CNRFC - Hydrology - Observed River/Reservoir Conditions

NAPA RIVER - SAINT HELENA (SHEC1)

Latitude: 38.51º N	Longitude: 122.45º W	Elevation: 195 Feet
Location: Napa County in California		Bulletin Group: Russian Napa		River Group: Russian Napa

Action/Monitor: 16.0 Feet

Minor Flood: 18.0 Feet

Moderate Flood: 20.0 Feet

Major Flood: 22.0 Feet

Plot Type:

Observed Data Credit
	Raw streamflow data is provided by the US Geological Survey (USGS). View US Geological Survey (USGS) Data for this station location.

Historical Mean Daily Stage/Flow Data
Water Year	Peak Discharge (cfs)	Stage (feet)	Date
Most Recent 5 Years
2025*	4,710	13.18	Feb 04, 2025
2024*	5,290	14.07	Feb 04, 2024
2023*	7,150	16.71	Jan 9, 2023
2022*	7,560	16.82	Oct 24, 2021
2021*	178	2.26	Jan 27, 2021
Historical High Stage/Flow Events (Period of Record - Jun 2000 to Present)* - Ranked by Flow
2006*	18,300	23.61	Dec 31, 2005
1986	16,900***	18.52	Feb 17, 1986
1997	13,100	17.70	Jan 1, 1997
1956	12,600	15.17	Dec 22, 1955
1963	12,300	15.30	Jan 31, 1963
1942	11,800	14.60	Feb 06, 1942
1965	11,800	14.96	Jan 05, 1965

* Discharge affected by regulation or diversion
** Most recent continuous record back to Jun 2000 with segmented periods back to Oct 1929
*** Flood of record at old gage site

Location Photographs
Upstream Photo	Gage House Photo	Downstream Photo

ESRI™ Locator Map

Flood Impacts
24.0 Feet	Disastrous Flooding. Widespread flooding across upper Napa Valley with travel essentially impossible. The peak water level during the flood of 12/31/2005 measured 23.6 feet.
22.0 Feet	Major Flood Stage. Major flooding throughout the upper Napa Valley with most roads inundated, making travel extremely difficult and unsafe.
20.0 Feet	Moderate Flood Stage. Moderate flooding of the lower portions of Silverado Trail along the reach. Inundation of low lying residential areas along the east river bank in the vicinity of Pope Street Bridge. Secondary and many primary roads inundated; most major cross roads inundated and unsafe to pass.
18.0 Feet	Minor Flood Stage. Minor flooding of low lying agricultural areas along river begins. Low lying rural residential areas immediately adjacent to the river and some secondary roads affected.
16.0 Feet	Monitor Stage. WFO Monterey may issue a Flood Watch-based products to cover Napa Valley regional flood potential at this stage.

Official 7 Day National Weather Service Forecast (CAZ506)

rest of Today: Mostly cloudy. A chance of showers and isolated thunderstorms. Highs in the 50s to lower 60s. West winds 10 to 20 mph.

Tonight: Mostly cloudy in the evening then becoming partly cloudy. A chance of showers in the evening. Patchy fog after midnight. Lows in the 40s to lower 50s. Northwest winds 10 to 20 mph and becoming north 5 to 10 mph after midnight.

Tuesday: Sunny. Highs in the 50s to mid 60s. Northwest winds 5 to 10 mph.

Tuesday Night: Mostly clear in the evening then becoming partly cloudy. Patchy fog in the evening. Areas of fog after midnight. Lows in the 40s to lower 50s. Northwest winds 5 to 10 mph and Becoming northeast after midnight.

Wednesday: Mostly cloudy. Patchy fog in the morning. A chance of rain in the afternoon. Highs in the lower 50s to mid 60s. East winds around 5 mph and becoming south in the afternoon. Chance of rain 40 percent.

Wednesday Night: Rain likely. Lows in the mid 40s to lower 50s.

Thursday: Rain likely. Highs in the lower 50s to mid 60s.

Thursday Night: Mostly cloudy in the evening then becoming partly cloudy. A chance of rain. Lows in the 40s to lower 50s.

Friday through Sunday: Partly cloudy. Highs in the 50s to upper 60s. Lows in the 40s to lower 50s.

Product Disclaimer

This river graphic is not intended to serve as a substitute for official flood watches, warnings, advisories, or statements issued by the NWS San Francisco Bay Area-Monterey Weather Forecast Office. Observations are preliminary and subject to change. River levels identified as "forecast" should be consistent with those contained in official NWS products. River levels identified as "guidance" have significant uncertainty due to future weather or reservoir regulation and are provided for planning purposes only.

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