Everglades and Biscayne National Parks, Biscayne Bay, and the Florida Keys

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PROJECTS Water Conservation Area 3 Decompartmentalization and Sheetflow Enhancement, Part 1 (DECOMP) Combined Structural and Operations Plan (CSOP), Including the C-111 Spreader Canal Biscayne Bay Coastal Wetlands Additional Water for Everglades National Park and Biscayne Bay Wastewater Reuse Pilot Florida Bay and Florida Keys Feasibility Study

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Overview

A number of CERP and other hydrologic restoration projects are intended to reintroduce flows from water storage components into the broad expanse of the northern, middle, and southern Everglades, with the intent of restoring natural hydropatterns and the sheetflows that historically moved from north to south through the Everglades into the Gulf of Mexico, Florida Bay, and the other nearshore estuaries. The CSOP project will develop an integrated structural and operational plan for two other projects: the Modified Water Deliveries Project, which will improve water deliveries from WCA-3A and WCA-3B into Everglades National Park, and the C-111 Project, which will create a buffer area between the park and the urban and agricultural lands to the east. The hydrologic improvements in Everglades National Park are to occur concurrently with reducing flood damage on the lower east coast. The CSOP project is expected to restore natural hydrology to Taylor Slough and to improve the hydrology in Shark Slough. The natural hydrology of Shark Slough will be restored by the DECOMP project, which will remove impediments to sheetflow in WCA-3A, restoring natural flow paths into WCA-3B and the southern Everglades. The Biscayne Bay Coastal Wetlands Project will restore these wetlands, recreating an estuarine zone and more natural freshwater flows into Biscayne Bay.

The CERP recognizes that these interrelated projects cannot, by themselves, provide water in sufficient quantities to fully achieve the goals of restoring the natural hydrology and ecology of the Everglades and Biscayne Bay. The Comprehensive Review Study identifies potential sources of additional water, which will be assessed in the Additional Water for Everglades National Park and Biscayne Bay Feasibility Study. The Water Reuse Project addresses the possible use of reclaimed water to support natural system restoration.

The Florida Bay and Florida Keys Feasibility Study will determine the additional modifications (in addition to the restoration of more natural flows through the southern Everglades) needed to restore natural water quality and ecological conditions to Florida Bay.

These projects raise a number of issues of critical concern to DOI. First, reintroducing the volume of sheetflow necessary to mimic the historic hydrology in the southern Everglades will significantly affect the hydrology in the middle and northern Everglades, where remnant communities and species have either adapted to the changed hydrology or are so stressed that drastic changes in hydrology during a transition period may precipitate their decline before a more naturally functioning system can be established. For example, the restoration of the southern Everglades, which is essential to certain species, such as the Cape Sable seaside sparrow and Everglade snail kite, raises questions about the protection of tree islands in the water conservation areas, which is a major DOI priority.

The timing and distribution of water deliveries are critical to Everglades communities. Because these plant and animal communities evolved under ecological conditions marked by alternating periods of intensive rainfall and drought, any hydrologic targets based on "average annual" rainfall (the outputs from the current models) will not adequately reflect the conditions needed to sustain these communities. The model target levels need to be translated into estimates of water distributions and levels during wet, dry, and transitional seasons, and during a particular week/day of a particular year. DOI needs to assist the USACE in developing "rainfall-driven" operating protocols that will mimic the natural timing and distribution of water into the natural system.

Another concern is the quality of the water being introduced into the natural system from storage reservoirs on agricultural lands and from deep wells.

Additional research to improve the understanding of linkages between hydrology and ecology in the Everglades and in Biscayne and Florida Bays, along with the identification and monitoring of indicators of desired ecological responses, will be critical to enhancing fish and wildlife values and to avoiding inadvertent impacts to federally protected species.

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 EVERGLADES NATIONAL PARK, BISCAYNE BAY, AND THE FLORIDA KEYS

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Water Conservation Area 3 Decompartmentalization and Sheetflow Enhancement

Project Purpose and Major DOI Interest

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One of the central projects in CERP is Decompartmentalization of Water Conservation Area 3 (Decomp). The compartmentalization of the water conservation areas has contributed to the loss of historic overland flows through the central Everglades slough system. This alteration of flows has resulted in temporal changes in hydropatterns and hydroperiods in the historic deepwater, central axis of the Shark River Slough system.

The purpose of this project is to restore sheetflow and reestablish the ecological and hydrological connections between WCAs- 3A and -3B, Everglades National Park, and Big Cypress National Preserve. The project includes raising and bridging portions of the Tamiami Trail and filling in portions of the Miami Canal within WCA-3. Due to the dependencies of project components, this project will be implemented with the Water Preserve Areas Project, which will create a bypass for water supply deliveries to the Miami Canal using the North New River Canal.

This project, which is planned to be implemented in two parts, is expected to deliver significant environmental benefits to WCAs-3A and -3B and to Everglades National Park by removing the Miami Canal, plugging and/or backfilling the L-67 A and C and the L-68 canals, degrading the L-28 tieback levee and the L-29 levee, and eliminating the deep pool in the southern end of the conservation area. It is expected to benefit Everglades National Park by restoring the natural flow paths through Shark Slough toward the west coast estuaries. Restoring historical sheetflow distributions, depth patterns, hydroperiods, and hydrologic connectivity in the southern Everglades will improve the health of habitats important to this ecosystem, including ridge and slough, marl prairie, and rocky glades landscapes.

At the same time that it anticipates these hydrologic improvements in the southern Everglades, DOI is concerned that increased stages through the northern and central Everglades will further stress the surviving tree islands in those areas. In working to restore the natural hydrology, with the assumption that natural ecosystem responses will eventually restore the mosaic of ecological communities indigenous to this region, DOI remains committed to protecting the tree island ecological community from adverse effects.

