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When Interior Secretary Bruce Babbitt mentions a specific flood-control project at the annual Everglades Coalition Conference, there is a good chance the project is important to many people.
By Chuck Sinclair and Richard Gibney
The 8.5 Square Mile Area (SMA), a component of the Modified Water Deliveries to Everglades National Park Project, has long been a source of controversy associated with the Everglades restoration. It has been referred to in public forums as the linchpin of the entire Everglades restoration initiative because of the political wrangling between public agencies, environmental groups, civic organizations, and Native American tribes.
Despite its name, the 8.5 SMA is an area of approximately 10 mi.2 in Miami-Dade County, FL, consisting of agricultural, residential, and undeveloped land. It sits in the East Everglades, on the eastern edge of Everglades National Park (ENP) and just west of the flood-protection levees that separate the natural Everglades system and the suburbs of Metropolitan Miami. Landowners have been allowed to develop the property since the 1970s despite the absence of flood protection for the area. In 1989, federal law mandated that flood mitigation be provided to ensure that the area would be unaffected by future increased restoration flows to the eastern Everglades. Implementation of sound practices in the 8.5 SMA, however, has been stonewalled for the past two decades–until now.
The history of the 8.5 SMA can be traced back to the Central and Southern Florida Flood Control (C&SF) Project, constructed to control flooding and manage water in south Florida. The C&SF Project included a system of canals, levees, and pumps designed primarily to keep water out of the developed areas.
In 1989, Congress passed the Everglades National Park Protection and Expansion Act, which authorized the US Army Corps of Engineers to modify the C&SF Project to improve the delivery of water to ENP and to develop a plan for restoring the natural hydrology within the park. In 1992, the corps completed a general design memorandum (GDM), which identified an array of modifications to the C&SF Project to accomplish the goals of the park act. The plan contained in the 1992 GDM, known as the Modified Water Deliveries (MWD) Project, identified several components necessary to increase the quantity and improve the timing of the water delivered to ENP. One component included the construction of a flood mitigation system for the 8.5 SMA.
Because of its location on the west side of the flood-protection levee, the 8.5 SMA would end up flooded by the increased flows resulting from the MWD Project. One of the MWD plan components authorized the design and construction of a flood control levee, an interior levee, and a seepage collection canal for the 8.5 SMA. The levee would be constructed around the perimeter of the area to keep the water levels from rising, increasing the flooding in the 8.5 SMA. The seepage collection canal would collect water that seeped under the levee and transport it to a pump station adjacent to the site for discharge back into ENP. This system would ensure that the agricultural and residential properties in the 8.5 SMA would not be adversely affected by the increased water stages and durations caused by the MWD Project.
Since 1992, there have been several additional studies and evaluations of the 8.5 SMA component of the MWD Project. Other scientific knowledge and technology regarding ecosystem restoration and improvements to hydrologic modeling capabilities furthered the understanding of the technical issues regarding this project. Numerous stakeholders took an interest in the 8.5 SMA, and many suggested other alternatives to meet the legislative requirements of the MWD Project, maximizing restoration to ENP and minimizing the impacts to the landowners and residents of the 8.5 SMA.
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| Click here for a larger view |
In the summer of 1999, the governing board of the South Florida Water Management District (SFWMD) asked the corps to develop and evaluate a full array of alternatives to provide flood mitigation to the landowners of the 8.5 SMA. The corps contracted HDR Engineering Inc. to assist in conducting a comprehensive study of the area, which would facilitate a decision as to the best alternative. The corps/HDR team had the task of preparing a general reevaluation report (GRR) to the 1992 GDM and a supplemental environmental impact statement (SEIS).
A congressional mandate required an accelerated project schedule–reduced from 24 months to 12 months. An early strategy took shape so that a draft GRR containing the plan formulation would be developed concurrently with a draft SEIS–necessary for complying with the National Environmental Policy Act (NEPA)–and combined into one document. While this is not unprecedented, the fact that the draft document was developed and published for review without a preferred alternative made it unique. Although this approach is technically allowable under NEPA, the standard NEPA practice asks for a preferred alternative to be advanced in the draft document. This "no preferred alternative" approach happened only once before in the history of the corps.
