There is good news and bad news. The bad news is that the vast majority of our urban infrastructure is exacerbating the risk of flooding and missing a serious opportunity to recycle our water in a sustainable and beneficial way. The good news is that urban planners realize this and we are starting to move toward the mentality of the Dutch — the pioneers of the water world.

We’re taking a closer look at how water pollution occurs more often in cities as opposed to other locations, and discuss how poor city planning is responsible for this short-sightedness. Then we’ll focus on methods cities can use to better plan for water management and wastewater management in a sustainable, environmentally friendly way.

What Is the Problem?

The problem lies in stormwater runoff and poor urban planning. Our urban areas have almost entirely lost their capacity to naturally recycle stormwater due to the impenetrable gray infrastructure engineering that has dominated construction techniques over the last century. New York City, for example, is 72 percent impervious surface.

More than 80 percent of the U.S. population abides in urbanized areas, and this is set to increase to almost 90 percent over the next three decades. The growing population means more stress on centralized stormwater systems, which are in fact only focused on doing one thing: moving stormwater to a treatment plant. Urban planning so far has centered on how to capture stormwater runoff and send it somewhere else, but with increased water scarcity and higher chances of flood damage, there has to be another way to deal with stormwater. Water is an asset, right?

It should be, but given how our urban planning has historically dealt with natural rainwater, stormwater becomes a major and expensive liability the minute it hits the ground. “Stormwater runoff is one of the largest water pollution issues facing the U.S. today,” says Larry Levine, a senior attorney in the Natural Resource Defense Council’s water program.

The EPA says urban stormwater is responsible for almost half the impaired ocean shoreline, over one-fifth of seriously polluted lakes and 14 percent of polluted rivers. What’s more, within cities that combine their systems to convey both sewage and stormwater such as New York, feces and other harmful waste are discharged in the event of serious storms or rainfall.

Every year, an estimated 10 trillion gallons of untreated stormwater is running off roofs, roads, through sewage systems and onto our beaches. This, in turn, degrades ecosystems, damages tourist economies and poses serious health risks when it gets into drinking supplies. Large coastal cities are particularly at risk of water pollution, because the stormwater drains into the sea without any treatment or filtration whatsoever.

If we could re-engineer our cities to handle stormwater in a way that harnesses the natural benefits of the water, as well as safely and efficiently dissipates excess rainwater, our waterways, streams, beaches and lakes would be much purer and healthier. So is this feasible?

What Can Cities Do About It?

In the U.K. in 2012, over £3bn of water damage claims were filed after a period of horrific flooding, causing the insurance industry the largest losses since 2007. As a result, 83 percent of respondents in a survey said today’s water-management designs are too little, too late. So is there hope for America?

Cities across the country are looking for solutions to this issue in one or other way. In response to the 30 billion gallons of combined sewage overflow in New York every year, the city plans to spend $730 million in public funds on green infrastructure over the next decade. This means that for every inch of rain or less, there will be a place for that water to go without making it into the sewer system.

How is this going to happen? Decentralizing the solution is a start, as going green is said to be far more cost-effective for cities than the further construction of more centralized wastewater treatment plants. Going green across the country would cost an estimated $63 billion, so it puts into perspective the cost of keeping things as is.

Green stormwater infrastructure would mean mimicking how nature deals with rainwater, and that’s via porous surfaces. As opposed to one treatment facility, the goal would be to eliminate the need for traditional stormwater storage through the implementation of green rooftops, strategically landscaped parks, rain gardens and barrels, roadside plantings and more. Plants and soil would collect stormwater and prevent or slow down the runoff into sewer systems.

This is where bioswales play a part. In addition to the natural absorption and retention of stormwater, excess rainwater can be contained in bioswales. These large pools or reservoirs would be used for stormwater only, treating it slowly and planted with trees and vegetation to filter out any contaminants through phytoremediation. This should remove the necessity to dredge rivers, dams and lakes.

The issue remains that our urban planning occurred without the hindsight we have today, and stormwater is creating a huge amount of pollution and hazards. Thankfully, there is now a strong movement toward green infrastructure to solve these problems and reengineer our cities.