Shaping a Sustainable Future

U.S. ARMY CORPS OF ENGINEERS – SHAPING SUSTAINABILITY

BY CRAIG COLLINS, AMERICA'S ENGINEERS

The 21st century has been an era of extremes for the Panama Canal: The region’s biggest droughts, and eight of the largest storms ever recorded, have happened in the last 20 years. In fact, 2014, and then 2016, were the driest years since the canal was completed in 1914.

But the dry season of 2019 was the worst yet. After five months of almost zero precipitation, river flows to the canal’s two lakes, Gatún and Alajuela, were down 60%. Gatún – one of the world’s largest artificial lakes, comprising a 21mile traverse through the Canal Zone for vessels with drafts of up to 50 feet – was dangerously low, forcing the Panama Canal Authority to lower customers’ maximum allowable draft and limit the amount their largest ships could carry. At the same time, it was forced to raise the rates it charged for passage.

A low water level in Gatún Lake, Panama, reveals tree stumps in 2015.

BALOU46 VIA WIKIMEDIA COMMONS

Panama’s constitution stipulates that water in the reservoirs must be used first to meet human needs – to supply water, for example, to the approximately 2 million people in the surrounding communities. But the Panama Canal is one of the most economically important waterways in the world, handling about 5% of the world’s maritime trade. Disruptions to its operation have far-reaching effects, particularly in the United States, where much of the canal’s traffic either begins or ends. And disruptions have become increasingly common as the climate changes.

As part of the Panama Canal Water Resources Program, a partnership between the Panama Canal Authority and USACE, David Bogema visits the Agua Clara Lock Feb. 4, 2022.

COURTESY PHOTO

The Panama Canal Authority took action to alleviate demand pressures in the short term – suspending hydropower generation, for example, and recycling water in its locks – while continuing with its medium-term reforestation project in the canal basin. But it still faced a longterm problem: The lakes in the canal were rapidly replenished by heavy rains, but the Canal Authority had nowhere to store that surplus water during the dry season.

To solve this long-term problem, canal administrators turned to the U.S. Army Corps of Engineers (USACE). In November 2021, the authority signed a contract for consulting and advisory services for its new $2 billion Water Projects Program, aimed at providing a sustainable long-term balance between the canal’s contribution to human needs –supplying water to communities, for example – and the canal’s economic viability. USACE had lent support to Panama with technical assistance that allowed it to formulate its plan for taking over administration of the canal during the historic 1999 transfer of the Canal Zone from the United States, and has participated in studies, maintenance, and improvements in the waterway since then, including studies of possible water supply alternatives. USACE was an ideal choice as a partner in the program.

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The program consists of projects that will supply water to more than half the population of Panama, as well as for the operation of the canal – a balance that will require studies of sustainability amid climate scenarios and growth projections.

USACE participation in the Canal’s Water Projects Program is a high-profile example of its work in building a sustainable future both at home and abroad. Panama is one of the 100 countries around the world to receive USACE technical assistance through its Interagency and International Support (IIS) program, which is aimed not only at providing services to valued partners and allies: In the case of the Panama Canal, it’s easy to see that creating sustainable solutions for an uncertain future is an effort to bolster the health, well-being, and economic security of local and global communities.

Climate Change’s Far-reaching Impact

Understanding how climate change intersects all USACE mission areas begins with understanding that it’s an agency designed to serve the U.S. Army and the Department of Defense (DOD), which has identified climate change as a critical national security threat. The Pentagon has assigned USACE a leading role in managing the unique climate change risks facing 5,000 DOD locations worldwide – and the department has adapted the Climate Assessment Tool developed by the Corps of Engineers for this very purpose.

According to Christine Altendorf, USACE’s director of Military Programs, these projections are notoriously difficult. “When I worked for Installation Management Command, we had to compare our performance over baseline, and in Alaska, describing how much water you save, how much energy you save – well, so much of that depends on the weather, right?” On paper, her team did great, racking up huge energy savings over the Alaskan winter – but everyone knew those savings were because the winter had been unusually warm. “So how do you truly measure the effect you’re having, and the true sustainability value of an installation?”

An F-15E Strike Eagle from the 336th Fighter Squadron returns to a runway surrounded by floodwaters at Seymour Johnson Air Force Base, North Carolina, after Hurricane Matthew. More than 40 Strike Eagles were repositioned to Barksdale Air Force Base, Louisiana, ahead of the hurricane to avoid potential damage from severe weather associated with the storm. The Department of Defense (DOD) has assigned USACE a leading role in managing the unique climate change risks facing 5,000 DOD locations worldwide.

U.S. AIR FORCE PHOTO BY SENIOR AIRMAN BRITTAIN CROLLEY

USACE’s ambitious Sustainable Building Materials pilot program for new barracks at Joint Base Lewis-McChord is an example of project management that looks at both the upstream and downstream effects of an installation, and is aimed at the strategic goals of lower energy consumption, water intensity, and carbon emissions.

