Kissimmee-Okeechobee Watershed and the Everglades Agricultural Area

[larger image]	PROJECTS Kissimmee-Okeechobee Watershed Projects: Kissimmee River Restoration and Lake Okeechobee Watershed Aquifer Storage and Recovery Everglades Agricultural Area Reservoirs	Home Executive Summary Background & Purpose Prioritization Water - Introduction > Kissimmee- Okeechobee & EAA - Upper East Coast - Loxahatchee - Marsh/Urban Interface - Lower West Coast - ENP/BNP/Biscayne Bay/Keys - Landscape Science Habitat & Species Land & Resources Tables PDF Version

Overview

Historically, Lake Okeechobee served as the primary regulator of flows into the Everglades. Rainwater from the Kissimmee Valley flowed south to Lake Okeechobee. The lake would periodically overflow its banks, and water would continue its slow journey southward through a 60-mile-wide shallow river flowing over the flat and level grasslands of the Everglades.

The Kissimmee-Okeechobee watershed projects (#1 on the map) are proposed to restore natural flows and storage in the Kissimmee basin and to improve riverine and wetland habitats throughout the region. The CERP water storage projects around Lake Okeechobee (#2 and #3) are intended to provide the water management capability to restore a more natural hydrology to Lake Okeechobee and to release water in more natural patterns into the downstream Everglades.

The major DOI interests in these projects fall into three broad categories: the effects on habitats and species within the Kissimmee-Okeechobee watershed, the quality of the water captured for release into the downstream Everglades, and the timing of releases of stored water into the downstream Everglades.

The Kissimmee-Okeechobee watershed supports a great number of federally protected species, including many wide-ranging species such as the Florida panther, wood stork, bald eagle, and West Indian manatee. DOI is concerned about the loss of habitat that will result from the construction and operation of the large reservoirs (four included in the Lake Okeechobee Watershed Project, three in the Aquifer Storage and Recovery Pilot Project, and three in the Everglades Agricultural Area Reservoirs Project). Many of the project areas have important fish and wildlife habitats, including increasingly rare upland forest and prairie habitats and natural wetlands. In an effort to minimize impacts to these lands while planning for and constructing these facilities, the FWS has developed a GIS-based tool to incorporate data on rare habitats, biodiversity, and threatened and endangered species for the Lake Okeechobee Watershed Project. This GIS tool will be refined and used to consider fish and wildlife values when selecting sites for all the large storage reservoirs.

Additional studies of population distributions and abundance will fill gaps in the databases for federally protected species, along with research and monitoring to anticipate and track species' responses to habitat changes. Landscape-scale restoration in the Lake Okeechobee watershed will require decisions that balance the needs of one species or trophic level with another or that maximize biodiversity within the system. For example, the restoration of wetland habitat, while expected to benefit many communities and species, must be achieved in a way that minimizes the risk to threatened and endangered species, including Audubon's crested caracara and the Florida grasshopper sparrow, that have adapted to the drier conditions created by the C&SF Project drainage canals.

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The quality of the water captured in these storage projects could be affected by contaminated soils, in areas where former agricultural lands will be flooded to create reservoirs, and by unnatural levels of metals and other contaminants leached from geologic formations, where in-ground wells will be used to store water.

DOI managers can most effectively participate in CERP projects during three project stages: (1) NEPA scoping in the early stages of project design, to help ensure that hydrologic targets accurately reflect the natural predrainage conditions, (2) review of project alternatives, to ensure that fish and wildlife and parks are adequately considered in compliance with DOI mandates, and (3) monitoring and assessment of project results, to support project modification if needed to ensure that the intended conditions are achieved. The major questions that DOI managers need to answer at each stage to effectively fulfill their responsibilities as partner and steward are summarized below, along with the highest priority science needs for answering those questions. This information is discussed in greater detail for each individual project following this summary.

SUMMARY OF DOI RESPONSIBILITIES AND SCIENCE NEEDS RELATED TO WATER PROJECTS IN THE KISSIMMEE-OKEECHOBEE WATERSHED AND THE EVERGLADES AGRICULTURAL AREA

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Kissimmee-Okeechobee Watershed Projects

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Two restoration projects, with separate authorizations, within this watershed are of particular interest to DOI: the Kissimmee River Restoration Project, which predates the CERP, and the CERP Lake Okeechobee Watershed Project.

