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Lake Tahoe Water Health and Facts

Published on: September 2024

As North America’s largest and oldest alpine lake – and the third oldest in the entire world – Lake Tahoe has offered visitors intrigue and wonder for generations. Interested to learn a little more about the lake itself? We’ve got you covered. Read on for a few little-known facts about the waters of Lake Tahoe.

The State of Lake Tahoe in 2024

The UC Davis Tahoe Environmental Research Center (TERC) conducts an annual report on the health of Lake Tahoe, analyzing the ways in which it has been affected by climate change over the past year. This report provides valuable insight into the steps needed to preserve Lake Tahoe, and allows environmental scientists to determine how best to protect regions similar to Lake Tahoe around the world. UC Davis researchers have been monitoring Lake Tahoe since 1968. In 2023, researchers found valuable information on the lake’s clarity, fluctuating temperature, water levels, algae content and more. Read the full report here. Learn more about visiting the TERC.

Photo Credit: IVCBVB

How Old is Lake Tahoe?

It is estimated that Lake Tahoe formed at least 2.3 million years ago — and for the last million years, it has remained just about the same size as we see it today. The surrounding wilderness, in contrast, is thought to have formed much more recently, only within the last 10,000 years or so. In that time, Lake Tahoe has captured the fascination of generations of travelers and residents, from the earliest Native Americans to famous artists such as Mark Twain (you can find an account of his time in Lake Tahoe in his book “Roughing It”). It is the third oldest lake in the world.

How Deep is Lake Tahoe?

The short answer? Very deep. The long answer? Lake Tahoe is 1,685 feet deep at its deepest recorded point, with the overall average depth being 989 feet. While you won’t be able to dive all the way to the bottom, the lake is an excellent place to enjoy a swim, a scuba dive and many other water activities. You’ll have plenty of room to explore: Lake Tahoe houses around 39.75 trillion gallons of water and spans 22 miles in length, 12 miles in width.

Photo Credit: Indiana State University, Center for Underwater Science

What is the Temperature of the Water in Lake Tahoe?

In the warmer months, the temperature in the Tahoe Basin does not tend to rise much above 80 degrees, and in the colder months, it does not tend to get much chillier than around 15 degrees. Because of this, the upper 12 feet of the water itself can warm to up to 68 degrees in the summer, though once you go deeper (around 600 feet), the temperature remains a consistent 39 degrees. And, due to the lake’s massive size and depth, it does not freeze over in the winter in spite of the cold temperatures it can reach.

How Clean is the Water in Lake Tahoe?

Lake Tahoe is one of the clearest lakes in the world, and its water purity hovers around 99.7% — about the same as distilled drinking water. (That’s why it’s always best to drink Tahoe Tap while you’re here!) The waters of Lake Tahoe are so beautifully clear that an object such as a white dinner plate can be seen from 70 feet below the surface. In order to keep it so pure, we all need to do our part to contribute to the Lake Tahoe region, no matter if you are a visitor or a resident. Discover tips on how you can Make a Clear Difference, such as ensuring your watercrafts are completely clean, disposing properly of trash and more.

Copyright: Ming T. Poon

Where to Learn More About Lake Tahoe Water Facts

In addition to the TERC, the friendly staff at the North Lake Tahoe visitor centers are always thrilled to chat with visitors about anything and everything related to the lake. Head to the Tahoe City Information Center or North Tahoe Visitor Information Center in Kings Beach visitor centers to see interactive exhibits about the water and environment of Lake Tahoe, courtesy of the researchers at TERC. Speak with experts at the Incline Village Welcome Center to learn more about the lake and tips for how to help maintain its beauty. Pick up informational brochures and find resources to plan your trip at any of the North Lake Tahoe visitor centers.

Discover True Tahoe Getaways

All year, sunny or snowy, you’ll find plenty to do in Lake Tahoe. Whether you’re after a laid-back, relaxation-focused getaway or you’re a thrill seeker looking for your next adventure, we’ve got you covered. Check out all the Lake Tahoe activities available to you — and if you’re feeling like you need some inspiration, check out our Tahoe Trifecta itineraries, designed to help you experience the best of Lake Tahoe’s “big three”: the mountains, the towns and the lake.

Plan your stay today and experience True Tahoe adventure, from the lake to the mountains and everything in between.