lake powell

California Storms And The Megadrought | Earth Wise

February 22, 2023 By EarthWise Leave a Comment

California experienced its wettest 10-day period in 25 years as a result of a series of storms driven by atmospheric rivers in January. The Rocky Mountains got buried in snow from the same weather pattern. For the drought-stricken West, the storms were good news. But they are not the cure for what’s been ailing the region.

In California, the snowpack in the Sierra Nevada mountains has been greatly enhanced, containing twice as much snow as is considered average for this time of year. Without a doubt, it will reduce the impact of the drought that has plagued the state for 23 years. But one big storm or even a series of them is not enough to undo years of minimal precipitation and rising temperatures. Many of the states’ largest reservoirs remain well below historical averages despite the record-breaking rain. It would take several wet years to really allow the state to recover from the drought.

The snowfall in the Rockies is crucial because it is the source of more than two-thirds of the water in the Colorado River. The Colorado River is the water lifeline for 40 million people from Wyoming to Mexico.

The ongoing shrinking of the Colorado River is a crisis that has created massive problems for the multibillion-dollar agriculture industry and for many large cities, including Denver, Phoenix, Salt Lake City, Las Vegas, and Los Angeles. Two of the nation’s largest reservoirs – Lake Mead and Lake Powell – are filled by the Colorado River. The historic low levels of these reservoirs have threatened the functioning of hydropower facilities that provide electricity to millions of people.

The January storms were good news for the West, but its problems are not over.

**********

Web Links

This Winter’s Rain and Snow Won’t be Enough to Pull the West Out of Drought

Photo, posted September 18, 2022, courtesy of Sarah Stierch via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Floating Solar | Earth Wise

June 7, 2022 By EarthWise 1 Comment

The largest floating solar array in Europe, 12,000 panels sitting on top of the Alqueva Reservoir in Portugal – will come online in July. Installing floating solar arrays, which are sometimes called “floatovoltaics”, produce renewable energy while shielding significant expanses of water from the sun’s heat. These dual benefits have led to floatovoltaic projects in multiple countries around the world.

The city of Cohoes, in New York’s Albany County, has proposed an 8,000-panel floating solar array on the city reservoir. Federal funding of $3 million for the project was obtained by local Congressman Paul Tonko and, in May, utility National Grid donated $750,000 towards the project. Engineering work will shortly be underway on the 3.2 megawatt grid of solar panels.

The city of Cohoes pumps its drinking water supplies from the Mohawk River into the 10-acre, manmade reservoir. The surface of the water is the largest undeveloped open space in the city. Such reservoirs constitute prime sites for solar arrays since the space cannot be used for other purposes. In addition, covering the water’s surface with the solar panels greatly reduces evaporation and helps to inhibit the growth of algae.

There are currently only 14 floating solar arrays in the U.S. and all of those are privately owned. The Cohoes municipal array will be the first of its kind. There are nearly 500 reservoirs in New York State and 24,000 nationwide that could be sites for floating arrays. Drought-stricken Western reservoirs like Lake Mead and Lake Powell could be ideal locations of solar arrays. Those reservoirs lose huge amounts of water to evaporation. There are estimates that floating arrays could provide as much as 10% of the nation’s electrical needs.

**********

Web Links

National Grid gives Cohoes $750,000 for floating solar array project

Photo, posted August 25, 2010, courtesy of Martin Abegglen via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Cloud Seeding And The Western Drought | Earth Wise

April 6, 2022 By EarthWise Leave a Comment

The massive megadrought affecting the American West is now considered to be the driest two-decade period in the past 1,200 years. The lengthy drought has led to increased wildfires, reduced agricultural productivity, and reduced electricity generation by hydropower plants. The historically low water levels in the largest two reservoirs in the U.S. – Lake Mead and Lake Powell – has triggered reductions in water allocations to Arizona, Nevada, and Mexico.

Several western states have expanded cloud seeding programs in an attempt to increase precipitation. During the past two years, Idaho, Utah, Colorado, Wyoming, and California have all stepped up their cloud seeding efforts. Outside of the US, the United Arab Emirates and China both have implemented massive cloud seeding programs.

A study by researchers at the University of Colorado and the National Center for Atmospheric Research looked at the ability of cloud seeding to increase snowfall. The study unambiguously demonstrated that cloud seeding can increase snowfall. Just how effective it is in terms of how much additional snow seeding produces is less clear.

Given the dire need for water and the fact that cloud seeding is not especially expensive, governments and other users are not hesitating to make use of it.

Unfortunately, the study shed no light on the efficacy of warm weather seeding to produce rain. There is in fact little evidence that seeding clouds to produce rain accomplishes very much. Once again, the prevailing view is that it is worth trying. There do not appear to be environmental downsides to seeding.

The hope is that cloud seeding may at least restore clouds to the state they had been in before industrial pollution and other human activities affected them.

**********

Web Links

Can Cloud Seeding Help Quench the Thirst of the U.S. West?

Photo, posted November 21, 2013, courtesy of Sharon Tate Soberon via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Drought And U.S. Hydropower | Earth Wise

November 29, 2021 By EarthWise Leave a Comment

The ongoing severe drought in the western U.S. has led to low water levels in the rivers and reservoirs that feed hydroelectric power systems. The Energy Information Administration is projecting a 13.9% decrease in hydroelectric generation this year compared to 2020.

Water levels in Lake Powell have fallen so low that it may not be possible to operate the power plant at Glen Canyon Dam starting as soon as 2022. California officials took the Edward Hyatt hydroelectric plant offline in August because of low water levels on Lake Oroville. Washington, the state with the most hydroelectric power generation, has seen an 11% drop in electricity generated to date this year as compared to last year. That state is actually doing better than others in the West, such as California, where hydro generation is down 38%.

