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Is Clear Lake safe to swim in?

6 min read

Asked by: Iman Moore

The expansive, warm water of Clear Lake makes it ideal for recreation, including swimming, water skiing, sailing, and boating.

Is Clear Lake toxic?

Lake County Public Health officials are urging caution when recreating on Clear Lake because of increasingly high levels of dangerous toxins produced by cyanobacteria at several test locations.

Is Clear Lake CA contaminated?

Rich mineral deposits around the lake were historically mined for borax, sulphur, and mercury. Thus, Clear Lake continues to be polluted by mercury and methylmercury which bioaccumulates in the food chain (Suchanek et al. 2008). In spite of pollution, the lake boasts an impressive diversity of biological life.

Does Clear Lake have mercury in it?

o The Northern California Coast Range, where Clear Lake is located, is naturally rich in mercury and other ores. o The Sulphur Bank Mercury Mine, located on the shore of Clear Lake, has caused mercury contamination of the lake sediments.

Is Clear Lake safe to swim in 2021?

Swimmers, boaters urged to stay out of certain Clear Lake areas because of blue-green algae. Lake County health officials are urging residents and visitors to stay out of certain areas of Clear Lake for the time being because of toxic blue-green algae and the potential health risks it poses to humans and their pets.

Is Clear Lake water clean?

Clear and clean are not synonymous!



A clear lake is easy to spot. There are no visible particles in the water; it is not muddied by sediment or algae blooms. You can usually see fish swimming around at the bottom. But a clear lake might be hiding bacteria, pesticides or toxins, like the ones algae produces.

Why does Clear Lake CA smell?

Costner has worked at the district for 32 years and he knows when lake conditions deteriorate. Mats of cyanobacteria ring Clear Lake during warm months, covering its crystal waters along the shoreline with paint-like swirls of green and white. When the wind comes from the west, foul odors waft toward his office.

What’s wrong with Clear Lake?

The waters in Clear Lake, the second largest in California, shelter a treacherous occupant — potentially toxic blooms of cyanobacteria. The harmful algal blooms are a threat to public health, recreation, and the local economy.

Why is Clear Lake empty?

About 100 miles north of San Francisco, Clear Lake, like other big lakes in the West, has suffered from too little inflow amid three years of drought.

How Full Is Clear Lake right now?

The level of Clear Lake is measured in reference to the “RUMSEY GAGE”. Zero Rumsey is equal to 1318.257 feet above mean sea level. A full lake, by definition, is reached when the lake measures 7.56 feet on the Rumsey Gage.



Historical Water Levels of Clear Lake.

10% chance each year 10.04 feet
0.2% chance each year 13.84 feet

Where can you swim in Clear Lake?

Clear Lake State Park, on the lake shore 20 miles from Camp, has a great beach with lake access for swimming. On the beach there are picnic tables, ramadas for shade, and restrooms. In the park you’ll also find other picnic areas, boat launches, fishing areas, and good hiking trails.

What lakes have blue-green algae in California?

The board released a map of the lakes and reservoirs with a dangerous level of toxic algae , which includes Big Bear Lake, Lake Elsinore, Lake Isabella, San Luis Reservoir and Almaden Lake. Officials are recommending people and their pets and livestock stay out of the water and avoid drinking it until further notice.

Where does Clear Lake get its water from?

Clear Lake (California)

Clear Lake
Primary inflows Scotts Creek Middle Creek Forbes Creek Morrison Creek Seigler Canyon Creek Shindler Creek Kelsey Creek Adobe Creek Manning Creek
Primary outflows Cache Creek
Basin countries United States
Max. length 19 mi (31 km)

What lakes have toxic algae?

Cyanobacteria blooms (blue-green algae) are a frequent occurrence in the Great Lakes, particularly in Lake Erie, Green Bay, and Saginaw Bay. These blooms may cause fish kills and discolored or foul-smelling water, affecting both human and ecosystem health.

How long do blue-green algae symptoms last?

Ingestion: Gastrointestinal (GI) effects include nausea, vomiting, diarrhea, and mild liver enzyme elevations. The time to onset of GI symptoms after oral exposure is usually 3–5 hours and symptoms can last 1–2 days. Exposure can cause conjunctivitis, rhinitis, earache, sore throat, and swollen lips.

What does toxic blue-green algae look like?

What do toxic algae look like? Toxic algae can look like foam, scum, or mats on the surface of water, said Schmale. Harmful algae blooms, which can be blue, vibrant green, brown or red, are sometimes mistaken for paint floating on the water.

What happens if you swim in blue-green algae?

Getting blue-green algae/microcystin on the skin may produce a rash, hives, or skin blisters (especially on the lips and under swimsuits). Swallowing water containing blue-green algae/microcystin may cause gastrointestinal symptoms such as stomach pain, nausea, vomiting, diarrhea, severe headaches, and fever.

How can you tell if blue-green algae is toxic?

Some blue-green algae produce toxins or poisons.



Signs of a toxic bloom may include:

  1. Dead fish, waterfowl, or other animals.
  2. Sudden, unexplained sickness or death of a cat or dog, especially if it has algae on its mouth, legs, or feet.
  3. Skin rashes on humans after being in the water.


How long does it take for blue-green algae to make you sick?

Q: How soon do symptoms appear? A: Symptoms may take hours or days to show up in people or animals, but normally show up within one week after exposure.

How can you tell the difference between blue algae and normal algae?

Furthermore, a significant difference between blue green algae and green algae is that the blue green algae do not possess chloroplasts, and other membrane-bound organelles while green algae possess chloroplasts and membrane-bound organelles.

How do I know if my lake has blue algae?

If the algae have formed a green ring at the top of the water, there is a strong possibility that your lake does have a blue- green algae community. If your lake or pond has a mat of green material floating on the surface, the stick test can help determine what it is.

What does blue algae do to humans?

Exposure to high levels of blue-green algae and their toxins can cause diarrhea, nausea or vomiting; skin, eye or throat irritation; and allergic reactions or breathing difficulties. Pet and livestock illness/deaths can happen if animals consume large amounts of water containing blooms, scums or benthic mats.

What happens if you swim in toxic algae?

This includes vomiting, diarrhea, coughing, weakness, cramping and headaches. Symptoms can develop within a few hours of exposure. Seek immediate medical attention if you suspect you or your child has been exposed to a harmful algal bloom.

What does harmful algae look like?

Harmful algal blooms can be green, blue, red or brown. They can be scummy or look like paint on the surface of the water.

How do I know if my lake has toxic algae?

The best thing to do is always look for and follow warnings from local authorities. Often the Health Department. These could be on the evening news in the newspaper online.

Can you swim in algae water?

Algae can be very slippery, causing swimmers to fall resulting in bumps, bruises, cuts and even broken bones. Don’t try to swim in a pool that’s full of algae. Besides causing injuries, an algae infested pool creates a higher risk of drowning for those who are not expert swimmers or those who fall unconscious.