canals

Manatees are not Florida natives

December 20, 2024 By EarthWise 1 Comment

Florida is very proud of its manatees. It has a county named after them and has pictures of them on license plates. These gentle creatures are part of Florida culture. But recent research indicates that manatees – also known as sea cows – might only be relatively recent residents of the Sunshine State.

Manatees have been spotted in Florida waters for several centuries but might have only been tourists visiting briefly before returning to their home waters in the Caribbean in places like Cuba.

The new research suggests that manatees might not have actually taken up residence in Florida until after Europeans colonized the area in the 1500s. There is a rarity of manatee bones on archaeological sites that date back further. It was particularly striking that Crystal River, which is an epicenter for modern manatee populations, had little evidence of their presence in earlier times.

Even into the early 1900s, Florida newspaper reports treated manatee sightings as a spectacle rather than a common occurrence. In the 1920s and 1930s, there started to be more routine sightings in places like yacht basins and canal harbors. In the 1950s, manatees became more plentiful in Tampa Bay and Crystal River. The warming waters and human activities creating shallow warm water refuges increased manatee populations, particularly near places like power plants.

The current Florida manatee population is between 8,000 and 12,000 and is classified as threatened under the Endangered Species Act, an improvement over its previous endangered status. But pollution is killing a lot of the seagrass that they eat, and their safety is by no means assured.

**********

Web Links

Why manatees are likely not Florida natives

Photo, posted March 25, 2012, courtesy of David Hinkel / USFWS via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Solar Panels On Canals | Earth Wise

August 25, 2023 By EarthWise Leave a Comment

There has been growing interest in installing solar panels on top of reservoirs to make use of the available space to make electricity and reduce evaporation. There has been far less interest in installing solar on canals and aqueducts. But that is changing and a new project in California is part of that change.

A study by the University of California, Merced estimates that 63 billion gallons of water would be saved by covering California’s 4,000 miles of canals with solar panels. All that installed solar would generate a significant amount of electricity.

The idea is going to be tested in the Turlock Irrigation District in Central California with Project Nexus, which is the installation of solar panels over 1.8 miles of canals that are between 20 and 110 feet wide. The panels will sit between 5 and 15 feet off the ground. UC Merced researchers will study impacts ranging from evaporation to water quality and use the results to make recommendations with respect to wider use of the technology.

California isn’t the first place to put solar on a canal. India pioneered it on one of the largest irrigation projects in the world. The Sardar Sarovar dam and canal project brings water to hundreds of thousands of villages in the dry, arid region of India’s Gujarat State.

Meanwhile, the Gila River Indian Community in Arizona received funding from the Bipartisan Infrastructure Law to install solar panels on their canals in an effort to save water and reduce stress on the struggling Colorado River.

The world of water infrastructure does not embrace change easily but covering canals with solar panels is an idea whose time may have come.

**********

Web Links

Solar panels on water canals seem like a no-brainer. So why aren’t they widespread?

Photo, posted December 11, 2005, courtesy of Dave Parker via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Two Lost Lakes Return To California | Earth Wise

May 10, 2023 By EarthWise Leave a Comment

The recent siege of powerful storms in California driven by a series of atmospheric rivers has had a significant effect on the severe drought that has plagued most of the state for many years. Many of the state’s reservoirs are at the highest level they have been for decades. The snowpack in the Sierras is well over 200% of its historical average. Many parts of the state are no longer considered to be in drought conditions, and, in fact, flooding has been a serious problem in some areas. This flooding has had some surprising results.

Two California lakes that drained a century ago have reappeared as a result of floodwaters from the recent storms.

Tulare Lake, in California’s Central Valley used to be fed by rain and snowmelt from the Sierras. A system of dams and canals constructed in the early 20th century to support regional agriculture diverted water away from the lake. It used to be the largest freshwater lake in the West but farmers ultimate planted crops in the dried lakebed.

The atmospheric river events in March inundated that farmland and once again there is water in Tulare Lake.

Owens Lake, on the eastern side of the Sierra Nevada, was long fed by mountain streams. The 1913 construction of the Los Angeles Aqueduct redirected water to that city and desiccated the lake. Floodwaters in March caused a partial collapse of the aqueduct and when the spill gates on the aqueduct were opened to drain the damaged areas, floodwaters poured in and partially refilled the lake.

California has suffered from drought for many years. With its massive snowpack, as the weather warms, the state may face even more flooding.

**********

Web Links

Two Long-Drained California Lakes Refilled by Floodwaters, Satellite Images Show

Photo, posted November 10, 2014, courtesy of CN via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Floating Homes In The Netherlands | Earth Wise

January 24, 2022 By EarthWise Leave a Comment

The Netherlands is a country that is largely built on reclaimed land and a third of it remains below sea level. The Dutch have long experience with dealing with rising waters. The city of Amsterdam has almost 3,000 houseboats in its canals.

As sea levels continue to rise across the globe, it is no surprise that the Dutch have taken the lead in creating communities composed of floating houses and buildings.

A floating house is a structure fixed to the shore, often resting on steel poles, and usually connected to the local sewer system and power grid. They are much like ordinary houses except that instead of a basement, they have a concrete hull that acts as a counterweight, allowing them to remain stable in the water.

The ones in the Netherlands are often prefabricated, square-shaped, three-story townhouses. Rotterdam, which is 90% below sea level, is home to the world’s largest floating office building as well as a floating farm.

