World renowned for its crystal clear, azure water, Lake Tahoe
straddles the Nevada-California border. However, the lake’s
clarity has declined in the last 40 years due to accumulated
effects of development.
At 1,645 feet, Lake Tahoe is the second deepest lake in the
United States and the 10th deepest in the world. Lake Tahoe sits
6,225 feet above sea level, and is 22 miles long and 12 miles
wide.
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.
The lake’s vitality is threatened by several factors
including invasive species (trout and bass), stormwater
runoff and increasing temperatures as a part of ongoing climate
change. Meanwhile, drought conditions have led the lake to be the
driest it has been in a century.
Caltrans got one step closer to its controversial $500 million
project to widen Highway 37, a notoriously trafficky corridor,
with an infusion of funding Thursday. But critics said the
money could be wasted as rising tides are expected to
flood the low–lying highway within decades. On
Thursday, the California Transportation Commission approved $73
million toward the plan, which calls for widening Highway 37
between Sears Point in Sonoma and Mare Island in Vallejo from
two lanes to four. Caltrans said the project will greatly
reduce congestion on a highway used by 47,000 daily. However,
the highway is also expected to be inundated by rising tides by
2050, threats that will not be addressed by the project,
Caltrans said. Instead, the agency has a separate $10 billion
plan to elevate and protect the highway in the future.
… Portions of Highway 37 “will be completely inundated
by 2050,” especially during major storms and king tides, and
there will be increased flooding leading up to that time,
Caltrans said in a statement.
As wildfires grow in size and intensity, older communities are
recognizing the need to update their municipal water systems.
In Lake Tahoe, a robust water infrastructure is now considered
one of the three cornerstones of wildfire readiness, alongside
forest and fuels management and community and home
hardening. Each summer, utility companies on both sides of
the lake race to complete water system upgrades within the
limited six-month construction window. Today, the Lake Tahoe
community is leading the way in ensuring that firefighters
always have access to water. … The Tahoe Water for Fire
Suppression Partnership estimates that the Tahoe Basin will
need an additional $125 million in funding over the next five
years to upgrade its water systems.
A sudden storm over Lake Tahoe Saturday afternoon churned up
towering waves and fierce winds that capsized a boat, killing
eight people and injuring more. What happened in less than an
hour is now being called one of the deadliest weather-related
boating accidents in recent Tahoe history — and a powerful
reminder of how quickly and violently mountain weather can
change. This tragic event raises urgent questions: What caused
such extreme weather? Could anyone have predicted it? And is it
something that could happen again? … While detailed regional
modeling of Lake Tahoe’s summer thunderstorms is limited, major
climate assessments point to broader trends that could impact
storm behavior in the Sierra Nevada. … Findings suggest a
shift toward stronger, more abrupt convective storms. That has
implications for Lake Tahoe, where an afternoon downdraft
hitting warm lake air could generate sudden wind spikes and
dangerous waves similar to those seen on June 21.
Seven people died and another person is missing after a boat
overturned near D.L. Bliss State Park at Lake Tahoe on Saturday
afternoon amid strong winds and rainy conditions. Elsewhere in
South Lake Tahoe, a number of boats crashed into each other and
came ashore near Camp Richardson. … The National Weather
Service in Reno noted in an early Saturday morning update that
occasional showers and thunderstorms were expected through the
afternoon around the Tahoe Basin and north of Highway 50, but
pegged those chances at 10-20%. Another update at 1:12 p.m.
also noted the chance for afternoon showers and thunderstorms.
NOAA/National Weather Service Meteorologist in Charge Chris
Smallcomb said the weather event that occurred on the lake that
afternoon was “sudden, localized and of limited
predictability.” It briefly produced wind gusts of 45 mph, he
said. … Below is how Smallcomb responded to KCRA’s
questions about Saturday’s event.
On a warm, Wednesday afternoon, scientists, community members
and local leaders gathered at the Grange Hall in San Luis
Obispo to discuss the Trump administration’s attempts to weaken
laws protecting public land and waters — and how those policies
could impact the Central Coast. … From an attempt
to reduce the scope of the Endangered Species Act to an effort
to allow the president to eliminate national monuments, here
are three issues to keep an eye on for the Central Coast.
… “Our nation’s public lands provide tangible goods that
we all depend on — things like water, safety from wildfire,
timber, grazing for cattle,” (Los Padres National Forest
wildlife biologist Ben) Vizzachero said. “We need to support
those things, and as a biologist, I’m making sure that our
forest can provide those without sacrificing wildlife habitat.”
The first day of summer in Lake Tahoe began under blue skies,
but the sunny Saturday suddenly turned dark when a thunderstorm
whipped up strong winds and waves of 6 to 8 feet high. At least
six people died when a boat capsized near D.L. Bliss State Park
around 3 p.m. … Gusts up to 45 mph were measured by a
NASA-maintained buoy in the middle of the lake when the cold
front hit. It’s likely that stronger winds materialized over a
smaller portion of the lake in a phenomenon known as a
downburst. Downbursts are caused by rain-cooled air that
falls out of a cloud into a drier environment below, often
accelerating as it reaches the ground. Once the downdraft
reaches the ground, winds spread out in all directions, like
water out of a faucet hitting a sink. Weather models estimated
favorable conditions for downburst winds over Lake Tahoe on
Saturday afternoon, with a mix of dry and moist air amid an
unstable atmosphere.