Threatened and endangered species affected by the project include wood stork, Everglade snail kite, Florida panther, Cape Sable seaside sparrow, eastern indigo snake, and West Indian manatee. The Cape Sable seaside sparrow and American crocodile will also be affected downstream from the Decomp project area.

DOI is interested in the ecological, as well as the hydrologic, dimensions of connectivity and flow, such as nutrient cycling and transport and wildlife migration. Consequently, evaluating these ecological aspects of connectivity will be an integral part of analyzing the potential outcomes of decompartmentalization scenarios. As the project is implemented and flow is improved, additional actions might be needed to ensure that the ecological response mimics the natural predrainage ecology.

Community structure and vegetation composition have changed markedly as a result of the C&SF Project within the water conservation areas and Everglades National Park. The Decomp Project Management Plan notes that the current system, the result of many years of compartmentalization, is considerably more complex than the original landscape. The presence of levees, roadways, canals, and structures to control water flow has created a patchwork of unnaturally varied landscape units.

Some overdrained areas, such as those in northern WCA-3, have been impacted not only by drought but also by frequent fires, which have damaged the organic soils that previously underlaid the area. Tree islands have been reduced in number and size, and marsh vegetation has shifted to that characteristic of shorter hydroperiods.

Other portions, such as those in southern WCA-3A, have been subjected to wetter conditions, and more stabilized water levels. In these areas, the local diversity of vegetation structure and composition has been reduced, resulting in a relatively homogenous composition. Tree islands have also been impacted in these areas, but as a result of long-term inundation and water stress instead of overdrying. Ridge and slough communities and marl prairies have also been significantly reduced.

Maybe the most marked change is the juxtaposition of the different conditions within the landscape. While the historic Everglades consisted of a long, continuous, interconnected marsh that varied very gradually, the placement of levees, canals, and roads leads to conditions where some of the wettest conditions occur immediately adjacent to some of the driest, with only a levee in between. The resulting patchwork of habitat types and conditions has disrupted the continuity that characterized the predrainage system. These habitat changes have caused significant reductions in populations of birds and other animals.

What Is Needed
Additional research to understand the linkages among the geologic, hydrologic, chemical, climatological, and biological processes that shaped the predrainage Everglades. Additional research will identify the range of water depths, hydroperiods, spatial distributions of water, flow characteristics, and water quality that existed in the project area prior to drainage. Information about the physical, chemical, and biological processes responsible for development and persistence of soils and geomorphological patterns in the historic Everglades landscape, such as the soil-forming processes in the ridge and slough habitats, will help managers of DOI lands and resources in the WCAs and Everglades National Park manage for a historic diversity and productive array of fish, wildlife, and plants.

Process-level investigations on the mechanisms controlling the interaction between biological and hydrological indicators are necessary. Information on the seasonal and annual controls on productivity rates, ecosystem water use, nutrient dynamics and limitations, competition, seedling germination, and mortality will provide the basis for simulation models and for predictions of how the natural systems will react to altered hydrologic and climatological regimes. A detailed understanding of the mechanisms controlling ecosystem productivity and dynamics is the only reliable way to predict how these systems will react to altered stressors.

Studies are needed for key invertebrate groups used for monitoring sheetflow restoration. It is important to know how their ecology is related to sheetflow, or more importantly, how they are adversely affected by unnatural flow conditions produced by present day structures.

Research to understand the critical factors for sustaining tree islands, ridge and slough habitats, and marl prairies. Additional research will help scientists describe a hydrologic regime that will allow the restoration of tree islands, ridge and slough habitats, and marl prairies in an expanse and configuration that will be sustainable. The restoration of these communities will depend on restoring ecosystem function, which includes the processes of flow, soil accretion and transport, and an appropriate disturbance regime that includes fires, floods, and droughts occurring with a more natural frequency Development of GIS-based databases that can map many hydrologic and biologic indicators will help researchers notice potential linkages between hydrology and ecology in this area, and allow them to evaluate the overall ecological response to project implementation. Another research project, the Loxahatchee Impoundment Landscape Assessment Study, being conducted on the Loxahatchee wildlife refuge, is a controlled experiment to determine the interrelationships among a number of hydrologic and ecological variables, including water levels, water flow, fish species, and vegetation types.

Research to understand and reduce the effects of hydrologic barriers on ecological connectivity. Research to understand sheet flow in key aquatic communities, and to understand interactions of hydrologic flow with nutrient and carbon cycling and transport, will help identify and reduce barriers to these critical processes.

Research to understand and reduce the effects of roads, levees, and canals on the spread of exotic species. Improved understanding of how linear features such as roads, levees, and canals may act to speed the spread of exotic species will allow development of measures to control or minimize this effect and the impacts of exotic species.

Understanding the effects of sea-level rise. The formation and sustainability of coastal communities is a result of the interaction between upland freshwater and tidal inputs. Both of these hydrologic processes are likely to change in the future with restoration projects and with sea level rise. Resource management and restoration efforts will require a thorough understanding of the biological and physical controls on the formation and maintenance of these coastal communities. Research is necessary to assess the current and historic relationships between sea level, salinity, overland freshwater flows, tidal regimes, water budgets, and climate on mangrove and oligohaline communities. This information will be used to develop and validate process-based models useful for simulating hydrologic fluxes, soil dynamics, productivity, carbon balance, and spatial variability in the mangrove and oligohaline zones in coastal areas.

