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

Plot Type:

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
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
2017*	9,340	19.20	Feb 7, 2017
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)

Rest of Today: Mostly cloudy. Scattered showers and isolated thunderstorms. Highs in the upper 70s to lower 90s. Southwest winds 10 to 20 mph.

Tonight: Mostly clear. Lows in the lower 50s to mid 60s. Southwest winds 10 to 20 mph.

Thursday: Sunny. Highs in the mid 70s to lower 90s. Southwest winds 10 to 20 mph.

Thursday Night: Mostly clear. Lows in the lower 50s to mid 60s. Southwest winds 10 to 20 mph.

Friday: Sunny. Highs in the upper 70s to mid 90s. Southwest winds 10 to 20 mph.

Friday Night: Clear. Lows in the lower 50s to mid 60s.

Saturday and Saturday Night: Mostly clear. Highs in the upper 70s to lower 90s. Lows in the 50s to lower 60s.

Sunday: Partly cloudy in the morning then becoming sunny. Highs in the mid 70s to upper 80s.

Sunday Night through Tuesday: Mostly clear. Lows in the mid 50s to lower 60s. Highs in the mid 70s to lower 90s.

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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