Reservoir Watch
Official storage levels across 481 reservoirs in 38 states. Data from the US Bureau of Reclamation.
Average fill
65.9%
Total volume
230.6 km³
Reservoirs
481
Critical
36
Low level
50
Fill by state
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US at a glance
National average fill
65.9%
230,579 of 349,818 hm³ stored
Reservoirs
481
States
38
Total capacity
349.8 km³
Volume stored
230.6 km³
Critical
36
Low level
50
Coverage: USBR (Bureau of Reclamation) reservoirs — primarily 17 western states. Eastern US reservoirs managed by USACE are not yet included. Last reading: 2026-06-12.
National fill — multi-year
By state
Sorted by capacityUtah
27 reservoirs
Average fill
33.3%
Nevada
7 reservoirs
Average fill
30.1%
Montana
24 reservoirs
Average fill
84.7%
California
32 reservoirs
Average fill
85.1%
South Dakota
14 reservoirs
Average fill
84.5%
North Dakota
10 reservoirs
Average fill
79.3%
Oklahoma
53 reservoirs
Average fill
85.7%
Texas
30 reservoirs
Average fill
65.7%
Kentucky
13 reservoirs
Average fill
67.8%
Missouri
9 reservoirs
Average fill
40.6%
Wyoming
25 reservoirs
Average fill
58.8%
Kansas
35 reservoirs
Average fill
80.3%
Louisiana
3 reservoirs
Average fill
71.8%
Idaho
20 reservoirs
Average fill
61.9%
New Mexico
16 reservoirs
Average fill
30.3%
Arizona
7 reservoirs
Average fill
83.6%
Minnesota
6 reservoirs
Average fill
67.0%
Colorado
40 reservoirs
Average fill
63.9%
Tennessee
6 reservoirs
Average fill
90.5%
Washington
14 reservoirs
Average fill
66.9%
Mississippi
5 reservoirs
Average fill
43.6%
Arkansas
2 reservoirs
Average fill
96.7%
Oregon
23 reservoirs
Average fill
43.7%
Virginia
2 reservoirs
Average fill
97.6%
Pennsylvania
13 reservoirs
Average fill
76.9%
Nebraska
15 reservoirs
Average fill
66.4%
Georgia
2 reservoirs
Average fill
103.6%
Illinois
5 reservoirs
Average fill
82.6%
Indiana
5 reservoirs
Average fill
99.5%
Iowa
4 reservoirs
Average fill
108.5%
Ohio
8 reservoirs
Average fill
96.6%
North Carolina
2 reservoirs
Average fill
87.7%
West Virginia
2 reservoirs
Average fill
66.8%
New York
1 reservoir
Average fill
1.5%
Alabama
1 reservoir
Average fill
96.9%
Florida
0 reservoirs
Average fill
0.0%
South Carolina
0 reservoirs
Average fill
0.0%
Wisconsin
0 reservoirs
Average fill
0.0%
All reservoirs
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States shown as N/A
Alaska, Connecticut, Delaware, District of Columbia, Hawaii, Maine, Maryland, Massachusetts, Michigan, New Hampshire, New Jersey, Puerto Rico, Rhode Island and Vermont have no reservoirs in the federal datasets we use — USGS NWIS, the Bureau of Reclamation (RISE) and USACE — which cover primarily the 17 western Reclamation states. Eastern, coastal and non-contiguous states are mostly managed by state agencies or USACE districts without a public storage API, so they appear as N/A on the map. We're adding sources as they become available.
Dataset coverage
Tracked
606
reservoirs
With data
606
reservoirs
Tracked capacity
387,696
hm³
Source: USGS NWIS · USACE CWMS · Bureau of Reclamation RISE · CDEC (California)
Federal systems track a subset of US reservoirs. Many state-managed and smaller reservoirs have no public machine-readable storage data. The US has thousands of reservoirs beyond those covered here.
About reservoirs in United States
As of June 12, 2026, the reservoirs we track across United States that report live levels hold roughly 230,581 hm³ of water — about 65.9% of their combined capacity. Taken together, United States's reservoirs are within their normal operating range.
Across the region, 36 reservoirs are at critically low levels and 50 are low. LAKE MOHAVE AT DAVIS DAM, AZ-NV is the fullest at 105.0%, while MUD MOUNTAIN LAKE NEAR BUCKLEY, WA is the lowest at 0.0%.
Over the most recent week on record, 10 reservoirs rose and 13 reservoirs fell across United States.
Storage figures for United States come from USGS · USACE · BOR · CDEC; the most recent reading is from June 12, 2026. Each reservoir below links to its own page with full history and seasonal context.
United States at a glance
- Reservoirs tracked
- 606
- Average fill
- 65.9%
- Water stored
- 230,581 hm³
- Combined capacity
- 387,696 hm³
- At critically low levels
- 36
- Fullest
- LAKE MOHAVE AT DAVIS DAM, AZ-NV (105.0%)
- Lowest
- MUD MOUNTAIN LAKE NEAR BUCKLEY, WA (0.0%)
- Last updated
- June 12, 2026
Frequently asked questions
How full are reservoirs in United States right now?
As of June 12, 2026, the reservoirs tracked in United States that report live levels are 65.9% full overall, holding about 230,581 hm³ of water.
How many reservoirs are there in United States?
reservoirs.earth tracks 606 reservoirs in United States, with a combined storage capacity of 387,696 hm³.
Which reservoir in United States is the fullest?
LAKE MOHAVE AT DAVIS DAM, AZ-NV is currently the fullest reservoir in United States, at 105.0% of capacity.
Which reservoir in United States is the lowest?
MUD MOUNTAIN LAKE NEAR BUCKLEY, WA is currently the lowest in United States, at 0.0% of capacity.
Where does the reservoir data for United States come from?
All storage figures for United States come from USGS · USACE · BOR · CDEC, an official source, last updated June 12, 2026.