Appendix D
Detailed Comments and Questions

SECTION I.
DETAILED COMMENTS

This section provides detailed recommendations and comments on specific sections, equations and definitions included in the Draft CCAM report. Many refer to Appendix C of the Draft CCAM, which contains equations and tables of coefficients for each module.

SCENARIO GENERATOR

  • Correct the planning unit labels on Figure 2.3 per the response to Question #12 in Appendix D.

  • Expand the definition of “scarified” in the Glossary (Draft CCAM p. 150) per response to Question #13 Appendix D.

  • Revise the definition of “retrofitting” per the response to Question #14 on January 2, 2002 (Appendix D).

  • Add a definition of “PC codes” to the Glossary.

  • Make it clear that wetlands are defined using the US Army Corps of Engineer’s criteria.

  • Revise Tables 3.1 and 3.2 and the accompanying text to make it clear that all A-zones and V-zones are treated as areas with flood hazards regardless of whether or not base flood elevations (BFEs) are mapped (i.e., not just AE and VE zones).



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A Review of the Florida Keys Carrying Capacity Study Appendix D Detailed Comments and Questions SECTION I. DETAILED COMMENTS This section provides detailed recommendations and comments on specific sections, equations and definitions included in the Draft CCAM report. Many refer to Appendix C of the Draft CCAM, which contains equations and tables of coefficients for each module. SCENARIO GENERATOR Correct the planning unit labels on Figure 2.3 per the response to Question #12 in Appendix D. Expand the definition of “scarified” in the Glossary (Draft CCAM p. 150) per response to Question #13 Appendix D. Revise the definition of “retrofitting” per the response to Question #14 on January 2, 2002 (Appendix D). Add a definition of “PC codes” to the Glossary. Make it clear that wetlands are defined using the US Army Corps of Engineer’s criteria. Revise Tables 3.1 and 3.2 and the accompanying text to make it clear that all A-zones and V-zones are treated as areas with flood hazards regardless of whether or not base flood elevations (BFEs) are mapped (i.e., not just AE and VE zones).

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A Review of the Florida Keys Carrying Capacity Study Clarify use of the terms “clustered” and “spread” in describing the “Configuration” options of the scenario generator per response to Question #25 in Appendix D. SOCIOECONOMIC MODULE Drop those variables that are based on the Independent Population Projections, which includes sections 1.2, 1.3, 1.6. The Planning Unit Capture Rate should be dropped. The amount of development within a planning unit is a function of the scenario-based land use decision. Introduce multiplier to convert permanent population to functional population; in addition more detail is needed as to how the figure 1.86 was derived. It should read the multiplier to convert permanent population to functional population = 1.86 (not vice versa). Provide more details with regard to how the multiplier to estimate seasonal population (0.33) was derived. It should read “to estimate seasonal population from permanent population = 0.33” (not vice versa). The persons per household variable does not mean the same thing as reported in 1990 Census. The 1990 Census is the data source, not the definition of the variable. A number of variables are set equal to their data sources. The Committee recommends making changes so that equal signs are only used to define variables. A description is needed of the census variables from which persons per household is derived. More information is needed as to how the residential densities are derived including the year for which it was derived and the base source of information. A similar comment holds for many of the following variable definitions where the Committee recommends “provide more details.” More information is needed as to how Floor area ratio was derived. More information is needed as to how Hotel/motel room density was derived. Gross floor area per capita is defined as gross floor area demand divided by population. Gross floor area demand is defined as gross floor area per capita times population, which presents a problem of circularity. Neither variable indicates the source for gross floor area or gross floor area demand. The hotel rooms per transient person variable uses independent population projections as a basis for estimating transient persons. The employment per 1,000 square feet of gross floor area variable comes from the Monroe County tax roll database and County Business Patterns. But no detail is provided as to what information comes from what source. Clarification is needed as to how this variable was derived.

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A Review of the Florida Keys Carrying Capacity Study The hotel employees per room variable comes from County Business Patterns and Florida Statistical Abstracts, but no detail is provided as to what information is taken from what source. Clarification is needed as to how this variable was derived. More information is needed as to how per unit construction costs were derived as well as the data source, Means Construction Cost. Clarification is needed as to what types of construction (e.g., residential, hotel/ motel, commercial, industrial) this cost estimate includes. More detail is needed with regard to how per unit average taxable value was derived. It is unclear whether “average” price of house indicates the “mean.” More details is needed about the rationale for using appraiser data in some cases and market sales data in others? The source for the 3.57 value of the qualifying income ratio is unclear. It should read “qualifying income ratio = 3.57” (not vice-versa). More detail is needed with regard to how mean household income was derived and why U.S. Department of Housing and Urban Development (HUD) data rather than census data was used? More detail is needed with regard to how multiple dwelling units were incorporated into median housing value and how this variable was derived. More detail is needed with regard to how average annual wage per employee was derived. Variables 26–28 (Section 1.4) are important constants and deserve scrutiny. It is unclear as to why they are based on historical data for each planning unit rather than on design principles. For variables 29–31, it is uncertain whether population per household can really be held constant across low, medium, and high-density dwelling units. The relationship between support population, permanent population and functional population is unclear. The second definition for support population is mystifying. Variable 37 is defined as variable 35 divided by variable 9. Variable 35, however, is defined as population divided by variable 9. So variable (37) is simply population. It is unclear why the extra manipulation is necessary. The definition of hotel support population is also mystifying. It is defined as variable 34 divided by variable 10, but variable 10 is defined as variable 34 divided by transient population. Variable (38) would then seem to define the transient population. It is unclear as to why gross floor area is not divided by 1000 in the employment demand calculations. Furthermore, the distinction between this variable (#39) and variables 41 and 43 is also uncertain. The distinction between hotel employment demand (#40) and variable #42 and #44 is unclear.

