There are no other Everglades in the world... they are, they always have been, one of the unique regions of the world, remote, never wholly known... It is a river of grass..."
Majory Stoneman Douglas,
"River of Grass"
Water is arguably our most precious resource. Without it, life as we know it would not exist. When water quality is comprised, personal and public health and agricultural and industrial development are put at risk. Ever since humans first settled in agricultural communities, water management has been an important community issue. This is just as true today as it was in the ancient civilizations of the Middle East and the Americas. The Florida Everglades provide an extreme but important contemporary example of the advantages-and perils-of water management.
Prior to its alteration by flood control and agricultural projects, the Everglades region of south Florida was a mosaic of habitat types, ranging from freshwater marshes to tidal creeks, from areas dominated by huge stand of cypress to hundreds of square miles of sawgrass interspersed with small islands.
The Everglades, formed about 6,000 years ago, covered about 10,000 square kilometers when Europeans settled the region. Florida, south of Orlando, drained in the Kissimmee River and Lake Okeechobee, the nation's third largest lake. Lake Okeechobee served as a natural reservoir, draining south into the Everglades on gently sloping limestone bedrock which directed a sheet of slow moving, shallow water across all of southern Florida. The amount of water present was greatly dependent on the rainfall over the previous months. The huge sawgrass prairies, which occupied up to seventy percent of the original area, would often dry temporarily during the hot summers, while the deeper sloughs typically held water all year. These hydroperiod differences and landscape features produced a number of specialized sub-habitats in the Everglades, each with its characteristic suite of highly adapted species. The Everglades is the only system of its kind in the world and it was home to an amazing variety of plants and animals. It is a system which has been sacrificed to water control.
In 1881, the first reclamation canal was dug between Lake Okeechobee and Miami. In 1907, spurned on by a series of disastrous floods, the state formed the Everglades Drainage District to direct efforts to "reclaim" the wetlands for agriculture. Hurricanes in the late 1920's provided the impetus to institute flood control measures around Lake Okeechobee as well. Work in the area continued throughout the late 1960's aided by massive federal and state programs intended to encourage agricultural development and control flood damage during hurricanes.
Four decades and 500 million dollars later, the Everglades is only a shadow of what it was. The Everglades, once a unified region has been split into several artificially-separated management areas. Just to the south of Lake Okeechobee, the Everglades Agricultural Area (EAA) was formed. A system of levees, canals and pumps directed water off the EAA into 3 large water management districts (3480 kilometers in total area). These districts contained retention structures to control the movement in floods and droughts. To the far south and the west, two national parks, Everglades National Park and Big Cypress National Preserve, were formed. The function of the Everglades was forever altered by the levees, holding ponds and canals which spread throughout the region. In addition, exotic plant species, such as the melalecua tree, were introduced to aid in draining the swamp. The melalecua absorbs 6-8 times the amount of water as the native vegetation and has aggressively spread throughout the Everglades basin.
Nearly eighty percent of the original wetland area has been diked and drained as part of the largest water project in the United States. Nearly 1500 kilometers of levees and canals and 18 massive pumping stations have allowed south Floridians to develop a 1.5 billion dollar farming industry and to expand urban development. However, these "improvements" have led to the loss of ninety percent of the Everglades' wading birds and between seventy-five and ninety-five percent of its other vertebrates. A system, once characterized by a sheet of water 50 miles wide but less than a foot deep in many places, was transformed into a system of stagnant pools and narrow canals.
In 1976, the state of Florida created the South Florida Water Management District (SFWMD) to manage the water over the 44,000 km project area, which include forty percent of the population and thirty-one percent of the land in the state. In cooperation with the United States Army Corps of Engineers (USACE), the SFWMD now controls virtually all of the water in south Florida. With more than 4.5 million people now living adjacent to the Everglades, the SFWMD has to balance the needs of a huge populace with the ecological needs of the Everglades.
In response to growing public concern about the environmental damage caused by water management strategies in the Everglades region, the USACE proposed six possible plans for restoring the Everglades in 1994. These plans varied from small changes in water delivery schedules to large scale alterations in the canal, basin and levee system to restore a more "natural" flow regime. In 1996, the Clinton administration proposed a 1.5 billion dollar restoration plan for the Everglades system including Biscayne Bay. What are some of the environmental problems driving this interest in better water management?
Most of the remediation efforts to improve water quality have focused on the farms in the area, and some elements of agricultural community felt they were being targeted for problems that were not entirely their fault. At the same time, environmental groups have claimed farming interests are not providing enough support to the remediation efforts. Representatives of the commercial and sport fishing industries demand more freshwater in Florida Bay, while some groups in the urban coast fear that flooding problems may be exacerbated by any changes. In the highly charged atmosphere of water politics, interest groups have made claims and counter claims that are difficult to evaluate, confusing the general public and making it difficult to reach a consensus on what needs to be done. Frequent court challenges have also made it difficult for any progress to be made on remediation. In addition, many of the recovery plans and models used for planning restoration efforts have been the target of criticism from a variety of groups. This puts managers in a difficult position. Since there is virtually no hydrology data on how the Everglades functioned before they were altered, it is difficult for scientists to be certain about the accuracy of their models and the likely effectiveness of the remediation efforts.
