CNRFC - Hydrology - Observed River/Reservoir Conditions

WEST WALKER RIVER - BELOW LITTLE WALKER RIVER NEAR COLEVILLE (WWBC1)

Latitude: 38.38º N	Longitude: 119.45º W	Elevation: 6591 Feet
Location: Mono County in California		River Group: Eastern Sierra

Monitor Stage: 5.5 Feet

Flood Stage: 6.0 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	1,300	4.24	May 11, 2025
2024	1,840	4.96	May 19, 2024
2023	3,820	6.67	Jun 19, 2023
2022	3,030	6.05	Oct 25, 2021
2021	909	3.65	May 7, 2021
Historical High Stage/Flow Events (Period of Record - Apr 1938 to Present)* - Ranked by Flow
1997	12,300	10.11	Jan 02, 1997
1951	6,220	8.10	Nov 20, 1950
1938	5,800**	--	Dec 11, 1937
1956	5,180	7.41	Dec 23, 1955
1996	4,610	6.55	May 16, 1996
2017	4,260	6.95	Jun 20, 2017
* Numerous small gage location changes, some including datum changes, prior to Mar 1997. ** Estimated

Location Photographs
Upstream Photo	Gage House Photo	Downstream Photo

ESRI™ Locator Map

Official 7 Day National Weather Service Forecast (CAZ073)

Tonight: Mostly cloudy. Areas of freezing fog in the evening. Chance of snow and rain after midnight. Snow level 7000 feet. Snow accumulation up to 2 inches. Lows 19 to 29. South winds 10 to 15 mph with gusts up to 40 mph. Ridge gusts up to 70 mph.

Saturday: Heavy snow and rain in the morning, then heavy snow and rain in the afternoon. Snow level 7500 feet. Snow accumulation up to 1 inch with 7 to 15 inches above 7000 feet. Highs 36 to 46. South winds 10 to 20 mph. Gusts up to 35 mph in the afternoon. Ridge gusts up to 65 mph.

Saturday Night: Snow and rain likely. Snow level 6500 to 7000 feet. Snow accumulation of 2 to 6 inches. Lows 20 to 30. South winds 15 to 25 mph decreasing to 10 to 15 mph after midnight. Gusts up to 35 mph. Ridge gusts up to 70 mph.

Sunday: Snow and rain likely in the morning, then heavy snow and rain in the afternoon. Snow level 6500 feet. Highs 34 to 44. South winds 10 to 15 mph. Gusts up to 30 mph in the morning. Ridge gusts up to 70 mph.

Sunday Night: Snow and rain likely in the evening, then chance of snow after midnight. Snow level 6000 feet lowering to the valley floor. Lows 13 to 23. Southwest winds 10 to 15 mph. Ridge gusts up to 55 mph.

Monday: Mostly cloudy with a chance of snow. Highs 33 to 43.

Monday Night: Mostly cloudy with a chance of snow. Lows 10 to 20.

Tuesday: Partly cloudy with a slight chance of snow. Highs 33 to 43.

Tuesday Night: Partly cloudy in the evening then becoming mostly cloudy. Lows 13 to 23.

Wednesday and Wednesday Night: Mostly cloudy with a chance of snow. Highs 32 to 42. Lows 4 to 14.

Thursday: Mostly cloudy with a chance of snow. Highs 27 to 37.

Thursday Night: Partly cloudy with a slight chance of snow in the evening, then clear after midnight. Lows 3 to 13.

Friday: Sunny. Highs 31 to 41.

Flood Impacts
10.5 Feet	Incredible flood disaster with massive and uncertain impacts in excess of the January 1997 event.
10.0 Feet	Flood of record. Highway 395 in West Walker River Canyon closed for months. Massive destruction to infrastructure and economy including transportation, power, water, homes, businesses, etc. Area isolated. Near this flow in January 1997 a 6.5-mile stretch of Highway 395 completely scoured with debris from the canyon deposited in the town of Walker.
9.5 Feet	Near record flooding. Area cut off as most transportation routes into area destroyed or flooded. Massive destruction of infrastructure and economy including utilities, roads, business, homes, etc.
8.5 Feet	Flood disaster from Walker River Canyon through Antelope Valley. Widespread flood damage to roads, bridges, homes and structures along river. Severe damage to Highway 395 in W Walker River Canyon with the highway likely closed. Historically this flow has been exceeded only once in January 1997.
8.0 Feet	Flooding near disaster levels in the West Walker Canyon and in Antelope Valley. Numerous structures flooded and roads washed out. Sections of Highway 395 likely destroyed in West Walker Canyon. Major damage to agricutural land due to erosion and destroyed diversion dams, headgates, canals and levees. Similar to the 2nd highest flood of record in November of 1950, and only exceeded in January 1997.
7.3 Feet	Major flooding in the West Walker River Canyon and in Antelope Valley including Walker, Coleville and Topaz California. Many buildings flooded and roads washed out. Major damage to agricultural lands. Extensive sandbagging required to protect propery. Transportiation affected. Damage to Highway 395 in the West Walker Canyon likely. Similar to the 4th highest peak flow in the 85 year gage record.
6.8 Feet	Moderate flooding of lowlands, agricultural land, yards, basements and rural roads in the West Walker River Canyon and in Antelope Valley including Walker, Coleville and Topaz California. Flooding of structures limited although some sandbagging necessary Roughly similar, but slightly below the June 2017 peak.
6.5 Feet	Expanding minor flooding of lowlands, pastures and some rural roads between the West Walker River Canyon and Topaz Lake, including Walker Coleville and Topaz California. Out of bank flows may cause significant erosion of agricuturural lands. Similar to the peak of June 2023.
6.0 Feet	Flood stage. Minor flooding of lowlands pasture & rural roads in Antelope Valley including Walker, Coleville and Topaz California. Roughly similar to June 2019 and October 2021 crests.
5.5 Feet	Monitor Stage, No flooding in reach from West Walker River Canyon through Antelope Valley CA including Walker, Coleville, Topaz CA.

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 Reno 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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