The purpose of the Kissimmee River Restoration Project is to restore 40 square miles of native river and floodplain habitat. Seven miles of the river have been restored, and this project has a priority to be completed as soon as possible.

The CERP Lake Okeechobee Watershed Project includes four separable elements¹ that were combined to address the interdependencies and tradeoffs between the different components. The purposes of this project are to improve the water quality of Lake Okeechobee, provide for better management of lake water levels, and reduce damaging releases to the estuaries. Water from the watershed and the lake will be captured during wet periods for later use during dry periods. Aboveground reservoirs will increase the storage capacity and reduce the duration and frequency of both high and low water levels in the lake (which are stressful to its littoral zone ecosystems) and reduce large discharges from the lake (which are damaging to the downstream estuarine ecosystems). Water from upstream tributaries will be diverted to STAs to reduce nutrient loading into the lake. In addition, the project will restore the hydrology of isolated wetlands by plugging the connections to drainage ditches and diverting canal flows to adjacent wetlands.

The Kissimmee River Restoration and the Lake Okeechobee Watershed Projects have the potential to significantly affect threatened and endangered species habitat in the Kissimmee-Okeechobee watershed. Dry prairie is one of the characteristic communities in the Kissimmee-Okeechobee watershed that supports the endangered Florida grasshopper sparrow and the threatened Audubon's crested caracara. It is also one of Florida's most endangered upland ecological communities. DOI is concerned about the timing and distribution of water deliveries and how they will affect habitats and species. DOI is also concerned that the construction of the Lake Okeechobee Watershed Project will convert 54 square miles of mostly upland agricultural lands that support Audubon's crested caracaras and Florida grasshopper sparrows into water treatment facilities and aboveground water storage reservoirs. Large reservoirs and treatment wetlands will effectively eliminate the fish and wildlife habitat values of the sites selected for these facilities. They need to be sited in locations that avoid harm to federally protected species and designed to potentially provide additional habitat benefits wherever possible.

Also, the Kissimmee Chain of Lakes is one of the main wetlands supporting the endangered Everglade snail kite, particularly during times of drought in South Florida. The Kissimmee Chain of Lakes has been plagued by human-caused nutrient enrichment, proliferation of exotic and nuisance aquatic plants, and static lake levels under the present water management system. Current management techniques to maintain shoreline habitat include extreme lake drawdowns, aggressive herbicide programs, and muck removal. Extreme drawdowns have been shown to severely reduce the amount of prey (apple snails) available for snail kites. Extreme drawdowns, coupled with post-drawdown herbicide treatments, create shoreline vegetation communities that are less likely to support snail kite nesting and foraging.

What Is Known
Only 16% of remaining dry prairie habitat in Florida is in conservation lands. The majority of loss of dry prairie habitat in this watershed has resulted from conversion to agricultural lands. According to the Central Florida Planning Council, counties within the watershed are likely to experience population growth rates above the South Florida average, making additional impacts on dry prairie habitats likely. If appropriately managed, existing agricultural lands, such as improved pasture, unimproved pasture, and rangeland may provide suitable habitat for Florida grasshopper sparrows and Audubon's crested caracaras.

The heart of the Audubon's crested caracara species distribution falls within the Kissimmee-Okeechobee watershed; however knowledge of the current distribution of Audubon's crested caracaras in this area is incomplete.

Six populations of Florida grasshopper sparrows are found on four tracts of land, one of which is in private ownership, all within the Kissimmee-Okeechobee watershed. Maintenance of the hydrologic and ecologic regime of dry prairies is required for Florida grasshopper sparrow feeding and breeding. With appropriate management, existing protected dry prairie lands can support existing populations of endangered Florida grasshopper sparrows. Recovery of the species will require restoring additional habitat to allow the species to occupy its historic range and increase its population size.

What Is Needed
Studies of threatened/endangered species population distributions and abundance. DOI needs better information on the distributions and abundance of Audubon's crested caracara, Florida grasshopper sparrow, and Everglade snail kite in the Kissimmee-Okeechobee watershed to make recommendations to the USACE regarding site selections and designs for the Lake Okeechobee Watershed Project. Once current distribution and habitat use have been characterized, restoration alternatives can be evaluated to minimize their impacts on these species' habitats and to maximize the enhancement of potential future habitats.