Publishing the document with no preferred alternative allowed for a completely unbiased presentation and evaluation of all alternatives. This presentation allowed the public and the regulatory agencies to form objective opinions, and the decision-making bodies could make unbiased decisions regarding the selection of a preferred plan.
A plan was formulated early in the project development whereby the corps would receive public comments on the draft, then choose a recommended plan in cooperation with its federal partners and in coordination with the SFWMD as the local sponsor. This plan would be incorporated into the final GRR/SEIS with justification of why it was the plan that best balanced environmental restoration benefits, cost, and social impacts.
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| Aerial view of the 8.5 SMA |
The key to this process involved providing numerous opportunities for public input and interaction. Because of the extremely controversial and often volatile nature of the project, the corps/HDR team made an early decision to conduct the project development and analyses in a public forum. In addition, because of the demographics of the area affected, the team presented much of the information in both English and Spanish.
The project team conducted many more than the "required" number of public meetings typically included in a NEPA process. It provided status reports and updates at regularly scheduled public workshops. The project team also hosted frequent meetings with technical representatives of the stakeholders. The team presented and discussed technical issues in a roundtable format, with all stakeholders having equal opportunity to present their viewpoints.
This was a politically complex project because it drew out very polarized viewpoints on appropriate actions. More than 25 stakeholder groups were included as part of the public coordination process. Representatives from federal, state, local, and tribal agencies got involved, along with numerous environmental, agricultural, civic, human rights, and homeowners groups. One of the fascinating aspects of this project is the bipolar view that many of these groups initially brought to the table. Many of the environmental agencies and groups were interested solely in the restoration of wetlands and protection or improvement of plant and animal habitat. The interests of the civic and homeowners groups lay primarily in the limited impacts to the residents and landowners. The corps/HDR team faced a very challenging task of trying to present the analyses results without showing favoritism to any one group.
One of the primary objectives of conducting this new analysis of the 8.5 SMA involved evaluating as many alternatives as possible given the available time and resources. The project team–in conjunction with the corps federal partners and the SFWMD, and with input from the other interested stakeholders–developed an array of nine alternatives:
- Alternative No. 1–Authorized GDM Plan
- Alternative No. 2B–Modified GDM Plan
- Alternative No. 3–Deep Seepage Barrier
- Alternative No. 4–Landowner’s Choice Land Acquisition/Flowage Easement
- Alternative No. 5–Total Buy-Out
- Alternative No. 6B–Western Portion as Buffer
- Alternative No. 7–Raise All Roads
- Alternative No. 8A–Western Portion as Flow-Way
- Alternative No. 9–Adaptive Refinement of GDM Plan
After presenting the draft document to the public for review, the SFWMD Governing Board requested that the corps evaluate two variations of Alternative No. 6B. Its intention was to evaluate the location of the levee/canal system under several different configurations, thereby finding the "optimum" that balanced the ecosystem restoration benefits while reducing cost and impacts to the landowners. The variations included:
- Alternative No. 6C–Western Portion as Buffer (Save Our Rivers Boundary)
- Alternative No. 6D–Modified Western Portion as Buffer
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| Click here for a larger view |
Thus, the final report included a full evaluation of all nine alternatives, plus two variations of one alternative. These alternatives generally fit into three categories: structural, nonstructural, and combination.
Three of the five structural alternatives (Nos. 1, 2B, and 9) consisted of a levee along the perimeter of the site (approximately 40,000 ft.) with an internal system of seepage canals and pump stations. Alternative No. 3 consisted of constructing a levee with a seepage barrier around the perimeter of the site to keep surface water on the outside of the area and groundwater from seeping into the area. Alternative No. 7 included raising the roads within the area for access maintenance during flooding events.
The team considered two nonstructural plans. Alternative No. 5 consisted of purchasing all property within the area and relocating the residents in the 8.5 SMA to a location outside. Alternative No. 4 would give the landowners a choice of either selling their property or selling flowage easements and staying in the area.