Additional research to understand the effects of different hydrologic regimes and ecological processes on restoring and maintaining ecosystem function

Identification of current stressors that are affecting the system

Baseline studies and monitoring. The MAP includes a number of components that are relevant for the decompartmentalization of WCA-3A and particularly important to DOI:

• plant community species composition, cover, and density in marl prairie and ridge and slough habitats in the southern Everglades
• wading bird nesting colony location, size, and timing in freshwater marshes
• American alligator population recovery and the role of alligator holes as aquatic refugia in major Everglades slough habitats
• fish and invertebrate sampling studies
• wood stork nesting and population monitoring
• American crocodile population monitoring
• habitat conditions on tree islands and conditions for restoration of historic tree island distribution and abundance

Additionally, DOI needs to fill gaps in baseline information and monitor the following:

• species composition, cover, and density in tree islands
• eastern indigo snakes
• West Indian manatee use of canals
• migratory bird occurrence and abundance
• exotic fish species
• snail kite habitat condition, nesting, and productivity
• Cape Sable seaside sparrow population monitoring
• wood stork habitat use, productivity, and survival
• processes affecting soil accretion, tree island restoration, and maintenance of the ridge and slough landscape pattern
• response of coastal communities to simultaneous effects of increased freshwater flows and sea-level rise
• Vegetation community monitoring in Taylor Slough and the Rocky Glades
• Freshwater marsh fish and invertebrate monitoring in the southern Everglades
• Mangrove land birds

Combined Structural and Operational Plan (CSOP), Including the C111 Spreader Canal

Project Purpose and Major DOI Interest

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The Combined Structural and Operational Plan (CSOP) is an integrated structural and operational plan for two modifications of the C&SF Project known as the Modified Water Deliveries to Everglades National Park (MWD) Project and the C-111 Project. The purpose of the CSOP is to define the operations for the C-111 and MWD Projects that will be consistent with their respective project purposes.

The MWD Project is authorized by the Everglades National Park Protection and Expansion Act of 1989. Its purpose is to modify the CS&F Project to improve water deliveries into the park and restore the natural hydrologic conditions within the park.

The C-111 General Reevaluation Report recommended additional modifications to the C&SF Project to provide for the restoration of the ecosystem in Taylor Slough and the eastern panhandle of the park while maintaining flood damage reduction within the C-111 basin. These modifications include the construction of buffer areas to provide a hydrologic separation between urban areas, where flood damage reduction is a priority, and natural areas, where restoration of the natural hydrology is a priority.

A CERP-related project is the C-111 Spreader Canal. The purposes of this project are to enhance the C-111 Canal to rehydrate the Model Lands, establish sheet flow and hydropatterns that will sustain native ecosystems in the Southern Glades and Model Lands, provide more natural sheet flow to Florida Bay by eliminating point sources of freshwater discharges through C-111 to the estuarine systems of Manatee Bay and Barnes Sound, and maintain some level of flood protection for agricultural and urban areas in the project area.

The primary DOI interests in the CSOP include improving water deliveries into both the Everglades and Florida Bay portions of Everglades National Park and the Model Lands, restoring the historic hydrologic conditions in the park as well as, Barnes Sound through Manatee Bay, protecting the natural values associated with the park and headwater of Biscayne National Park, and exploring opportunities for enhancing the recovery of threatened and endangered species that will be affected by the project, notably the Cape Sable seaside sparrow and Everglade snail kite.

Additionally, DOI is concerned with the operating rules and water quality in the C-111 buffer component of the CSOP. Because of the porous nature of the soil in this area it is important that the buffer areas be designed and operated to avoid interference with natural flows in the park. Operation of the buffers using "marsh-driven criteria" will ensure that the adjacent natural marsh is not flooded in an unnatural pattern by water leaking out of the buffer areas. Some of the water used in the buffer areas will likely come from urban and agricultural basins and could be introduced into wetlands. DOI has a strong interest in ensuring that this water is clean enough for introduction into the park.

What Is Known
Both the modeling and the field observations needed to predict and monitor changes in hydrology are currently in place, and no additional work in those areas is contemplated.

DOI agencies, as well as the USACE, SFWMD, and EPA, conduct extensive and continuous monitoring in the CSOP footprint. The parameters collected range from observations of rainfall and water levels to across-the-landscape monitoring of wading birds and American alligators. Federal and state agencies monitor Everglade snail kites, Cape Sable seaside sparrows, wood storks, and American crocodiles. Population models of snail kite and sparrow are used in project evaluations. Because CSOP is a project that is in its final design stages, it will be necessary to use available information to evaluate alternatives.

A network for monitoring water quality, aquatic communities, and vegetation is in place to detect changes in native flora and fauna related to operation of the CSOP. The report A Synthesis of Research on Florida Bay compiles the current knowledge of the ecosystem history, structure, and function and of the ecological effects of human activities in Florida Bay.

What Is Needed
Research and possible model refinement to support the refinement of hydrologic targets and operating protocols. Additional research will support refinements to the hydrologic targets needed to achieve fully natural flows in Taylor Slough and Shark Slough. The targets need to address appropriate timing, cleanliness, distribution of flow, and ecological connectivity to replicate natural function in the marsh. The operating protocols developed from the refined targets should allow water managers more flexibility to manage the marsh based on actual rainfall rather than on projections of annual averages, in order to avoid engineering the wetlands into an unnatural state. The NSM target levels need to be translated into real-time estimates of "natural" targets for the marshes, mangrove zone, and the northeast Florida Bay. These predictions can then provide the basis for operational rules for the new structures. In the short tem DOI must provide input based on what is known today to improve the operating program being developed for this project. Information on the volume, timing and distribution of overland flows and the relationships with nearby structure and canal operations is necessary. Flow measurements should be used to validate large-scale hydrologic models such as the SFWMD 2 x 2, since these models are used to simulate the pre-drainage and current systems to design restoration alternatives, and to set restoration targets.

