CNRFC - Hydrology - Observed River/Reservoir Conditions

*** IMPORTANT *** Week of June 16 - Website Data Outage - Due to a major computer upgrade the week of June 16, nearly all data on the CNRFC web site will not be updated. We anticipate the down time to be approximately 4 days. The latest deterministic hydrologic forecasts for official forecast points will continue to be available at the National Water Prediction Service during this time.

MERCED RIVER - YOSEMITE NP AT HAPPY ISLES (HPIC1)

Latitude: 37.73º N	Longitude: 119.56º W	Elevation: 4017 Feet
Location: Mariposa County in California		Bulletin Group: San Joaquin		River Group: San Joaquin

Action/Monitor: N/A

Minor Flood: 7.5 Feet

Moderate Flood: 10.0 Feet

Major Flood: 13.27 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 Stage/Flow Data
Water Year	Peak Discharge (cfs)	Stage (feet)	Date
Most Recent 5 Years
2024	2,980	6.80	May 19, 2024
2023	4,980	8.42	May 23, 2023
2022	2,430	6.25	Oct 25, 2021
2021	1,410	5.02	May 7, 2021
2020	2,160	5.96	Apr 30, 2020
Historical High Stage/Flow Events (Period of Record - Aug 1915 to Present) - Ranked by Flow
1997	10,100	13.27	Jan 2, 1997
1956	9,840	12.73	Dec 23, 1955
1951	9,260	11.55	Nov 18, 1950

Location Photographs
Upstream Photo	Gage House Photo	Downstream Photo

ESRI™ Locator Map

Flood Impacts
13.27 Feet	Flood of Record: 1/2/97. $178 million in damage to Yosemite Valley.
10.0 Feet	Northside Drive at Wosky Pond, Southside Drive at Chapel Meadow, El Capitan crossover, and Sentinel crossover are impassable to vehicles.
8.2 Feet	Swinging Bridge overtops. Water on road at Northside Drive, Southsie Drive, El Capitan crossover, and Sentinel crossover.
7.5 Feet	Flood Stage. Housekeeping camp and Yosemite Valley backpacker campground begin to flood.
7.0 Feet	North Pines and Lower Pines campgrounds begin flooding.

Official 7 Day National Weather Service Forecast (CAZ324)

Today: Sunny in the morning then becoming mostly sunny. Chance of rain showers and slight chance of thunderstorms in the late morning and early afternoon. Slight chance of thunderstorms late in the afternoon. Highs 70 to 82. Southwest winds up to 10 mph. Chance of precipitation 30 percent.

Tonight: Mostly clear. A 20 percent chance of thunderstorms in the evening. Lows 53 to 61. West winds up to 10 mph shifting to the east after midnight.

Friday: Sunny. Highs 72 to 84. Northeast winds up to 5 mph shifting to the southwest in the afternoon.

Friday Night: Mostly clear. Lows 56 to 64. West winds up to 10 mph shifting to the northeast after midnight.

Saturday: Sunny. Highs 76 to 88. East winds up to 5 mph shifting to the west in the afternoon.

Saturday Night through Sunday Night: Mostly clear. Lows 59 to 66. Highs 77 to 89.

Monday: Sunny. Highs 79 to 91.

Monday Night: Mostly clear. Lows 60 to 66.

Tuesday through Wednesday: Clear. Highs 76 to 92. Lows 58 to 64.

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 Joaquin Valley-Hanford 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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