[Mick]

The Colorado River's underwater basin has been seriously depleted. It has lost an amount equivalent to Lake Mead (U. S. largest reservoir) since 2003.

The Colorado River is running low. The picture looks even worse underground, study says.

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https://cdec.water.ca.gov/

If you access the link, go to the daily statewide reservoir report.

The "water year" runs from October 1 through the following September 30, so this is the eight-month update after the new year. Reservoir capacity updated for May 28, 2025 (using threepointer's scale). Listed with % of Average to date, and the % change from two months ago:

Large (1 MM+ AF):
Oroville, 99% (+30%) / 121% / (-3%) 
Shasta, 92% (+15%) / 110% / (-20%)
Pine Flat, 85% (39%) / 124% / (-8%)
San Luis, 67% (-2%) / 94% / (-15%)
New Melones, 81% (+4%) / 129% / (-10%)
Trinity, 92% (+17) / 117% / (-7%) 
Don Pedro, 93% (+24%) / 117% / (-16%)  
Lake McClure, 92% (+29%) / 139% / (-5%)  
Berryessa, 95% (+2%) / 115% / (-11%) 
Almanor, 83% (+10%) / 110% / (-7%) 

Medium (300k - 999k AF, where available)
Folsom, 94% (+57%) / 117% / (+28%) 
New Bullards, 98% (+21%) / 111% / (-12%)
Diamond Valley, 96% (-1%) / 127% / (-9%)
Millerton Lake, 89% (+45%) / 115% / (+32%)
Isabella, 61% (+34%) / 130% / (+22%) 
Lake San Antonio, 71% (0%) / 121% (-32%)
Lake Tahoe/Tahoe City, 90% (+25%) / 180% / (-26%) 
Nacimiento, 60% (+8%) / 99% / (-38%) 
New Hogan, 66% (+14%) / 121% / (-21%)
Castaic, 95% (+19%) / 109% / (+10%) 
Clear Lake, 100% (+22%) / 129% / (-73%)

SF Bay Reservoirs (and of local interest, where available)
Hetch Hetchy, 97% (+30%) / 120% / (+17%)
Calaveras, 79% (+1%) / 149% / (-33%)
Del Valle, 52% (+18%) / 100% / (+10%)
Lexington Reservoir, 66% (+22%) / 99% / (-24%)
San Antonio Reservoir, 71% (-27%) / 121% / (+5%)
Crystal Springs Reservoir, 65% (-9%) / 86% / (-18%)

[Mick]

The Colorado River's underwater basin has been seriously depleted. It has lost an amount equivalent to Lake Mead (U. S. largest reservoir) since 2003.

The Colorado River is running low. The picture looks even worse underground, study says.

---

https://cdec.water.ca.gov/

If you access the link, go to the daily statewide reservoir report.

The "water year" runs from October 1 through the following September 30, so this is the eight-month update after the new year. Reservoir capacity updated for May 28, 2025 (using threepointer's scale). Listed with % of Average to date, and the % change from two months ago:

Large (1 MM+ AF):
Oroville, 99% (+30%) / 121% / (-3%) 
Shasta, 92% (+15%) / 110% / (-20%)
Pine Flat, 85% (39%) / 124% / (-8%)
San Luis, 67% (-2%) / 94% / (-15%)
New Melones, 81% (+4%) / 129% / (-10%)
Trinity, 92% (+17) / 117% / (-7%) 
Don Pedro, 93% (+24%) / 117% / (-16%)  
Lake McClure, 92% (+29%) / 139% / (-5%)  
Berryessa, 95% (+2%) / 115% / (-11%) 
Almanor, 83% (+10%) / 110% / (-7%) 

Medium (300k - 999k AF, where available)
Folsom, 94% (+57%) / 117% / (+28%) 
New Bullards, 98% (+21%) / 111% / (-12%)
Diamond Valley, 96% (-1%) / 127% / (-9%)
Millerton Lake, 89% (+45%) / 115% / (+32%)
Isabella, 61% (+34%) / 130% / (+22%) 
Lake San Antonio, 71% (0%) / 121% (-32%)
Lake Tahoe/Tahoe City, 90% (+25%) / 180% / (-26%) 
Nacimiento, 60% (+8%) / 99% / (-38%) 
New Hogan, 66% (+14%) / 121% / (-21%)
Castaic, 95% (+19%) / 109% / (+10%) 
Clear Lake, 100% (+22%) / 129% / (-73%)

SF Bay Reservoirs (and of local interest, where available)
Hetch Hetchy, 97% (+30%) / 120% / (+17%)
Calaveras, 79% (+1%) / 149% / (-33%)
Del Valle, 52% (+18%) / 100% / (+10%)
Lexington Reservoir, 66% (+22%) / 99% / (-24%)
San Antonio Reservoir, 71% (-27%) / 121% / (+5%)
Crystal Springs Reservoir, 65% (-9%) / 86% / (-18%)