Bonneville Dam & Lake on Columbia River

June 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	7625	318	96	236.00	241.00	78.30	150.30	74.20	74.20	19.50	54.70	19.50	7491	76.80
2	7371	307	96	237.60	237.60	75.50	149.60	74.10	73.90	19.40	54.50	19.40	7012	72.00
3	7291	304	96	236.50	236.50	74.90	149.30	74.20	73.90	19.30	54.60	19.40	7291	74.90
4	5740	239	96	210.90	219.90	58.30	149.20	73.40	73.40	18.50	54.90	18.50	5740	58.30
5	6153	256	96	227.60	225.60	63.60	149.60	73.60	73.10	18.60	54.50	18.50	6153	63.60
6	4798	200	96	223.00	210.00	47.40	150.20	74.90	74.50	17.90	56.60	17.90	4798	47.40
7	4921	205	96	215.70	209.70	47.80	149.50	75.50	74.90	17.70	57.20	17.70	4921	47.80
8	7582	316	96	227.30	238.30	77.00	148.90	74.40	74.50	19.20	55.30	19.20	7222	73.30
9	3844	160	96	205.70	198.70	37.60	148.70	75.10	74.40	17.50	56.90	17.50	3844	37.60
10	3243	135	96	194.90	192.90	31.00	149.60	75.30	75.00	16.80	58.20	16.80	3243	31.00
11	3308	138	96	194.60	193.60	31.60	149.60	75.30	75.00	16.80	58.20	16.80	3229	30.80
12	3339	139	96	189.60	193.60	31.90	149.30	74.90	74.80	16.80	58.00	16.80	3339	31.90
13	3317	138	96	181.40	181.40	31.50	137.40	74.90	74.50	16.00	58.50	16.00	3317	31.50
14	3521	147	96	174.30	183.30	33.60	137.30	74.20	74.30	15.90	58.40	16.00	3521	33.60
15	3570	149	96	189.60	196.60	35.10	149.10	73.00	73.40	17.00	56.40	17.00	3391	33.30
16	7120	297	96	182.10	176.10	68.50	95.20	73.90	73.50	15.90	57.60	15.90	7120	68.50
17	7389	308	96	181.60	178.60	71.20	95.00	74.20	73.60	15.80	57.80	15.90	7389	71.20
18	7765	324	96	177.30	182.30	74.80	95.20	73.70	73.80	15.90	57.90	16.00	7765	74.80
19	5911	246	96	164.20	163.20	55.90	94.90	73.80	73.50	14.80	58.70	14.90	5911	55.90
20	3813	159	96	145.60	142.60	34.90	95.40	74.20	74.00	13.30	60.70	13.40	3813	34.90
21	4023	168	96	157.50	144.50	36.40	95.70	75.40	74.40	13.20	61.20	13.20	4023	36.40
22				143.80	145.80	37.20	96.20	75.10	74.80	13.10	61.70	13.10		37.20
23				151.00	157.00	48.60	96.00	74.60	74.60	13.90	60.70	14.00		48.60
24				187.60	185.60	78.80	94.50	74.80	74.70	15.90	58.80	15.90		78.80
25				170.10	169.10	62.20	94.50	74.90	74.70	15.00	59.70	15.10		62.20
26				159.70	162.70	55.80	94.50	74.60	74.70	14.60	60.10	14.60		55.80
27				154.80	145.80	38.60	94.80	75.60	75.10	13.60	61.50	13.60		38.20
28				127.80	129.80	31.40	86.00	75.30	75.40	12.40	63.00	12.30		31.40
29
30

TOT	111644		2016
AVG	5316	222	96	187.42	187.21	51.76	123.05	74.54	74.31	16.23	58.08	16.25	5263	51.35

MAX	7765			237.60	241.00	78.80	150.30	75.60	75.40	19.50	63.00	19.50	7765	78.80
MIN	3243			127.80	129.80	31.00	86.00	73.00	73.10	12.40	54.50	12.30	3229	30.80