Combination plans consisted of both structural and nonstructural alternatives; part of the 8.5 SMA would be included within a levee/canal system, and the rest would be purchased. Alternative Nos. 6B, 6C, and 6D all included part of the 8.5 SMA within a levee, with varying amounts of the western area purchased and maintained as a buffer between developed area of the 8.5 SMA and ENP. Alternative No. 8A was similar to the buffer alternatives except that the western area would be graded as a flow-way to convey water around the 8.5 SMA.
Goals and Performance Measures
During the plan formulation process, the corps/HDR team constructed a process for first establishing goals, objectives, and performance measures for project alternatives, then developing a system for objectively evaluating the alternatives. The project team met numerous times early in the project in an open forum with representatives of all stakeholders who wanted to participate. The stakeholders agreed upon seven objectives to establish the basis for project success. The objectives included analyzing effects on the hydrology in ENP, the impact on the natural resources, the impacts on the residents and landowners, and the cost-effectiveness.
The team defined performance measures as quantitative or qualitative indicators of how well (or poorly) an alternative met a specific objective. These performance measures have specific metrics related directly to each of the seven objectives. This facilitating process among the stakeholders took the greatest amount of time because environmental groups looked for higher standards for ecosystem restoration objectives, while civic groups and landowners wanted to minimize impacts to landowners, residents, and nearby tribal lands.
Nine different alternatives were developed and included in the draft GRR/SEIS. In addition, formulation and analysis of two variations of one of the alternatives occurred at the request of the local sponsor. Twenty-three performance measures were developed to support seven project objectives. Performance measures ranged from hydrologic restoration to wetlands created or impacted, number of residents relocated, and relationship with other restoration projects. An evaluation matrix was formulated with a quantitative or qualitative "answer" for each performance measure as it related to each alternative. The resulting matrix table had spaces for 253 of these answers, each representing the result of an individual evaluation or analysis. The results of the analysis for each alternative and performance measure were presented for both the absolute values and the relative change in value compared to the original plan.
Because public opinion of the alternatives differed tremendously, it was essential to provide the same level of detail for each of the alternatives. This was especially challenging as shifts in plant composition within habitats had to be predicted based on changes in hydrology (both stage and duration), land use, and extent of future management (private- vs. public-owned lands). The team used a consensus-building approach to take full advantage of the expertise held by the various stakeholders.
The analysis proved technically complex because it required detailed modeling and associated interpretation of modeling results. Flood-control operations, water resource and preservation initiatives, and other restoration projects were all under consideration during the analysis. These were especially critical to evaluating secondary and cumulative impacts related to hydrology, wetlands, and natural habitat.
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| The Everglades, also known as the "River of Grass," is one of the most sensitive ecosystems in the US. |
In the years since the implementation of the C&SF Project, the Everglades evolved into an extremely complex system of interconnected canals, levees, and pumps designed to quickly move large volumes of water. The restoration goals specified in the MWD Project require raising the water levels within ENP to provide the hydration source for wetland improvement and development and for fish, birds, and animals using this area as their habitat. This area of south Florida is also home to some of the most productive and unique farmland in the country. Crops grown in the area to the east of the 8.5 SMA, within the flood-protection levee, represent a significant source of income to the residents in western Miami-Dade County. This farmland requires maintaining that water level at a certain range below land surface to facilitate crop growth.
The 8.5 SMA–a mixture of primarily vacant, residential, and agricultural land–lies between these two areas of conflicting hydrologic needs. The dilemma for the project designers included providing increased water levels in ENP while avoiding significant variations in the water levels of the agricultural area.
Simulating the flow regimes in the study area and the impacts of rainfall to accommodate the goals of the MWD Project required the use of a sophisticated surface/groundwater model (MODBRANCH). This simulation tool, operated by the Corps of Engineers modeling staff, evaluated both the effects of the rainfall/runoff relationship and the interflow. Interflow is critical because the ground surface of the 8.5 SMA and its surrounding area is actually within the surficial aquifer.
