San Andreas Lake a Dam water level — California
San Andreas Lake a Dam in California was last measured at 443.80 ft (datum NGVD29), as of Aug 31, 2026, 12:45 AM (UTC-07:00) (USGS Water Services). Over its recent trend window the level has been rising (+0.3 ft). This reading is provisional and subject to revision.
- % of conservation pool full
- Not reported
- Storage
- Not reported
- Recent trend
- ↑Rising
+0.3 ft over the trend window
Recent trend
Readings this station published between Jun 2, 2026 and Aug 31, 2026 — a 89-day window — downsampled for display.
Data: USGS Water Services (waterservices.usgs.gov) and USACE CWMS Data (cwms-data.usace.army.mil), retrieved 2026-08-31. Both public domain (a work of the U.S. Government, 17 U.S.C. §105).
Source: USGS site 11162730, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00). Official page for this lake →
About this gauge's record
This site's drainage basin covers approximately 5 sq mi of contributing watershed.
The dam behind San Andreas Lake a Dam
San Andreas Lake a Dam is held back by San Andreas , an earthfill embankment, holding the pool back by sheer mass and an impervious core rather than by the strength of concrete , standing 107 ft high and running 727 ft along its crest , built across San Andreas Creek in San Mateo County , near San Mateo . It was completed in 1870 , and is owned by City and County of San Francisco (a local government owner) .
Its recorded primary purpose is water supply — delivering water to its customers comes first, so drawdown here follows demand as much as it follows rainfall .
NID classes it high hazard potential. That describes what a failure would cost downstream — loss of life would be expected — and says nothing about how likely a failure is, or what condition the dam is in. Its most recent condition assessment was fair: sound under normal loading, though a rare or extreme event could expose a deficiency. That assessment is dated 12/31/2019.
At its normal pool the reservoir covers about 550 acres. NID records a maximum storage of 19,027 acre-ft. It is regulated by DWR, Division of Safety of Dams.
Dam facts: National Inventory of Dams record CA00129 , filed by California — U.S. Army Corps of Engineers, public domain. Water levels above come from USGS Water Services and are a separate source. (How this dam was matched to this gauge →)
How San Andreas Lake a Dam compares nearby
None of the 6 nearby lakes with a current trend are rising right now — this lake's movement looks specific to its own operation rather than shared regional conditions.
Nearby lakes
The six nearest published lakes by centroid distance (great-circle) — cross-state neighbors included.
| Lake | State | Level | Distance |
|---|---|---|---|
| Pilarcitos Lake | CA | 679.13 ft | 6 km |
| Lower Crystal Springs Reservoir | CA | 272.37 ft | 12 km |
| San Antonio Reservoir | CA | 455.56 ft | 51 km |
| Calaveras Reservoir | CA | 725.83 ft | 54 km |
| Del Valle Dam & Reservoir | CA | 695.18 ft | 60 km |
| Lake Sonoma-Pool | CA | 449.04 ft | 135 km |
Frequently asked questions
- What is the current water level of San Andreas Lake a Dam?
- As of Aug 31, 2026, 12:45 AM (UTC-07:00), the pool elevation was 443.80 ft (datum NGVD29), provisional and subject to revision. See the trend chart above for the recent direction.
- Is San Andreas Lake a Dam full right now?
- Its managing agency does not publish a %-of-conservation-pool-full figure for this lake, so we show the bare level rather than estimate one.
- Where does this data come from?
- From USGS site 11162730, retrieved Aug 31, 2026, 8:24 AM (UTC+00:00).
More in California
See every lake tracked in California, or read the methodology behind these figures.