Bonneville Dam & Lake on Columbia River

April 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	21220	884	96	239.20	238.20	214.70	11.10	75.30	75.30	19.70	55.60	19.50	12921	132.80
2	20301	846	96	222.70	219.70	202.00	5.40	75.40	75.30	18.90	56.40	18.80	12502	126.00
3	20341	848	96	212.40	211.40	197.50	1.50	75.60	75.40	18.10	57.30	18.00	11945	117.10
4	20831	868	96	212.00	218.00	204.00	1.50	75.00	75.40	18.30	57.10	18.20	12469	123.30
5	20639	860	96	216.90	217.90	204.00	1.50	75.10	74.90	18.20	56.70	18.10	12407	123.80
6	20472	853	96	214.50	214.50	200.50	1.60	74.80	75.10	18.00	57.10	17.90	12161	120.10
7	20021	834	96	205.50	210.50	196.60	1.50	74.40	74.60	17.80	56.80	17.60	11744	116.10
8	18531	772	96	188.50	193.50	179.60	1.50	74.00	74.00	16.70	57.30	16.50	10820	105.80
9	17418	726	96	186.50	178.50	164.60	1.50	74.80	74.10	15.50	58.60	15.30	10488	100.20
10	3391	141	96	179.20	189.20	33.00	143.70	73.90	74.20	16.30	57.90	16.30	3384	33.00
11	3602	150	96	189.80	193.80	35.90	145.50	73.50	73.40	16.70	56.70	16.70	3602	35.90
12	4295	179	96	214.90	205.90	43.40	150.20	74.40	74.00	17.50	56.50	17.40	4295	43.40
13	4922	205	96	199.90	212.90	50.30	150.20	73.10	74.00	18.00	56.00	18.00	4922	50.30
14	5052	210	96	213.60	213.60	52.40	148.70	73.20	73.10	18.20	54.90	18.20	5052	52.40
15	4284	178	96	208.50	205.50	43.80	149.20	73.50	73.40	17.90	55.50	17.90	4284	43.80
16	4544	189	96	209.30	208.30	46.60	149.30	73.60	73.50	18.10	55.40	18.10	4544	46.60
17	6196	258	96	227.80	226.80	64.80	149.60	73.70	73.60	19.00	54.60	19.00	6196	64.80
18	7811	325	96	246.00	245.00	83.00	149.60	73.70	73.60	20.00	53.60	20.00	7811	83.00
19	5491	229	96	217.00	219.00	57.40	149.30	73.60	73.20	18.70	54.50	18.80	5491	57.40
20	4336	181	96	209.10	207.10	44.80	149.90	73.70	73.40	18.10	55.30	18.10	4336	44.80
21	5096	212	96	214.10	215.10	52.10	150.50	73.60	73.80	18.50	55.30	18.50	5096	52.10
22	4730	197	96	213.10	211.10	48.60	150.10	73.90	73.60	18.20	55.40	18.30	4730	48.60
23	6689	279	96	236.60	232.60	69.80	150.40	74.30	73.80	19.20	54.60	19.20	6689	69.80
24	9022	376	96	249.10	260.10	97.50	150.20	73.10	73.70	20.80	52.90	20.70	8650	93.50
25	7015	292	96	248.80	236.80	73.90	150.50	74.40	73.90	19.70	54.20	19.70	6977	73.50
26	6667	278	96	232.50	232.50	68.50	151.50	74.30	74.50	19.30	55.20	19.30	6667	68.50
27	6774	282	96	232.80	233.80	70.30	151.00	74.20	74.20	19.40	54.80	19.40	6774	70.30
28	6281	262	96	226.00	227.00	64.40	150.20	74.10	74.00	19.00	55.00	19.00	6281	64.40
29	5726	239	96	225.10	220.10	57.30	150.40	74.60	74.30	18.50	55.80	18.60	5726	57.30
30	7431	310	96	227.70	238.70	76.00	150.30	73.50	74.30	19.30	55.00	19.40	7295	74.60

TOT	299129		2880
AVG	9971	415	96	217.30	217.90	99.91	105.58	74.14	74.12	18.39	55.73	18.35	7542	76.44

MAX	21220			249.10	260.10	214.70	151.50	75.60	75.40	20.80	58.60	20.70	12921	132.80
MIN	3391			179.20	178.50	33.00	1.50	73.10	73.10	15.50	52.90	15.30	3384	33.00