repairs

Natural solutions for coastal defense

May 30, 2024 By EarthWise Leave a Comment

Protecting coastal cities and towns from the dangers of tsunamis, storm surges, and sea-level rise has become an ever-increasing challenge. There are so-called hard coastal defenses as well as nature-based solutions. A new study by the University of Tokyo has found that combining the two types of defenses may be the most effective way to protect, support, and enrich coastal communities.

Sea walls, dikes, dams, and breakwaters are the traditional hard measures. They are popular and have proven track records but are facing challenges to keep pace with increasing climate risks. They are expensive to build and require continuous upgrades and repairs. While they do provide protection from many disaster risks, they also can cause significant disruption to coastal ecosystems as well as to coastal communities.

Nature-based coastal defenses include such things as mangroves and coral reefs. So-called soft measures involve restoring, rehabilitating, reforesting, and nourishing natural ecosystems that protect coastal areas.

The Tokyo researchers analyzed the defense strategies in terms of risk reduction, climate change mitigation, and cost-effectiveness over a 20-year period. The results of the study were that among all coastal defense options in lower-risk areas, hybrid measures provide the highest risk reduction and can harness the advantages of both hard and soft measures.

The findings provide strong evidence for integrating nature-based components into coastal defenses, but these approaches have not yet been adequately tested in circumstances of extreme events and high-risk urgency. Research in this area has important implications for policy makers, coastal planners, and communities looking to make evidence-based decisions.

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A natural touch for coastal defense

Photo, posted October 22, 2021, courtesy of Kevin Dooley via Flickr.

Earth Wise is a production of WAMC Northeast Public Radio

Concerns About Dam Safety

August 22, 2019 By EarthWise Leave a Comment

The United States has a total of 91,000 dams of various sizes and types. Many of them are aging and sorely in need of repairs. All that maintenance would add up to tens of billions of dollars. Experts are increasingly worried that as extreme precipitation events become increasingly common, dams are increasingly at risk of failure, threatening lives and posing environmental risks.

In 2017, Oroville Dam in California – the tallest dam in the country – nearly collapsed. That incident forced the evacuation of 190,000 people and cost the state of California $1.1 billion in repairs. California is considered one of the nation’s leading states in dam safety management and yet the partial disintegration of Oroville’s two spillways during a heavy rainstorm was not anticipated.

So far, federal and state dam safety officials have not been able to get disinterested state legislatures and the U.S. Congress to fork up the money needed for repairs to the nation’s aging dam infrastructure.

Th American Society of Civil Engineers gave the nation’s dams a D grade on the latest infrastructure report card. They estimate that the cost of rehabilitating dams whose failure would threaten human life at nearly $45 billion, and the cost of fixing all dams in need of repair at more than $64 billion.

Scientists say the likelihood of dam failures – which not only threaten lives but also release toxic sediments trapped in reservoirs behind many dams – will increase as extreme precipitation events become more frequent in a warming world. Apart from about 1,500 dams owned by federal agencies, regulating dam safety is primarily the responsibility of the states. So far, states have not applied remotely sufficient resources to a growing problem.

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In an Era of Extreme Weather, Concerns Grow Over Dam Safety

Photo, posted August 20, 2014, courtesy of Flickr.

Earth Wise is a production of WAMC Northeast Public Radio.

Capital Region Community Solar

May 22, 2017 By EarthWise

Community solar is a cooperative enterprise in which customers can make use of the output of a large local array of solar panels when they are not able to install a solar power system on their own property. The customers of a community solar system can offset as little or as much of their electrical usage as they want by participating in a community solar program.