THE LATEST CLARITY MEASUREMENT
(Click here) for the average clarity readings from 2011
Lake Tahoe is one of the clearest lakes in the world, currently you can see into its cobalt waters to a depth of 68 feet. The problem is that forty years ago, you could see to a depth of over 100 feet. So, what has happened?
Lake Tahoe is located at the bottom of a very deep basin. There are 63 streams and tributaries that flow into the lake and only 1 that flows out. This means that dirt, lawn chemicals and runoff (among other things) are flowing into the lake, but very little is flowing back out of it. These nutrients feed the algae growing in the lake and cause the cloudiness and loss in clarity.
Clarity is the most obvious sign of Lake Tahoe's health and is therefore one of the most important aspects of the work we do at the TRPA. There are numerous ongoing projects happening around the lake to protect it from runoff and pollution. In addition, we are putting many plans into place that will help improve the lake's clarity.
Some of the things we are doing include:Requiring that all homeowners and business owners install Best Management Practices (BMPs).
(Click here for more information about BMPs.)
This will help reduce the amount of erosion and sediment from entering the lake and feeding the algae in the first place.
Enforcing the ban on two-stroke engines on the lake. These engines previously dumped tremendous amounts of pollution into the lake, but since the ban on these engines was implemented in 1999 the pollution levels in the lake have dropped dramatically.
(Click here to go to the watercraft page)
Implementing major erosion control projects around the lake. Currently, whenever major development projects happen, they are required to install strong erosion-control measures to reduce and/or eliminate runoff from the project. In many cases, the runoff from the area after the project is completed is significantly reduced from what existed prior to the development.
Monitoring all development projects to ensure compliance with their permit and to enforce the regulations that are designed to protect Lake Tahoe.
Lake Tahoe's water clarity hit an all-time low in 1997 but through the Environmental Improvement Program and the efforts of the entire community, we're striving to turn the corner on declining lake clarity.
(Click here) to view the TRPA Water Quality Management Plan for the Tahoe Basin (25 MB! Long Download).
(Click here) to read more about the science of saving Lake Tahoe.