StormCast — Weather & Emergency Alerts

San Lorenzo River (CA) at Lomond Street Bridge
California — Water Level & Flood Stage

Located in Santa Cruz County, California on the San Lorenzo River (CA). Live water level data from USGS, updated every 15 minutes.

Current Water Level

Gage Height

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Streamflow

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Last Reading

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This is an NWS forecast point (LID: IWNC1). Live data may be limited. View on NWS AHPS →

Flood Stages

Major Flood

28 ft

Moderate Flood

26 ft

Minor Flood

24 ft

Action Stage

21 ft

Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.

What Floods at Each Level

28 ft

Major Flooding. Major flooding of homes and businesses in downtown Boulder Creek between Railroad Avenue and the San Lorenzo River and riverfront properties both up- and downstream of the town center. Highway 9 is not expected to flood at these levels, but could be damaged and/or blocked by slides and other hazards.

26 ft

Moderate Flooding. Increased inundation of downtown Boulder Creek between Railroad Avenue and the San Lorenzo River, and of riverfront properties along Irwin Way, Camp Joy Road, and Lorenzo Avenue.

24 ft

Minor Flooding. Lomond Street/Irwin Way begins to flood. As flood water rise, inundation may expand westward into E Lomond Street, Middleton Ave, and Junction Ave. Riverfront homes along Irwin Way, Camp Joy Road, and Lorenzo Avenue may be flooded. NWS will issue a Flash Flood Warning, if not yet already issued.

21 ft

Monitor Stage. Water reaches bridge chord. Backwatering is possible. Flood wave travel time from Boulder Creek to the Big Trees gage in Felton, near Felton Grove, is 30 to 145 minutes. NWS may issue a Flash Flood Watch, if not yet already issued.

Impact statements from the National Weather Service, describing what typically happens at each water level.

7-Day Water Level Chart

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About This Gauge

NWS LID

IWNC1

River

San Lorenzo River (CA)

County

Santa Cruz, CA

Coordinates

37.1258°N, 122.1189°W

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Frequently Asked Questions

What is the current water level of San Lorenzo River (CA) at Lomond Street Bridge?

The San Lorenzo River (CA) at Lomond Street Bridge gauge is maintained by USGS and reports water levels every 15 minutes. Visit this page to see the latest reading updated live, or download StormCast to get push alerts when levels rise.

What is flood stage for San Lorenzo River (CA) at Lomond Street Bridge?

The NWS-defined flood stage for San Lorenzo River (CA) at Lomond Street Bridge is 24 feet. Action stage begins at 21 feet. Moderate flooding starts at 26 feet, and major flooding at 28 feet.

How do I get alerts when San Lorenzo River (CA) rises?

Download StormCast free on Google Play, go to River Gauges, and add San Lorenzo River (CA) at Lomond Street Bridge to your watchlist. StormCast will send a push notification to your phone whenever the water level crosses into a new NWS flood category — even when your screen is off.

Where is the San Lorenzo River (CA) at Lomond Street Bridge gauge located?

The gauge is located in Santa Cruz County, California at coordinates 37.1258°N, 122.1189°W. Data is provided by the U.S. Geological Survey and the National Weather Service.

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Source & Notes

Data provided by: County of Santa Cruz Public Works