Header link June 22, 2020

LinkedIn

  • Read more
Header link September 15, 2014

Cart

  • Read more
Header link November 3, 2015

Donate Now

  • Read more
Header link May 15, 2014

Twitter

  • Read more
Header link May 15, 2014

Facebook

  • Read more
Instagram
Header link May 15, 2014

Instagram

  • Read more
Header link May 15, 2014

Contact Us

  • Read more
More options
Water Education Foundation
Home

Water Education Foundation

Everything about California water that matters
  • Water Academy
    • Agriculture
      • Agricultural Conservation
      • Agricultural Drainage
    • Background Information
      • Legislation — California and Federal
      • Regulations — California and Federal
      • Water History
      • Water Rights
    • Bay-Delta
      • Bay Delta
      • Bay Delta Conservation Plan
      • Delta Issues
      • Delta Smelt
      • Sacramento San Joaquin Delta
      • San Francisco Bay
      • Suisun Marsh
    • Dams, Reservoirs and Water Projects
      • California Aqueduct
      • Central Valley Project
      • Folsom Dam
      • Friant Dam
      • Hetch Hetchy
      • Hoover Dam
      • Infrastructure
      • Lake Mead
      • Lake Powell
      • Oroville Dam
      • San Luis Dam
      • Shasta Dam
      • State Water Project
    • Environmental Issues
      • Anadromous Fish Restoration
      • Ecosystem
      • Endangered Species Act
      • Invasive species
      • Lake Tahoe
      • Mono Lake
      • Public Trust Doctrine
      • Salmon
      • San Joaquin River Restoration
      • Watershed
      • Wetlands
    • Leaders and Experts
    • Regions
      • Central Coast
      • Central Valley
      • Mexico
      • Nevada
      • North Coast
      • Pyramid Lake
      • Sacramento Valley
      • Salton Sea
      • San Joaquin Valley
      • Sierra Nevada
      • Southern California
      • Tulare Lake Basin
    • Rivers
      • Carson River
      • Colorado River
      • Klamath River
      • New River
      • North Coast Rivers
      • Russian River
      • Sacramento River
      • Truckee River
      • San Joaquin River
    • Water Issues
      • Climate Change
      • Coronavirus
      • Drought
      • Earthquakes
      • Energy and Water
      • Flood Management
      • Fracking
      • Growth
      • Hydropower
      • Levees
      • Tribal Water Issues
      • Water Conservation
      • Water Equity
    • Water Quality
      • Drinking Water
      • Nitrate contamination
      • Pollution
      • Stormwater
      • Wastewater
      • Water Quality
    • Water Supply and Management
      • Acre Foot
      • Aquifers
      • California Water Plan
      • Conjunctive Use
      • Desalination
      • Grey water
      • Groundwater
      • Integrated Regional Water Management
      • Recreation
      • Surface Water
      • Water Marketing and Banking
      • Water Rates
      • Water Recycling
      • Water Supply
      • Water Transfers
  • Tours & Events
    • Water Tours
      • 2023 Tour Sponsors
    • Events
    • Event Calendar
    • Past Tours & Events
      • Anne J. Schneider Fund Lecture Series
  • Specialized Programs
    • Water Leaders
      • Class Rosters
      • Yearly Class Reports
      • Your Alumni Network
      • Alumni Profiles
    • Project WET
      • Workshops
      • Special Workshops & Events
      • Supplementary Materials
      • California Content Standard Correlations
      • Facilitator's Trainings
      • Foundation School Programs
        • Elementary Programs
        • Secondary Programs
      • Water Kids
      • California Project WET Gazette
      • Gazette Archives
    • Colorado River Project
    • GRA Scholastic Fund Program
  • Maps & Guides
    • Maps & Posters
    • Layperson's Guides
    • Map & Guide Bundles
    • Books
    • Colorado River Materials
    • California Runoff Rundown
    • Other Publications
    • Water Awareness Materials
    • Downloadable Publications
    • Videos and DVDs
      • Video Clips
    • School Age Publications
    • Stickers
    • Free Programs and Publications
  • Newsroom
    • Western Water News
    • Aquafornia
      • About Aquafornia
    • Information Desk
    • Western Water Magazine Archive
      • Full Print Edition
      • Print Edition Excerpts
    • River Report Archive
  • Aquapedia
    • Alphabetical List of Subjects
      • A
      • B
      • C
      • D
      • E
      • F
      • G
      • H
      • I
      • J
      • K
      • L
      • M
      • N
      • O
      • P
      • Q
      • R
      • S
      • T
      • U
      • V
      • W
      • X
      • Y
      • Z
    • Historical Water People
    • Where Does My Water Come From?
      • Northern California
      • Sacramento
      • North Bay
      • South Bay
      • Central Valley
      • Los Angeles
      • Inland Empire
      • San Diego
      • All California Water Sources
    • Timelines
    • Videos
    • Image Gallery
    • Water Directory
      • Federal Agencies
      • State Agencies in California
      • Environmental Organizations
      • Other California Organizations
      • State and Federal Legislative Committees
      • Water Associations and Groups
      • Western States Water Agencies and Districts
    • Online Resources
    • Useful Acronyms
    • About Aquapedia
  • About
    • About Us
      • Board of Directors
      • Staff Biographies
      • Job Openings
    • Announcements
    • Support Our Mission
      • Become a Member
      • Donate in Honor/Memory
      • Donate to Aquapedia or Aquafornia
      • Shop Amazon
      • Planned Giving
    • Contact Us
Aquapedia background February 11, 2014 Lakes