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A Review of the Florida Keys Carrying Capacity Study The assumptions regarding square feet of new construction are unclear in the calculations for new residential construction costs. It’s also uncertain whether variable #13, commercial construction cost, is appropriate for residential construction. “New commercial construction costs” may be a better moniker for Variable #46. It is unclear why the variable is divided by 1,000,000. It is uncertain whether it is valid to use variable #13, commercial construction cost, for new hotel/motel construction cost. It is also unclear why the variable is divided by 1,000,000? It is unclear why residential taxable value is divided by 1,000,000. Variable #14 is based on the taxable value of a single-family residence. It is unclear why it is being used to define the value of square foot of nonresidential gross floor area in the calculations of nonresidential taxable value Variable #14 is based on the taxable value of a single-family residence. It is unclear why it is being used to define the value of a hotel room in the calculations for hotel taxable value, nor is it clear why the latter is being divided by 1,000,000. The same variables are used for both projected and existing total dwelling units so it appears that this variable for projected new units will always be zero. More clarification is needed. Required income, #52, is unnecessary. It is unclear as to how the retail concentration index is defined and how it relates to the CCI. It is unclear why total employment wasn’t simply defined as the number of employees per gross floor area times the gross floor area plus the number of employees per hotel room times the number of hotel rooms. The range from red to yellow to green for the threshold for affordable housing index seems to be a narrow range. FISCAL MODULE The description of the trip generation method is not consistent with the equations detailed in Appendix C, nor does Appendix C fully explain how trips are apportioned among the planning units. Various formulas in Appendix C contain errors. The explanation for how speed is calculated does not refer to other equations in the appendix. The parameters for calculating internal-internal trips per segment are not explained: it is unclear if TPI refers to equation #85 and the source for the 0.85 coefficient is not readily apparent. The calculation for the “n” value for internal-external trips per segment and external-internal trips per segment is not clear. Explanation is needed as to how “distance per trip” is calculated.

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A Review of the Florida Keys Carrying Capacity Study The calculation for the “m” value for external-external trips per segment is also unclear: explanation is needed as to how “distance per trip” is calculated. There is no explicit use of the trip attraction per segment variable, though it appears that this should be involved in calculating external-internal trips. HURRICANE EVACUATION No explanation is provided of the basis for the three “threshold” population estimates reported in Appendix C, equations 95–97. If the population extrapolation method is retained despite the above recommendations, the rationale for this choice should be explained. SECTION II. QUESTIONS & COMMENTS This section contains a set of questions posed by the NRC during the period of December 21–23, 2001 after receiving the Draft CCAM. The contractors provided answers (indicated in bold) prior to a public meeting held on January 17, 2002. GENERAL COMMENTS The concern for the well-being of the ecological system and the people who inhabit the Keys is laudable. The effort to limit growth and to protect the remaining habitat is a meritorious societal issue and requires sound theory and scientific backing if it is to achieve its objectives. Part of the concern is based on the population at risk because of the threat of hurricane storm surge whereas other parts of the concern regard the quality of the natural and cultural environments. I worry about any and all development in the coastal zone that proceeds with the assumption that the system is static or that the dynamics are too difficult to model or too modest to accommodate within the planned modification of the environment. The coastal zone is very dynamic and is constantly undergoing change as a product of sea-level rise, sediment mobility, biotic processes, and cultural impacts. Sea-level rise is an especially important variable in low-lying coastal systems because it is altering the spatial associations of boundaries and is encroaching on all of the static elements within the purview of coastal development. Sea-level rise as determined by the Key West tide gauge (NOAA website) is modest, on the order of 1 inch per decade. In terms of the planning horizon of two decades, the slight rise in mean sea-level during this time would seem to be a minor item as indicated in the report (p. 21). However, the Keys are relatively

