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				225.50	219.50	192.90	15.10	74.50	74.30	19.20	55.10	19.10		114.90
13				234.90	238.90	196.20	31.60	73.90	74.20	20.90	53.30	20.80		113.90
14				253.50	256.50	191.80	52.20	73.80	74.10	22.20	51.90	22.10		111.60
15				278.20	283.20	200.90	69.90	73.50	73.10	23.20	49.90	23.00		111.40
16				266.80	258.80	192.50	53.90	74.40	74.10	22.00	52.10	21.90		113.00
17				210.20	216.20	188.60	15.20	73.40	73.90	19.40	54.50	19.30		116.80
18				211.50	212.50	198.80	1.30	73.30	73.20	18.60	54.60	18.40		126.70
19								73.50
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31

TOT	200083		1056
AVG	18189	758	96	207.25	207.19	182.98	14.32	74.12	74.17	18.10	56.07	17.96	10575	108.60

MAX	19518			278.20	283.20	200.90	69.90	75.70	75.70	23.20	59.40	23.00	11214	126.70
MIN	17305			178.20	173.90	164.60	1.20	73.00	73.10	15.60	49.90	15.50	9368	90.30