Bonneville Dam & Lake on Columbia River

March 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	18081	753	96	185.20	186.20	176.80	1.20	73.10	73.50	16.50	57.00	16.30	10632	104.80
2	18244	760	96	189.30	190.30	181.20	1.30	73.00	73.20	16.80	56.40	16.60	10776	108.00
3	17318	722	96	186.20	178.20	169.10	1.30	73.90	73.20	16.10	57.10	15.90	10507	103.50
4	17519	730	96	180.20	176.20	167.00	1.30	74.30	74.20	15.90	58.30	15.80	10424	100.40
5	17938	747	96	180.50	181.50	172.40	1.30	74.20	74.10	16.20	57.90	16.00	10582	114.30
6	17305	721	96	180.90	173.90	164.60	1.40	74.90	74.50	15.70	58.80	15.60	9368	90.30
7	17734	739	96	178.20	175.20	166.10	1.30	75.10	75.00	15.60	59.40	15.50	10339	97.90
8	17917	747	96	186.50	187.50	178.20	1.30	75.00	74.90	16.40	58.50	16.20	10361	104.00
9	19472	811	96	201.80	195.80	184.90	1.40	75.70	75.70	16.90	58.80	16.80	11209	107.50
10	19037	793	96	185.00	193.00	181.70	1.40	75.00	75.20	16.70	58.50	16.60	10913	105.20
11	19518	813	96	196.10	206.10	189.90	5.40	73.70	74.70	17.50	57.20	17.40	11214	110.60
12	19090	795	96	225.50	219.50	192.90	15.10	74.50	74.30	19.20	55.10	19.10	11144	114.90
13	18993	791	96	234.90	238.90	196.20	31.60	73.90	74.20	20.90	53.30	20.80	10684	113.90
14	17875	745	96	253.50	256.50	191.80	52.20	73.80	74.10	22.20	51.90	22.10	10148	111.60
15	17563	732	96	278.20	283.20	200.90	69.90	73.50	73.10	23.20	49.90	23.00	9678	111.40
16	17674	736	96	266.80	258.80	192.50	53.90	74.40	74.10	22.00	52.10	21.90	10289	113.00
17	18349	765	96	210.20	216.20	188.60	15.20	73.40	73.90	19.40	54.50	19.30	11240	116.80
18	19370	807	96	211.50	212.50	198.80	1.30	73.30	73.20	18.60	54.60	18.40	12231	126.70
19	19524	814	96	217.80	211.80	198.10	1.30	73.50	73.60	18.30	55.30	18.20	12259	125.60
20	20221	843	96	212.90	223.90	210.20	1.30	72.80	73.00	19.00	54.00	18.80	12797	134.00
21	20279	845	96	258.60	238.60	210.30	15.90	74.80	74.10	19.80	54.30	19.60	12821	134.10
22				259.20	260.20	217.90	29.90	74.80	74.80	21.20	53.60	21.00		134.70
23				259.70	257.70	213.00	32.20	74.90	74.90	21.00	53.90	20.80		132.80
24				257.90	258.90	211.60	34.90	74.90	75.10	20.90	54.20	20.80		132.20
25				239.40	258.40	217.60	28.40	72.80	74.10	21.10	53.00	20.90		134.90
26				263.10	250.10	217.10	20.60	74.30	73.40	20.70	52.70	20.50		134.90
27				262.60	251.60	216.30	22.80	75.40	75.00	20.20	54.80	20.00		135.00
28				258.30	262.30	214.50	35.50	74.80	75.50	20.90	54.60	20.70		134.30
29								74.50
30
31

TOT	389021		2016
AVG	18525	772	96	222.14	221.54	193.58	17.16	74.21	74.24	18.89	55.35	18.74	10934	117.40

MAX	20279			278.20	283.20	217.90	69.90	75.70	75.70	23.20	59.40	23.00	12821	135.00
MIN	17305			178.20	173.90	164.60	1.20	72.80	73.00	15.60	49.90	15.50	9368	90.30