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A Review of the Florida Keys Carrying Capacity Study low and development has flattened much of the pre-existing topography. Thus, small elevational increases in storm surge levels caused by SLR could translate into sizeable horizontal excursions through the developed communities. SLR is encroaching on all of the static infrastructure in the Keys. Any item that incorporates elevation as a variable is being compromised and it, in turn, is affecting all related development, such as: road elevations, clearance under bridges, gravitational hydraulic head, storm sewer drainage, etc. Further applications of the SLR variable in the existing report would seem to be of importance in the establishment of categories of vulnerability to flood and to the creation of buffer zones separating development from biotic systems. In the case of the former situation, FIRM maps of the Federal Emergency Management Agency are used to rank exposure/suitability of land parcels to flood (X, AE, and VE categories in Table 3.1). Because FIRM maps are established relative to a base flood elevational datum, the application of SLR would cause the inundation lines to shift through time to accommodate the changing base. Indeed, if the existing FIRM maps are a decade or more old, their utilization and subsequent projection several decades hence is under-estimating the flood potential (as applied in the Smart Growth Scenario, Residential, p. 72). A second situation would apply to the horizontal dimensions of buffer zones separating development from protected habitats. If the protected habitat were wetland, for example, the wetland zone would shift spatially under the influence of SLR. The dimensional shift would be dependent on the slope of the adjacent land and the presence of obstacles. However, the net effect would be to reduce the dimensions of the buffer and compromise the intention of the buffer. Coastal zones are dynamic and subject to a range of natural and cultural processes. They are hazardous areas and will likely become more hazardous as SLR elevates the effects of any class-interval storm and as the natural protective buffers are removed or compromised by cultural development. Planning and management of the coastal zone should at least recognize the existence of this dynamic process, identify its effects within the system, and should have a long-range goal of reducing the population and infrastructure at risk in these hazardous environments. There are many pieces of the scenario development package presented in these pages. There are many data sets identified. However, there seems to be a paucity of conclusions that are determined from the application of the approach. We appreciate the comments regarding SLR. While the model may not able to detect such small, anticipated changes, SLR adds to environmental constraints of development in the Florida Keys. The paucity of conclusions evident in our report is due to the fact that our efforts to date have been focused on testing whether the model works. It is premature to put too much weight on results until we are satisfied with the workings of the model and its internal consistency.

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A Review of the Florida Keys Carrying Capacity Study GENERAL CONCERNS 1. The model seems to assume that the value of each coefficient remains constant regardless of changes in the population, available land, and other state variables. For example, the cost/house remains constant despite reductions in available land and increasing population and property values do not change with changes in the “quality of life” parameter. Is this correct, and if so, is there any evidence that such constancy is, in fact, observed with the growth levels anticipated of the Keys? Yes. This is commonly accepted practice when preparing land use forecasts in urban planning. See references in standard texts such as F. Stuart Chapin and Edward J. Kaiser, Urban Land Use Planning, 3rd Edition. Besides, the small amount of projected population growth expected in the Keys will significantly limit the amount that an average, or per capita, land use coefficient can be changed. See the expanded draft report on the socioeconomic module, “Documentation of Socioeconomic Module for the Florida Keys CCAM” (DO9) for a more complete description of these relationships. 2. The model does not seem to deal in much detail with visitors (seasonal, short-term or day trippers) except through projected demands for hotel rooms. For example, shouldn’t tourists contribute to the CCI? Another example is on p. 41 where it is stated that traffic on Rt. 1 is related to land use using national data, but how are projected changes in traffic due to changes in different tourist components handled? The database for tourists and other seasonal or temporary residents is of only marginal accuracy throughout Florida (and especially the Keys), and measurement of their impacts on local competitive advantage would have a large amount of uncertainty. There is no known reliable source of “day-tripper” data for the Florida Keys. The traffic calculations take into account observed traffic levels which, in turn, consider all traffic in the Keys, both residents and tourists. Monroe County uses “functional population” as the basis for planning— functional population is the average number of people in Keys on any given day. 3. On P. 43. Is evacuation time really a linear function of population? Wouldn’t it be some power function? We applied the most parsimonious approach.

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A Review of the Florida Keys Carrying Capacity Study 4. Please rationalize the population basis. It is incredible that the U.S. Census has come up with 19% more population than the Contractor team has established for the year 2000, and that the population estimates for the year 2020 that are the basis for the model are significantly less than the Census produces for Monroe County in 2000. Also, given the information presented on page 84, the contractor’s scenarios estimate significantly less “functional population” in 2020 than today. Please explain. In the model, permanent population is calculated in terms of number of households, people per household, and percent households occupied by permanent residents. We calculated the number of permanent residents for 2000 and compared the result to the Census result, which shows a difference of 19%. The land use database that served as the foundation for population estimates for 2000 was provided by the Monroe County Property Appraiser. The calculated population for Key West is significantly lower than that reported in the Census, and accounts for much of the 19% difference throughout the Keys. The discrepancy in Key West is being evaluated. The population calculated for the Smart Growth Scenario is lower because it is calculated on the same land use database. The model is consistent in that a small amount of growth led to a small increase in population. Once the discrepancy between the current conditions calculations and the Census count is resolved, the scenarios should fall into place as well. 5. Why does the draft model report not reflect the Scenario Development Guidelines produced in July 2001? Each of the two scenarios “Current” and “Smart Growth” should be preceded by a narrative that spells out their “vision.” The GUI and scenarios reflect the guidelines developed in July 2000. Both the GUI and the guidelines were sent to the NAS in mid-December. There is no vision associated with “current conditions.” Current conditions were run to check whether model results conform with known aspects of the Keys (see page 71 of the report). Attached at the end of this document, please find the “Smart Growth” scenario, as provided to us by the local planners. 6. What is the Current Conditions Scenario? Is it a portrait of existing conditions that would be maintained for a time till 2020? Practically no community can maintain “stable” demographic and economic conditions over such a long period of time, and there is plenty of experience to demonstrate that. This would be a totally unrealistic option over the period to 2020.

