4
22	0.00	75.2	75.0	43.10	18	12.4
23	0.00	75.2	75.2	32.20	18	12.4
24	0.00	75.4	75.3	30.80	18	12.4

AVG	0.00	74.4	74.3	36.40	18	12.4

MAX	0.00	75.4	75.3	43.30	18	12.4
MIN	0.00	74.0	73.8	30.80	18	12.4

* Miscellaneous Flow includes fish ladders, PH1 sluiceway, navigation lock, PH2 DSM, UMT, and PH2 corner collector (B2CC). When all routes are in operation (March-August), total Misc Flow will be ~12.4 kcfs. Flow through the B2CC is ~5 kcfs, so fluctuations of +/-5 kcfs at any time of year indicate the B2CC is open/closed.