Is the lake safe?

Mono County, California

East Walker River algae bloom status

No recent reports

Checked against state data on 24 October 2026

Is East Walker River safe to swim in?

There are no bloom reports for East Walker River in the last 30 days of California's data. The most recent was a Caution advisory on 24 August 2025 at Downstream Bridgeport Reservoir. Blooms have been reported here in two separate years since 2024.

No recent report isn't the same as safe, because most lakes are only checked occasionally. Look at the water and the signs before you swim.

Check today on the California HABs Portal map
Years with blooms
2 of 2
Advisories issued
1
Data checked
24 October 2026
See it on the California map

East Walker River algae bloom history

California's Water Boards hold 2 bloom reports for East Walker River going back to 2024. Reports came in every year since then.

State staff recommended an advisory 1 time: 1 Caution. Caution is the lowest level and means people and pets should stay away from scum and discoloured water.

  1. 2024 1 report
  2. 2025 1 report
Caution advisoryReported, no advisory level

When do algae blooms happen at East Walker River?

About 100% of reports fall between May and September, when warm, calm, sunny weather lets blue-green algae multiply.

Blooms can appear, move with the wind and fade within hours or days, so the time of year is only a guide.

January: 0% of reports
February: 0% of reports
March: 0% of reports
April: 0% of reports
May: 0% of reports
June: 0% of reports
July: 0% of reports
August: 100% of reports
September: 0% of reports
October: 0% of reports
November: 0% of reports
December: 0% of reports
Share of reports by month. Darker bars are the peak months.

Recent East Walker River algae reports

Recent reports came from 2 different locations around East Walker River, including Downstream Bridgeport Reservoir and Bridgeport Reservoir. A bloom in one cove or beach doesn't mean the whole lake is affected, and conditions can differ a short distance away.

DateLocationResult
24 August 2025 Downstream Bridgeport Reservoir Caution
17 August 2024 Bridgeport Reservoir Bloom reported

What the California results mean

California recommends one of three advisory levels when a bloom is checked, matched to the signs posted at the shore.

Caution
Toxins may be present. Stay away from scum and keep pets and livestock from drinking the water.
Warning
Toxins are at higher levels. No swimming, and keep children and pets away from the water.
Danger
High toxin levels. Stay out of the water and off the shore until further notice.
Bloom reported
A bloom was reported, often by a member of the public, without a formal advisory level.

Is East Walker River safe for dogs?

Dogs are at the greatest risk from toxic algae. They swallow water while swimming, eat scum on the shore and lick algae off their fur afterwards, and a small amount can kill a dog within hours.

  • Keep your dog on a lead near water that looks green, scummy, foamy or discoloured, and away from algae washed up on the shore.
  • If your dog gets in, rinse it straight away with clean water and don't let it lick its coat.
  • Call a vet immediately if your dog vomits, drools, has diarrhoea, staggers, shakes or seems weak after being near the water.

Read the full guide to toxic algae and dogs: symptoms, what to do in the first minutes and how vets treat it.

Health effects of toxic algae

Blue-green algae (cyanobacteria) can produce toxins that affect the liver, nervous system and skin. Swallowing water during a bloom can cause stomach pain, vomiting and diarrhoea. Skin contact can cause rashes, and breathing spray from the water can irritate the eyes, nose and throat. Children are at higher risk because they are smaller and more likely to swallow water.

How to spot a bloom

Toxic blooms can look like pea soup, spilled paint or green streaks on the surface, and they can also be blue, brown, white or red. Scum often collects along the shore downwind. If you can't see your feet in knee-deep water, or you aren't sure, stay out.

Don't drink untreated lake water, and don't boil it to make it safe: boiling doesn't destroy algal toxins. If you feel unwell after contact with the water, contact a doctor or Poison Control on 1-800-222-1222.

Nearby lakes with algae reports

All Mono County lakes with algae reports

Questions about East Walker River

Is there algae in East Walker River right now?

There are no bloom reports for East Walker River in the last 30 days of California's data. The most recent was a Caution advisory on 24 August 2025 at Downstream Bridgeport Reservoir. California's data is checked every day, so for today's conditions check the California HABs Portal map and the signs at the shore.

When was the last algae bloom at East Walker River?

The most recent entry in California's data is from 24 August 2025 at Downstream Bridgeport Reservoir: a Caution advisory.

Has East Walker River had toxic algae before?

Yes. Blooms are recorded every year from 2024 to 2025.

Can dogs swim in East Walker River?

Keep dogs out of the water whenever a bloom is reported or the water looks green, scummy or discoloured. Dogs are the animals most often killed by algal toxins because they swallow water and lick their fur. If your dog swims in water that might have algae, rinse it with clean water and call a vet if it vomits, drools, staggers or seems weak.

Can you eat fish caught in East Walker River during a bloom?

If you keep fish caught during a bloom, health agencies advise removing the guts and liver and rinsing the fillets in clean water before cooking, because toxins collect most in the organs. Some agencies advise not eating fish from an active bloom at all, so follow local guidance.

About this data

This page uses official records from the California State Water Resources Control Board, which updated daily. Reports are grouped by waterbody. The site was last rebuilt on 24 October 2026.

States only test some lakes, some of the time, so a lake without a recent report hasn't necessarily been checked. This page is independent, isn't affiliated with the State of California, and isn't health advice. View the source data.