Over 250 million acres of public lands could be eligible for
sale if the President’s budget reconciliation package,
something he has called the “big, beautiful bill,” is passed. A
map and analysis were created by The Wilderness Society using
source data from BLM, USFS, USGS, NPS, and SENR reconciliation
bill text (Senate Energy and Natural Resources) as of June
16, 2025. … The map includes Kiva Beach, much of Fallen Leaf
Lake, Tallac Historic Site, and even ski resorts who lease land
from USFS, including Alpine Meadows, Heavenly Valley, as well
as other treasured acreage through the Sierra and beyond.
… The mandates of the bill call for the sale of .5-.75
percent of each BLM and USFS land across 11 western states, or
about 3.3 million acres. It opens up 250 million acres for
“developers to pick from,” to get to the 3.3 million acres,
according to Oliva Tanager of the Sierra Club.
… The Colorado River system rushes through
turbines inside Glen Canyon Dam on Lake Powell, producing
affordable, carbon-free hydropower. … Climate change and
chronic water overuse continue to constrict the mighty river’s
flows, though, jeopardizing the dam’s ability to produce
hydroelectric power. The lack of water has also created a slew
of environmental problems in the Grand Canyon’s ecosystem,
which sprawls below Glen Canyon Dam — most notably for an
ancient, threatened fish species, the humpback chub, which is
hunted by invasive smallmouth bass. Under Biden last year, the
U.S. Bureau of Reclamation finalized a decision that allows the
dam to periodically release surges of water that bypass the
machinery that generates power. These flows cool the river
below the dam, which curbs smallmouth bass reproduction. Utah
Republicans and power providers say that decision has only
further threatened the valuable energy source — and they hope
to undo it.
Lake Tahoe’s iconic blue waters were the third murkiest on
record last year and the worst they’ve been in several years,
according to data from scientists who have studied the lake for
decades. Clarity of the alpine lake — measured by dropping a
white disk into the water and noting when it disappears from
sight — is a signal of its overall health. Tiny particles are
major culprits of reduced clarity, including the sediment and
other pollutants that wash into the lake from runoff and air
pollution and the plankton that grow in its
waters. Researchers with UC Davis’ Tahoe Environmental
Research Center reported today that the average murkiness in
2024 was exceeded only in 2021, when fires blanketed the lake
in smoke and ash, and in 2017, when the lake was clouded by
sediment-laden runoff during a near-record wet year. The
report says that clarity levels are “highly variable and
generally not improving,” and recommends that “future
research should focus on examining the nature of the particles
that affect water clarity.”
Lake Tahoe is famous for its clear blue waters — but new
research suggests that clarity may come with a catch. A study
from the UC Davis Tahoe Environmental Research Center,
published in the Association for the Sciences of Limnology and
Oceanography, shows that ultraviolet radiation in Lake Tahoe
can vary by up to 100 times between wet and dry years. The
findings are based on 18 years of underwater data through 2023
and highlight how climate-driven weather swings — especially
between drought and heavy precipitation — are changing the
light that reaches beneath the surface, according to a release
from the University of California, Davis. The data shows
that during dry years, clearer water allows ultraviolet rays to
reach far deeper into the lake. … That shift has big
implications: UV radiation influences the lake’s carbon cycle,
affects aquatic organisms like zooplankton and fish and can
suppress photosynthesis, the foundation of the lake’s food web.
Last weekend, watercraft inspectors found golden mussels,
a highly invasive aquatic species, on a 65-foot boat
that was headed to Lake Tahoe. Experts say golden
mussels pose an extreme threat to Lake Tahoe. To stop
the mussels from getting into the lake, this spring, Tahoe
implemented much stricter measures that go beyond the norm,
requiring that every single motorized boat not just be
inspected but also be decontaminated before hitting the
water. The boat carrying the golden mussels was put into
quarantine until it’s deemed risk-free, according to the Tahoe
Environmental Planning Agency. The close call was the first
time officials intercepted the golden mussels at one of Tahoe’s
boat inspection stations. … If the mussels were to reach
Lake Tahoe, they would wreak havoc on the ecosystem and degrade
water quality, and there’s no getting them out, experts
say.
… Lake Tahoe is famous for its blueness. The growth and
spread of algae is one reason blue lakes around the world can
appear green in the summer. Algae form the base of many food
webs, and most algae in Lake Tahoe, though sometimes
unattractive, do not pose a health risk to people or animals.
Harmful algal blooms are a different story. HABs can be
mistaken for harmless types of algae that naturally occur in
Tahoe and can be found clinging to rocks, washing up on
beaches, and attached to the bottom of creek and river
channels. HABs, however, pose a risk to public health and
safety as they can produce toxins. The Lahontan Regional
Water Quality Control Board (Water Board) places a focus on
algae and HABs in Tahoe’s waterbodies. They are not alone. The
Tahoe Science Advisory Council (Science Council), and notably
its member the UC Davis Tahoe Environmental Research Center,
study the presence, abundance, and distribution of Tahoe’s
algae over time and how those characteristics are shifting with
climate change.