Rainfall and evapotranspiration are the two major components of hydrologic balance in south Florida. While rainfall is measured regularly throughout the system, ET is not. ET is of primary importance in all the hydrologic models used to simulate south Florida ecosystems. To date, only a very limited dataset exists with which to calibrate and validate these models. Moreover, there currently is only very limited understanding of the variability in evapotranspiration rates across community types occurring in ENP. As communities shift with increasing freshwater flows, spatial patterns of ET and water budgets will also change with implications for regional water management.

Sheetflow is the defining characteristic of the Everglades. The restoration of historic sheetflow patterns is therefore a primary goal of CERP and CSOP, yet there currently exists no widely accepted method for evaluating sheetflow volumes, velocities, or spatial patterns with respect to nutrient dynamics, landscape, or community type. Understanding the current relationships between large scale sheetflow patterns and nutrient fluxes, water quality, sediment transport and microtopography, and the sustainability of ridge and slough and tree island habitat is necessary to develop operating protocols, restoration targets and to monitor the success of these projects.

Environmental risk assessments of water-quality contaminants. The C-111 project raises many water quality issues for Everglades and Biscayne National Parks. Water quality investigations will assess the environmental risks from using water derived from agricultural basins to augment ground and surface water flows into natural areas. Current information does not resolve the nutrient uptake capacity of the limestone aquifer and the effectiveness of periphyton stormwater treatment areas. The potential for increases in toxic contaminant loads, such as pesticides, and their ecological effects require further study.

Improvement of ecological models to make them more suitable for applications and analysis. Considerable information is available about the interrelated responses of salinity levels, vegetation, fish and macroinvertabrates, and wading birds to hydroperiod and flow. Improved understanding about the linkages among these variables will be possible once the ecological models, particularly ATLSS, are refined and linked to the more detailed hydrologic models, with suitable user interfaces provided.

Development of methodology to quantify ecological connectivity especially across major potential barriers of flow such as Tamiami Trail and Alligator Alley

Modeling to predict salinity in the mangrove community, northeast Florida Bay, Manatee Bay and Barnes Sound. Local models that couple with the regional 2 x 2 Model are needed.

Monitoring of ecological communities and threatened and endangered species. Continued monitoring of hydrology, ecology, and water quality in the Everglades and Florida Bay will determine whether actual changes are consistent with predictions, improve the predictive capability of models, and detect unforeseen adverse impacts in time to correct them through adaptive management. In addition to ongoing systemwide monitoring, monitoring of key parameters in the footprint of the CSOP needs to focus on the vegetation, periphyton, and aquatic communities in the vicinity of the proposed C-111 buffers and on Everglade snail kite and Cape Sable seaside sparrow habitats and populations.

Detailed community descriptions for Barnes and Card Sounds. The ecology of the two coastal estuaries Barnes and Card Sound could be dramatically affected by changes in water deliveries via the C-111, the placement of culvert across US1 roadway and the rehydration of the Model Lands. Intensive documentation of the biotic structure in these basins to ensure that we do not alter these two estuarian basins to something other that natural function

Biscayne Bay Coastal Wetlands

Project Purpose and Major DOI Interest

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The Biscayne Bay Coastal Wetlands (BBCW) Project, scheduled for completion in 2015, is intended to correct the effects of diverting overland freshwater flows into canals, a process that has drained wetlands, caused unnatural surface discharges of freshwater into Biscayne Bay, and reduced groundwater inflows into the bay. The purposes of this project are to rehydrate and reconnect freshwater and estuarine wetlands, to reestablish a more natural estuarine zone along the western side of Biscayne Bay, and to reduce point source discharges into Biscayne Bay. The project will replace lost overland flow and partially compensate for the reduction in groundwater seepage by redistributing the available surface water entering the area from regional canals.

The proposed redistribution of freshwater flow across a broad front is expected to restore or enhance freshwater wetland, tidal wetland, and nearshore bay habitats, including habitats in Biscayne National Park. The project is expected to result in sustained lower-than-seawater salinities in the tidal wetlands and the nearshore bay and be conducive to the reestablishment of oyster bars and other components of the oyster reef community. Achieving these results is dependent on the project being designed to provide additional freshwater to these areas. If only the existing water volume is redistributed, then salinities would actually increase. Diversion of canal discharges into coastal wetlands is expected not only to reestablish productive estuarine nursery habitat all along the shoreline but also to reduce the abrupt discharges of freshwater into the bay near canal outlets, which are physiologically stressful to fish and benthic invertebrates.

Threatened or endangered species within the project area include manatees, crocodiles, smalltooth sawfish, sea turtles, wood storks, bald eagles, and eastern indigo snakes. Changes in timing, distribution, and volume of freshwater delivery could potentially affect the existing or potential habitats of these species.

What Is Known
Historically, a significant amount of freshwater flowed into Biscayne Bay through a system of sloughs, which originated in the Everglades via rivers and creeks, transverse glades, and sheetflow through coastal wetlands. Some work has been done to estimate surface flow through the transverse glades. Groundwater inputs are known to have been significant and large enough to create coastal and offshore springs.

The scientific understanding of the historic conditions of the bay is increasing. Based on recent paleoecological studies, which partially document historic salinity patterns, scientists have established that the historic pattern of freshwater inflows from surface and ground sources resulted in fewer high and low salinity extremes than what occur under current conditions. Today's seasonal, high-volume freshwater canal discharges cause high-magnitude, rapid salinity fluctuations near canal outlets. The nearshore bay experiences seasonal periods of low salinity during the wet season, when canal discharges are high, and periods of high salinity during the dry season, in the absence of freshwater inputs. While some fluctuation is expected, the nearshore bay salinity regime is now much less stable than it was historically.

