Station Name: TUOLUMNE R NR HETCH HETCHY CA
Data Source: Water Data - usgc.gov

Elevation Above Sea Level: 3,484 feet / 1,062 meters

Nearest Address:
Hetch Hetchy Road
Groveland, CA 95321
Tuolumne County

GPS Coordinates: 37.93742147, -119.7982326

Nearby Water Temperatures

Winter Storm Watch issued December 19 at 12:07PM PST until December 26 at 10:00AM PST by NWS Sacramento CA

Effective: Fri December 19, 2025, 12:07 PM
Expires: Sat December 20, 2025, 4:00 PM

* WHAT...Heavy snow possible. Accumulation amounts uncertain at this time but may range from around a foot at 5500 feet and up 4 feet at highest elevations. Winds could gust as high as 45 mph. * WHERE...West Slope Northern Sierra Nevada and Western Plumas County/Lassen Park including Interstate 80 and Highway 50. * WHEN...From Tuesday evening through Friday morning. * IMPACTS...Dangerous travel conditions with chain controls and road closures possible. Low visibility due to combination of wind and heavy snow. * ADDITIONAL DETAILS...Snow accumulations will remain near or above pass level through Tuesday, then drop to around 5500 feet during the day Wednesday.

Check the latest road conditions from Caltrans online at quickmap.dot.ca.gov or dial 5 1 1.

Flood Watch issued December 19 at 8:24AM PST until December 26 at 4:00PM PST by NWS Sacramento CA

Effective: Fri December 19, 2025, 8:24 AM
Expires: Sat December 20, 2025, 4:00 PM

A series of warm atmospheric rivers will bring moderate to heavy rain to the Valley, foothills, and mountains the week of Christmas. The prolonged period of rain will bring the risk of flooding to the Sacramento Valley, northern San Joaquin Valley, northern Sierra Nevada and adjacent foothills, as well as the Coastal Range. * WHAT...Flooding caused by excessive rainfall is possible. * WHERE...A portion of northern California, including the following areas, the Sacramento Valley, northern San Joaquin Valley, Delta region, Sierra Nevada and adjacent foothills, and Coastal Range. * WHEN...From Saturday afternoon through next Friday afternoon. * IMPACTS...Excessive runoff will result in rises along area rivers, creeks, streams. Small streams and creeks may rise out of their banks. Flooding may occur in low-lying, poor drainage, and urban areas. Mudslides and rockslides may occur in mountain and foothill areas. * ADDITIONAL DETAILS... - Periods of moderate to heavy rain are forecast the week of Christmas. Debris flows are not expected over recent burn scars, but do anticipate enhanced runoff in/below scars. - http://www.weather.gov/safety/flood

You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop.

Winter Storm Watch issued December 20 at 4:13PM PST until December 26 at 10:00AM PST by NWS Sacramento CA

Effective: Sat December 20, 2025, 4:13 PM
Expires: Sun December 21, 2025, 4:00 PM

* WHAT...Heavy snow possible. Accumulation amounts uncertain at this time but may range from around a foot at 5500 feet and up 4 feet at highest elevations. Winds could gust as high as 45 mph. * WHERE...West Slope Northern Sierra Nevada and Western Plumas County/Lassen Park including Interstate 80 and Highway 50. * WHEN...From Tuesday evening through Friday morning. * IMPACTS...Dangerous travel conditions with chain controls and road closures possible. Low visibility due to combination of wind and heavy snow. * ADDITIONAL DETAILS...Snow accumulations will remain near or above pass level through Tuesday, then drop to around 5500 feet during the day Wednesday.

Check the latest road conditions from Caltrans online at quickmap.dot.ca.gov or dial 5 1 1.

Flood Watch issued December 20 at 1:03PM PST until December 26 at 4:00PM PST by NWS Sacramento CA

Effective: Sat December 20, 2025, 1:03 PM
Expires: Sun December 21, 2025, 4:00 PM

A series of warm atmospheric rivers will bring moderate to heavy rain to the Valley, foothills, and mountains the week of Christmas. The prolonged period of rain will bring the risk of flooding to the Sacramento Valley, northern San Joaquin Valley, northern Sierra Nevada and adjacent foothills, as well as the Coastal Range. * WHAT...Flooding caused by excessive rainfall continues to be possible. * WHERE...A portion of northern California, including the following areas, the Sacramento Valley, northern San Joaquin Valley, Delta region, Sierra Nevada and adjacent foothills, and Coastal Range. * WHEN...Through Friday afternoon. * IMPACTS...Excessive runoff will result in rises along area rivers, creeks, streams. Small streams and creeks may rise out of their banks. Flooding may occur in low-lying, poor drainage, and urban areas. Mudslides and rockslides may occur in mountain and foothill areas. * ADDITIONAL DETAILS... - Periods of moderate to heavy rain are forecast the week of Christmas. Debris flows are not expected over recent burn scars, but do anticipate enhanced runoff in/below scars. - http://www.weather.gov/safety/flood

You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop.