Lake Tahoe

World-renowned for its crystal clear, azure water, Lake Tahoe straddles the Nevada-California border, stretching 22 miles long and 12 miles wide and hemmed in by Sierra Nevada peaks.

At 1,645 feet deep, Tahoe is the second-deepest lake in the United States and the 10th deepest in the world. The iconic lake sits 6,225 feet above sea level.

Approximately 40 percent of the Tahoe Basin’s rain and snow fall directly into the lake, contributing to Lake Tahoe’s legendary clarity. The remaining precipitation drains through granitic soils, which are relatively sterile and create a good filtering system.

Formed by uplifting, glaciation and erosion about 2 million to 3 million years ago, Lake Tahoe today is facing major challenges.

Lake Tahoe Challenges

Lake Tahoe’s vitality is threatened by several factors, including invasive species such as trout and bass, stormwater runoff and increasing temperatures as a part of ongoing climate change. California’s historic five-year drought, which ended in 2017, led the lake to be the driest it had been in a century. But the historic precipitation that followed caused the lake to fill to the brim, making popular beaches smaller in size.

The influx of people and development into Lake Tahoe during the last century adversely affected the lake’s famed clarity. Urban runoff containing such things as fertilizers feeds algae growth in the lake while other sediment flushed into the lake causes it to be less clear. Once in the water, these ultra-fine sediments are one of the primary culprits for loss of clarity as they reflect sunlight.

Experts believe the biggest problem affecting Lake Tahoe’s clarity is algae. Because the lake is a contained body of water with only one outlet, the Truckee River, the lake has difficulty “flushing,” despite inflow from several surrounding creeks.

Meanwhile, many of the basin’s natural wetlands have been filled in to make room for development, which increases runoff into the lake and decreases the natural filtration process provided by wetlands.

Lake Tahoe Restoration Efforts

For more than 20 years, the Tahoe Regional Planning Agency, a joint planning effort between California, Nevada and the federal government, has worked to protect Lake Tahoe by restoring wetlands, preventing contaminants from reaching its shores and monitoring water quality. A summit led by President Clinton in the 1990s helped draw attention to the issues facing the lake.

Returning Lake Tahoe to near-pristine conditions is a long-term effort and requires more work. Researchers use a variety of methods to determine Lake Tahoe’s clarity, including a Secchi disk, a dinner plate-sized object dropped into the lake until it is no longer visible. In 1962, the first year of measurements, the Secchi disk was visible at 136 feet.

Heavy rains in 2016-2017 deposited a massive amount of sand and mud into the lake. Consequently, in 2017, the disk could be seen only at 60.4 feet, the lowest visibility level recorded. In 2019, the University of California, Davis Tahoe Environmental Research Center reported a five-year average in lake clarity of 70.3 feet, an increase of about a foot from the previous five-year average.

