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		River Group: Russian Napa

Monitor Stage: 16.0 Feet

Flood Stage: 18.0 Feet

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

Historical Stage/Flow Data
Note: Water Year 2025 is currently showing peak daily mean values. These will be updated to instantaneous peaks in the coming months.
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

Official 7 Day National Weather Service Forecast (CAZ506)

rest of Today: Sunny. Highs in the upper 70s to mid 90s. East winds up to 5 mph and becoming south in the afternoon.

Tonight: Clear. Lows in the lower 50s to mid 60s. Northwest winds up to 5 mph.

Thursday: Sunny. Highs in the 80s to 90s. North winds up to 5 mph.

Thursday Night: Mostly clear. Lows in the lower 50s to mid 60s. Northwest winds up to 5 mph.

Friday: Sunny. Highs in the lower 80s to mid 90s. North winds up to 5 mph and becoming west in the afternoon.

Friday Night: Mostly clear in the evening then becoming mostly cloudy. Lows in the 50s to lower 60s.

Saturday through Sunday Night: Partly cloudy. Highs in the 70s to 80s. Lows in the 40s to upper 50s.

Monday: Partly cloudy. Highs in the upper 60s to lower 80s.

Monday Night: Mostly cloudy in the evening then becoming partly cloudy. Lows in the 40s to upper 50s.

Tuesday: Partly cloudy in the morning then becoming mostly cloudy. A slight chance of rain. Highs in the mid 60s to upper 70s.

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.

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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