Flood Watch issued December 20 at 11:57AM PST until December 26 at 4:00PM PST by NWS Hanford CA

Effective: Sat December 20, 2025, 11:57 AM
Expires: Sat December 20, 2025, 8:00 PM

* WHAT...Flooding caused by excessive rainfall continues to be possible. * WHERE...A portion of central California, including the following areas, Mariposa-Madera Lower Sierra, San Joaquin River Canyon, Upper San Joaquin River, Yosemite NP outside of the valley and Yosemite Valley. * WHEN...From 4 PM PST this afternoon through Friday afternoon. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Low-water crossings may be flooded. * ADDITIONAL DETAILS... - Marginal Risk of Excessive Rainfall. - http://www.weather.gov/safety/flood

You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop.

Winter Storm Warning issued December 20 at 11:57AM PST until December 26 at 4:00PM PST by NWS Hanford CA

Effective: Sat December 20, 2025, 11:57 AM
Expires: Sat December 20, 2025, 8:00 PM

* WHAT...Heavy snow possible. Total snow accumulations of 6 to 8 feet. Winds could gust as high as 50 mph. * WHERE...Yosemite NP outside of the valley. * WHEN...From 4 PM this afternoon to 4 PM PST Friday. * IMPACTS...Travel could be very difficult to impossible. The hazardous conditions could impact the Monday morning and evening commutes. Gusty winds could bring down tree branches.

If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1.

Winter Storm Warning issued December 20 at 7:39PM PST until December 26 at 4:00PM PST by NWS Hanford CA

Effective: Sat December 20, 2025, 7:39 PM
Expires: Sun December 21, 2025, 4:00 AM

* WHAT...Heavy snow possible. Total snow accumulations of 6 to 8 feet. Winds could gust as high as 50 mph. * WHERE...Yosemite NP outside of the valley. * WHEN...Until 4 PM PST Friday. * IMPACTS...Travel could be very difficult to impossible. The hazardous conditions could impact the Monday morning and evening commutes. Gusty winds could bring down tree branches. * ADDITIONAL DETAILS...Snow levels around 8,000 to 9,000 feet until Monday, then 7,000 to 8,000 feet through Tuesday, and lowering to 6,000 feet by Christmas Day.

If you must travel, keep an extra flashlight, food, and water in your vehicle in case of an emergency. The latest road conditions for the state you are calling from can be obtained by calling 5 1 1.

Flood Watch issued December 20 at 7:39PM PST until December 26 at 4:00PM PST by NWS Hanford CA

Effective: Sat December 20, 2025, 7:39 PM
Expires: Sun December 21, 2025, 4:00 AM

* WHAT...Flooding caused by excessive rainfall continues to be possible. * WHERE...A portion of central California, including the following areas, Mariposa-Madera Lower Sierra, San Joaquin River Canyon, Upper San Joaquin River, Yosemite NP outside of the valley and Yosemite Valley. Mainly up to 9,000 feet until Monday, then gradually lowering to 6,000 feet by Christmas Day. * WHEN...Through Friday afternoon. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Low-water crossings may be flooded. * ADDITIONAL DETAILS... - http://www.weather.gov/safety/flood

You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop.

