The pressures of population growth in the Bay watershed continue to change its landscape, transforming forests and agricultural fields into roads, housing developments and shopping centers.

The state-federal Bay Program partnership estimates that about 400,000 acres of forest — more than twice the area of Shenandoah National Park — will be lost to development between 2006 and 2025, sending an additional 8 million pounds of nitrogen to the Bay.

That loss of forest, in other words, means states will need to achieve 10 percent more nitrogen reductions than originally planned in the next decade.

That is why some believe it is time to find incentives that help keep high-quality forests growing trees, instead of buildings.

“Forests have been recognized as one of the best land uses for meeting our water quality objectives,” said Greg Evans of the Virginia Department of Forestry. “But if they are so good, why is no credit being given for conserving them?”

Indeed, conservationists in recent years have been frustrated by the paradox that high quality forests may be the most valuable land use from a Bay perspective, but protecting them from development gets no credit in Chesapeake cleanup efforts.

Granting that credit is easier said than done, though. In computer models used to track pollution reaching the Bay, simply keeping land in forests does not help reach cleanup goals — it just keeps pollution from increasing.

Land conservancies and other land protection advocates are trying to figure out ways to recognize the pollution prevention benefits of desired land uses like forests.

A 2013 Chesapeake Bay Commission report, “Crediting Conservation: Accounting for the Water Quality Value of Conserved Lands Under the Chesapeake Bay TMDL” recommended four ways that land conservation might be credited under the Bay TMDL. If adopted, the recommendations would provide new incentives to local and state governments to protect land from development to avoid pollution. The concept is called “crediting conservation.”

These policy recommendations are being explored by land trusts, watershed advocates and workgroups within the Bay Program.

“Over the long run, conservation of forests and healthy watersheds is going to be a cheaper, longer-lasting solution than practices to address pollution after it is created,” said Mark Bryer of The Nature Conservancy. Bryer is chair of the Bay Program’s Maintain Healthy Watersheds Goal Implementation Team, which has been promoting ways to keep healthy, intact ecosystems from being developed.

“We have all seen the changes in the watershed over the years,” Bryer said. “We know that if we don’t do something to protect what we have today, if we don’t recognize the value of a forest today that is producing clean water, then we will not achieve the goals we want for a clean Chesapeake Bay and clean local waters.”

History of land conservation

The Bay Program has a long history of promoting land conservation. Multi-state Bay agreements drafted in 1987, 2000 and 2014 all include land conservation goals.

But the mandated pollution reductions in the Chesapeake Bay Total Maximum Daily Load put in place in 2010 concentrated attention — and some say most of the resources — on reducing nitrogen, phosphorus and sediment pollution as opposed to conserving land.

Achieving TMDL pollution reduction goals has put most of the focus on implementing upgrades at sewage treatment plants and best management practices such as cover crops or stormwater ponds that reduce runoff, and therefore pollution, from urban areas and farms.

Every year, the six Bay states and the District of Columbia report the number and kind of actions undertaken to the Bay Program, which uses a suite of computer models to simulate the Bay watershed and estimate nutrient and sediment reduction progress toward meeting TMDL cleanup goals.

But this type of accounting “has made integrating the water quality values of conserving land an awkward fit — not unlike ‘fitting a square peg into a round hole,’” according to the Chesapeake Bay Commission’s 2013 study. That is because conserving land does not produce “new” pollution reductions that count toward reduction goals. As a result, states get no credit for land protection.

Crediting conservation

But what if, the commission’s report reasoned, credit could be given not just for pollution reduction measures, but also for protecting land to keep forests and other beneficial landscapes intact and thereby prevent pollution? This would put land conservation on an equal footing with other pollution reduction measures — and provide an incentive for local governments and states to make land use decisions and investments that protect forests and fields from turning into roads, shopping centers and housing developments.

“The ideas in our 2013 report have been percolating ever since,” said Ann Swanson, the commission’s executive director.

One policy recommendation, called the “perpetual BMP (best management practice) multiplier,” would confer an additional credit to a pollution-reducing practice if implemented on land protected from development. For example, tree planting to establish a riparian buffer along stream banks has a certain pollution reduction value. But if the land where that protective buffer is installed is also permanently protected, shouldn’t it be worth more in the TMDL calculus?