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A Review of the Florida Keys Carrying Capacity Study Current conditions were run only to test whether the model produced results that resembled observed conditions in the Keys. For example, this test helped us identify the discrepancy between observed (Census data) and calculated (model-based) population numbers discussed in Question 4 above. 7. Were other scenarios tested? No. 8. How do you treat “parking,” which for non-residential uses, is probably the largest source of impervious surfaces and one of the biggest contributors to stormwater runoff? A land use is designated for each developed and undeveloped parcel as part of the geo-spatial database of the CCAM. Imperviousness for each parcel is determined by a user manipulated look-up table in the Stormwater Component that assigns a runoff coefficient (c) to each of the defined land uses, and this coefficient value is consistent with Monroe County’s adopted Stormwater Management Master Plan (CDM, 2001). Parking lots are not treated as a separate component of the parcel, but are included as an aggregate component of the parcel. Consideration of parking lots has been factored into the runoff coefficient assigned to each land use. BACKGROUND AND LEGAL MANDATE 9. Do the Monroe County Comprehensive Plan sub-areas correspond with the Sanitary Wastewater and Stormwater Master Plan sub areas (p.7)? The numbered planning areas used in the CCAM have a one-to-one correspondence with the wastewater planning units identified in the Sanitary Wastewater and Stormwater Master Plan. The designated hotspots and focus areas are identified in the Wastewater Component by the same names. However, the sub-units of the numbered planning areas, called wastesheds in the Wastewater Component and catchments/watersheds in the Stormwater Component, have no equivalent in the Sanitary Wastewater and Stormwater Master Plan. SCENARIO GENERATOR 10. Explain how land use change is specified for a given spatial unit of analysis: Does the term “footprint,” as it is used in explaining the “type” of land use change (p. 22), refer to the footprint of a structural improvement on an individual property parcel? If not, to what does it refer?

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A Review of the Florida Keys Carrying Capacity Study The future land use pattern conveyed by a given scenario can be derived from the following sources of change: Conversion of vacant land to a new use (e.g., “new development”); Conversion of previously developed land to a different use (e.g., “redevelopment,” “restoration”); or Increased or decreased intensity of development in previously developed land, while maintaining the same use (e.g., “redevelopment,” “retrofitting”). The term “footprint” indicates the physical extent of development activities or land uses contemplated by an overall scenario or a particular scenario element. The term is used to define land use types for individual parcels, and not the structural improvement per se. 11. Can the “Scenario Type” only be set for one of the four options for a given wastewater planning unit: (1) new land development, (2) redevelopment, (3) restoration, or (4) retrofitting—or does the “Other (rubber band)” setting in the “Target Area” menu of the GUI allow different scenario types to be defined within a single planning unit for individual or multiple property parcels? The model only accounts for the four “types” of development, whether in a planning unit or a rubber-banded area. Within a planning area (or rubber-banded area), different sub-areas can be subjected to different development types. 12. Where are the following planning units (not shown on Figure 2.3): (1) Marathon Secondary, (2) PAED 22? Marathon secondary has been renamed to Key Colony Beach. PAED 22, a small unit located in northern Key Largo, is not labeled. This will be corrected in the final report. 13. Can you expand on the term “scarified”, p. 23 and p. 150 in the glossary? Does this mean any lot in a subdivision, whether it has been developed or not? The term is used in the same manner as is currently applied in the Monroe County Code. It refers to parcels that have been environmentally disturbed through the removal/clearing of native vegetation or through topographic modification.

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A Review of the Florida Keys Carrying Capacity Study 14. Can you give a more direct and clear description of “retrofitting” than is contained on p. 23? Retrofitting refers to improvements made to existing infrastructure systems (e.g., stormwater, wastewater, potable water, etc.) in order to bring them in line with modern practices, state-of-the-art technologies, and/or changing regulatory requirements. 15. Can someone clarify the statement regarding non-residential development on p. 25: “It was assumed that most types of nonresidential development will be attracted first to vacant land that is visually and functionally accessible to US 1.” I would quarrel strenuously with that statement. For the following reason: Any “vacant” land currently accessible to Route 1, especially given the long history of development in the Keys, probably has serious problems attached to it (environmentally or ownership). As a planner I would see the biggest attraction for non-residential development to occur in already-developed parcels that consist of obsolete or significantly undeveloped projects. Slipping something into currently “vacant” pieces would seem to be very difficult. No need to quarrel. Visibility from U.S. 1 has historically been a key consideration for nonresidential development in the Florida Keys. In addition to being adjacent to U.S. 1, it is assumed that the land most likely to be developed first for nonresidential uses will also be free of habitat and flood-related constraints. The suitability scale does not assume that development on a vacant parcel adjacent to U.S. 1 is preferable to a vacant parcel in the same situation, but that, among all vacant land available for nonresidential development, parcels that meet these three conditions would most likely be developed before others that do not. “Land Use change from conditions” input screens 16. What “conservation” and “open space” designations were used to classify otherwise vacant land as unavailable for development (p. 24)? The PC codes from the Monroe County Property Appraiser’s tax roll were used to identify which lands are in public ownership. However, we have recently become aware that these codes might also include parcels assigned for other land uses. In the final model these PC Codes will be checked against the (corrected) zoning data to avoid inaccuracies. 17. How does the wetland vegetation data used to classify otherwise vacant land as unavailable for development (p. 24) correspond to the classifica-