Flood Watch issued December 20 at 11:57AM PST until December 26 at 4:00PM PST by NWS Hanford CA

Effective: Sat December 20, 2025, 11:57 AM
Expires: Sat December 20, 2025, 8:00 PM

* WHAT...Flooding caused by excessive rainfall continues to be possible. * WHERE...A portion of central California, including the following areas, Bakersfield, Buena Vista, Buttonwillow - Lost Hills - I5, Caruthers - San Joaquin - Selma, Coalinga - Avenal, Delano-Wasco-Shafter, Frazier Mountain Communities, Fresno-Clovis, Fresno-Tulare Foothills, Fresno-Tulare Lower Sierra, Grant Grove Area, Grapevine, Hanford - Corcoran - Lemoore, Indian Wells Valley, Kaiser to Rodgers Ridge, Kern River Valley, Kings Canyon NP, Los Banos - Dos Palos, Mariposa Madera Foothills, Merced - Madera - Mendota, Mojave Desert, Mojave Desert Slopes, Piute Walker Basin, Planada - Le Grand - Snelling, Sequoia NP, South End San Joaquin Valley, South End Sierra Foothills, South End of the Lower Sierra, South End of the Upper Sierra, Southeast San Joaquin Valley, Tehachapi, Visalia - Porterville - Reedley, West Side Mountains South of 198, West Side Mountains north of 198 and West Side of Fresno and Kings Counties. * WHEN...From Tuesday afternoon through Friday afternoon. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Flooding may occur in poor drainage and urban areas. Low-water crossings may be flooded. * ADDITIONAL DETAILS... - Marginal Risk of Excessive Rainfall. - http://www.weather.gov/safety/flood

You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop.

Flood Watch issued December 20 at 7:39PM PST until December 26 at 4:00PM PST by NWS Hanford CA

Effective: Sat December 20, 2025, 7:39 PM
Expires: Sun December 21, 2025, 4:00 AM

* WHAT...Flooding caused by excessive rainfall continues to be possible. * WHERE...Much of Central California. Around 7,000 to 8,000 feet on Tuesday, then gradually lowering to 6,000 feet by Christmas Day. * WHEN...From Tuesday afternoon through Friday afternoon. * IMPACTS...Excessive runoff may result in flooding of rivers, creeks, streams, and other low-lying and flood-prone locations. Flooding may occur in poor drainage and urban areas. Low-water crossings may be flooded. * ADDITIONAL DETAILS... - http://www.weather.gov/safety/flood

You should monitor later forecasts and be alert for possible Flood Warnings. Those living in areas prone to flooding should be prepared to take action should flooding develop.

Winter Storm Watch issued December 20 at 11:57AM PST until December 26 at 5:00PM PST by NWS Hanford CA

Effective: Sat December 20, 2025, 11:57 AM
Expires: Sat December 20, 2025, 8:00 PM

* WHAT...Heavy snow possible. Total snow accumulations of 3 to 5 feet possible. Winds could gust as high as 50 mph. * WHERE...A portion of central California. * WHEN...From Tuesday afternoon through Friday afternoon. * IMPACTS...Roads, and especially bridges and overpasses, will likely become slick and hazardous. Travel could be very difficult to impossible. The hazardous conditions could impact the Tuesday evening and Wednesday morning commutes. Gusty winds could bring down tree branches.

Monitor the latest forecasts for updates on this situation. Persons should consider delaying all travel. If travel is absolutely necessary, drive with extreme caution. Consider taking a winter storm kit along with you, including such items as tire chains, booster cables, flashlight, shovel, blankets and extra clothing. Also take water, a first aid kit, and anything else that would help you survive in case you become stranded.

Winter Storm Watch issued December 20 at 7:39PM PST until December 26 at 5:00PM PST by NWS Hanford CA

Effective: Sat December 20, 2025, 7:39 PM
Expires: Sun December 21, 2025, 4:00 AM

* WHAT...Heavy snow possible. Total snow accumulations of 3 to 5 feet possible. Winds could gust as high as 50 mph. * WHERE...Sierra Nevada south of Yosemite NP. * WHEN...From Tuesday afternoon through Friday afternoon. * IMPACTS...Roads, and especially bridges and overpasses, will likely become slick and hazardous. Travel could be very difficult to impossible. The hazardous conditions could impact the Tuesday evening and Wednesday morning commutes. Gusty winds could bring down tree branches. * ADDITIONAL DETAILS...Snow levels around 8,000 to 9,000 feet until Monday, then 7,000 to 8,000 feet through Tuesday, and lowering to 6,000 feet by Christmas Day.

Monitor the latest forecasts for updates on this situation. Persons should consider delaying all travel. If travel is absolutely necessary, drive with extreme caution. Consider taking a winter storm kit along with you, including such items as tire chains, booster cables, flashlight, shovel, blankets and extra clothing. Also take water, a first aid kit, and anything else that would help you survive in case you become stranded.