Floating buildings have their challenges, not the least of which are the effects of severe wind and rainstorms, or even the passing of large ships which can make the buildings rock. Infrastructure like electricity and sewer service is not that simple to implement for the buildings. But the benefits of floating buildings may outweigh the costs.

For cities facing worsening floods and a shortage of buildable land, floating homes are a potential solution for expanding urban housing in the age of climate change. Dutch engineers are spearheading floating building projects in Britain, France, and Norway, as well as in threatened island locations like French Polynesia and the Maldives.

**********

Web Links

Embracing a Wetter Future, the Dutch Turn to Floating Homes

Photo, posted May 23, 2007, courtesy of Jeff Hutchison via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

The Potential For Solar Canals In California | Earth Wise

April 29, 2021 By EarthWise Leave a Comment

California’s network of almost 4,000 miles of aqueducts is the world’s largest water conveyance system. It serves the state’s Central Valley which produces a quarter of America’s food. About 20% of the nation’s groundwater demand is pumped from Central Valley aquifers.

A recent study by the University of California Santa Cruz and UC Merced has determined that covering these aqueducts with solar panels could be an economically feasible way to advance both renewable energy and water conservation. California’s aqueducts might more properly be called canals because they are located at ground level.

The concept of solar canals has been gaining increasing interest around the world as the changing climate leads to more droughts in many regions. Placing solar panels above the canals can shade them to help prevent water loss through evaporation. In addition, some types of solar panels can work better situated over canals because the cooler environment improves their operation. In addition to the increased solar panel output and the water evaporation savings, shade from solar panels could help control the growth of aquatic weeds, which are a costly canal maintenance issue.

Spanning canals with solar panels can be accomplished either by using steel trusses or suspension cables, either of which is more expensive to build than ordinary ground-mounted solar panel supports. But the research study showed how the benefits of solar canals combine to outweigh the added costs for cable-supported installations.

Apart from the economic benefits of a solar canal system, producing solar energy in the canal system could eliminate the use of 15-20 diesel-powered irrigation pumps, helping to reduce air pollution in a region with some of the nation’s worst air quality.

Solar canals could be a real winner.

**********

Web Links

New analysis shows potential for ‘solar canals’ in California

Photo, posted July 23, 2015, courtesy of Lance Cheung / USDA via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Coronavirus Shutdowns And The Environment | Earth Wise

May 11, 2020 By EarthWise Leave a Comment

Our stories often discuss how human activities change the natural environment. With most of us confined to our homes, the lack of human activities is having profound effects on the environment. We are talking about some of these this week.

The COVID-19 pandemic is a global catastrophe, but it has ironically been a boon for the environment. By taking billions of people off the streets around the globe and slashing all forms of travel, the global environment has seen dramatic changes.

Sea turtles in many countries are prospering by not having to compete with humans for precious beach space. Animals everywhere have more freedom to roam and are taking advantage of the opportunity. The Himalayas are visible from parts of India for the first time in decades.

Satellite imagery has shown dramatic drops in nitrogen dioxide emissions in China, where pollution from vehicles is a serious public health problem. Similar reductions in air pollution are evident in India, Italy and even in Los Angeles. The city that is notorious for its smog suddenly has pristine air.

In Venice, water in the canals has become clear in the absence of heavy boat traffic stirring up sediments from the bottom. Wildlife that normally is invisible such as jellyfish are being spotted.

Not all the changes to animal behavior are desirable. Some wildlife that have become dependent on humans as a source of food are becoming aggressive and are taking to the streets of cities to look for food. Monkeys in Thailand are mobbing towns and brawling, hunting for things to eat. Rats in New York City are fighting over suddenly meager food supplies.

In many ways, the natural world is reacting to much of humanity sheltering in place.

**********

Web Links

On Earth Day 2020, coronavirus shutdowns are a gift to the environment

Photo, posted April 2, 2020, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Beavers And Biodiversity

October 10, 2019 By EarthWise Leave a Comment

Beavers are large, semi-aquatic rodents known best for their ability to construct dams, canals, and lodges (their homes). They are among the largest rodents in the world. With powerful jaws and strong teeth, beavers fell trees to use as building materials, often changing their environment in ways few other animals can. But in a good way. As it turns out, beavers are important for biodiversity.

According to new research from the Faculty of Natural Sciences at the University of Stirling in Scotland, reintroducing beavers to their native habitats is an important step towards solving the freshwater biodiversity crisis.

Researchers surveyed water plants and beetles in 20 wetlands in Sweden – 10 created by beavers and 10 that were not – in order to understand what impact beavers might have on the variety of plant and animal life around them.

The research team’s findings build on previous work that has shown that beavers have an important impact on biodiversity. This latest study discovered that the number of species found only in beaver-built ponds was 50% higher than in other non beaver-built wetlands in the same region.

Beavers are known to be profound engineers of the environment. They use wood to build dams across rivers in order to form ponds behind them. They do this to raise the water level in order to avoid predators, like bears and wolves. But it turns out many other plants and animals, like water plants and beetles, also benefit from their work.

According to the research team, reintroducing beavers to their native habitats should benefit the wider biodiversity and be seen as an important step towards solving the freshwater biodiversity crisis.

**********

Web Links

Beaver reintroduction key to solving freshwater biodiversity crisis

Photo, posted October 2, 2014, courtesy of USFWS Midwest Region via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.