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A Review of the Florida Keys Carrying Capacity Study the median(?) in Appendix C (Table 4.4, p. 198). How were these values used? Mean values are used in the reporting of Event Mean Concentration (EMC) values per the protocols established by USEPA for the stormwater aspect of their NPDES Program. Use of the mean concentration values for pollutant concentrations is a standard practice in stormwater management programs. The 10th and 90th percentile values are not currently used in the computation of pollutant loads in stormwater runoff, but were included to allow the user to assess the uncertainty associated with the default values that have been used in the look-up table in the Stormwater Component. 130. P. 48. Rainfall. Monthly rainfall values were used to drive the stormwater runoff model, for average, wet, and dry years. These averages not only miss extremes (e.g., high intensity bursts during typical thunderstorm rainfall) but also ignore the variation inherent in a long-term rainfall record (e.g., sequences of wet and dry periods). Please justify the use of monthly averages over, at least, daily values (apparently available for the Keys), or better, hourly rainfall values. Why wasn’t continuous simulation used, since it could be employed even on a spreadsheet with the simple runoff and loading models used? If a sensitivity analysis or other comparative analysis was performed to justify the use of monthly averages, please show this. There is no list of stations used or other background presented in Appendix C. Please provide tables or other documentation of: Rainfall locations analyzed. Availability of hourly and daily data. Any statistical comparisons made. Any comparisons made using monthly averages vs. continuous simulation using daily or hourly values. The Project Team appreciates the significance of rainfall event variability and the importance of hourly rainfall in developing rainfall-runoff models and the significance in annual variability and cyclic rainfall patterns. However, the CCAM is not a conventional event simulation model that uses a fixed time-step and a series of specific simulation events to predict time variable flow, stage and pollutant flux values for specific locations. The Florida Keys has very little conventional drainage infrastructure and virtually no treatment facilities. Existing facilities are generally not mapped and no data is available on the actual discharge characteristics of stormwater runoff to the receiving waters. To a large extent, the anecdotal observation

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A Review of the Florida Keys Carrying Capacity Study that “whatever hits the Keys is in the near-shore waters 20 minutes later” tends to have high creditability. The CCAM was developed to consider normal seasonal effects in a quasi-steady state modeling environment, using available data, for planning purposes. Data limitations control the extent to which a detailed model can be developed. Time and budget constraints imposed upon CCAM development, coupled with limitations imposed by the size/scale of the model, its inter-module connectivity, and available computational/processing capacity, precluded the development of a more comprehensive simulation approach in CCAM, or the use of continuous simulation using daily or hourly values. Sensitivity analysis was not conducted as part of this work. Detailed station listings and rainfall data characteristics are presented in the Delivery Order-8 report. 131. P. 49. Atmospheric Deposition. Presumably any atmospheric deposition will be incorporated into “background” effects. Since atmospheric deposition may be expected to increase with increasing population around the Gulf, is there any basis for assessing the relative impact on marine waters (e.g., vs. stormwater, wastewater, groundwater loadings)? Atmospheric deposition has been treated in two different manners within the CCAM in the Stormwater and Marine Components of the Integrated Water Module: Atmospheric deposition was considered to be a component of the pollutant load washed off land surfaces, which was accounted for in the EMC values used for specific land uses. The runoff volume, with its attendant pollutant load, is routed to both the near-shore waters and groundwater system depending upon the impervious characteristics of the individual land uses. Atmospheric deposition was also included as an input source for the marine waters for selected pollutants. 132. P. 51. Computation of EMC Values. What are the ten communities from which data were used to estimate stormwater loads. What were the results of the uncertainty analysis? Detailed information on the communities that were used in developing the EMC values for the selected pollutants, as well the EMC values for the communities, are presented in the Delivery Order-8 report. 133. P. 51. Stormwater BMPs. Please present some additional explanation (in lieu of having the Monroe County Stormwater Master Plan) about

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A Review of the Florida Keys Carrying Capacity Study how conventional BMPs evaluated elsewhere in Florida are expected to perform in the geology of the Keys. How was expert opinion used in estimating BMP effectiveness (p. 110)? Who were the experts consulted? Detailed discussion of the rationale for adopting BMP performance characteristics from other Florida communities for use in the Florida Keys, as well as the performance characteristics, are presented in the Delivery Order-8 report. Eric Livingston of the Florida Department of Environmental Protection, and Scott McClelland of CDM (Monroe County’s stormwater consultant) were consulted with respect to the values and the potential issues arising from the surface materials and geology of the Keys. 134. P. 52. Pollutant Load Reductions. Are constant removal rates (load reductions) used regardless of incoming concentrations? There is some evidence (Strecker et al., 2001) that BMPs tend to produce a defined output concentration range regardless of the influent concentration. Was the ASCE-BMP database of any use here? (http://www.bmpdatabase.org/) Strecker, E.W., Quigley, M.M., Urbonas, B.R., Jones, J.E. and J.K. Clary (2001) Determining Urban Storm Water BMP Effectiveness. J. Water Re sources Planning and Management, Vol.127, No. 3, pp. 144-149. Constant load reductions are used in the Stormwater Component since the CCAM does not consider highly variable pollutant input concentrations and, consequently, has no provision for variable treatment efficiencies. The ASCE-BMP database was reviewed as part of this work to see if any Keys-specific data was available for any BMP—there was no data. Consequently, the BMP efficiencies from Monroe County’s adopted Stormwater Management Master Plan were utilized in the Stormwater Component. 135. P 54. Treatment Loads. How is the impact of cruise ships at Key West included in waste treatment loads? Is there any dumping problem from small craft in harbor areas? Is the small craft population included in EDUs? Increased wastewater loads associated with cruise ships in Key West were reviewed as part of this work. The Project Team concluded that, in the context of the CCAM, that there would be no appreciable impacts because the wastewater flows are intermittent, are treated in the Key West WWTP, and are relatively minimal in terms of flow and loading impacts on the WWTP. Perhaps the more important factor in the finding of no appreciable impact is the fact that the Key West WWTP discharges to a deep-well (2,000+