GIS mapping of habitat. In an effort to minimize impacts to the existing habitat where large reservoirs and treatment wetlands, that are part of the CERP, are being constructed, the FWS is refining a GIS-based tool to incorporate data on rare habitats, biodiversity, and threatened and endangered species for the Lake Okeechobee Watershed Project. This project will provide the data needed to maximize potential habitat improvements and minimize the negative impacts in the planning and construction of these management features.

Research and possible model refinement to establish operating protocols. DOI needs to provide recommendations to the USACE regarding the design and operation of water storage and treatment facilities to ensure that they do not have impacts on existing fish and wildlife and to maximize potential habitat benefits for species in the area. These recommendations need to be developed on a timeline that will allow input into alternative selection for each component of the project based on the most current knowledge available to support protection of fish and wildlife values.

Research to evaluate effects on dry prairie species. Research into the effects of alternative water management scenarios is necessary to define the best management for dry prairie species.

Research and modeling to evaluate effects on Everglade snail kites. Additional research and information is needed to support development of water regulation schedules in the Kissimmee Chain of Lakes and Lake Okeechobee that maintain and improve Everglade snail kite prey availability, nesting habitat, and foraging habitat in these regions (see "Avian Species Recovery," page). Detailed information about the effects of various drawdown scenarios on apple snail abundance, distribution, and recovery will allow the development of operating protocols to foster healthy apple snail populations, which are critical to Everglade snail kite recovery. Research will evaluate the effects of extreme drawdowns on snail kite foraging efficiency. A model will be developed to evaluate the cumulative effects on kite habitat due to lake drawdowns in the Kissimmee Chain of Lakes and other CERP projects. This information will also be applicable to an evaluation of potential effects on the population on a wider regional scale.

Monitoring and assessment to determine species responses to habitat changes. Information about the impacts of habitat changes on Audubon's crested caracara, Florida grasshopper sparrows, and Everglade snail kites will assist DOI in providing input into the adaptive management phases of these projects.

Aquifer Storage and Recovery Pilots and Regional Study

Three ASR pilot projects will be located near Lake Okeechobee, adjacent to the Hillsboro Canal, and near the Caloosahatchee River. These projects will identify the most suitable sites for ASR wells in the vicinities of these surface water bodies and the optimum configurations of those wells. The pilot projects will provide information regarding the characteristics of the aquifer system within the proposed basins, including the hydrogeological and geotechnical characteristics of the aquifer. By addressing technical uncertainties about many aspects of well construction and operation, the pilot projects will provide the information needed to properly design the rest of these facilities.

An ASR Regional Study will address regional issues that are beyond the scope of the ASR Pilot Projects, including potential effects of the full-scale CERP ASR Program on the environment and on economically disadvantaged communities and existing users of the Floridan aquifer system.

The results from the ASR Pilot Projects and the ASR Regional Study will be utilized to determine the feasibility of large-scale ASR and its potential effects on water levels, water quality within the aquifer, surface water quality, biota, and ecosystem processes.

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A successful ASR program will benefit fish and wildlife resources by providing a significant part of the additional water supply needed to achieve CERP restoration goals and other benefits. DOI is particularly concerned that careful attention to the lessons learned in the pilots and regional ASR studies be applied to minimize the potential for direct, indirect and/or cumulative effects on managed resources through habitat modifications and/or contaminant introduction.

The ultimate success of the ASR program will require understanding which geological environments are capable of serving as storage zones while minimizing the potential for adversely affecting the physical and chemical properties (temperature, pH, metals, and radionuclides) of the stored water. The efficacy of ASR at the scale proposed needs to be verified. If the initial assumptions concerning the application of ASR prove to be inaccurate, understanding the relationships between the geological, chemical, and biological processes will be critical to understanding the potential tradeoffs among benefits or impacts to the natural system, and/or to determining the extent to which ASR will be used and what, if any, other water storage contingencies will be necessary. Much information will be garnered from the proposed pilot studies, although individual well characteristics may be highly site specific.

Given the current uncertainty of the projected 70% recovery rates from 330 proposed wells, storage contingency planning is being undertaken by the federal and state partners to evaluate alternatives to replace any realized deficits in storage capacities that are essential to the success of the CERP.

