Interim Review of the Florida Keys Carrying Capacity Study (2001)

If properly designed, implemented, and maintained, the CCAM assessmenttool could be extremely useful for a number of applications. Foremost,the tool is intended to help evaluate proposed comprehensive planamendments as well as the regulations designed to implement thoseplans. This is evident from the list of future scenarios developedfor testing, some of which are described in terms of land use patterns(as for a comprehensive plan) and some of which are described interms of regulatory policy (e.g., no more than 10 permits per yearin Islamorada). Although the project team described how to inputand thus assess a particular snapshot of land use, the committeesaw no obvious input mechanism for evaluating regulatory policies.

To serve its main purpose, the CCAM must be capable of acceptinginputs either as an end-of-period land use picture or as a set ofregulatory policies designed to achieve such land uses. In otherwords, it must accommodate spatially explicit build-out scenariosbased on future land use plans, zoning regulations, and other landdevelopment regulations that govern density and intensity of landuse. From these scenario characteristics the CCAM should generatethe parameters needed as inputs to the ecosystem, water-quality,and socio-economic and land use modules. The CCAM should be capableof assigning new development and redevelopment to specific land parcelsto generate spatially explicit outputs that represent developmentimpacts.

The assessment tool could have several very valuable additional applications.Although there will probably not be enough time to develop all ofthese applications immediately, it will be helpful to keep them inmind during the design phase in order to facilitate their additionat a later date. To ensure that actual development on the groundis consistent with amended comprehensive plans or land developmentregulations, the CCAM should be able to serve two additional functions:evaluation of permit applications and adaptive management. Once thecomprehensive plans are amended and supporting regulations developedbased on the results of the Keys Study, the permit limitations andconditions implied by those regulations can be incorporated intothe assessment tool. The CCAM could then automate many of the labor-intensivefunctions required for evaluation of permits, resulting in reducedadministrative costs and more consistent evaluations. This is anextension of the role currently envisioned for the routine planningtool, a still undeveloped component of the CCAM which, as described,would only make the underlying data in the CCAM available for use in the evaluation of permits.

To implement adaptive management it is important to know whetherlocal comprehensive plans and their implementing regulations arehaving the desired effect over time. Because of the unpredictableinfluence of natural variables, it is necessary to use models toassess the extent to which actual impacts are consistent with originalexpectations. If the CCAM databases are updated to include newlypermitted development, then the predicted impacts can be comparedto the results of actual monitoring. Assuming that the original CCAMwent through a rigorous validation process, deviations between predictedand observed conditions could uncover ongoing

violations of environmental permits or indicate that regulationsare not achieving what was intended. In either case the CCAM couldbe revised as appropriate and then used to develop improved adaptive-managementactions.

Scenario testing serves several functions in the CCAM, and as manytests as possible should be run. Such testing will provide sensitivityanalyses and help to identify errors by uncovering anomalous results.In consultation with the expert advisors, a battery of test scenariosshould be designed for the sole purpose of exploring the performanceand limitations of the assessment tool.

Of course, scenario testing is also at the heart of the goal of theKeys Study. By examining a range of possible futures for populationgrowth, economic and land development, and environmental managementin the Keys, planners can make meaningful, well-informed choicesabout the future. The alternatives currently being considered (aslisted in the Project Strategy Outline, Dames & Moore, 2000a) aredescribed in very different ways. Although some are described interms of land use patterns, others depict potential land developmentregulations designed to manage future development. It is not at allclear how the CCAM will handle such scenarios as input, nor is itclear how land development regulations will be converted into thekinds of spatially explicit inputs that will be needed by the othermodules to determine the impacts of alternative scenarios. As mentionedabove, efforts will be required either to develop an input formatfor such regulations or to craft reasonable protocols for automaticallyor manually converting such scenarios into spatially explicit datasuitable for analysis.

Evaluation of one or more hurricane disaster scenarios can provideuseful information to state and local land use planners about therelative vulnerability of different future development patterns (Deyleet al., 1998). It is much more difficult, however, to develop hurricaneimpact scenarios for biological communities that will provide usefulinformation for the evaluation of planning and land use alternatives.While a comprehensive evaluation of the full range of possible hurricanescenarios is not possible under current time and budget constraints,it may be feasible to assess one or more scenarios that simulatethe likely damage to the built environment from a Category 3 or Category4 hurricane. Local disaster mitigation policies and programs canhelp lessen the impacts of hurricanes of this magnitude, while catastrophicstorms (Category 5) generally are viewed as “acts of God” beyond feasible mitigation(Godschalk, Brower, and Beatley, 1989). Such a vulnerability assessmentshould be possible using existing land use and property data availablefrom county and municipal agencies in the Keys and the TAOS softwareavailable from the Florida Department of Community Affairs. TAOScan be used to estimate damage from storm surge, wave height, maximumsustained surface winds, and inland flooding (Watson, 1995; FloridaDepartment of Community Affairs, 1998). It also may be worthwhileto explore the effect of sea-level rise on storm surge levels 25and 50 years into the future to assess the altered vulnerabilityof the built environment.