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A Review of the Florida Keys Carrying Capacity Study feet) disposal system and is idealized in the Groundwater Component as being “lost” forever with no return to the marine waters. No way of estimating equivalent EDU and assigning spatial coordinates, based upon the existing small craft population (approximate numbers only, no geo-spatial data), has been devised—despite a number of attempts—that the Project Team felt was viable and technically defensible. Consequently, wastewater flows associated with small craft are not included in the current version of the CCAM. 136, P. 56. Gross Pollutant Loads. There is some discussion of pathogens (e.g., bacteria) late in the report (p. 110) and in Appendix C (pp. 214+). It would seem like beach closing, violation of coliform standards, etc. are well-defined impacts of population growth, sewage discharges etc. Why is there not more attention paid to pathogens? Similarly, water quality in finger canals will likely be more objectionable to residents than in open coastal waters. Would this highly localized water quality result in some limit on growth, especially since finger canals are difficult to protect using stormwater BMPs? The Project Team is aware of several studies of pathogens and a number of beach closings related to pathogen concentrations. Unfortunately, the available data is not sufficient to document background conditions within the Florida Keys, develop a defensible GIS coverage, or support development of an algorithm for generation/decay and transport of human pathogens. Little detailed information is available concerning the depth and cross-section characteristics of canals, their flushing characteristics, or ambient water quality data. SECTION 3.6 137. P. 58. Dispersal Model. The model essentially predicts the concentration in a plume discharged perpendicular to the shore, well illustrated in Figure 4.7 (p. 91). What are Florida’s mixing zone regulations? How are comparisons made with the sampled data for N:P of Figs. 4.8–4.11? That is, how are the localized, individual plumes combined for comparisons of the type discussed on p. 92? The marine waters of the Florida Keys are designated as Outstanding Florida Waters. State regulations prohibit discharges that would increase the concentration of the pollutant over ambient levels. The main comparison we made was between the highest predicted concentration and ambient values recorded through the Water Quality Monitoring Program (EPA).

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A Review of the Florida Keys Carrying Capacity Study 138. P. 58. Dispersal Model. Is there any calibration or verification of the dispersal model? How was a choice of transverse dispersion coefficient (1 m2/s) made? Based on the data of Okubo, (1971) as reported by Fischer et al. (1979) and Chapra (1997) we estimated the horizontal turbulent diffusion coefficient was at the midrange of the coefficients characteristic of lakes and oceans. In the next several months we will program the look-up tables in the spatial simulation portions of the dispersal model with other values to evaluate the impact of using both lower and higher values on resulting water quality. However, so far the dilution effect of near-shore waters are the controlling variable. References; Chapra, S.C. 1997. Surface Water Quality Modeling. The McGraw-Hill Companies, New York. 844 p. Fischer, H.B., E.J. List, R.C.Y. Koh, J. Imberger, and N.H. Brooks. 1979. Mixing in Inland and Coastal Waters. Academic Press, New York. 483 p. Okubo, A. 1971. Oceanic Diffusion Diagrams. Deep Sea Research 18:789-802. 139. P. 59. Dispersal Model. If depth varies, velocity, u, will not be constant. In fact, would not a 2-dimensional formulation for velocity be more appropriate (using flow per unit width instead of velocities) if measured circulation patterns are used? Possibly. In our original formulation of the dispersal model we anticipated acquiring velocity data with a much higher spatial resolution than we actually were able to obtain. In light of this fact, we could have used the 2-dimensional formulation suggested. However, as dilution is the main controlling parameter in the determination of concentrations of nutrients and pollutants in the marine environment, the reformulation of velocity may not make much difference. We used depth and velocity data from independent sources. Depth was obtained from bathymetric maps, and velocities were extracted from existing effort to measure circulation patterns in the Florida Keys. 140. P. 59. Dispersal Model. The concentration decreases continuously with distance off shore. At what distance or location are predictions made for later comparisons with standards? Are concentrations from overlapping plumes combined? We compared concentrations at the highest point—immediately nearshore—against ambient data.

