Reservoir Report

Crystal Sprgs Res A Dam Nr San Mateo Ca reservoir

California, USA USGS
Today high
--
Tonight low
--
Current storage
276ft
% of normal
-1%
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Right now · current storage
Crystal Sprgs Res A Dam Nr San Mateo Ca
USGS · 11162750
276 ft
As of 2026-05-11
Seasonal avg
281
Record max
293
24h change
0.0%
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Crystal Sprgs Res A Dam Nr San Mateo Ca -- None reservoir
Crystal Sprgs Res A Dam Nr San Mateo Ca None
About this reservoir

Crystal Sprgs Res A Dam Nr San Mateo Ca

Crystal Springs Reservoir is located near San Mateo, California, and was created by the construction of the Crystal Springs Dam in 1878. The reservoir is operated by the San Francisco Public Utilities Commission and serves as a major water supply for the Bay Area, providing up to 23 million gallons of water per day. The area is known for its unique hydrology, as it is fed by both surface flow and snowpack from the nearby Santa Cruz Mountains. The reservoir also serves as a popular recreational destination for activities such as hiking, fishing, and boating, and is surrounded by several parks and nature preserves. While there is some agricultural use in the surrounding area, the primary focus of the reservoir is on providing a reliable water source for the region.

StateNone
OperatorUSGS
Site ID11162750
Percent of normal-1%
Last updated2026-05-11
Records since2007
Storage trends

Daily levels at Crystal Sprgs Res A Dam Nr San Mateo Ca

Storage volume, pool elevation, and total release plotted from the operating agency's daily observations.

Lake or reservoir water surface elevation above NAVD 1988, ft

ft · code 62615

Detailed forecast

Plan around the weather

Same NOAA / yr.no feed Snoflo's iOS app uses. Watch the precipitation column on the meteogram -- rain on the basin upstream typically lifts inflow 24-72 hours later.

Hourly detail

Next 5 days, hour by hour

Temperature line with weather symbols on top, snow + rain accumulation as columns, humidity as a dotted line.

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Deep dive

5-day forecast table

Every 3 hours, broken out across temperature, snow, rain, humidity, and wind. Each cell is colour-coded relative to the column min/max.

TimeConditionTemp (°F)Snow (in)Rain (in)Humidity (%)Wind (mps)Wind dir
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Long-term outlook

15-day temperature & precipitation

Daily temperatures, snow, and rain projected over the next two weeks.

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Regional inflow

Nearby streamflow gauges

USGS streamgauges around Crystal Sprgs Res A Dam Nr San Mateo Ca -- inflows here typically show up in storage 24-72 hours later.

Track Crystal Sprgs Res A Dam Nr San Mateo Ca in the Snoflo app

Save this reservoir as a favorite and set push alerts when storage crosses a threshold (e.g. "alert me at 80% of normal").

FAQ

About Crystal Sprgs Res A Dam Nr San Mateo Ca

Where does the data for Crystal Sprgs Res A Dam Nr San Mateo Ca come from?

Daily storage, pool elevation, and release rates are sourced from USGS, USBR, and USACE monitoring stations. Weather forecast comes from NOAA / yr.no -- the same feed Snoflo's iOS app uses.

How often is the report updated?

Storage observations are updated daily by the operating agency. The 15-day weather forecast refreshes throughout the day. Snoflo caches and renders the most recent observation -- check the "as of" timestamp on the storage card.

What does the Hazard hazard rating mean?

The Corps of Engineers' hazard potential classification grades probable consequences if the dam fails: High = probable loss of human life; Significant = no probable loss of human life but possible economic loss / environmental damage; Low = no probable loss of human life, only minor economic / environmental losses. See the Dam Data Reference card above for the full definitions.

What's "% of normal"?

The current storage value compared to the historical average storage on this calendar day. 100% = right on average; values above 100% mean above-normal storage (wet year); values below mean below-normal (dry year or drought).

Can I get alerts when storage crosses a threshold?

Yes -- alerts are managed in the Snoflo iOS app. Favorite this reservoir, set a threshold, and you'll get a push the moment conditions cross.

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Premium feature

Favorites and alerts are part of Snoflo Premium. Save reservoirs, set storage thresholds, and get push notifications when conditions cross.

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Manage alerts in the Snoflo app

Custom alerts are configured in the iOS app -- favorite this reservoir, set a threshold, and you'll get a push the moment conditions cross.

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