PlainLakes

National ranking · latest reservoir storage

Largest reservoir in the U.S.

Reservoirs whose U.S. Geological Survey gauge reports daily storage in acre-feet, ranked by the latest observation in the USGS National Water Information System (trailing 365 days of daily values). This ranks the 17 reservoirs this corpus can rank, not the 106 lake sites USGS reports storage for: a reservoir is absent when no site name identified one assessed waterbody, and absent again when its operator is another agency without a USGS storage gauge.

1,692,000
#1: Lake Mohave (acre-ft)
17
Ranked reservoirs
acre-ft
Storage unit

This ranking in one line

Lake Mohave in AZ reports the largest current storage among USGS-gauged reservoirs PlainLakes tracks: 1,692,000 acre-feet as of 2026-08-15.

#1
Lake Mohave, AZ
Latest storage
1,692,000 acre-ft
As of
2026-08-15

Data updated 2026-08-17

According to the U.S. Geological Survey's National Water Information System, USGS reports daily reservoir storage at 106 lake sites in the August 2026 extract, and this ranking orders the 17 largest linked reservoirs PlainLakes could match to assessed waterbodies. See our methodology for linkage limits and refresh cadence.

Where the gauged reservoirs are

States contributing entries to this ranking

ranked units

What this shows CO contributes 6 of the 17 ranked reservoirs, and 6 states appear in total; USGS storage gauging concentrates on large managed reservoirs in the arid West.

Source USGS NWIS As of Trailing 365 days, through 2026-08-16

Every row

Full ranking

Download CSV
# Name Storage (acre-ft)
1 Lake Mohave (AZ) As of: 2026-08-15 1,692,000
2 Walker Lake (NV) As of: 2026-08-15 1,165,000
3 Milford Lake (KS) As of: 2026-08-15 406,500
4 Lake Hudson (OK) As of: 2026-08-15 208,800
5 Ute Reservoir (NM) As of: 2026-08-15 179,600
6 Stanley Draper Lake (OK) As of: 2026-08-16 87,140
7 Ridgway Reservoir. (CO) As of: 2026-08-15 69,820
8 Topaz Lake (NV) As of: 2026-08-15 31,320
9 Spavinaw Lake (OK) As of: 2026-08-15 25,720
10 Eagle Nest Lake (NM) As of: 2026-08-15 22,320
11 Lemon Reservoir. (CO) As of: 2026-08-15 12,980
12 Vega Reservoir. (CO) As of: 2026-08-15 3,537
13 Lake Maloya (NM) As of: 2026-08-15 3,480
14 Bluewater Lake (NM) As of: 2026-08-15 3,147
15 Crawford Reservoir. (CO) As of: 2026-08-15 2,531
16 Rifle Gap Reservoir. (CO) As of: 2026-08-15 2,329
17 Paonia Reservoir. (CO) As of: 2026-08-15 285

Ordered by the latest daily value of USGS parameter 00054 (reservoir storage, acre-feet) among gauges linked to assessed waterbodies. USGS reports storage at 106 lake sites; 21 of them carry a name this site could match to a single assessed waterbody, and 17 of those carry an indexed record and a positive latest reading, which is what is ranked here. Bureau of Reclamation and Corps reservoirs without a USGS storage gauge are outside the source entirely. USGS does not file one daily statistic for every gauge: 8 of these 17 rows are a daily mean and the rest are a reading at 08:00 or a reading at 24:00. A row's change, range and latest value are all that statistic's. Every storage reading ranked here is provisional and subject to revision by USGS, which has not yet completed quality review on it.

Reading this ranking

Rankings order reported source data; they are not endorsements or safety determinations.

Rankings are computed from state assessment decisions in EPA's ATTAINS system and USGS National Water Information System daily values; the ordering metric and any exclusion floor are stated above the table, no number is typed in by an editor. Recomputed from the trailing-365-day USGS daily-values pull on every data refresh. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2026-08-17. Primary sources: EPA ATTAINS and USGS National Water Information System.