Conn Creek at Lake Hennessey
California — Water Level & Flood Stage
Located in Napa County, California on the Conn Creek. 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: CVZC1). Live data may be limited. View on NWS AHPS →
Flood Stages
Major Flood
16 ft
Moderate Flood
13.2 ft
Minor Flood
10.2 ft
Action Stage
8 ft
Flood stages defined by the National Weather Service. Gage height data from USGS Water Resources.
What Floods at Each Level
16 ft
Major Flood Stage. Water is several feet deep across floodplain on northern side of creek. Vineyards and local properties flooded, possibly exacerbated by backwatering of Lake Hennessey below. Local creek crossings inundated and impassable.
13.2 ft
Moderate Flood Stage. Water spilling onto left bank floodplain (north side of creek). Local crossings flooded and backwatered.
10.2 ft
Minor Flood Stage. Backwatering begins at local bridge crossings. Water level is approaching elevation of bridge decks, with possible overflow. NWS will issue a Flash Flood Warning if not yet already issued.
8 ft
Monitor Stage. Water is 2 feet below backwatering at local landowner crossing at gaging site. NWS will 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
CVZC1
River
Conn Creek
County
Napa, CA
Coordinates
38.5081°N, 122.4061°W
Get Flood Alerts for Conn Creek
StormCast monitors this gauge and sends a push notification to your phone when the water level crosses into a new flood category — even at 3 AM.
Frequently Asked Questions
What is the current water level of Conn Creek at Lake Hennessey?
The Conn Creek at Lake Hennessey 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 Conn Creek at Lake Hennessey?
The NWS-defined flood stage for Conn Creek at Lake Hennessey is 10.2 feet. Action stage begins at 8 feet. Moderate flooding starts at 13.2 feet, and major flooding at 16 feet.
How do I get alerts when Conn Creek rises?
Download StormCast free on Google Play, go to River Gauges, and add Conn Creek at Lake Hennessey 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 Conn Creek at Lake Hennessey gauge located?
The gauge is located in Napa County, California at coordinates 38.5081°N, 122.4061°W. Data is provided by the U.S. Geological Survey and the National Weather Service.
More Resources
Source & Notes
Data provided by: City of Napa