While water management issues are as old as human society, our technology has enabled us to alter water resources to such an extent undreamed of in earlier times. Coupled with rapid increases in population, the complex nature of water management defies the old, local "business as usual" approach which has been able to deal with water issues on a smaller scale. As our understanding of systems like the Everglades increase, we have an ever greater chance of discovering potential solutions to water quality problems. What is missing is the political will to put science into practice.
Environmental groups have countered that the sugar lobby has distorted the issue and has lied to the public about the true costs of not adopting tougher water regulations. Tourism is Florida's number one industry, with 10 million visitors a year coming to south Florida alone. Millions of these will visit the Everglades and people who make their living from these tourists are concerned about the health of the Everglades-and for their jobs.
The control structures of the SFWMD were designed to contain storms and to provide a source of water during droughts. While the system does work to control water quantity during floods, it has produced serious problems in water quantity and in water quality in the Everglades. In the 1970-71 drought, so little water was delivered to the Everglades that nearly 300,000 hectares burned in wildfires. Exposure of the formerly water-logged soil to air has also greatly accelerated the breakdown of the peat layer, which has increased nutrient concentrations in the water running off these areas (see below). Toward the coast, the diversion of water from the Everglades historic waterways has the bay's sea grasses were dying off. Researchers think that there is not enough freshwater flowing into the bay to create the unique environment the sea grasses prefer. These grasses are critical habitat for the fishes and crustaceans that are an important part of Florida's tourist and fishing industries. Commercial and sport fishing groups have been pressuring the SFWMD to alter the control structures so more water is delivered to the bay.
When water is present, it is often heavily loaded with nutrient run-off from outside the park. Water running off the EAA directs an estimated 20 tons of phosphorus yearly into the Everglades. In some areas, the sawgrass has been replaced by other plants such as cattails which rapidly respond to high nutrient levels and out-compete the sawgrass and other native plants. The nutrient run-off has also altered the Everglades food web. Before alteration, huge mats of diatoms and green algae were the base of the food chain here, but with the advent of nutrient enrichment their biomass has steeply declined in many places. They have been replaced by blue-green algae (actually bacteria) which are a poor food source for many Everglades animals. As the water leaves the Everglades and drains into Florida Bay, it still has a high nutrient load, which is being blamed for massive algal blooms in the bay.
In 1995, USACE began a 370 million project to restore the Kissimmee's meanders and its historic hydrology. The project will eventually restore 56 miles of river and 26,500 acres of wetlands. Projects like these in the Everglades are extremely expensive because they require the purchase of prime agricultural lands at "fair market value" from their owners. Some citrus farmers around the Dade County area have claimed that the state water managers have deliberately allowed their lands to flood so the state can buy them up for a reduced price. While no proof of this has emerged so far, it is illustrative of how much friction and distrust there is among the competing water interests in the Everglades area.
The huge drainage projects in southern Florida have had many obvious surface effects, but perhaps the most complex problems are those posed by the groundwater. The water control structures altered groundwater recharge and the rapidly growing population in the area has been aggressively pumping water to meet public demand. As a result, the water table in south Florida has dropped more than 1.5 meters since 1900; and the Biscayne Aquifer, the source of essentially all of south Florida's drinking water, has been threatened by salt water intrusion from the Atlantic. In one area, Taylor Slough, the USACE has proposed pumping more water into the park from the canals to raise the park water table and avoid the drying events which have led to fires and other ecological problems. The federal and state governments have also initiated buy-out programs to create buffer zones in the old agricultural lands that surround the park.
Some local agriculture groups oppose the USACE plan to increase recharge of the groundwater. They are worried that higher groundwater levels would decrease their land's productivity and have asked that the USACE construct a sixteen mile curtain wall around some of the agricultural areas to protect them as the park's water table is raised at an estimated cost of nearly 96 million dollars. Other groups point to the tremendous cost of soil subsidence, pumping to keep salt water out of the Biscayne Aquifer, and the needs of the rapidly growing urban areas. To these groups, the loss of some agricultural lands seems a reasonable alternative.
Crop production and water use can be found in Chapter 9(pages 205-207). Chapter 11 gives good summaries on water management problems and solutions. Pages 284-285 contain a good summary on the use of irrigation water. Pages 279-281 discuss overdrawing groundwater resources and saltwater intrusion.
 |
© Prentice-Hall, Inc. A Simon & Schuster Company Upper Saddle River, New Jersey 07458 |