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A Review of the Florida Keys Carrying Capacity Study Concentrations from overlapping plumes are summed. Section 4 Test Scenario Results 141. General questions: A remarkable result of the Study is that water quality gets better as more growth occurs, due to use of better technology for stormwater management and wastewater disposal. How realistic is the assumption that 1) the technology will work, and 2) the technology will be implemented as proposed? Does the Smart Growth scenario assume that 100% of stormwater runoff, including highways, will be retrofitted and controlled? Similarly, will 100% of existing cesspits be upgraded? Apparently there is a 20-year time frame for implementation of the Smart Growth scenario. Will the schedule of implementation keep up with the forecast of population growth (so that the rate of population increase and its increase in loadings will not outpace the rate of improvements due to implementation of improved technology)? The model runs assumed that the technology will work and that it will be implemented as proposed in the Stormwater and Wastewater Master Plans. Master plans have a 20-yr implementation schedule. We will not comment on whether these assumptions are “realistic.” 142. P. 85. Hurricane Evacuation. The evacuation times with and without population increase seem highly optimistic (on the order of 27 hours). What provisions are available for the people unwilling or unable to leave during a hurricane? No provisions are made to account for people unwilling or unable to leave. 143. Pp. 85+. Apologies if this is explained clearly elsewhere, but how are the seasonal population changes and influx/efflux of tourists included in EDUs used to drive the wastewater loadings? Seasonal population variations—consisting of seasonal residents, tourists, and day trippers driving down from Miami—were taken into consideration by correlating FKAA water sales records for the Keys with the parcel database. As in Monroe County’s adopted Sanitary Wastes Master Plan, all the potable water provided to the Keys was converted into wastewater. Total EDUs represent approximately 185% of the permanent resident EDU, showing the significant loads imposed on the Keys by seasonal population.

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A Review of the Florida Keys Carrying Capacity Study 144. Pp. 87+. Several tables are presented of pollutant loads but they are separated for each component. Please present one or more tables with all loads by source (i.e., stormwater, wastewater, groundwater, etc.) so that an easier comparison can be made of the relative contributions of each. Do this for the current and proposed scenarios discussed, loading reductions by BMPs and treatment, etc. The idea is to be able to identify the most important sources and the most likely reductions. The pollutant loads developed, treated and routed in the CCAM are contained within temporary work tables that are manipulated through the GIS programming, but not saved as an output report. Due to our intent of returning comments to NAS within a short time, we cannot comply with this data management/reporting request. We will work on the development of an integrated load-tracking table after the issuance of these review comment responses that will provide a summary of pollutant load components for a representative catchment for both scenarios. We will bring this summary table to the interview session on January 17th and will be prepared to discuss its basis and contents. 145. Pp. 87+. Are there any loading tables for specific locations (e.g., Key West), that are contrary to the reduction in loads forecast for the overall Keys? Do the all-inclusive tables for the overall Keys hide any local problems? Is it safe to generalize the fairly optimistic loading scenario based on these overall tables? We are not sure what is being asked in this question. Loadings are developed for each catchment, and then aggregated to the level of the planning unit, and thence to the entire Study Area. It is possible that there may be one or more largely undeveloped catchments that, when fully developed in a scenario with whatever structural interventions are elected by the CCAM user, may show increased water quality impacts. We have not checked the current scenarios for this possibility. The “fairly optimistic” characterization of the reported loading scenario represents a value judgement on the part of the reviewer—the Project Team has made no judgment as to whether the loading scenario is optimistic, pessimistic or otherwise. We believe that it is a fair and accurate assessment of current loading conditions based upon available data. 146. Were there any comparisons of water model predictions (concentrations, loads, etc.) with monitored data, either on land or in the coastal zone? That is, are there any calibration or verification studies?

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A Review of the Florida Keys Carrying Capacity Study Besides the comparisons discussed above between calculated and observed concentrations, no other data exist to verify the loads. MARINE MODULE 147. Fishing pressure—appendix (pg 200) indicates that it will be treated graphically and not spatially in CCAM. However, I cannot find any mention of it in the actual text. As with other marine issues, insufficient data exist to “model” a relationship between “land development activities” and parameters such as prop scars and fishing pressure. We understand that many of these issues are management issues, not land development-dependent issues. Graphs of fishing pressure are shown in the report on pages 203–205. Additional graphs showing trends in Catch Per Unit Effort for all indicator species are shown in the errata for Appendix D, pages 3–4. 148. The Water Module serves as an input to the Marine module but the definitions of watershed areas are unclear as presented. They use watershed and catchment interchangeably but define only watershed in appendix (p. 153) and on pg 51 of the text. I have always viewed a catchment as smaller than a watershed and I think they should use only one, well-defined term throughout the document. Watersheds and catchments have been used interchangeably within the context of the Integrated Water Module. We agree that a catchment is a subset of a watershed. Having said this, each of the planning units could conceivably be defined in terms of two watersheds—The Florida Bay watershed containing those catchments that discharge to Florida Bay, and the Atlantic watershed containing those catchments that discharge to the Atlantic Ocean. However, given the relatively small size of the resulting watersheds, there is no particular benefit to creating watersheds for each planning unit. We will revise the discussion of the subunits in the Water Component to use the term catchment exclusively. 149. It appears to me that the issue of the lack of quantitative data relative to the issue of seagrass loss from propeller scars and fisheries species might still be used if the CCAM authors use only the segment of the relationship where it is linear. It is clear from Thayer et al. 1999 that seagrass density is related to fish density regardless of any non-linearities that might exist. That is, reduction of seagrass, regardless of species

