Cities float new ideas to address rising sea levels

The seas are rising. Between 2000 and 2019, cities in parts of the United States experienced $ up to 150 percent more high-tide flooding$ . $ By 2040, coastal counties in most states will be affected$ . By 2100, it’s $ estimated that sea levels will rise globally by more than 6 feet (2 meters)$ .

The reality is, communities around the world are and will be impacted by rising sea levels. The question is increasingly — and urgently — what are local governments going to do about it?

Luckily, districts around the world are racing to find solutions. Many are overarching efforts aimed at stalling climate change: Cities are setting emissions limits or $ creating low-emissions zones$ . Municipal wind and solar plants are becoming more common. Local governments are $ committing to 100-percent green energy$ .

Some cities and towns are standing out as leaders in the battle against rising seas, specifically. These communities have taken a range of creative actions to resist or ride out the changes, from IoT water sensors to floating neighborhoods.

These efforts are playing out in small towns and huge metropolises, on coastal hubs or inland flood zones. Some projects work. Others don’t. But many of them provide learnings for other cities to build upon.

Let’s take a look at seven innovative ways local governments are staying resilient and working to respond to the rising tide.



1. Mapping current and future flood risk

If you’re going to prepare for flooding, you need to know where it’s going to happen. Cities and counties around the world are turning to maps to identify problem areas, and warn citizens about them.

Interactive maps that flag homeowners’ flood risks are being utilized from Canada to New Zealand. In L'Assomption, QC, the $ city produced a flood zone map$  and then distributed informational door hangers to get the word out. $ Nelson City Council, NZ$  and $ Wellington Regional Council, NZ$  the predictive maps can be manipulated to see what will happen in different climate change and sea level rise scenarios.

In Broward County, FL, residents helped $ create a live map via social media$ . The county piloted the MIT-developed $ RiskMap$  application, which uses Twitter DM, Telegram and Facebook Messenger chatbots to log and visualize crowdsourced reports of flooding, including during hurricanes. The app even $ integrates with Ube$ r so local drivers know which areas to avoid.

Kangaroo Island, SA also $ brought its citizens into the mapping process$ , as it worked to map areas at risk of coastal erosion and inundation. Local residents were $ chosen as “Project Champions”$  and served as influencers to inform and engage the greater community, as well as collect feedback.

2. Smarter flood preparation with IoT

Local governments are turning to smart technology to solve all sorts of challenges. Sensors and gauges are being used from $ Virginia Beach, VA$  to $ Auckland, NZ$  to address changing water levels and better prepare for flooding.

In Chatham County, GA, home to the city of Savannah, the city and county partnered with Georgia tech to launch a $ pilot program using sensors that monitor sea level and flood risk$ . Over 40 sensors have been installed around the county, including on bridges, at marinas, and in flood-prone areas.

Not only were the use of the sensors themselves pretty groundbreaking ($ Georgia is now reported to have one of the highest density water sensor systems in the world)$ , the installation process was also innovative. The county $ recruited local high school students$  to assemble the sensors, and at least one area school is using the data collected in science and math classes to educate about sea level rise.

It’s important to remember that a community doesn’t have to be located on the coast to feel the impacts of climate change-related flooding. Rivers are rising, too, and Cary, NC sits atop three river basins. To help monitor and ultimately predict flooding, $ the town turned to smart water level sensors$  and rain gauges to send real-time data on potential flooding events.

Not only has this IoT technology helped the town proactively reroute traffic, it has benefits for regional communities as well, $ Terry Yates, Cary’s smart cities and IT project manager told GCN$ :



“While we may not get flooding from a particular rain event in Cary, our partners downstream … may be getting flooding, and that whole regional data-sharing element is important.”

3. Creative funding for climate projects

$ Community investment$  is being applied to many aspects of climate change prevention, including flooding. In $ Hampton, VA, this innovative type of funding is being applied to address the rising sea level$ .

The coastal city is launching a handful initiatives to combat its flooding problem; it’s paying for them through Environmental Impact Bonds. Hampton is only the $ third city in the United States to use these bonds$ , which allow private investors to provide up to $12 million for the environmental projects up front, and the city to pay them back over time.

$ Congressman Bobby Scott praised the approach$ , as well as the partnership with investors and the Chesapeake Bay Foundation:

"These projects and partnerships are examples of what we are doing to heal these places that we love.”

4. Virtual reality to visualize coastline transformation

Sometimes, it takes virtual reality to make a problem seem real. $ Local governments are recognizing the power of VR$  to help citizens visualize changes in the community. This applies to climate change, too.

Hermosa Beach, CA introduced "$ Look Ahead Hermosa Beach," an immersive VR experience$  that showed residents what their surroundings would look like in 30 years, given sea level and climate change predictions.

The program included an on-the-ground VR experience, $ plus videos and images on the city’s website$ . The visualizations were paired with information and steps the public could take to mitigate the impacts of climate change and try to stall the future they were viewing. The town also conducted a survey to gauge public opinion after seeing the VR.

Hermosa Beach $ Mayor Mary Campbell explains$  the power of the technology:

“Climate change is one of those issues that is kind of hard to wrap your head around. You hear a lot about it in the news, but you don’t really personalize it. This makes it real and it’s really striking.”