Simulations of the flow regimes provided information on the level of flood mitigation afforded the 8.5 SMA with the various alternatives developed. The simulation evaluated wet (100-year event), dry, and average-year hydrologic events. Because of the cause-and-effect relationship with the whole MWD program, the model grid encompassed the southeastern tip of the Florida peninsula, roughly south of the Tamiami Trail down to the Biscayne Bay.
The Everglades is one of the most sensitive ecosystems within the United States. This "River of Grass" has long been a home for unique and endangered species of flora and fauna, invertebrates, freshwater and marine fish, amphibians, reptiles, mammals, and birds. The goals, objectives, and performance measures focused on the improvement to ENP wetland hydrology, including habitat diversity. The analysis proved environmentally complex because there were many different ideas of what price, in the form of socioeconomic impacts and costs, to pay for restoration.
The analysis evaluated both short- and long-hydroperiod wetlands to determine not only whether wetland areas would be increased, but also the type and location of wetlands. A multiagency team of biologists and ecologists developed Wetland Rapid Assessment Procedure (WRAP) scores for the wetlands that existed within the region. Prediction of future WRAP values for all alternatives took place using the results of the hydrologic modeling.
The team also evaluated the impacts to threatened and endangered species. Of the many such species that use the Everglades’ habitat, one essential species is the Cape Sable seaside sparrow. Critical habitats for this unique bird require very specific water levels and hydroperiods to promote nesting. A primary basis for evaluation was the hydrologic modeling, which identified the water-surface elevations and durations, ensuring maintenance of critical habitats.
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| This area of south Florida is also home to some of the most productive and unique farmland in the country. |
Social impacts became a primary consideration when evaluating alternatives. Performance measures for these impacts included quantifying areas affected by increased water levels and identifying the number of businesses, residences, and agricultural areas impacted by the project.
Project team planners and economists used a very structured system for estimating the number and location of residents and landowners in the project area. Information came from a variety of resources, including databases from state and county agencies from other stakeholders. A general lack of accurate or recent data, and large discrepancies in the same information among different data sources, presented a major challenge to the team. The team conducted site visits wherever practical to verify data. They made every effort to compare and correlate the data in a manner that ensured the most accurate representation of human and economic resources in the area. Although numbers varied greatly among data sources, the team estimated there were more than 850 permanent residents in 200 residential structures within the 8.5 SMA. Only four businesses existed in the area, but 2,600 ac. of agricultural area accounted for $6.5 million in annual revenue.
The evaluation of the alternatives occurred by overlaying the spatial results of various model runs with the database of the business, residential, and agricultural areas. Identifying the impacts to businesses and residences was a relatively simple process of counting the units within the flooded areas. The agricultural impacts proved more complex: Consideration had to be given for not only the water level, but also the duration of water levels that could affect the root zones of the crops grown in the area.
Cost is one of the main considerations for any large capital project. For this project, the team developed and compared several cost numbers for each alternative. Initial project costs for the alternatives ranged from $30 million for the original project to nearly $180 million for the total buy-out alternative. Real estate costs were estimated from a gross assessment performed by a certified real estate appraiser brought in as part of the team.
Engineers on the study team also estimated costs for operation and maintenance of the system and for periodic equipment replacement costs. These costs ranged from $270,000 for the original plan to $430,000. In general, it would have cost more to maintain the nonstructural alternatives, including the financial burden of maintaining the acquired land, than it would to maintain the levees and canals in the structural alternatives.
The team also estimated the capital and operation and maintenance costs incurred by Miami-Dade County or its residents. These costs included any additional services that might be provided to the area, such as water, sewer, solid waste, road maintenance, and emergency services. The team determined that only in the cases where supplemental flood protection was provided would the county actually be required to provide additional services to the 8.5 SMA. This estimated amount came to as much as $36 million in capital costs and $900,000 in annual operation and maintenance costs.