Historic estuarine conditions sustained extensive sawgrass prairies, mangrove communities, seagrass beds, and oyster bars and provided productive nursery habitats for a spectrum of fish, shellfish, crocodiles, manatees, and other animals. Recent studies have defined the importance of mangrove and seagrass communities to the ecology of the bay. The paleoecological studies mentioned above draw some conclusions about the historical salinity patterns and ecology of the bay and work to refine this history is ongoing. These studies have also provided information about the contemporary use of habitats in and near the bay by migratory birds and many endangered species, such as the West Indian manatee.

What Is Needed
Additional research to understand predrainage hydrology. Additional research will identify the range of water depths, hydroperiods, spatial distributions of water, and flow characteristics that existed in the Biscayne Bay coastal wetlands prior to drainage. Information about the physical, chemical, and biological processes responsible for the development and persistence of soils and geomorphological patterns in the historic wetlands will help DOI managers better understand the historic hydrologic regime.

Biscayne Bay hydrologic model. Hydrologic targets for the coastal wetlands must be established. In order to establish these targets, a clear understanding of the relationship between hydrology, salinity, and ecology/biological response is required. A local model of Biscayne Bay capable of simulating coastal surface and groundwater hydrology and associated nearshore salinities will then be required in order to determine whether or not these targets are met. The NSM and 2 x 2 Models do not simulate these variables and the BBCW project area lies at the fringe of the models' domain. However, two local models are being developed that can be coupled with the regional model used by the USACE and SFWMD to make NSM-linked predictions of salinity in Biscayne Bay. Information about how much freshwater was delivered historically to the Bay, and in what seasonal patterns, will provide a basis for establishing and adjusting hydrologic targets. The ensuing ecological responses and desired future ecological conditions, along with the relationship between historical, current, and desired future condition should also be factored into target adjustments Research is needed to characterize and evaluate the importance of groundwater and karstlike flows to the coastal estuaries.

Water Quality Performance Targets. There are no water quality standards for estuarine systems. There is sufficient documentation in the scientific literature to indicate that marine, and possibly estuarine, systems are far more sensitive to low level contamination than more robust terrestrial ecosystems. Research is needed to document the sensitivity of marine organisms and quantify the potential magnitude of biomagnification that might occur in juvenile and nursery habitats characteristic of the south Florida estuaries. Water quality performance targets for coastal marine and estuarine systems need to be established.

Research to determine the clearing and saturation capacities of sawgrass and mangrove habitats Research through a pilot project is needed to help identify what the "pollution clearing" capacity of the wetlands and the potential for biomagnification is as water enters Biscayne Bay

Additional research to understand the links between hydrology and ecology. Output from the hydrologic model will be analyzed. Ongoing paleoecological studies will continue, and proposed studies of the historic types and distributions of habitats, flora, and fauna will be used to draw conclusions about the relationships that existed historically between hydrologic and ecological factors in the nearshore, estuarine, and freshwater areas of western Biscayne Bay. These historic conditions and relationships must then be used to develop desired future conditions and thus, project targets. Projections can then be made about how close various project alternatives might come to approximating these desired targets and conditions and to restoring habitat features such as creeks, glades, and wetlands. This effort should include ecologic models for Coastal Estuaries, which are key assessment tools for these areas.

Research of critical habitat factors for threatened and endangered species. Additional research into the critical factors that contribute to suitable habitat for West Indian manatees, American crocodiles, smalltooth sawfish, sea turtles, wood storks, bald eagles, and eastern indigo snakes will inform the analysis of potential impacts and help avoid adverse effects.

Baseline ecological data. An important gap in the science needed to plan and monitor this project is baseline ecological data, particularly about the existing vegetation coverage, including, but limited to, West Indian manatee, American crocodile, and roseate spoonbill. Baseline conditions will provide the basis for identifying changes in key species and understanding the relationships between those changes and the environmental factors that affect species' habitat and sustainability.

Additional Water for Everglades National Park and Biscayne Bay Feasibility Study

Project Purpose and Major DOI Interest
This project addresses the additional water needed to achieve the ecological goals for both Everglades and Biscayne Bay National Parks. During the development of the CERP it was determined that additional water could be captured to meet predrainage hydrologic targets for Everglades National Park and Biscayne Bay. This project assesses the options for achieving those targets. If successful this project will reduce extreme events like regulatory releases to estuaries, excessive flooding in the water conservation areas, and severe damaging dryouts in the marsh. Urban and agricultural areas will benefit from the extra water storage and be less dependent on the natural areas to meet their needs.

The USACE completed a final reconnaissance study report in June 2003 that investigated and confirmed the need for providing additional water to the park and the bay, in addition to the amount that will be provided upon implementation of the CERP. The reconnaissance study confirmed that federal participation is warranted to proceed to a feasibility-level study; however, a nonfederal sponsor for the feasibility phase has not yet been identified. The report also recommends deferral of the feasibility phase until completion of the technical documentation report to be prepared for the Initial CERP Update Project currently underway by RECOVER. It is anticipated that once RECOVER updates the CERP, a nonfederal partner will be identified.

Generally, the feasibility study considers design configurations for routing water from Palm Beach and Broward Counties to Everglades and Biscayne Bay National Parks. DOI is interested in understanding (1) how water can be redirected from the water conservation areas in the upper part of the system into the park without adversely affecting the desired ecological response in the water conservation areas, (2) the feasibility of establishing and achieving the hydrological targets expected to improve ecological conditions in the parks, and (3) the risks related to the introduction of urban runoff into the Everglades Protection Area and Biscayne Bay.

What Is Known
The reconnaissance study confirmed the need for additional water to Everglades National Park and Biscayne Bay in addition to the amount that will be provided upon implementation of the CERP. The Modified Waters, Decompartmentalization, and CSOP Projects all contribute additional water, but not enough to achieve predrainage hydrologic targets and the improved ecology that is expected to result from improved hydrology. The reconnaissance report outlines a number of alternatives for capturing water in urban areas, which need additional investigation in the feasibility study.

