The world's largest conservation non-governmental organization is a 63-year-old environmental activist group that has drawn 119 million acres of sensitive lands under its protective wings. It has amassed assets of $6 billion and now annually collects $500 million in donations from its one million members to fight the green fight.

The Nature Conservancy has 3,500 employees, 600 of them scientists, including 380 water-resource professionals with advanced degrees. Over the past several years, under the leadership of Mark Tercek, the president and chairman who came on board in 2008, it has expanded its strategy from acquiring and sequestering environmentally important land to identifying and influencing new development projects that have potential to impact freshwater resources. It now partners with planners and developers on selected projects to optimize outcomes for both humans and nature.

These days, TNC staffers are more likely to show up on wetlands and waterway projects as scientists, engineering consultants, and planning and funding partners, rather than as spoilers to derail development.

"The organization had been evolving in that [new]direction before I got here, but that view is what attracted me to the role," Tercek tells ENR.

Tercek, a former investment banker, seems an improbable choice to run a conservation group. But he has come to see a business advantage in sustainability, as he explains in his recent book, "Nature's Fortune: How Business and Society Thrive by Investing in Nature," co-authored with Jonathan S. Adams.

Before taking the helm at TNC, he was at Goldman Sachs, where he analyzed sustainability for investment opportunities. He saw that companies that improved their environmental behavior delivered two benefits: good commercial results and good environmental outcomes. Sustainability is good business, he concluded. With that, he found a new mission.

"The work of conservation is, ultimately, working with others to ensure the vital services nature provides remain available to future generations," Tercek says. He notes that, with the global population expected to rise to 9 billion in 2050 from 6.6 billion today, sequestering lands from development is no longer enough.

Tercek says we simply have to rethink our relationship with nature because the "services" nature provides—clean air and water, pollination and a stable climate—are the basic underpinning of our quality of life, prosperity and economies. "We have to feed and sustain people without damaging the natural systems we all rely on. By helping people understand how closely tied their well-being is to the health of the natural systems, we hope we can help them understand that nature is a smart investment," Tercek says.

TNC has chapters in every state and is consulting on development programs affecting watersheds in 35 countries. It has project partners almost everywhere.

Starting in 2000, it began signing what has become a series of memoranda of understanding to develop partnerships with the U.S. Army Corps of Engineers, first at the national level and then at division and district levels all around the country.

According to the MOUs, the Corps benefits from TNC's "extensive and active network of conservation partnerships, biological expertise, presence and successful history of work in hundreds of local communities" and from "its position as a leading conservation organization known for its use of sound science and collaborative approaches in resolving natural-resource management issues."

TNC benefits from the Army's large, geographically dispersed, multidisciplinary staff, and the Corps' extensive experience with water-resource projects, including projects for environmental restoration and protection and development or modification of decision-support models for evaluating management options. The MOUs include no funding or competitive advantages for TNC, but they do endorse partnering from the top of the Corps' chain of command.

The regional memoranda are tailored to address regional issues, ranging from the loss of seabed habitat for oysters and grasses in the Chesapeake Bay and off Long Island to floodplain management and the operation of locks and dams and inland navigation systems across the Midwest to dam removal and ecosystem restoration nationwide.

TNC's chapter-based scientists and specialists become participants in project planning and execution who influence design and operation of projects likely to impact freshwater resources. TNC's goal is to help find the optimal balance between serving human needs and protecting nature, says Tercek.