What Is Known
Of the three major aquifer systems underlying the Everglades area (the surficial, intermediate, and Floridan systems), the upper 250 feet of the surficial aquifer system, which includes the highly permeable Biscayne aquifer, is the principal source of freshwater for the more than 6 million people in southeastern Florida.

The intermediate aquifer system, which underlies the shallow surficial aquifer, is a source of freshwater mostly along the gulf coast. The Floridan aquifer, which is the principal source of fresh ground water in many parts of Florida, is the deepest aquifer in the region; however, south of Lake Okeechobee, water in the Floridan aquifer is too mineralized for most uses. Subtle changes in land elevation or slight rises in sea level can increase the potential for coastal flooding and also can reverse the hydraulic head and allow saltwater intrusion into aquifers.

The physiography and hydrology of the intermediate aquifer system (upper Floridan) and its confining units are partially described for the area under the Florida mainland. However, as this formation extends out under the continental margin, the physiographic and hydrologic descriptions decreases dramatically. The area of discharge for this aquifer, if there is one, is poorly understood but presumed to be located in the deeper regions of the western Straits of Florida, or possibly further east.

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While most of the few large-capacity, large-diameter (greater than 20-inch) ASR wells in southern Florida are operated at rates of 1 to 2 million gallons per day (mg/d), the CERP-proposed 5 mg/d recharge and production rates per well remain unverified. CERP assumes a recovery efficiency of 70% of the injected volume. The USGS reports highly varying rates of recovery ranging from as low as 2% to as high as 84%, with ten sites achieving a recovery efficiency above 30% during at least one cycle. Recovery rates of 4 to 5 mg/d achieved during recent ASR cycle testing at the Miami-Dade West Well Field, however, offer evidence that the desired recharge rates are possible.

What Is Needed
Water quality studies. The areas of study related to ASR include the specific water quality characteristics of waters to be injected, the water quality characteristics of water recovered, and the water quality characteristics of water within the receiving surface and ground waters.

Hydrogeologic studies. Knowledge of the hydrologic framework and hydrology of the intermediate aquifer system (upper Floridan) and its confining units needs to be improved with further geotechnical and hydrologic studies in areas underlying the Florida mainland and especially between the internal greater Everglades, Biscayne Bay and Florida Bay.In addition, descriptions of the physiography of the Floridan aquifer needs to be developed for areas that extend out under the continental margin and into the Biscayne Bay. If any discharge areas are identified additional research and modeling will be needed to determine effec ts on the ecology in Biscayne or Florida Bay as ASR is implemented.

Research to understand the tolerance of plants and animals to changes in water quality. Understanding the tolerances of plants and animals to the ranges of water quality conditions likely to result from ASR operation will be critical to minimizing the potential for unanticipated adverse impacts on fish and wildlife resources. The ASR Regional Study incorporates a myriad of proposed studies that include geotechnical, microbiological, water quality, biological, and ecological elements. They will investigate, among other things, the potential environmental effects of recovered waters, by testing their toxicological properties and exposure pathways. The pilot projects will afford the opportunity to perform some of these studies during the two years of proposed cycle testing. If the pilot projects do not produce the anticipated results, additional data will be needed to support analysis of alternatives.

Baseline analysis and monitoring in downstream wetlands. DOI needs to support baseline analyses and continued monitoring to ensure that the waters from these facilities are of appropriate quality and thus do not pose any threat to fish and wildlife resources.

Baseline studies and monitoring at ASR locations. An ecological characterization baseline study will establish biotic community conditions in the vicinity of proposed ASR well concentrations. The proposed five-year duration of this baseline study should incorporate sufficient natural variability to enable monitoring and adaptive management during full ASR operations in the future. This information will help improve site selection and facility design in targeted ASR locations.

Studies of the effects of intake pumps and control structures. In order to reduce impacts to fish species in the region, studies will identify better designs for intake pumps and control structures that will minimize impingement (trapping organisms against intake screens) and entrainment (passage of organisms through a pump) of aquatic organisms at intake sites.

Everglades Agricultural Area Reservoirs

Project Purpose and Major DOI Interest
The purposes of this project are to reduce damaging flood releases from the Everglades Agricultural Area (EAA) to the water conservation areas, to reduce Lake Okeechobee regulatory releases to the estuaries, to meet supplemental agricultural irrigation demands, and to increase flood protection within the Everglades Agricultural Area.