On average, more than 60 percent of
California’s developed water supply originates in the Sierra
Nevada and the southern spur of the Cascade Range. Our water
supply is largely dependent on the health of our Sierra forests,
which are suffering from ecosystem degradation, drought,
wildfires and widespread tree mortality.
This tour ventured into the Sierra to examine water issues
that happen upstream but have dramatic impacts downstream and
throughout the state.
Sixty percent of California’s developed water supply
originates high in the Sierra Nevada mountains. Our water
supply is largely dependent on the health of our Sierra forests,
which are suffering from ecosystem degradation, drought,
wildfires and widespread tree mortality.
We headed into the foothills and the mountains to examine
water issues that happen upstream but have dramatic impacts
downstream and throughout the state.
GEI (Tour Starting Point)
2868 Prospect Park Dr.
Rancho Cordova, CA 95670.
Lake
Tahoe, the iconic high Sierra water body that straddles
California and Nevada, has sat for more than 10,000 years at the
heart of the Washoe tribe’s territory. In fact, the name Tahoe
came from the tribal word dá’aw, meaning lake.
The lake’s English name was the source of debate for about 100
years after it was first “discovered” in 1844 by people of
European descent when Gen. John C. Fremont’s expedition made its
way into the region. Not long after, a man who carried mail on
snowshoes from Placerville to Nevada City named it Lake Bigler in
honor of John Bigler, who served as California’s third governor.
But because Bigler was an ardent secessionist, the federal
Interior Department during the Civil War introduced the name
Tahoe in 1862. Meanwhile, California kept it as Lake Bigler and
didn’t officially recognize the name as Lake Tahoe until 1945.
Sixty percent of California’s developed water supply
originates high in the Sierra Nevada mountains. Our water
supply is largely dependent on the health of our Sierra forests,
which are suffering from ecosystem degradation, drought,
wildfires and widespread tree mortality.
This 25-minute documentary-style DVD, developed in partnership
with the California Department of Water Resources, provides an
excellent overview of climate change and how it is already
affecting California. The DVD also explains what scientists
anticipate in the future related to sea level rise and
precipitation/runoff changes and explores the efforts that are
underway to plan and adapt to climate.
30-minute DVD that traces the history of the U.S. Bureau of
Reclamation and its role in the development of the West. Includes
extensive historic footage of farming and the construction of
dams and other water projects, and discusses historic and modern
day issues.
This beautiful 24×36-inch poster, suitable for framing, displays
the rivers, lakes and reservoirs, irrigated farmland, urban areas
and Indian reservations within the Truckee River Basin, including
the Newlands Project, Pyramid Lake and Lake Tahoe. Map text
explains the issues surrounding the use of the Truckee-Carson
rivers, Lake Tahoe water quality improvement efforts, fishery
restoration and the effort to reach compromise solutions to many
of these issues.
This 24×36 inch poster, suitable for framing, illustrates the
water resources available for Nevada cities, agriculture and the
environment. It features natural and manmade water resources
throughout the state, including the Truckee and Carson rivers,
Lake Tahoe, Pyramid Lake and the course of the Colorado River
that forms the state’s eastern boundary.
The 28-page Layperson’s Guide to Nevada Water provides an
overview of the history of water development and use in Nevada.
It includes sections on Nevada’s water rights laws, the history
of the Truckee and Carson rivers, water supplies for the Las
Vegas area, groundwater, water quality, environmental issues and
today’s water supply challenges.
A new look for our most popular product! And it’s the perfect
gift for the water wonk in your life.
Our 24×36-inch California Water Map is widely known for being the
definitive poster that shows the integral role water plays in the
state. On this updated version, it is easier to see California’s
natural waterways and man-made reservoirs and aqueducts
– including federally, state and locally funded
projects – the wild and scenic rivers system, and
natural lakes. The map features beautiful photos of
California’s natural environment, rivers, water projects,
wildlife, and urban and agricultural uses and the
text focuses on key issues: water supply, water use, water
projects, the Delta, wild and scenic rivers and the Colorado
River.
Lake Tahoe is one of the world’s most beautiful yet vulnerable
lakes. Renowned for its remarkable clarity, Tahoe straddles the
Nevada-California border, stretching 22 miles long and 12 miles
wide in a granitic bowl high in the Sierra Nevada.
Tahoe sits 6,225 feet above sea level. Its deepest point is 1,645
feet, making it the second-deepest lake in the nation, after
Oregon’s Crater Lake, and the tenth deepest in the world.
Lake Tahoe is one of the Sierra Nevada’s crown jewels, renowned
for its breathtaking clarity. The high-altitude, clear blue lake
and its surrounding basin, which lie on the California-Nevada
state line, is a spectacular natural resource that provides
environmental, economic, recreational and aesthetic benefits.