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A Review of the Florida Keys Carrying Capacity Study composition changes, is quantitatively linked to fish density of canopy species. I think the CCAM authors should reconsider this omission. The CCAM authors should also examine Koenig and Coleman 1998 (Transactions of the American Fisheries Society 127:44–55) for similar data from Florida on seagrass density and density estimates of groupers and Sogard et al. 1987 (Marine Ecology Progress Series 40:25–39) for data from Florida Bay seagrass. The CCAM intends to determine the ability of the Florida Keys ecosystems to withstand all impacts of “additional land development activities”. Insufficient data exist to make a connection between land development and loss of seagrass. Another report within our study, prepared by Florida International University did not find a significant statistical relationship between developed areas and the distribution and composition of benthic communities within 1 km from shore. TERRESTRIAL MODULE 150. The CCAM apparently does not consider the key deer directly in the document. They indicate on pg. 68 that an ongoing HCP is underway and that the “Scenarios incorporate the findings of the HCP.” I cannot find where this has occurred and is a large and continual oversight of the CCAM. The Key Deer HCP is nearing completion. Monroe County has already committed to a moderate amount of development in Big Pine Key for the next 20 years. This is reflected in the definition of the Smart Growth Scenario. Any future scenario will incorporate the same amount of development in Big Pine Key. 151. The CCAM authors apparently did not consider our interim report document as we indicated that mangroves must be considered either as part of the marine or terrestrial sections. Mangroves on their own are important and as indicated in the terrestrial module, they are critical habitat for a number of species (Tables 3.15, 3.18, and 3.19) that the CCAM does address. Mangroves are being impacted and fragmented and must be incorporated into CCAM. Mangroves are included in the Terrestrial Module, just like any other habitat type. The smart growth scenario avoids development in mangroves, thus no impacts are detected.

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A Review of the Florida Keys Carrying Capacity Study Our historical vegetation study shows a 16% decrease in the total acreage of saltwater wetlands (including mangroves) and an increase of 74% in the number of saltwater wetland polygons from 1945 to 1995. Mangroves have been impacted and fragmented, but the smart growth scenario includes no additional impacts to mangroves. GENERAL ISSUES 152. There are a great number of misspellings, citations not found in Literature Cited (many!), incorrect (old) scientific names (pink shrimp, p. 200) and other editorial requirements that must be corrected prior to the final document. The document is also poorly organized. Results were pouring in to the last minute of report preparation. The report itself will be edited and improved as it is revised. 153. I think it would be very useful to have a table somewhere early in the document that organizes all data input and output by the “scale” of calculation. This would allow us to directly access these important data. Appendix C includes all look-up values, relationships, and thresholds used in the model. Smart Growth Scenario (as provided to us by the local planners) A Smart Growth initiative will be implemented in Monroe County to preserve the natural environment, redevelop blighted commercial and residential areas, remove barriers to innovative design concepts, reduce sprawl and direct future growth to appropriate infill areas. All CARL lands and any adjacent habitat areas will be closed to future development and purchases in an accelerated acquisition program, In sparsely developed areas, a one thousand (1000 ft. ) buffer will be designated around the boundary of the CARL/Habitat areas and any land within this boundary also designated for purchase. Infill will only be permitted on suitable parcels and will include those subdivisions, that are at least 75% (50%?) developed. The number of lots (maximum of 3,000) remaining in these subdivisions that are scarified will be permitted in a lottery system over the next 20 years. Scattered lands

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A Review of the Florida Keys Carrying Capacity Study within subdivisions that contain habitat or redflag wetlands will be purchased and a conservation easement placed on the lots to prevent future development. Ocean Reef and other subdivisions, that are vested will continue to build out on lots with habitat, but red flag wetland lots will not be filled and developed. In the Urban Residential District and the Suburban Commercial District in Key Largo/Tavernier, and from Stock Island to Big Coppit an additional 500 multi-family, affordable housing units will be developed on scarified lands at a density of 15 to 20 units per acre. Redevelopment of trailer parks and other substandard housing throughout the Keys will be at the existing density, above base flood, and with sanitary sewer. Twenty-five percent of the existing commercial stock will be redeveloped, resulting in improved stormwater management and landscaping. Infill sites for commercial development will be within 200 feet of existing commercially developed areas. A total of 700,000 square feet of commercial will be permitted over the next 20 years either in expansion of existing uses or in infill sites. Institutional uses will be deducted from the 700,000 square feet, although they will not have to compete for square footage. Fifty percent of the existing Industrial and Marine Industrial sites will be cleaned up and redeveloped with stormwater management and landscaping. Future uses will be of a more light industrial nature. All County owned buildings would be landscaped and retrofitted for stormwater management. Two additional Parks of 5–10 acres each will be developed in the lower Keys; one on Big Pine Key and one on Sugarloaf. With full implementation of the Overseas Heritage Trail and the Scenic Highway program, US#1 will be landscaped the full length. The stormwater management plan will be implemented on State and County roadways and for all new development. The sewer master plan will be fully implemented with the removal of all cesspits. An active program of water conservation will be instituted for existing development; the building code will assure new development conserves water.