Predictions based on the NSM can be used to provide restoration targets for water depths in the southern Everglades. New information is being added to better reflect current understanding of the predrainage system.

Several approaches are being used to estimate the historical surface and groundwater flows to Biscayne Bay and Florida Bay. A suite of potential models has been developed for use in predicting salinity in Florida Bay.

What Is Needed
Analysis of historic conditions in Everglades National Park and southern estuaries: Biscayne Bay, Card Sound and Barnes Sound Dated soil cores in Taylor Slough will help DOI managers understand the predrainage vegetation and hydrology in that region of the park. Paleoecological investigations will provide a historical profile of salinities in Biscayne and Florida Bays and the basins between them. Vegetation, topography, soils, and hydrologic surveys along tree island and ridge and slough transects in WCA-2, WCA-3, Northeast Shark River Slough, Taylor Slough, and southern Shark Slough will provide information needed to understand spatial variability and to assess hydrologic needs based on site-specific physical and ecological conditions. By measuring flow, water depth, and vegetation characteristics along a topographic and vegetation gradient, response curves can be generated to estimate the predrainage vegetation distribution and the vegetation distribution expected from restoration alternatives. These response curves are required to establish the need for additional water and to assess the ecological integrity of restoration alternatives.

Research quantifying the linkages of freshwater flows to the eastern coastal estuaries, Barnes and Card Sounds through central Biscayne Bay, on the flow of water through the Taylor Slough and the Model Lands.
Both Barnes and Card sound are the headwater of central and lower Biscayne Bay and any modification to the ecological function and character within those basins will be reflected in the ecological function of Biscayne Bay.

Environmental risk assessments of water quality contaminants. Water quality investigations will assess the environmental risks from rerouting urban and agricultural runoff and from reusing wastewater, both of which are under consideration as a source of water for this project. These investigations will include source water characterization, ecosystem response to contaminants, and models of contaminant fate and transport. This work will require field studies of body burden in indicator species, field studies of biogeochemical cycling, and development of tools for water quality modeling.

Wastewater Reuse Pilot Project

Project Purpose and Major DOI Interest
The main goals of this pilot project are to address uncertainties, including water quality, costs, and timing, associated with the possible use of reclaimed water in environmentally sensitive areas including Everglades and Biscayne National Parks. If the pilot project concludes that the use of reclaimed water is not practicable in this regard, a full-scale project will not be initiated.

DOI has a great interest in the quality of the water delivered into Everglades and Biscayne Bay National Parks. Because urban wastewater has been identified as a possible source of the additional water needed to meet predrainage hydrologic targets in the parks, DOI is interested in the wastewater treatment technology and whether it will be adequate to meet the goals of resource protection and ecosystem restoration. Currently, two CERP projects propose reuse of wastewater.

This pilot project is one of four pilot projects authorized in CERP. It will address water quality issues associated with discharging reclaimed water into natural areas, such as the West Palm Beach water catchment area, Biscayne National Park, and the Bird Drive basin. The pilot facility will be constructed in south Miami-Dade to determine the ecological effects of using superior, advanced treated reuse water to replace and augment freshwater flows to Biscayne Bay and to determine the level of superior, advanced treatment required to prevent degradation of freshwater and estuarine wetlands and nearshore waters. The constituents of concern in wastewater will be identified, and the ability of superior, advanced treatment to remove those constituents will be determined. The City of West Palm Beach is constructing a pilot facility to treat wastewater from the East Central Regional Wastewater Treatment Facility using advanced and superior wastewater treatment processes to remove nitrogen and phosphorus.

What Is Known
The impacts of stormwater and municipal, industrial, and agricultural wastewater on water quality variables are well documented. Many different treatment technologies are available, and the resulting wastewater varies significantly depending on the technology used. Some treatment processes, such as chemical additions and filtration, can add or remove essential water constituents that can impact water-receiving ecosystems. Also, treated wastewater, even though it may have very low concentrations of nutrients, pharmaceuticals, endocrine disrupters, and heavy metals, can discharge significant loads of these pollutants into receiving waters because of the large flow volumes. This added load of pollutants often has detrimental effects on the natural ecosystem, causing imbalances of the natural flora and fauna.

What Is Needed
Environmental risk assessments of water quality contaminants. DOI needs to understand the potential ecological effects and human health effects of discharging reclaimed water into natural systems, including freshwater wetlands, estuarine wetlands, and Biscayne Bay. A detailed comparison of wastewater constituents versus constituents of the receiving waters and downstream ecosystems will determine if the reuse water contains constituents that have potential to affect downstream ecosystems. If so, a risk analysis will determine the concentrations and loads of these constituents as they move through the surface and ground water and sediments in downstream ecosystems. If adequate information on the impacts of these constituents on native flora and fauna is not available, bioassay experiments need to be performed on native species to provide this information for the risk assessment.

Research evaluating the potential for natural system biological "scrubbing" of treated waste water are needed.

Research is needed to document the sensitivity of marine organisms and quantify the potential magnitude of biomagnification that might occur in juvenile and nursery habitats characteristic of the south Florida estuaries. Much of the water produced by treating waste water will be use to make up water delivery short falls to the coastal estuaries. It is well documented in the literature that the coastal systems are more sensitive to low levels of pollutants and biomagnification of low pollution levels is greater in marine systems. Research is needed to document the sensitivity of marine organisms and quantify the potential magnitude of biomagnification that might occur in juvenile and nursery habitats characteristic of the south Florida estuaries. This research needs to include the developing list of environmental pollutants of concern, or EPOC's. Controlled dosing experiments on the Phytoplankton and smaller zooplankton assemblages could be used to better understand issues of sensitivity and biomagnification.