Hydropower accounts for over 7% of the electricity generated in the United States. Five states – Washington, Idaho, Vermont, Oregon, and South Dakota – generate at least half of their electricity from hydroelectric dams.

The current decrease in hydropower is alarming, but it is not unprecedented. The more significant question is whether the drop in generation this year is a sign that this power source is declining and becoming less reliable. According to some scientists, the West is in a “megadrought” that could last for decades.

The greater concern is whether the bad years are likely to become more common because of climate change. Climate projections agree that temperatures will continue to rise, but what will happen to precipitation levels in specific places is much less certain. That is what will determine what the future holds for hydroelectric power.

**********

Web Links

Inside Clean Energy: Drought is Causing U.S. Hydropower to Have a Rough Year. Is This a Sign of a Long-Term Shift?

Photo, posted May 7, 2014, courtesy of Tyler Bell via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A New Low For Lake Powell | Earth Wise

November 2, 2021 By EarthWise Leave a Comment

Lake Powell is the second largest reservoir by capacity in the United States. It straddles the border of southeastern Utah and northeastern Arizona and was created by the Glen Canyon Dam, completed in 1963. The reservoir serves as a bank account of water that is drawn upon in times of drought and has made it possible to weather extended droughts by sustaining the needs of cities, industries, and agriculture in western states. Hydroelectric power by the dam’s eight generators provides electricity to seven states.

As a result of the protracted drought in the west, the water levels in Lake Powell have reached the lowest point since 1969. As of September 20, the lake held only 30% of its capacity and federal managers started releasing water from upstream reservoirs to help keep Lake Powell from dropping below the so-called minimum power threshold which is the water elevation that must be maintained to keep the dam’s hydropower turbines working properly.

With the entire Lower Colorado River water system below 40% of capacity, Bureau of Reclamation recently announced that water allocations in the U.S. Southwest would be cut over the next year. The Colorado River basin is managed to provide water to millions of people including those in San Diego, Las Vegas, Phoenix, and Los Angeles.

Successive dry winter seasons over the past two years along with a failed 2020 summer southwestern monsoon, have led to the lowest precipitation levels on record in the Southwest going at least as far back as 1895. With warm temperatures, reduced snowpack, and increased evaporation of soil moisture, most of the American West suffers from persistent and widespread drought.

**********

Web Links

Lake Powell Reaches New Low

Photo, posted June 28, 2021, courtesy of the USFWS – Mountain Prairie via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

A Record Low For Lake Mead | Earth Wise

October 4, 2021 By EarthWise Leave a Comment

Lake Mead is the reservoir that was formed by the Hoover Dam on the Colorado River. The lake spans the Arizona-Nevada border. It is the largest reservoir in the United States in terms of water capacity. The lake is part of a system that supplies water to at least 40 million people in seven states and in Northern Mexico.

As of August 22, this year, Lake Mead was filled to just 35% of its capacity. This low water level is happening while 95% of the land in nine Western states is under some level of drought conditions and 64% of the land is under extreme drought conditions. A so-called megadrought has been going on for 22 years and may be the worst dry spell in the region in twelve centuries.

As of the end of July, the water elevation at the Hoover Dam was 1,067 feet above sea level, the lowest it has been since April 1937 when the lake was still being filled after dam construction. The level has dropped by 132 feet since July 2000. At maximum capacity, Lake Mead reaches an elevation of 1,220 feet and holds 9.3 trillion gallons of water.

With Lake Mead at 35% of capacity, Lake Powell on the Colorado at 31%, and the entire Lower Colorado system at 40%, water allocations for the coming water year are being cut back. Mexico will see a 5% reduction, Nevada will be cut 7%, and Arizona will lose 18% of its apportionment. This unprecedented official declaration of a water shortage demonstrates the severity of the drought and low reservoir conditions.

**********

Web Links

Lake Mead Drops to a Record Low

Photo, posted August 7, 2018, courtesy of Renee Grayson via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Trouble On The Colorado

April 4, 2019 By EarthWise Leave a Comment

The 1450-mile-long Colorado River begins in the Rocky Mountains and wends its way to the Gulf of California, creating the Grand Canyon along the way, and providing water to some 40 million people. The amount of Colorado River water promised to users is far more than actually flows between its banks, and that amount is dropping.

An unrelenting drought since 2000 has resulted in the water levels of the two largest reservoirs of Colorado River water – Lake Mead and Lake Powell – being at all-time lows.

Lake Mead, just outside of Las Vegas, is the reservoir of Hoover Dam, which provides power for millions of people in Southern California, Nevada, and Arizona. The last time Lake Mead was full was in 1983. It has slowly declined and now is 40% full.

If the lake level drops another 7 feet to 1075 feet above sea level, it will trigger a Tier 1 declaration, mandating cuts to water allocations to Arizona and other states. If the level drops to 1050 feet, it would reach Tier 2 at which point Hoover Dam would have to stop generating electricity because water levels would be too low to flow through it. If the lake level drops all the way to 895 feet, it would be below the level at which water can be piped out of it. This is known as the “dead pool”.

These scenarios are no longer doomsday fantasies. Water managers in the Southwest see the writing on the wall and are busy making contingency plans and developing ways to use less water from the Colorado River. The booming city of Phoenix in particular is hard at work finding alternative ways to provide water for its millions of citizens. On the Colorado, drought in the new normal.

**********

Web Links

On the Water-Starved Colorado River, Drought Is the New Normal

Photo, posted October 24, 2016, courtesy of Sharon Mollerus via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.