The EAA, located between Lake Okeechobee and the water conservation areas, encompasses an area totaling approximately 718,400 acres (1,122 square miles) of highly productive organic peat or muck soils, making it one of Florida's most important agricultural regions. Approximately 77% of the EAA is in agricultural production for crops including sugar cane, vegetables, sod, rice, and citrus. Flooded and cultivated agricultural fields attract foraging birds, including wading birds. The southern rim of the EAA (the Holey Land, Rotenberg, and Browns Farm tracts) contains wildlife management areas that support populations of wading birds, deer, wild hogs, and waterfowl.

Agriculture in the EAA is highly dependent on the current system of canals running through the region to drain excess water during the wet season and supplement water supplies for irrigation during the dry season. Water quality concerns, soil subsidence, and encroachment of urbanization are all ecosystem stressors related to maintaining agriculture in this area. Water quality, particularly phosphorus loading, is being addressed through improved farming practices and stormwater treatment.

Hydrologic improvements will be accomplished through improved storage and canal conveyance capacity. This two-phase project will construct three aboveground reservoirs of approximately 20,000 acres each and restore more natural timing of deliveries to the water conservation areas.

Changes in the hydrology and water quality in the water conservation areas from implementation of these projects will affect the Loxahatchee National Wildlife Refuge, located in WCA-1, and downstream areas, such as Taylor Slough, the mangrove communities, and northeast Florida Bay, inside Everglades National Park. DOI has a strong interest in ensuring that the waters introduced into the natural system mimic the natural predrainage hydrology in terms of quantity, quality, timing, and distribution patterns. DOI is also interested in the potential habitat and recreational values of the water storage reservoirs themselves and in ensuring that wildlife attracted to the reservoirs are not harmed by the quality of the water impounded on former agricultural lands.

What Is Known
The southern rim of Lake Okeechobee was historically a dense swamp of pond apple, willow, and elderberry. Areas farther to the south were dominated by sawgrass mashes, part of the "river of grass" that flowed south through the Everglades into Florida Bay. Significant changes in the hydrology of this area have had wide reaching effects far outside the boundaries of the EAA.

What is Needed
Research and modeling to refine hydrologic targets, including targets for water quality. Additional research and modeling are needed to help DOI managers better understand the natural quantity, timing, and distribution of water in the park and how to restore those conditions.

The water quality performance targets for this project will initially be based on water quality targets for the Everglades Construction Project and other designated uses of the EAA waters. Additional research will help refine these targets to ensure that the quality of the water from potential sources throughout the watershed is suitable for ecosystem restoration.

Research and possible model refinement to establish operating protocols. DOI needs to provide the operating protocols to the USACE that will allow operators to replicate natural system functioning in the marshes and the surficial Biscayne aquifer. These protocols should provide water managers more flexibility, based on actual rainfall (real-time conditions) rather than on projections of annual averages, in order to avoid engineering the wetlands into an unnatural state. These protocols will help ensure that the quantity, timing, and distribution of water into the park mimics the hydropatterns of natural flows through Taylor Slough and the mangrove communities to the coastal estuaries: northeast Florida Bay, Manatee Bay, and the landlocked areas, Barnes and Card Sounds.

The operating protocols should include a drought management plan that addresses the onset, progression, recession, and termination of drought stages, based on rainfall data, soil moisture, and reservoir level indicators.

Restoration partners need more information about how to mimic natural hydrologic patterns simultaneously with other CERP goals and objectives.

Environmental risk assessments of water quality contaminants. Water quality investigations will assess the environmental risks from storing water on former agricultural lands.

Research to support design and operational rules to enhance fish and wildlife resources. FWS needs to identify ways in which the EAA reservoirs can be managed and operated to provide favorable habitat for fish and wildlife while maintaining the water management functions.

Monitoring and assessment to determine the effects of the reservoirs on the natural system. As phase one of this project comes on line, DOI scientists need to focus on assessing how the increased water and canal flow capacity and changes in water quality affect the natural system and on how to improve these outcomes during the second phase of this project.

¹ These four projects are the North of Lake Okeechobee Storage Reservoir, the Taylor Creek/Nubbin Slough Storage and Treatment Area, the Lake Okeechobee Watershed Water Quality Treatment Facilities, and Lake Okeechobee Tributary Sediment Dredging.