USACE’s environmental program embraces both these strategic military concerns and the long-term value and benefits of the nation’s water infrastructure. The agency’s Environmental Operating Principles reinforce its roles and responsibilities in the sustainable use, stewardship, and restoration of natural resources – and all decisions, across all programs, are viewed with these principles in mind: USACE work considers not only the environmental impacts of a project, but ensures that those actions are sustainable into the future, using mechanisms such as the Climate Assessment Tool. “In 10 years, is Fort Hood going to be 5 degrees hotter? And what impact is that going to have on Soldiers when they’re doing their outside training?” asked Altendorf. “What’s going to be the water availability in these areas? We need to look at all of these questions.”

Planning for the Future(s)

When you experience record flooding one year, and record drought three years later, how do you plan for a sustainable future? According to Will Veatch, a hydrologist, technical specialist, and acting lead for USACE’s Climate Preparedness and Resilience Community of Practice, you don’t plan for the future – you plan for several futures, within the range of what you might expect to see amid ongoing trends in precipitation, sea level rise, storm frequency, and intensity, and many other variables. USACE uses several sophisticated models to take these into account – and is comparing these models to refine their own projections.

The incorporation of natural and nature-based features in USACE projects was codified by the Corps of Engineers in 2010, when it established its Engineering With Nature (EWN) initiative, which has expanded into a multimission, multisector effort.

“When the Corps designs and constructs a project, it wants to make sure that project is going to do whatever it is that it’s supposed to do, for as long as it is supposed to do it,” said Veatch. “Whether it’s a levee or a dam or a navigation channel or a restored ecosystem, performance and project life cycle can mean different things – but in simplest terms, we want to make sure we are delivering what we said we would, even though we’re uncertain about the future climate conditions.”

Bulldozers spread dredged sand on Rockaway Beach after Hurricane Sandy in 2012. USACE’s Rockaway and Jamaica Bay project will combine structural- and nature-based solutions to protect against shoreline erosion and mitigate the effects of future storms, and has flexibility, including two triggers for sea level change, built into the plan.

U.S. ARMY CORPS OF ENGINEERS PHOTO BY CHRIS GARDNER, PUBLIC AFFAIRS

Climate change is a difficult variable to plan for, Veatch said, because it’s deeply uncertain. “The range of what’s plausible in the future is very broad. But in the simplest terms, it’s not really that different from other uncertainties” – such as inflation, land-use changes, population shifts, and more. “So we can project a plausible range of future conditions and then we can make sure that whatever it is, we’re planning to do whatever it’s supposed to do in that possible range.”

One of Veatch’s favorite examples of this is the Rockaways and Jamaica Bay project in Queens, New York, one of several coastal storm risk management projects in a planned $52 billion effort to protect the New York harbor region from storms such as 2012’s Hurricane Sandy, which caused $19 billion in damages across New York City alone. The Jamaica Bay project will combine structural- and nature-based solutions – a composite seawall, built inside a sand dune, that will protect against shoreline erosion – but it’s also planned for flexibility, said Veatch. “The authorized project includes two triggers for sea level change.”

The project’s authorization specifies that adjustments will automatically be made – the addition of more structural and natural material, and the modification of access ramps and stairs to the beach – when sea levels reach certain elevations. “By putting it into the authorized project, they don’t have to go back to Congress and get new authority to do this,” Veatch said, “or do another study to determine whether there’s a federal interest. It’s all authorized and they’ve included the costs and benefits in the analysis.”

USACE and its contractor Barnegat Bay Dredging Company completed a dredg ing and marsh restoration project near Stone Harbor, New Jersey, in December 2018. Work involved dredg ing sediment from the channel of the New Jersey Intracoastal Waterway and beneficially using the material to create habitat on marshland owned by the New Jersey Division of Fish and Wildlife. USACE Commander Lt. Gen. Scott Spellmon’s goal is to use a majority of dredged material for beneficial uses.

PHOTO BY JITZE COUPERUS

Engineering With Nature

This hybrid approach to project design, combining elements of natural and engineered systems, isn’t new to the Corps of Engineers – for example, they’ve long combined their dredging operations with beneficial efforts to restore or create islands that provide wildlife habitat and recreation opportunities, while reducing coastal storm and flood impacts. Since 1978, the New Orleans District has created and maintained more than 1,000 acres of coastal habitat – wetlands and islands – in the Baptiste Collette Bayou navigation channel.

The incorporation of natural and nature-based features in USACE projects was codified by the Corps of Engineers in 2010, when it established its Engineering With Nature (EWN) initiative, which has expanded into a multimission, multisector effort: At six “proving grounds” throughout USACE districts, engineers and project managers are testing innovative ideas on the ground and documenting what they learn.