5. Community outreach to drive awareness and advocacy

While rising sea levels are a major problem, the majority of the public doesn’t think about it too much day to day. That is, until a flood hits.

To get people out of this reactionary mindset and work toward preventative approaches, local governments are finding new ways to engage with their citizens and keep sea level rise and its impact top-of-mind.

In Ipswich, Queensland, the $ city council introduced a flooding awareness campaign to teach residents how to recognize flood threats$ . The campaign centered around $ a video series titled "Don't Be a Dinesh,$ " which won a Local Government Award at the 2020 Resilient Australia Awards. The video is complemented by a website housing flood resources, an interactive map, and a link to a photo archive detailing the city’s history of flooding.

Progress can be made without technology, too. After the city of Charleston, SC experienced historic levels of chronic flooding, the $ mayor introduced a monthly “Flood Stat” meeting$ . Open to the public, the meetings review flood-related data and ask for community input.

By holding a regular meeting that brings in residents, Charleston promotes transparency in local government, and keeps the issue on the public radar, $ says Tracy McKee, the city’s chief innovation officer$ :

“The stat program is really about creating an environment for accountability and collaboration.”

6. Building barriers that enhance public spaces

Of course, engineering plays a major role in cities’ physical fight against sea level.

Sea walls have long been used to keep the tide at bay, though their effectiveness compared to other techniques like natural barriers have been called into question. The walls also frequently come with community challenges — over design, funding, or equity. (A seawall project in Sydney, NSW has taken $ nearly 40 years to negotiate$ .)

Still, local governments are pushing forward with evolved engineering to combat rising seas, including walls, berms, and parks designed to soak up floodwater.

Take New York City. When Hurricane Sandy hit the city, more than 40 people lost their lives, the city suffered $19 billion in damages, and an entire swath of Lower Manhattan was flooded. To prevent repeated disaster in the future, $ the city is undertaking a massive flood prevention project, constructing a 10-mile protective system$  called the BIG U.

Designed “$ to respond to individual neighborhood typology as well as community-desired amenities$ ,” the project will wrap Lower Manhattan in a protective barrier containing two compartments:

“Like the hull of a ship, each can provide a flood-protection zone, providing separate opportunities for integrated social and community planning processes for each. Each compartment comprises a physically separate flood-protection zone, isolated from flooding in the other zones, but each equally a field for integrated social and community planning. The compartments work in concert to protect and enhance the city, but each compartment’s proposal is designed to stand on its own.”

The city is facing local challenges to the development, and $ the seawall’s plans continue to evolve$  and face pushback from groups based on some changes, $ according to the New York Times$ .

Still, New York’s BIG U is an example of how cities are seeking out multi-purpose developments. Berms and elevated roads will be constructed to protect against storm surges, but they’ll also be designed as a community space, with waterfront access, public art, and places to relax and socialize. (NYC’s plans even call for a $ “Reverse Aquarium,” where the public can observe changes in tidal behavior and learn about rising sea levels$ .)

In North Miami, a similar effort is underway, albeit on a much smaller scale. In order to protect homes in a city neighborhood, $ the council bought a frequently-flooded lot and is transforming it into a public park$ .

The twist? The park doubles as a flood reduction zone, with local plants and trees that help reduce flooding. A centerpiece of the park will be a water retention pool with markers that show the current level of flooding. It’s flood mitigation-meets-community engagement, $ says Maggie Tsang, cofounder of a design firm that collaborated on the project:$ 

“I think that this is an opportunity to create sites that simultaneously reduce risk, provide community gathering places, as well as grow public awareness.”

7. Float the city

If you can’t beat the rising water, learn how to live with it. That’s what Rotterdam, NL, and a handful of other cities are doing.

The Dutch are no strangers to managing water, and Rotterdam, which sits largely below sea level, has developed a system of solutions to prevent flooding.

Of course there are the infamous dykes, which have kept the sea at bay for nearly 1,000 years. There’s the $ Maeslant Barrier$ , a massive gate $ that’s been called the “storm drain of Europe.$ ” There’s the “$ Waterplein$ ,” a park and amphitheater in dry weather that transforms into a series of pools and water features when it rains. There’s a world championship rowing course that $ doubles as a water storage facility$ .

And then there are the floating city features: A $ floating neighborhood$  featuring premium housing and a park. An $ experimental floating pavilion$ . A $ floating dairy farm$  designed to create a more resilient and sustainable local food source. As $ Peter van Wingerden, the creator of the floating farm, puts it$ :

“The river is no longer just for industry. We need to find new uses, which keep us safe from climate change, and help the city grow and prosper.”

Key takeaways

Rotterdam isn’t the only city experimenting with buoyancy — $ Amsterdam also has a floating neighborhood$ , for example. But Rotterdam has taken a lead in the climate space due to its efforts to not only adjust life to the changing seas, but its desire to share its learnings and practices with others.

The city was the site of the $ first Climate Adaptation Academy$ , a training program produced by the $ C40 Cities Climate Leadership Group$ . It hosts experts from around the world to $ share its learnings on dealing with rising sea levels$ .

This information sharing is a key piece of the fight against climate change. There isn’t one solution that will work worldwide; each community’s unique setting and characteristics will require a modified set of tactics.

But for cities facing climate change and rising waters, resilience quite literally comes down to sink or swim. It’s critical for local governments to act quickly and strategically by adopting and building upon the successes of others.