•  Carrier

When Florida became a state more than 150 years ago, it was a wild and inhospitable frontier. Over the years, as interest in settling Florida grew, many private citizens and elected officials worked hard to tame Florida’s wilds. Canals and levees were built to prevent floods. Swamps were drained and other natural areas were leveled and developed into agricultural and urban centers. Pesticides were used to keep mosquitoes at bay.

Industrial initiatives, so often hailed as “progress,” have come at a price. Much of Florida’s native landscape was dramatically changed; perhaps the most severely damaged was the Everglades. The U.S. Army Corps of Engineers (USACE) is one of the principal agencies in a joint effort to restore the Everglades, the Comprehensive Everglades Restoration Plan (CERP), the world’s largest restoration project ever. The plan is designed to create a sustainable future for the state and its residents. It will not only restore much of the South Florida ecosystem, but it also will enhance urban and agricultural water supplies.

This task is not easily accomplished. It will take many years to complete and success will require that all involved use cutting-edge science and engineering. The plan is likely to have a major impact on both the future of the environment and the future of our country. It stands to be a model for all succeeding restoration efforts; it stands to alter man’s symbiotic relationship with nature; and it stands to change the way in which agencies like USACE do business. Ultimately, CERP may even influence man’s ability to survive on Earth.

Reversing the Damage
USACE’s history in the Everglades began almost 100 years ago. In response to devastating hurricanes in the 1920s and 1940s, USACE was called upon to provide flood protection and water to people and agriculture in South Florida. In 1948, Congress tasked USACE with a massive water management venture known as the Central and Southern Florida (C&SF) Project. Starting in 1950, USACE began construction on the C&SF Project, building 1,000-mi of canals, 720-mi of levees and nearly 200 other water control structures, all designed to make South Florida more inhabitable. The C&SF Project achieved its goals of water control and urbanization, but resulted in seriously negative consequences for the Everglades’ natural environment.

Today, the extent of the Everglades wetlands has been reduced by 50 percent, water flow has dropped 70 percent, water quality has substantially deteriorated and 68 species of plants and animals in the region are listed as threatened or endangered. Congressional legislation passed in 1992 and 1996 authorized USACE to reevaluate the C&SF Project and find ways to restore much of the natural function of the Everglades ecosystem. In a four-year process that became known as the “Restudy,” the USACE reevaluation resulted in CERP, which was authorized by Congress in the Water Resource Development Act of 2000 (WRDA 2000). WRDA 2000 states “the overarching purpose of CERP is the restoration, preservation and protection of the South Florida ecosystem while providing for other water-related needs of the region, including water supply and flood protection.” To achieve these goals, CERP will take more than 30 years to complete, will cover an 18,000-mi2 area, and will cost more than $7.8 billion in 1999 dollars.

CERP is designed to modify the C&SF Project to “get the water right.” The Restudy found that many of the environmental problems associated with the C&SF Project are related to issues of quantity, quality, timing and distribution of water. Currently, billions of gallons of fresh water are diverted by C&SF Project canals and other works every day, and that massive flow—once destined for the Everglades—now empties into the Gulf of Mexico and the Atlantic Ocean. One of CERP’s primary goals is to capture this resource and make sure it reaches the Everglades. The C&SF Project also destroyed and disrupted many of the Everglades’ natural filtration systems, so much of the water that does flow into the Everglades contains harmful levels of nutrients and other contaminants. CERP plans to restore the ecosystem’s natural filtering mechanisms to ensure the water reaching the Everglades is of appropriate quality. Lastly, because the C&SF Project has altered natural runoff patterns, much of the water flowing into the region comes at the wrong times or is distributed to areas that do not need it. CERP aims to get the water to the right places at the right times.

A Team Approach
Because of the massive scope and cost of restoration, USACE is not working alone. In fact, WRDA 2000 specifies that CERP’s planning and implementation will be conducted through a partnership led by the federal government and state of Florida. Work will be accomplished via a large interagency, interdisciplinary team of federal, state and private entities. This collaborative effort is one of the hallmarks of CERP.

Sixteen county governments, more than 130 municipalities, two tribal governments, numerous special interest groups, five regional planning councils, five state environmental and planning agencies and eight federal agencies are involved in the massive restoration effort. Some of these diverse entities include the Florida Department of Environmental Protection, the South Florida Water Management District, the U.S. Department of the Interior, the Miccosukee and Seminole Indian tribes, environmental groups, recreationalists such as fishermen and the U.S. Fish and Wildlife Service. All of these groups are working together during each step of the project, making certain that agency missions are achieved and that all stakeholders have a chance to influence the restoration.