A second recommendation, called “crediting conservation in offset calculations,” would give conserved lands involved in a nutrient trading scenario additional reduction credits. For example, a jurisdiction may allow a polluter, say a sewage treatment plant, to offset its pollution by installing one or more pollution-reducing actions elsewhere in the watershed to offset the pollution produced at the plant. This policy change would allow additional credit when the pollution-reducing practices are installed on permanently protected land.

But getting a premium credit for BMPs on protected lands doesn’t match the science, said Rich Batiuk, associate director for science with the Bay Program. “Putting a conservation easement on a parcel of land where a BMP has also been installed won’t change the amount of runoff or pollution coming from that parcel,” Batiuk said. It does confer an extra measure of assurance that the land will not be developed in the future, which is important, he said, though an easement (one form of protecting land), just like a BMP, needs to be monitored.

“Making the policy leap that putting a conservation label on it gets an additional reduction or additional credit — I don’t think the Bay program partnership has made that leap yet,” Batiuk said. But he added, “We’d know that at least on that piece of land, offsetting for future growth wouldn’t be necessary.”

A third recommendation would provide “premium credit for targeted conserved lands.” Research is showing that headwater streams that are protected by forest buffers do more for nitrogen reduction in the Bay watershed than buffers on other, larger waterways. A “premium credit” would allow additional pollution reduction credits for those areas — protected in perpetuity — in recognition of their greater value to downstream water quality relative to other properties that are located lower in a stream’s watershed.

Identifying specific “high conservation value” headwater streams and landscapes could become a reality because of a new methodology, often called “precision conservation,” being pioneered by the nonprofit Chesapeake Conservancy and others. The conservancy is using high-resolution land-cover data to identify where in the river system pollution-reducing best management practices will offer the greatest pollution reductions. These same mapping techniques can be applied to identifying the best parcels for permanent protection.

Peter Claggett, U.S. Geological Survey research geographer at the Bay Program office and coordinator of the Bay Program’s Land Use Workgroup, sees great promise in the tools of precision conservation. “We’re hoping to get to the point where we could incentivize the targeting of BMPs through some sort of crediting scale.”

Offsetting growth

The fourth Bay commission recommendation — called the “2025 baseline” approach — is getting significant attention in preparation for the Bay Program’s 2017 Midpoint Assessment of progress toward meeting the TMDL goals. That process will also refine estimates of nutrient reductions needed from 2018 through 2025 — figures that will be used by states to write new “Phase III” watershed implementation plans to achieve those goals.

Because the TMDL establishes a maximum amount of nutrients and sediment that can reach the Bay and still maintain its water quality standards, it implicitly acknowledges — and explicitly requires — that all new sources of nutrient pollution must be offset.

Some argue that if nutrient reduction allocations are based on the growth estimated through 2025 and explicitly factored into reduction allocations given states, it would open the door to crediting land protection actions that would reduce the impact of future growth. In other words, if the water quality impact of anticipated forest losses were factored into nutrient goals in advance, there would be an incentive to instead protect those lands and head off that increase.

No decision about taking such an approach has been agreed upon by the Bay Program partnership. And there are challenges to estimating the population and development increases the jurisdictions will experience by 2025.

But better science, new data and improved technologies being incorporated into the watershed model that was used to set the TMDL’s target loads in 2010 will help answer those questions. The improved model, along with projections from the program’s land use model, will better estimate where and how population growth and related land use changes associated with that growth might occur.

“If our planning target is based on the 2025 land use, and if jurisdictions are able — through planning, conservation or other means — to reduce the impact of growth, then they should get some credit for that,” Claggett said.

The ultimate TMDL target doesn’t change, he said, but the states’ watershed implementation plans would be based on what the future is likely to be, rather than present conditions. “We should be moving into the future with our eyes open.”

New ‘math’ required

But figuring out precisely how much to credit land conservation requires a “new math,” Batiuk said, one which factors in credit for actions not taken.

“It’s complex,” TNC’s Bryer acknowledged, “but just because it’s complex doesn’t mean we should shy away from it.”

“The alternative is to continue to lose thousands of acres of forestland and the clean water they are providing every day with the false assumption that we can cheaply and easily mitigate that impact and can somehow replace the function of that forest.”

Preliminary results from a new study by the Virginia Department of Forestry has increased momentum behind finding ways to put conservation on an even basis with other pollution-reduction techniques.

The Healthy Watersheds Forestry Pilot Project showed that local governments in the Rappahannock River basin’s central region could save as much as $125 million between now and 2025 if they preserve high-value forests rather than allow them to be developed. Conservation would avoid the costs of having to offset the pollution brought by new people and development, which will require more stormwater management, sewage system capacity and other practices.

