Four decades of “Environmentalism 1.0” has landed us a long way from a healthy planet. The tools created by the first generation of environmentalism—litigation, procedural requirements, etc.—were built in direct response to industrial over reach. These tools were used to slow bad developments, stop species from going extinct, and prevent pollution. These pioneering efforts achieved great success over the last 40 years. But if we expect a functional planet forever, we can’t just “hold the line.” Today, holding the line means we are losing—losing the basic life-supporting benefits that natural systems provide to humans.

To realize environmental gain, we must restore our natural systems faster than we degrade them, and to do this, we have to fundamentally change how conservation works. We must create a market-based, “quantified conservation” future that lets us fully account for our actions.

Water, the cornerstone of all life on Earth, can serve as a logical starting point for this shift. Let me explain.

When the Clean Water Act passed in 1972, regulators focused on toxins, heavy metals, and the cleanup of rivers so polluted that they literally caught fire, just as Ohio’s Cuyahoga River did in 1969.

While we no longer see flames, our rivers are still burning. With more than a third of our 3.6 million stream miles in the country impaired, water quality now implicates less obvious parameters, such as river temperature, nitrogen, phosphorous and water quantity.

Today, the Mississippi River is so choked with excess fertilizers and runoff it gives birth to a dead zone (a reduced level of oxygen in the water that cannot support aquatic life) in the Gulf of Mexico that is the size of New Jersey, Rhode Island, and Connecticut combined—an area the size of 10 Deepwater Horizon oil spills each year. Further, because cities like Los Angeles, Phoenix, and Las Vegas take their cut of water first, the Colorado River, once strong enough to carve the Grand Canyon from stone, no longer reaches the sea.

There have been many attempts to deal with these challenges, but one in particular—water quality trading—is promising because it creates for the first time a lingua franca between the environment and its once biggest enemy, the economy. The two biggest forces in the biosphere can now do business together, not just fight.

While the idea of water quality trading has long been discussed in white papers and at conferences, the actual implementation of this kind of program as it relates to water is only now coming online in a quantifiable and replicable way. Water quality trading gives cleanup or restoration activities value in the form of a credit that municipalities, conservationists, philanthropists, developers, or others can trade and purchase. Credits are simply an accounting unit to reflect the value of improving water quality, not dollar costs. In many cases, trading saves communities money in complying with water quality regulations, while offering a return to investors engage in generating the offset credits—a combined benefit that will encourage investment in restoring waterways at a necessary scale.

One example of water quality trading recently caught the attention of President Obama. In Oregon, the City of Medford’s wastewater treatment facility was returning treated wastewater to the river, but it was too warm for native fish species, which are critical to the overall healthy function of the region’s ecosystems. This is a common problem, even outside of the region. Historically, the town’s solution has been to build cooling towers, which cost millions of dollars in construction and many more dollars in operation and upkeep with massive energy requirements.

With water quality trading in place, the facility now has another option that is cheaper and ecologically superior, and creates local jobs. Here’s how.

Re-planting trees along rivers and streams has long been an important restoration effort. Streamside trees provide shade that reduces the thermal load into the watershed.  That reduction is translated into a credit that Medford purchases to offset its temperature impacts and meet regulatory compliance spelled out by the Clean Water Act. For the first time, a wastewater treatment facility can use dollars that would otherwise be spent on concrete and steel (such as a cooling tower) and quantifiably convert them into miles and miles of restored stream banks by planting trees on nearby farms and ranches. This system costs Medford $8 million less, creates more than 100 local restoration jobs, and pays landowners to grow “bushels of nature.”

Water quality trading is an affordable way to address America’s freshwater problems today. The idea that we can address these problems by simply stopping pollution or reducing consumption is foolish. Consumption is up, not down. Population is exploding. Growing impacts on freshwater are inevitable—we must offset these for ecological gain. In other words, we must create a system whereby one unit of environmental ill costs two units of environmental good. We can now do this in an efficient, cost-effective and quantified way.

Everywhere, cities are getting letters from the EPA saying they must comply with new caps on water temperature, nitrogen, and phosphorous. We want them to comply in a smart and affordable way. Yesterday, it was environment versus the economy. From here on out, we need both. With more than 200,000 permit holders like Medford, across the country that must treat their wastewater, this model has massive potential.