Solving the Water Problem
Water is the lifeblood of the Everglades, and almost all of CERP’s components are aimed at getting the area’s water resources back to a more natural state. To achieve this goal, CERP contains more than 60 different engineering projects, each designed to address the four factors of quantity, quality, timing and distribution of water.

Quantity. To provide flood protection for South Florida, the C&SF Project’s canals, levees and other features diverted much of the Everglades’ natural water flow. This caused, on average, more than 1.7-billion-G of water destined for the Everglades to be discharged into the sea every day. The CERP factor of quantity goes toward capturing this wasted resource and storing it for use in the Everglades. To capture and hold the water, USACE will build 180,000 acres of new reservoirs and as many as 330 underground aquifer storage and recovery (ASR) wells. Most of this new water will go to the environment.

In addition to using established methods of water storage such as above-ground reservoirs, CERP will utilize a new method of in-ground storage using rock quarry pits left over from limestone mining projects. The captured water will be pumped into these pits and stored for later use.

The ASR wells, another new water storage technology, use the Floridan Aquifer as a holding tank. To get the water into the aquifer, USACE will pump it far below the Biscayne Aquifer, which provides South Florida’s drinking water. The deeper Floridan Aquifer is brackish and isolated from the Biscayne Aquifer. Because fresh water does not readily mix with salty water, the Floridan Aquifer will serve as a storage area so that fresh water can be pumped back out when it is needed to augment environmental and drinking water supplies. ASR will allow large amounts of stormwater runoff to be gathered and pumped underground, where huge fresh water “bubbles” form in the brackish aquifer. Unlike other water storage technology, very little evaporation is associated with ASR.

Quality. Today, much of the water that feeds the Everglades is of poor quality. The region’s water used to flow through meandering rivers and vegetated wetlands that acted like giant filters as the water flowed south. But canals and levees have obstructed this flow; wetlands have been drained and surface waters have been redirected. Water that now makes its way to the historic Everglades carry nutrients, fertilizers and other contaminants that have disrupted the natural balance of an ecosystem that has evolved over millions of years in a nutrient-poor environment.

To reverse this situation, USACE plans to design stormwater treatment areas that mimic the natural filtering mechanism once found throughout the Everglades watershed. In order to establish these filter systems, USACE will take around 36,000 acres of land once used for agriculture and create constructed wetlands. The water will then be pumped through these wetlands for filtration.

Timing. Timing also is critical to getting the water right. The Everglades go through alternating periods of wet and dry seasons. These natural patterns of wet and dry conditions are essential to maintaining the ecosystem’s health. But many of these patterns have been dramatically altered by the C&SF Project’s flood protection structures and urban water projects, throwing the natural plant and animal habitats completely out of synch.

To mimic the natural timing of hydration of soils, or “hydroperiods,” USACE and agencies such as the National Park Service are carefully studying the natural water flow rates and levels of the Everglades. By understanding the seasonal target water levels and flows, USACE can adjust its management actions to better suit the ecosystem. By getting the timing right, the Everglades’ hydroperiods should be restored, thus getting the ecosystem back on its natural rhythm.

Distribution. Getting water to the right places relates to distribution. Because much of the Everglades has been separated and compartmentalized by the C&SF Project’s canals and levees as well as other development, many locations that once received large amounts of natural water flow are left with only a fraction of what they need to survive.

To improve the connectivity of these areas and enhance water flow, USACE plans to remove many barriers to natural water flows. Achieving this may mean more than 240-mi of the C&SF Project’s canals and levees will be dismantled. Additionally, the Tamiami Trail (U.S. Route 41), which also blocks natural water flows, will be modified to enhance distribution.

A Challenging Future
CERP is set to challenge USACE and all the other agencies involved. Restoring something as vast and complex as the Everglades is going to be extremely difficult. There are still many unanswered questions about the way the ecosystem will respond to further alterations, but these uncertainties have been acknowledged. USACE and its restoration partners have pledged to use the best science available, which is always evolving. Ecosystem restoration is a relatively young field of research.

As each of the CERP projects is implemented, ecologists and engineers will closely observe the ecosystem’s response. Learning as restoration progresses and applying those lessons by tweaking an existing project and designing new projects is the basis of adaptive management and incremental adaptive restoration. This iterative process of building-learning-modifying-incorporating will ensure that achieving restoration goals becomes possible and that the restoration effort continually improves over its decades-long timeframe. Restoring ecosystems is a task that’s relatively new to USACE and the nation in general; much of what is accomplished will set precedents for man’s future relationship with the environment and efforts to achieve a sustainable future.