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| The project team conducted site visits whenever practical to verify data. |
The federal objective for this project was the same as for the 1992 GDM: restore hydropatterns in ENP to the extent practicable while mitigating for adverse impacts to the 8.5 SMA. In addition, the recommended plan had to be cost-effective and maximize ecosystem restoration benefits. Categorizing the alternatives made possible the identification of the best performing alternative for each category, which then was put forward for further comparison. Alternative No. 1 was determined to be the best among the structural alternatives, as it provided relatively the same level of hydropattern restoration and mitigation as Nos. 2B and 9 but did it at a lower cost. Alternative No. 5 won selection over No. 4 among the nonstructural plans because it would provide the highest level of restoration to ENP and remove present and future impediments in the area.
The combination alternatives proved harder to compare. Close analysis of Alternative No. 8A showed it would be ineffective as a flow-way, so it was removed from further consideration. Alternative Nos. 6B, 6C, and 6D were all relatively similar in operation and concept. The only difference was the position of the flood mitigation levee and, subsequently, the amount of area within the 8.5 SMA not adversely affected. Among these three, Alternative No. 6D provided the most hydropattern restoration and impacted the fewest landowners in the 8.5 SMA.
The next phase of plan selection involved comparing the three alternatives selected from each of the three categories. WRAP functional units for wetlands, endangered species impacts and benefits, increased water depths, social impacts, and project costs received particular consideration. The ultimate selection of the recommended plan took place with the goal of achieving the greatest ecosystem restoration benefits with the least impact to landowners and residents. Alternative No. 6D was the plan that optimized the environmental benefits and social impacts.
The recommended plan calls for building a 34,500-ft.-perimeter levee around approximately 45% of the 8.5 SMA. The levee will have a top width of 20 ft. and range from 4 to 6 ft. in height above the ground surface. The seepage canal, running inside the levee’s perimeter, will be approximately 21,000 ft. long and will range in depth from 12.5 to 15 ft. and in width from 25 to 30 ft. In addition, the construction of two small interior levees on either side of the seepage canal will keep surface water within the 8.5 SMA from directly entering the seepage canal. A 500-cfs pump station will be located at the southern terminus of the seepage canal to discharge seepage water off-site through a 96-in. pipe.
The government will purchase all lands west and north of the perimeter levee, approximately 2,300 ac. All residences, structures, and roads, as well as fill pads and septic systems, will be removed. In addition, the management of the area will include removing exotic plants and preventing new exotics from growing. The intent is for the area to gradually migrate back to its more natural state.
Federal law has established the cost-sharing arrangements between the federal government and the nonfederal sponsor (SFWMD). An implementation schedule provides for construction of the project by December 2003. In December 2000, the assistant secretary of the Army (Civil Works) signed a Record of Decision, which approved the recommended plan to move forward for design and construction.
Perhaps the traditional engineering approach would have been to attempt to apply some magic formula to this project that could have satisfied some rule of hydrologic improvement, environmental restoration, or even the number of landowners and residents impacted. There was a temptation to concentrate on developing conceptual designs of the alternatives, do a cost-benefit analysis, and force the best "engineering" plan onto the public.
The team took a different approach for this project. Team members realized early in the process that they could not attempt to quantify the value of human impact or weigh it in comparison to ecosystem restoration. The team understood that the success of this project would be determined by its ability to develop a process that educated stakeholders about the "big picture," in hopes that they would be open-minded to compromise and tolerant of necessary impacts for the greater good.
HDR worked closely with the corps to implement that education process so that when an alternative was chosen, even if the stakeholders did not agree with the result, they could at least understand the reason behind the decision. In an age of computer models, pilot projects, and digital simulations, this is a project goal too often overlooked. The recommended plan resulting from the analysis of the 8.5 SMA represents a best-case compromise between costs, environmental benefits, and social impacts.
Chuck Sinclair, P.E., is a vice president and senior project manager with HDR Engineering in Miami, FL. Richard Gibney, P.E., is a senior project manager and water resources specialist with HDR Engineering in Tampa, FL.
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