United States39 states · USBR official data

Reservoir Watch

Official storage levels across 550 reservoirs in 39 states. Data from the US Bureau of Reclamation.

Average fill

56.3%

Total volume

201.4 km³

Reservoirs

550

Critical

Low level

Fill by state

Hover for details · USBR coverage

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Status:Critical (<20%)Low (20–40%)Normal / High (>40%)States without color = no USBR reservoirs

US at a glance

National average fill

56.3%

201,368 of 357,578 hm³ stored

Reservoirs

550

States

Total capacity

357.6 km³

Volume stored

201.4 km³

Critical

Low level

Coverage: USBR (Bureau of Reclamation) reservoirs — primarily 17 western states. Eastern US reservoirs managed by USACE are not yet included. Last reading: 2026-10-09.

National fill — multi-year

By state

Sorted by capacity

Utah

27 reservoirs

Low

Average fill

29.1%

11,296 hm³ storedView →

Nevada

7 reservoirs

Low

Average fill

26.8%

9,966 hm³ storedView →

Montana

24 reservoirs

Average fill

79.8%

27,547 hm³ storedView →

California

33 reservoirs

Average fill

59.2%

20,047 hm³ storedView →

South Dakota

14 reservoirs

Average fill

76.2%

24,618 hm³ storedView →

North Dakota

11 reservoirs

Average fill

75.0%

18,008 hm³ storedView →

Oklahoma

48 reservoirs

Average fill

68.5%

12,813 hm³ storedView →

Texas

28 reservoirs

Average fill

64.3%

11,220 hm³ storedView →

Kentucky

17 reservoirs

Average fill

55.3%

8,809 hm³ storedView →

Wyoming

25 reservoirs

Low

Average fill

36.4%

3,625 hm³ storedView →

Missouri

10 reservoirs

Low

Average fill

36.9%

3,550 hm³ storedView →

Kansas

34 reservoirs

Average fill

71.7%

6,180 hm³ storedView →

Louisiana

3 reservoirs

Average fill

66.7%

4,839 hm³ storedView →

Idaho

20 reservoirs

Low

Average fill

23.1%

1,647 hm³ storedView →

Arizona

10 reservoirs

Average fill

61.1%

4,070 hm³ storedView →

New Mexico

16 reservoirs

Low

Average fill

24.9%

1,561 hm³ storedView →

Minnesota

9 reservoirs

Average fill

63.2%

3,392 hm³ storedView →

Tennessee

6 reservoirs

Average fill

84.4%

4,028 hm³ storedView →

Colorado

34 reservoirs

Average fill

45.9%

2,111 hm³ storedView →

Georgia

6 reservoirs

Average fill

75.0%

3,073 hm³ storedView →

Arkansas

2 reservoirs

Average fill

85.3%

2,953 hm³ storedView →

Mississippi

12 reservoirs

Average fill

51.3%

1,660 hm³ storedView →

Oregon

24 reservoirs

Critical

Average fill

13.7%

414 hm³ storedView →

Washington

14 reservoirs

Critical

Average fill

19.1%

468 hm³ storedView →

Virginia

5 reservoirs

Average fill

68.9%

1,572 hm³ storedView →

New York

8 reservoirs

Average fill

80.9%

1,771 hm³ storedView →

Alabama

7 reservoirs

Average fill

98.8%

1,853 hm³ storedView →

Ohio

27 reservoirs

Average fill

51.9%

937 hm³ storedView →

Massachusetts

2 reservoirs

Average fill

79.6%

1,437 hm³ storedView →

Nebraska

26 reservoirs

Average fill

50.0%

788 hm³ storedView →

Pennsylvania

13 reservoirs

Average fill

69.9%

1,075 hm³ storedView →

Indiana

6 reservoirs

Average fill

74.9%

900 hm³ storedView →

Iowa

4 reservoirs

Average fill

90.9%

1,065 hm³ storedView →

Illinois

5 reservoirs

Average fill

81.6%

761 hm³ storedView →

West Virginia

9 reservoirs

Average fill

63.2%

500 hm³ storedView →

North Carolina

3 reservoirs

Average fill

63.6%

364 hm³ storedView →

Florida

1 reservoir

Average fill

88.7%

445 hm³ storedView →

South Carolina

0 reservoirs

Critical

Average fill

0.0%

0 hm³ storedView →

Wisconsin

0 reservoirs

Critical

Average fill

0.0%

0 hm³ storedView →

All reservoirs

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US territory · tracked separately

Puerto Rico — 19 reservoirs

Puerto Rico publishes reservoir elevation, not storage, so its reservoirs cannot be given a fill % or ranked on the map above. They have their own page, in metres above sea level, with records back to 1990.

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States shown as N/A

Alaska, Connecticut, Delaware, District of Columbia, Hawaii, Maine, Maryland, Michigan, New Hampshire, New Jersey, 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

58%of national storage capacity has public data

Tracked

573

reservoirs

With data

573

reservoirs

Tracked capacity

370,262

hm³

Source: USGS NWIS · USACE CWMS · Bureau of Reclamation RISE · CDEC (California) · SRP (Arizona)

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 October 9, 2026, the reservoirs we track across United States that report live levels hold roughly 201,368 hm³ of water — about 56.3% of their combined capacity. Taken together, United States's reservoirs are within their normal operating range.

Across the region, 89 reservoirs are at critically low levels and 91 are low. Bankhead Lock and Dam is the fullest at 105.0%, while Mud Mountain Lake is the lowest at 0.0%.

Over the most recent week on record, 54 reservoirs rose and 84 reservoirs fell across United States.

Storage figures for United States come from USGS · USACE · BOR · CDEC · SRP; the most recent reading is from October 9, 2026. Each reservoir below links to its own page with full history and seasonal context.

United States at a glance

Reservoirs tracked: 573
Average fill: 56.3%
Water stored: 201,368 hm³
Combined capacity: 370,262 hm³
At critically low levels: 89
Fullest: Bankhead Lock and Dam (105.0%)
Lowest: Mud Mountain Lake (0.0%)
Last updated: October 9, 2026