Criteria for site selection of pilot. DOI needs to provide input into the development of criteria for selection of an appropriate wetland test area that replicates the southern section of the Everglades. The limited data on capturing, treating, and reusing water comes from a recent project in the northern part of the system. The water treatment technologies constructed and tested through this project will provide important input into a DOI analysis of whether the water derived from the pilot is of marsh quality and if the process can be replicated to deliver water to the natural system at the right times and in the right amounts.

Florida Bay and Florida Keys Feasibility Study

Project Purpose and Major DOI Interest

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The Florida Bay and Florida Keys Feasibility Study is designed to evaluate Florida Bay and its connections to the Everglades, the Gulf of Mexico, and the Florida Keys marine ecosystem to determine the modifications needed to successfully restore the water quality and the ecological conditions of the bay.

Florida Bay is a large, shallow, coastal saline ecosystem. Between 1987 and the early 1990s it experienced rapid and extensive ecological degradation. During the summer of 1987 approximately 100,000 acres of seagrass "died off" in western Florida Bay. This die-off was followed by phytoplankton blooms and sponge die-offs. These ecological changes came at the end of a multiyear drought. Salinity, especially in the eastern basins, is highly dependent on local rainfall. During the drought, bay salinity levels greatly increased and made the bay resemble more of a marine rather than an estuarine ecology. Conditions within Florida Bay have continued to visibly decline, including losses of seagrass habitat, diminished water clarity, micro-algal blooms of increasing intensity and duration, and population reductions in economically significant species such as pink shrimp, sponges, lobster, and recreational gamefish. Wading birds, forage fish, juveniles of game fish species, and other species that historically utilized the bay and adjacent estuarine wetlands have relocated, often at greatly reduced population levels, as their habitats have changed.

This project is of critical interest to DOI, which has management responsibilities in the project area including the Florida Bay portion of Everglades National Park, Dry Tortugas National Park, four national wildlife refuges (Crocodile Lake, National Key Deer, Great White Heron, and Key West), and critical habitat for a number of federally protected species. This region also encompasses the Florida Keys National Marine Sanctuary, an area of submerged lands administered by the National Marine Fisheries Service. The sanctuary contains part of Florida Bay and the entire Florida Reef Tract, the largest reef system in the continental United States.

Florida Bay will be the eventual recipient of increased sheet flows through Taylor Slough and Shark Slough, both within Everglades National Park. It is therefore important to consider the hydrology of the coastal estuaries as well as the historic hydrology of the southern Everglades region, including the now isolated Model Lands, when setting targets for water entering the park. The restoration of more natural flows through the southern Everglades is expected to also restore more natural flows into Florida Bay, restoring more natural salinity patterns. However, DOI remains concerned about the quality of the water to be introduced into the coastal estuaries. For example, increasing freshwater flow to the bay could increase nutrient (particularly nitrogen) loading, which might induce more frequent and more extensive phytoplankton blooms. High nitrogen levels may reflect the historic quality of water within the Everglades, but it may not reflect the historic quality of water in the coastal estuaries. These adjacent ecological systems may have different requirements and different problems that will require balancing their conflicting needs.

DOI managers also need to understand how a related project, the Florida Keys Tidal Restoration Project, will affect the circulation of water in the bay and Keys. This project uses bridges or culverts to restore some tidal connections between Florida Bay and the Straits of Florida in a section of the Middle Keys where this tidal flow was eliminated in the early 1900s during the construction of Flagler's railroad. Altered tidal flows between Florida Bay and the Straits of Florida have resulted in adverse water quality and fish and wildlife habitat impacts. However, changing water circulation patterns through the Keys by changing the configuration of the Keys passes could affect water quality conditions and the health of the coral reefs in the Florida Keys National Marine Sanctuary and Biscayne National Park that have adapted to the current circulation patterns. Increasing the water flow could also increase trace contaminant loading, depending on sources and flow pathways.

At least 22 commercially and/or recreationally important aquatic species are known to use the coastal estuaries Florida Bay and Biscayne Bay as nursery grounds. A guideboat industry operates within Florida Bay and Biscayne Bay. Target species of the recreational fishing industry include snook, redfish, tarpon, permit, bonefish, spotted seatrout, and mangrove snapper. Target species of the commercial fishing industry include Penaeid shrimp, stone crabs, and blue crabs (all in Biscayne Bay). The coastal estuaries are nurseries for many species, including young spiny lobsters and several species of snappers, grunts, and sparids. Florida Bay and nearby coastal estuaries and embayments are the principal nursery habitat for pink shrimp, which is the basis of a multimillion dollar fishery in the Tortugas. Pink shrimp are an important species commercially and form a prey base for higher trophic level organisms.

What Is Known
Although scientists disagree about the basic causes of problems within Florida Bay, most agree that they are probably symptomatic of disruptions of natural processes within the bay. Scientists and engineers from state and federal agencies as well as the academic community are working together for the purpose of identifying the problems and potential corrective measures to solve or at least minimize the causes of Florida Bay's problems.

Ecologically and hydrologically Florida Bay may be divided into three basins: eastern, central, and western. Overland freshwater flows through Taylor Slough and direct rainfall are the sources of freshwater for the eastern zone, which currently has extreme variations in salinity and high levels of dissolved organic matter. High methyl mercury levels occur in eastern Florida Bay and its biota. Health advisories are posted, warning of elevated mercury levels in some fishes.