Tahoe Regional Planning Agency’s environmental improvement program, financed by nearly $1 billion in local, state and federal funds, aims to restore and maintain the ecosystem health of Lake Tahoe. Projects and programs undertaken by TRPA and other agencies include:

  • Replacing 23 acres of wetlands near the mouth of the Upper Truckee River, a $10 million restoration project
  • Monitoring the amount of sediment and nutrients flowing into the lake from the Tahoe Basin’s tributary streams and groundwater aquifers
  • Constructing rock trenches and retention basins; a $7 million program by the California Department of Transportation to keep stormwater runoff and sediment out of the lake by allowing polluting sediments time to settle out and be absorbed into land

Overall lake health remains a concern and is affected by climate change.

In its 2017 annual report, UC Davis’ Tahoe Environmental Research Center found that the number of days during which Lake Tahoe exhibited summer-like conditions increased by 26 days since 1968. Furthermore, the lake has been warming by one-half degree Fahrenheit each year, which is 14 times faster than the long-term warming rate.

One of Lake Tahoe’s biggest future challenges may not be environmental but managerial. California and Nevada’s joint jurisdiction over the lake has been tested. In 2013, Nevada lawmakers proposed legislation to end the arrangement but ultimately decided to continue the joint jurisdiction.

  • Print-friendly

Referring Pages

Aquapedia background May 4, 2021 Lake Tahoe State Water Project Oroville Dam Lake Perris

Pauline Davis

Pauline DavisPauline Davis (1917-1995), who represented all or portions of 12 rural Northern California counties in the California Assembly, guided some of the state’s most significant water development proposals through the Legislature.

During her legislative career from 1952 to 1976, Davis concentrated on water issues important to her constituents by championing area-of-origin protections for water targeted for export as part of the fledgling State Water Project.

  • Read more
Aquapedia background September 1, 2016 Lake Tahoe Lake Mead Mono Lake Diamond Valley Lake

Lakes

Definition

Lake TahoeA lake is an inland standing body of water.

Lake, Pond or Wetland?

Scientifically and legislatively, lakes are indistinguishable from ponds, but lakes generally are considered to be longer and deeper lentic, or still, waters. In the 18th and 19th centuries, scientists attempted to distinguish the two more formally, stating that ponds were shallow enough to allow sunlight to penetrate to the bottom, but this exists today as an unofficial point.

  • Read more

Share this page

  • Share on Facebook
  • Share on Twitter
  • Share on LinkedIn
  • Sent to a friend.
Print-friendly

Related Links

Aquapedia background February 11, 2014 Lakes
Aquapedia background September 1, 2016 Lake Tahoe Lake Mead Mono Lake Diamond Valley Lake

Lakes

Definition

Lake TahoeA lake is an inland standing body of water.

Lake, Pond or Wetland?

Scientifically and legislatively, lakes are indistinguishable from ponds, but lakes generally are considered to be longer and deeper lentic, or still, waters. In the 18th and 19th centuries, scientists attempted to distinguish the two more formally, stating that ponds were shallow enough to allow sunlight to penetrate to the bottom, but this exists today as an unofficial point.

  • Read more
Back
This item appears in:
  • Topic: Climate Change
  • Topic: Lake Tahoe
  • Topic: Stormwater
  • Topic: Water Quality
  • Topic: Surface Water
  • L
  • T
Footer pod May 20, 2014

Water Education Foundation

Copyright © 2023 Water Education Foundation. All rights reserved.

The Water Education Foundation is a nonprofit, tax-exempt, 501(c)3 organization, federal tax ID #942419885.

Privacy Policy

Donor Privacy Policy

  • Read more
Footer pod May 20, 2014

Contact Information

2151 River Plaza Drive, Suite 205
Sacramento CA 95833

Telephone (916) 444-6240

Contact Us via email

  • Read more

Quicklinks

Footer quicklink May 20, 2014

Contact Us

  • Read more
Footer quicklink May 20, 2014

Donate Today

  • Read more
Footer quicklink May 20, 2014

Tours

  • Read more
Footer quicklink May 20, 2014

Newsletter Signup

  • Read more
Footer quicklink May 20, 2014

Foundation News

  • Read more
Footer quicklink May 20, 2014

Calendar

  • Read more

Log in

  • Create new account
  • Request new password

Commands

  • Support portal
  • Log in