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
Water Year	Peak Discharge (cfs)	Stage (feet)	Date
Most Recent 5 Years
2022*	7,560	16.82	Oct 24, 2021
2021*	178	2.26	Jan 27, 2021
2020*	696	4.31	Dec 7, 2019
2019*	9,570	19.50	Feb 27, 2019
2018*	3,970	11.31	Mar 22, 2018
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

* 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)

Tonight: Mostly cloudy in the evening then becoming partly cloudy. Patchy fog after midnight. Lows in the 40s to lower 50s. Southwest winds 10 to 15 mph.

Thursday: Mostly cloudy. Patchy fog in the morning. Highs in the 60s to lower 70s. West winds 10 to 20 mph.

Thursday Night: Mostly cloudy. Lows in the upper 40s to mid 50s. West winds 10 to 20 mph.

Friday: Partly cloudy in the morning then becoming sunny. Highs in the 60s to lower 70s. Northwest winds 10 to 20 mph.

Friday Night: Clear. Lows in the 40s to lower 50s. Northwest winds 10 to 20 mph with gusts to around 35 mph.

Saturday: Sunny. Highs in the 60s to lower 70s.

Saturday Night: Mostly clear. Lows in the mid 40s to lower 50s.

Sunday through Monday Night: Clear. Highs in the 60s to mid 70s. Lows in the 40s to lower 50s.

Tuesday through Wednesday: Mostly clear. Highs in the 60s to 70s. Lows in the 40s to lower 50s.

Impacts - E19 Information
16.0 Feet	Monitor Stage. WFO Monterey/San Francisco Bay Area may issue a Flood Watch to cover Napa Valley region flood potential at this stage.
18.0 Feet	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.
20.0 Feet	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.
22.0 Feet	Major flooding throughout the upper Napa Valley with most roads inundated, making travel extremely difficult and unsafe.
24.0 Feet	Disastrous flooding. Widespread flooding across the upper Napa Valley with travel essentially impossible. The peak water level during the flood of 12/31/2005 measured 23.6 feet.

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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