A Sustainable Water Supply
Because water is such a necessary part of our lives, ensuring an adequate supply must be a priority. The mission of the Southwest Florida Water Management District is to ensure a sustainable water supply to meet public demand, while protecting the environment and the water resources. With a population increase of approximately 44 percent for the period between 1980 and 1995, and predictions of more than 1,100 new permanent residents each week through 2010, achieving that balance becomes more difficult.
Where Our Water Comes From
The average rainfall of west central Florida is 53 inches a year, making it one of the rainiest regions in North America. However, much of the rainfall occurs in June through September, and most is lost to evaporation or provides for runoff. The remainder replenishes the region’s ground waters. Ground water is rainwater that has soaked into the ground to an aquifer, an area of underground rock and sand, where it is “stored.” Surface water refers to water on the surface of the earth, such as lakes, rivers and streams.
Of the approximately 14 inches of rainfall that remains after evaporation has taken its toll, about 9 inches go to surface waters, leaving only an average of 5 inches to resupply Florida’s underground water reserves. Water users in the area regulated by the District use more than 1 billion gallons of water daily. More than 80 percent of this water comes from ground water in the Floridan aquifer, the deepest and most productive of the three aquifers found within west central Florida.
In some areas of the District, aquifers are connected with the lakes, rivers and wetlands above them. If too much water is withdrawn from the aquifers, the water level of the lake or river above may decline. Excessive groundwater withdrawals could also cause the salt water that surrounds the Floridan aquifer to move or intrude into freshwater areas, which decreases the amount of fresh water available and increases the cost for providing clean, potable water to residents.
It’s expected that ground water will always be a source of drinking water, but access to other sources is essential. The balance of the region’s water supply comes from surface water. The use of surface water will most likely increase in the future because the ability of the groundwater system to satisfy an ever–growing need for fresh water is limited. But there are limits to surface water as well. It is anticipated that by 2020, about 400 million gallons of additional water may be necessary each day to supplement current water resources to meet the projected water demand of all the current and future water users within the District.
The District’s Role
The District is responsible for managing and protecting the water resources and related environmental systems. To protect natural systems that sustain ground water, there must be limitations on how much water can be withdrawn. This is accomplished through planning, permitting and regulation. Local and regional governments, agricultural and other users come to the District to request water use permits. In addition to protection through regulation, the District technically and financially assists regional water supply authorities and local governments in developing new water sources.
As local governments update their comprehensive plans, the District offers information, data and technical assistance to them to prepare and implement their plans. Although the District’s role is strictly advisory, its goal is to foster the integration of land–use planning and growth management activities of local governments with the water–use planning and management activities of the District. Along with technical assistance, the District offers financial assistance for water users to develop new water sources. Two District programs, the New Water Sources Initiative (NWSI) and the Cooperative Funding Program, assist water users in funding the development of alternative, non–traditional water sources. Under each program, the District funds up to half of a selected project’s cost.
These programs help water users overcome the “cost” hurdle in conservation and water supply development, while furthering the mutual objectives of the District and water users. Alternative sources — conservation, reclaimed water, aquifer storage and recovery, surface water storage during high flows, and desalination — will help ensure a sustainable water supply.
Steps to Sustainability
In those areas where existing or the implementation of reasonably anticipated sources of water and conservation efforts will not be adequate to meet current or future water supply needs, the District has prepared a Regional Water Supply Plan (RWSP) to further investigate conservation and water resource and supply development opportunities. The RWSP covers a 10–county region of the central and southern portions of the District.
Conservation – Conservation can be the most cost–effective “new” water source available.
Reclaimed water – Reclaimed water is defined as “water that has received at least secondary treatment and is reused after flowing out of a wastewater treatment facility.” Reclaimed water is currently used for agricultural irrigation, groundwater recharge, industrial processes, and the irrigation of lawns, landscapes, cemeteries and golf courses. Reuse saves fresh water for drinking and other daily needs and relieves the stress on the environment by reducing the demand for water from ground and surface waters.
Aquifer storage and recovery – Aquifer storage and recovery (ASR) involves the withdrawal of water from a river or other surface water source during our rainy season, when water is more plentiful, and the storage of this water underground for later use. The water is treated and pumped into a confined zone of the underground aquifer, and when it is needed, it can be recovered, treated and pumped into water supply systems. ASR helps balance our demand for water, which is highest during spring months, with our water supply, which is replenished during our summer rainy months.
Offstream reservoirs – During our rainy season, water can be skimmed from the high flows of rivers and stored for later use in offstream reservoirs.
Desalination – Desalination is a process that removes salt from seawater or from brackish (slightly salty) water to produce fresh, drinking–quality water. The process would allow us to benefit from the vast quantities of water available in the Gulf of Mexico. Until recently, obstacles to seawater desalination have been the costs of producing the water and environmental concerns over the disposal of the concentrated salt by–product. Estimated costs of seawater desalination continue to decrease and are now comparable to other alternative sources. Recent studies have indicated no significant environmental impacts from the process. Environmental monitoring will measure any impacts.
Land acquisition – Another key to a sustainable water supply is land acquisition and management. Three legislative acts — Save Our Rivers, Preservation 2000 and Florida Forever — have given the water management districts the important responsibility of acquiring lands necessary for water management, water supply and the conservation and protection of the water resources. The District has acquired more than 370,000 acres in the public interest for a number of water resource protection and management projects. Substantial acreage of both wetlands and uplands has been acquired.
Wetland and upland health play an important role in a sustainable water supply. Wetlands contribute to water supplies, especially in areas that rely on surface waters. Wetlands also help filter out impurities from stormwater runoff and contribute significantly to ecosystem health by providing habitat for fish and wildlife. Close to 50 percent of the lands acquired by the District are uplands. Uplands are important water resource areas, especially because of their potential to recharge the Floridan aquifer.
Water is crucial to the quality of life that has attracted so many people to Florida. Demand for water continues to grow. Safe, cost–effective, sustainable and environmentally friendly water sources are needed. If we are to preserve the environment that makes Florida unique, then the District, local governments, all user segments, and residents must work together to sustain west central Florida’s water resources.
swfwmd.state.fl.us |