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One of these proving grounds is in the San Francisco District, where Julie Beagle is the Environmental Planning Section chief. The EWN perspective, she said, considers the multiple types of achievable benefits over a project’s lifetime, instead of focusing narrowly on one particular goal. An obvious example in the district is a levee built in 1949 to control flooding along the Pajaro River, which passes through several low-income agricultural communities and empties into Monterey Bay. As a flood-control project, it’s never been particularly effective – it provides an eight-year level of flood protection, one of the lowest of California’s federal flood control systems, and the region has suffered several costly – and sometimes tragic – flood events.

Beagle sees the levee structures, placed high and tight alongside the river, as an opportunity to integrate EWN principles. “The idea of integrating Engineering With Nature into this project is that if you set back the levees, and you let the river do what rivers do – which is meander, deposit, scour, move around a little bit more than it does now – it recharges groundwater in an overdrawn valley,” she said. “It provides critical habitat for endangered species that live along this river corridor, which is our federal objective. It provides actual flood protection for communities who have not had it – there has been loss of life in that area.” Expanding the floodplain – which will involve buying up some parcels, and securing easements from farmers – will protect and replenish some of the most productive farmland in the world, and provide additional benefits, such as recreation and water supply. A re configured Pajaro River project is among those funded by the new Bipartisan Infra structure Law.

“If we just do things the same way we’ve been doing them for the last 150 years,” said Beagle, “and just build levees right along the river’s edge – when climate changes come, in California, we’ll have atmospheric rivers that create massive floods. This approach provides more space to absorb that energy, protect people, and provide critical habitat and corridors for the environment. ... It’s more than an economic gain. It’s economic, social, environmental – it’s everything. To me, that’s our responsibility as a federal agency, with big dollars currently targeted to support such approaches.”

Too often, skeptics of nature-based solutions make the mistake of thinking in either/or terms. Courtney Chambers, the research ecologist who serves as the EWN communications lead, says this is a crucial misunderstanding: “We’re not trying to do away with our hard infrastructure by any means,” she said, “but to get more resilient solutions whenever we nest within the landscape – and in many instances, to get better multiple-use outcomes.”

The idea of integrating Engineering With Nature into this project is that if you set back the levees, and you let the river do what rivers do – which is meander, deposit, scour, move around a little bit more than it does now – it recharges groundwater in an overdrawn valley.

– Julie Beagle, USACE Environmental Planning Section Chief

Driving Innovation

While funded, the Pajaro River reconfiguration project hasn’t yet been constructed, because USACE and its partners are still working on finalizing permits and engineering designs. In the past, this project had suffered because a pure cost-benefit analysis ignored other necessary variables. “What are knowns as ecosystem services, such as groundwater recharge, habitat corridors, carbon sequestration – none of that had been accounted for,” Beagle said. “But I think with this new funding, and with our new approach to looking at multiple benefits of projects, that’s how we can get this done.”

The meandering course of the Pajaro River between hard – and often ineffective – levees, is shown in this aerial photo during a LightHawk mis sion. LightHawk is an organization of volunteer pilots who lend their skills and aircraft to environmental causes. A reconfigured Pajaro River project that incorporates Engineering With Nature concepts is now underway.

USACE PHOTO BY JOANNE CASTAGNA

To compose a new way of calculating the long-term costs and benefits of a project will require innovation; rapidly evolving global circumstances demand new ways of thinking about problems and projects. In the San Francisco District, Beagle and her EWN colleagues are experimenting with an approach that’s been tried in the Netherlands, but not yet in the San Francisco Bay: strategic shallow-water placement of dredge material. USACE has replenished many drowning or eroding wetlands and marshes around the shores of the bay over the years using “direct placement” techniques, but the cost of direct placement and physical constraints of reach ing certain areas have proven challenging. “What we’re doing is taking a certain amount of sediment that’s dredged from a channel in the bay,” Beagle said, “and we’re dropping it in the shallow subtidal waters, and then we’re monitoring the ability of waves and tides, and potentially storms, to move that material and deposit it on the mudflats and marshes. So, it’s essentially mimicking a natural process of a storm delivery, which feeds marshes and mudflats over time, and it’s what we know our marshes and mudflats need to keep pace with sea level rise.”

If the San Francisco proving ground can figure out a way to use natural processes to reseed marshes and wetlands, it may be a significant step toward USACE Command er Lt. Gen. Scott Spellmon’s goal of turning the Corps of Engineers’ current approach to using dredged material – using 30% for beneficial uses, and disposing of the other 70% – on its head. Ultimately, Beagle would like to see USACE use 100% of its suitable dredged material for beneficial purposes –but she’d be OK with 70%, for now.

“Nature has a huge role to play in climate adaptation,” said Beagle. “And for the Corps to remain the nation’s engineers, nature-based solutions are going to be a major part of how we do business mov ing forward, because of all the benefits it provides. Our future solutions are going to be a combination of green and gray infrastructure. If you’re only thinking gray, you’re missing out on a ton of the available options.”

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