The Rappahannock project is poised to enter a second phase that will take the tabletop evaluation into the real world of local land use planning. The next step, said Evans, of the Virginia Department of Forestry, who leads the project, is to work with local governments in the Rappahannock basin to develop a “toolbox” of techniques. These tools will help localities make choices based on the conservation value of local lands when developing comprehensive plans or considering whether to permit a development.

The next phase will also be an opportunity to look at how land protection of high-quality forests in the upper watershed could benefit downstream users.

“If we develop these tools right, relative to the property and the project,” said Joe Grzeika, supervisor of King George County, “we have empowered our local governments and our business community to improve water quality without spending tax dollars for capital facilities, and empowered the businessperson to invest in water quality improvements with a positive return on investment.”

Kathleen Harrigan, before becoming executive director of Friends of the Rappahannock, worked in the TMDL program for many years and is encouraged to see this project taking place in the river basin. “In the TMDL world, load reduction is so often achieved on a project-by-project basis, and we can lose sight of the bigger picture that values existing forests,” she said.

She is optimistic the project will help jurisdictions that have the financial burden of meeting the Bay TMDL find value in retaining forest lands. “It’s one thing to know in your heart that these lands are valuable — but it’s a whole other thing to know the numbers support this.”

The land trust community is also encouraged, especially about the potential for using the 2025 baseline as a way to credit land protection under the Bay TMDL.

Megan Gallagher, co-chair of the land trust workgroup of the Chesapeake Bay Funders Network, said, “the Rappahannock project makes a compelling case for the link between conservation, ecosystem services and public cost avoidance and the TMDL offset requirements.”

Economic benefits

But conservationists say that pollution reduction under the Bay TMDL doesn’t have to be the only incentive for governments to protect land from development.

Forests slow the flow of water from field to stream, absorbing excessive nutrients and controlling erosion. Wetlands absorb pollution and help control flooding. Intact ecosystems maintain habitat for diverse organisms, filter water destined for human consumption, and provide resilience in the face of climate change and invasive species.

Communities and society benefit from the “ecosystem services” that result from keeping natural landscapes lightly or undeveloped in public parkland and wildlife management areas or in privately held land under conservation easements that minimize disturbances.

Using the value of the benefits of undisturbed or highly functioning ecosystems to drive environmental protection and land conservation has long been a strategy of conservationists — in spite of the challenges inherent in attaching a monetary value to complex natural systems.

But studies abound, and, “in almost every case it is more cost-effective to avoid ecological impacts than trying to go back and recreate the service [provided by nature] through gray infrastructure,” said Elliot Campbell, ecological economist with Maryland’s Department of Natural Resources.

Maryland is developing an “Ecosystem Service Valuation Framework” that will establish metrics for communities to use when considering development projects. The framework is being tried in Charles County, where Planning Director Steve Ball said protecting farmland and forests — especially those with high conservation value — could reduce sprawl, which is especially important in watersheds that support healthy waters. The study, Ball said, is helping the county to be “proactive instead of reactive.”

John Rogers, a principal in the Keystone Conservation Trust, has worked with local governments in Pennsylvania to evaluate their natural assets using valuation studies that put a monetary value on the activities and opportunities that conserved lands offer, things like recreational opportunities, groundwater filtration, and water supply and flood protection.

“If you were a CEO, you would never overlook a revenue stream, and never miss an avoided cost,” Rogers said. “Every local government should look at nature as a portfolio for what it provides.”

After Rogers calculated Northampton (PA) County’s “return on environment,” the county government allocated $2.2 million toward land conservation.

And the federal government, said MD DNR’s Campbell, is making a real push toward ecosystem services valuation. “Under a new directive, federal agencies that manage land must take into account ecosystem services.”

Maintaining existing healthy watersheds and ecosystems is one of the top-level goals of the 2014 Chesapeake Bay Program Partnership Watershed Agreement, which strived to balance the Bay TMDL quantitative water quality goals with other objectives, including land conservation.

“As the 2017 Midpoint Assessment approaches, the magnitude of the gap between what we have achieved and what we need to achieve is becoming more obvious,” said Swanson of the Bay Commission. “If land conservation can provide offset credits under the Bay TMDL, it could provide the market incentives we need.”

The Rappahannock project, she said, “begins to offer the economic information that will compel policy-makers to conserve land.”