Although such extremes have not been observed in the costal estuaries northeast of Florida Bay, in the basins from Barnes Sound and north, salinities have increased steadily since the 1960's, and possibly as far back as the 1910, the period of construction for the extensive Central and South Florida (C&SF) drainage system. Both Card and Barnes Sounds are typically hyper saline to saline and some areas of Biscayne Bay become hypersaline during the warmer summer months. Isohaline marine species of fish are now commonly observed along the western and northern shorelines of Biscayne Bay and Card Sound. Five canals drain directly into Biscayne Bay so salinities along the shoreline vary widely, closely following rainfall patterns. Salinity condition are more stable in Card and Barnes Sounds because only one canal, C-111, drains into Barnes Sound. Card Sound essentially receives no water except though rainfall "sheet flowing" to the basin across isolated landward wedge known as Model Lands

The central zone is hypersaline and has unnaturally high nitrogen and phosphorus levels and high levels of dissolved organic matter. The western zone, which is open to the Gulf of Mexico, has fairly stable marine conditions. Shark Slough indirectly provides freshwater inputs via tidal and current flows along Florida's west coast.

What Is Needed
Models to simulate how restoration projects will alter the hydrology of Florida Bay. More freshwater alone will not return Florida Bay to more natural conditions. The quantity, timing, distribution, and quality of freshwater released to Florida Bay must be considered separately and holistically. A significant amount of research has been conducted on how the Florida Bay system functioned historically, how it functions currently, and how the recent changes relate to hydrologic management of the upstream system. However, because distinguishing between the numerous possible natural and man-caused changes in an ecosystem is difficult at best, particularly when they are superimposed spatially and temporally, a number of information gaps need to be addressed before critical decisions can be made about upstream water management that affects Florida Bay.

The complexity of the system and the impacts of restoration and management scenarios can only be evaluated through modeling. The USGS Water Resources Division is adapting a coastal hydrological model that will simulate how restoration projects will alter the physical environment in terms of water elevation and salinity in coastal wetlands, lakes, and streams. An additional model will be needed to link to the coastal hydrological model and translate the output from that model into corresponding changes in Florida Bay. Several such models are under development and should be able to be tested and become operational within three years. The USACE is developing a hydrodynamic model to simulate water circulation patterns in the bay. Among other things this model will support predictions of salinity resulting from varying temporal and spatial freshwater inflows. For example, the model will accept output from surface and groundwater hydrologic models to predict the impacts that C&SF Project restoration alternatives will have on Florida Bay. DOI needs to complete the models it is developing and actively participate in the development of models by other agencies to ensure that this work is carried out efficiently with no overlap.

Water quality studies. Nutrient, toxic contaminant levels, and emergent pollutants of concern and how they relate to inputs from freshwater inflow, run-off from the developed areas of the Upper Keys, and inputs from the Gulf of Mexico are key water quality issues.

Regarding inputs from freshwater inflow, the water entering Florida Bay through the Taylor Slough is derived from agricultural runoff and urban flood control operations. The establishment of water quality targets and recommendations for management will require additional studies of the role of plant nutrients, their sources, and amounts arriving in Florida Bay. Measures to address pollution specific to the Everglades may not be adequate to protect Florida Bay. Nitrogen levels, which may have been relatively high in the historic Everglades, are thought to be elevated above natural background levels in parts of Florida Bay and may be contributing to phytoplankton blooms. Because upstream water management activities may affect nitrogen inputs (even from natural sources) into the bay, it is important that nitrogen levels within Florida Bay, their sources, and the ramifications for the bay be studied and understood. Increased freshwater inflow from the agriculturally dominated C-111 basin could result in increased pesticide loads into Florida Bay.

Other potential sources of contaminates, such as the Florida Keys and the Gulf of Mexico, will also need to be assessed to determine their potential for affecting the water quality of Florida Bay.

Modeling of ecological responses to hydrologic change. It is anticipated that, but not completely understood how, restoring historic circulation patterns to waters that have been impeded and stagnant for decades will significantly improve water quality, benthic floral and faunal communities, and larval distribution of both recreational and commercial species (e.g. spiny lobster) in the nearshore waters in the vicinity of these restoration sites. Simulations of ecological responses to proposed project design and operation will be evaluated first on the basis of anticipated changes in the quality and quantity of habitat for important indicator species, and second (where feasible and appropriate) on anticipated changes in the population sizes of those species. Information on the life history requirements of indicator species, including their responses to hydropattern change, will be needed to address anticipated changes in species populations. Indicator groups that should be represented in these evaluations include estuarine fish (coastal marshes and streams), wading birds (e.g., spoonbills, egrets), marine fish (e.g. spotted sea trout, mangrove snapper), submerged aquatic vegetation (sea grasses), mangrove forest species, and federally listed species (American crocodiles). Dilution studies combined with hydrodynamic models for Florida Bay that extend onto the offshore platform are needed.

Monitoring of ecological responses. Monitoring will ensure the accuracy of predictions and measure the success of restoration projects. For each of the indicator species or biological communities selected for simulation-based project evaluation, a monitoring program will be initiated as part of the model refinement and adaptive management process. Monitoring will be an essential part of the long-term management of the bay and will provide continuous data observations of the restoration/management changes to the upstream system that will help improve the value and calibration of the models.

Understanding the effects of sea-level rise. The formation and sustainability of coastal communities is a result of the interaction between upland freshwater and tidal inputs. Both of these hydrologic processes are likely to change in the future with restoration projects and with sea level rise. Resource management and restoration efforts will require a thorough understanding of the biological and physical controls on the formation and maintenance of these coastal communities. Research is necessary to assess the current and historic relationships between sea level, salinity, overland freshwater flows, tidal regimes, water budgets, and climate on mangrove and oligohaline communities. This information will be used to develop and validate process-based models useful for simulating hydrologic fluxes, soil dynamics, productivity, carbon balance, and spatial variability in the mangrove and oligohaline zones in coastal areas. Large salinity corrections that are to be achieved in Florida Bay will have a similar, although admittedly smaller effect on the physiochemical conditions in coastal water immediately seaward of the string of Key bounding and defining the coastal estuaries from Florida Bay to northern Biscayne Bay. The coral reef ecosystem within this coastal zone is highly stressed and, some predict, near collapse.