Lake Temescal - South

Oakland, California

Located in Oakland, California as the central attraction of Temescal Regional Park, Lake Temescal is a reservoir lake that was created when its source; Temescal Creek was dammed in 1868 to fill in the sag pond left behind by the Hayward Fault. It sports a Beach along the northeastern shore, park and picnic benches, full restroom facilities and is a popular fishing site for Rainbow Trout, Largemouth Bass, Redear Sunfish, Bluegill and Catfish. It receives 200 000 visitors annually and is a part of the greater East Bay Regional Park District. There are two monitoring locations at this beach. South is tested for bacterial levels weekly from April to October. The swim area is closed from November through March.

Water Quality
  • Met water quality standards less than 60% of the time

  • Historical Status
  • This status is based on the latest sample, taken on May 30th, 2023. Swim Guide - Main updates the status of this beach as soon as test results become available. These results were posted to Swim Guide on June 2nd, 2023 at 3:05 PM.
For water quality icon legend, click:  
Current Weather
14°C
A few clouds
Monitoring Frequency

Lake Temescal - South is sampled weekly from April 1st to October 31st.

Source Information

The East Bay Regional Park District’s recreational water quality is monitored as a collaborative effort between East Bay Parks, Contra Costa and Alameda County Departments of Environmental Health. Sites are monitored weekly from April - October and many continue to be monitored twice a month from November - March. East Bay's fresh water beaches are tested solely for E.coli.

The standards for indicator bacteria are as follows:

Single sample maximum
E.coli > 235 MPN / 100 ml

Geometric Mean (5 samples collected over a 30 day period)
E.coli > 126 MPN / 100 ml

A fresh water beach is marked Green when bacteria levels for a single day and geometric mean are below the standards mentioned.

A fresh water beach is marked Red when bacteria levels for a single day or the geometric mean are above the standards mentioned. In Swim Guide, a red icons will be assigned to beaches posted with a cautionary advisory as well as emergency closures. East Bay monitoring agencies do not close beaches unless there is a sanitary sewer overflow or other emergency. Beach are posted with a yellow icon on East Bay’s website when bacteria levels are above the standards mentioned.

A beach is marked Grey when there is no current or reliable monitoring information available.

When visiting a beach, EB Parks encourages you to protect your health. Keep water out of your mouth. After you leave the water, shower and towel dry as soon as possible. Do not swim in the lake for 3 days after a rainstorm or swim within 100 feet of a flowing storm drain. Check posted signs for water quality information.

Read more
Water Quality Graph

Lake Temescal - South

Oakland, California

Water Quality
  • Met water quality standards less than 60% of the time
  • Historical Status
  • This status is based on the latest sample, taken on May 30th, 2023. Swim Guide - Main updates the status of this beach as soon as test results become available. These results were posted to Swim Guide on June 2nd, 2023 at 3:05 PM.
For water quality icon legend, click:  
Current Weather
14°C
A few clouds

Located in Oakland, California as the central attraction of Temescal Regional Park, Lake Temescal is a reservoir lake that was created when its source; Temescal Creek was dammed in 1868 to fill in the sag pond left behind by the Hayward Fault. It sports a Beach along the northeastern shore, park and picnic benches, full restroom facilities and is a popular fishing site for Rainbow Trout, Largemouth Bass, Redear Sunfish, Bluegill and Catfish. It receives 200 000 visitors annually and is a part of the greater East Bay Regional Park District. There are two monitoring locations at this beach. South is tested for bacterial levels weekly from April to October. The swim area is closed from November through March.

Monitoring Frequency

Lake Temescal - South is sampled weekly from April 1st to October 31st.

Source Information

The East Bay Regional Park District’s recreational water quality is monitored as a collaborative effort between East Bay Parks, Contra Costa and Alameda County Departments of Environmental Health. Sites are monitored weekly from April - October and many continue to be monitored twice a month from November - March. East Bay's fresh water beaches are tested solely for E.coli.

The standards for indicator bacteria are as follows:

Single sample maximum
E.coli > 235 MPN / 100 ml

Geometric Mean (5 samples collected over a 30 day period)
E.coli > 126 MPN / 100 ml

A fresh water beach is marked Green when bacteria levels for a single day and geometric mean are below the standards mentioned.

A fresh water beach is marked Red when bacteria levels for a single day or the geometric mean are above the standards mentioned. In Swim Guide, a red icons will be assigned to beaches posted with a cautionary advisory as well as emergency closures. East Bay monitoring agencies do not close beaches unless there is a sanitary sewer overflow or other emergency. Beach are posted with a yellow icon on East Bay’s website when bacteria levels are above the standards mentioned.

A beach is marked Grey when there is no current or reliable monitoring information available.

When visiting a beach, EB Parks encourages you to protect your health. Keep water out of your mouth. After you leave the water, shower and towel dry as soon as possible. Do not swim in the lake for 3 days after a rainstorm or swim within 100 feet of a flowing storm drain. Check posted signs for water quality information.

Read more
Water Quality Graph

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Alameda, California
Berkeley, California
Oakland, California
Berkeley, California
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