PaveDrain pavers

Arched pavers reshape stormwater management

Greater attention to the effects of climate change is prompting a larger focus on water, from clean water access to stormwater management. 

Climate change-induced weather volatility and stronger storms are putting a spotlight on the need for better flood mitigation solutions. That importance is underscored by the steady growth of urban areas and the increased use of impervious building and infrastructure materials that cause water to stay at the surface of the ground instead of being absorbed into it.

Groundwater makes up almost one-third of the Earth’s total freshwater, according to the U.S. Geological Survey. But the amount of groundwater in aquifers is shrinking because humans are using it faster than it’s being renewed. 

A Midwest entrepreneur familiar with these issues came up with an innovation that lessens water problems without breaking the bank. Doug Buch founded PaveDrain, which creates pavers for stormwater management. A unique aspect is the arch shape of the pavers’ underside. Arches are considered one of the greatest architectural achievements because of their extreme load-bearing qualities, and they have been used in aqueducts since ancient times.

How it started

Cross-section diagram shows the arched shape of the paver block.
Credit: PaveDrain / Courtesy

Buch was driving across the Midwest and heard a radio ad that mentioned the St. Louis Gateway Arch. “I started wondering if I could put an arch in a paver block. I pulled over and started drawing on a piece of paper, then threw it in the back of the car and it stayed there for about a month,” he said.

Buch launched PaveDrain, first in Milwaukee and now located in Iowa, to advance this novel paver concept. 

What it does

The permeable blocks absorb surface water and channel it into the ground. The patented arch design creates an internal storage chamber that serves as a reservoir for stormwater runoff, allowing the blocks to take on a greater volume of water than other permeable surfaces. The arch also makes the blocks stronger than traditional pavers and able to support heavy vehicle loads.

The blocks’ interlocking capability allows the pavers to be installed without the standard practice of filling the cracks with sand or gravel. The blocks also filter sediments from surface water.

The benefits over other stormwater management solutions such as retention ponds are huge, Buch said. Retention ponds take up valuable land, require a lot of time and money to engineer, create a safety risk, and attract mosquitoes and other pests. They also keep captured groundwater at the surface, making it more prone to evaporation instead of absorption to underground aquifers.

When considering the lifecycle costs, “this is a cheaper, better alternative than traditional infrastructure to meet stormwater regulations,” Buch said. “Everybody always is worried about the almighty dollar, and so are we.” 

Firetruck on PaveDrain pavers
The pavers’ arched shape makes the blocks stronger than traditional pavers. Credit: PaveDrain / Courtesy

Challenges

When Buch first started trying to sell the pavers, he targeted progressive areas known for being open to and trying environmentally focused solutions. But he encountered resistance from those who had been early adopters of other permeable surfaces that didn’t deliver on their promises.

“They spent money on other surfaces thinking they would help save the planet. But it didn’t work, and it was expensive to make that mistake. They got burned by the maintenance and freeze-thaw cycles and all the issues engineers warn you about,” he said.

PaveDrain is a “second-generation” solution that is cheaper, easier to install, and requires little maintenance in most cases, Buch said. The hard part is convincing those who had bad experiences with other first-generation innovations to give PaveDrain a try.

The long lag time from a product sale to installation is another big issue for the water tech and construction sectors. 

“It just takes a long time for things to gain a reputation and respect … before they get widespread use,” Buch said. “Water tech is hard. That sphere is really tough. … Our main problem in the water sphere is I may talk to a potential customer today and by the time the project is permitted, funded, constructed, and built, it might be two to seven years later.”

A closeup of the P4 sensors among a group of PaveDrain blocks.
Sensors from P4 Infrastructure gather data and track the pavers’ performance. Credit: PaveDrain / Courtesy

What’s next

PaveDrain has done some pilot projects that incorporate sensors from Milwaukee civil engineering product company P4 Infrastructure. The sensors gather data and track the pavers’ performance, such as how fast the blocks’ storage chamber fills and how well the water is draining. Updates come in 15-minute intervals to provide a near-real-time view.

The tests found that the product works even better than initially thought, and “municipalities and landowners are overdesigning their infrastructure by millions of dollars to meet stormwater regulations they probably already met,” Buch said. 

The goal is to eventually make these sensors standard with all PaveDrain installations instead of an add-on feature. Another goal is to expand the sensor capabilities to inform a user about how much water has been captured and exactly when the pavers need maintenance.

“Green infrastructure can be less costly upfront, and we can prove it and show you what you’re getting,” Buch said.

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