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A Review of the Florida Keys Carrying Capacity Study (2002)

Chapter: Appendix D Detailed Comments and Questions

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Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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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).

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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  • 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.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×
  • 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.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×
  • 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.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×
  • 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

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

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.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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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.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

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.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

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?

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

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.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

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-

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

tion systems used by the US Army Corps of Engineers and the State of Florida to identify wetlands for which development would be prohibited?

All wetlands are unavailable for development unless the user chooses, in the GUI, to ignore current regulatory constraints regarding development in wetlands.

18. How are property parcels that are located in an A flood zone or V velocity zone for which no base flood elevation (BFE) has been specified included in a scenario? (Note that the keys to tables 3.1 and 3.2 (p. 26) indicate that the “AE” flood hazard area designation applies to all A-zones, not just those with BFEs, and the “VE” velocity zone applies to all areas with velocity hazards, not just those with BFEs.)

The model assumes that for all future development, compliance is required with current flood elevation regulations. The distinction with regard to “suitability” is based on consideration of both the flood hazard and additional cost related to mitigating that hazard. Therefore, land is considered most likely to be developed first where conditions would allow for the most cost-effective construction.

“Land use change to conditions” input screens

Vacant land

19. How do the density and intensity coefficients used to define development capacity of vacant land correspond to those in the current zoning code (i.e. in what ways have they been “adopted or adjusted”) (paragraph 5, p. 27)?

The density and intensity coefficients used come directly from current regulations contained in the Monroe County and City of Key West Land Development Regulations. The “adjustments” referred to were made in conjunction with the corrections to the data in the zoning field of the tax roll, which contained outdated zoning categories (old Code), typographical errors, or other shortcomings. For example, if a record showed the code “0S” (zero-S) under the zoning field, this was adjusted to “OS”, Offshore Island, and assigned the corresponding density allocation.

20. Is this done parcel by parcel using all of the existing zoning classifications? Or has there been some aggregation of zoning classes? If so,

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

please provide a table that compares the aggregate density and intensity coefficients with those for each of the subsumed zoning classes.

This is done parcel by parcel using the zoning data available in the tax roll. However, as explained in (19) above, some equivalencies were established only in cases where an outdated zoning category was shown in the database, or where a typographical error was found.

21. What is the extent of the inaccuracies in the zoning data set contained on the Tax Roll (paragraph #5, p. 28)? How much of an effort is required to make the needed corrections? Is such an effort beyond the scope of the current contract?

Data creation is out of the scope of the project but, corrections have been made, to the extent possible, using hard copy zoning maps for Monroe County, Key West, Layton, and Key Colony Beach. No zoning maps were available for Islamorada or Marathon, which have only recently undergone or are currently undergoing comprehensive plan and land development regulation processes. For these two “new” municipalities, County zoning designations were used, but can be modified/updated when the zoning is finalized.

22. If sewers are not currently available, is new development permitted under current zoning in some or all zoning districts?

Current zoning regulations specify the type of development, if any, that is permitted under each zoning district. The model, by using the density and intensity allowances from these regulations, takes existing constraints under consideration

Land suitable for redevelopment

23. What are the explicit criteria used to define land suitable for redevelopment (paragraph 4, p. 27)?

The criteria for selection of developed land suitable for redevelopment were identified in collaboration with, and in many cases recommended by, local planners, and include the following options that are shown in the GUI:

For Residential Redevelopment Activities:

  • Existing trailers/mobile homes

  • Waterfront parcels

  • Parcels <5,000 sq. ft.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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  • Structures older than 25 years

  • For Nonresidential Redevelopment Activities (Commercial/Industrial/ Institutional):

    • Parcels developed at <19% F.A.R

    • Structures assessed at <33% of the land value

    • Structures >20 years

    • Structures <1,200 sq. ft.

    24. Are these criteria applied within a given target area only where the target area is greater than the land area required to accomplish the specified amount of redevelopment? In other words, can a user specify a set of property parcels within a planning unit to which they want redevelopment to be applied and thereby define their own criteria for which parcels are to be redeveloped? Does this process apply to retrofit scenarios as well?

    One or more criteria can be selected by the user to “find” parcels meeting those criteria, or the user can specify a target “redevelopment” area (“Other”) within a planning unit.

    Development configuration

    25. How is the distinction between “cluster” or “spread” development operationalized in defining land use scenarios (paragraph #1, p. 23)?

    A clustered pattern of development may be generated by selecting blocks of “contiguous” parcels that meet other desired criterion or criteria (e.g., scarified, within a certain distance of U.S. 1; within platted subdivisions only, etc.).

    Residential input screen

    26. What is meant by the “per current condition” density setting—Does this invoke the density allowed under current zoning for every parcel in the target area?

    Yes, the “per current condition” option does invoke the density allowed under current zoning for parcels in the target area.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

27. How do the magnitude settings work? If the target area is an entire planning unit, where do the new dwelling units get assigned under each of the magnitude options: (1) number of dwelling units, (2) percent of selected parcels, (3) land area? How is “development suitability” (page 25) used in the allocation of new development? How is the assignment accomplished if the target area is a specified set of property parcels within a planning unit?

The dwelling units get assigned based on their suitability ranking. Those parcels with the highest suitability get developed first. Within suitability rankings, parcels are selected randomly.

28, How does the density setting interact with the magnitude setting (e.g., if the number of dwelling units specified under “Magnitude” exceeds the allowable density)?

The options in the Residential “Magnitude” screen are an “either/or” statement (i.e., the user can choose to specify the magnitude of development by total number of anticipated units), or by entering a fraction (percentage) of the total available land selected in the “Change from” screens for development, or by choosing a density allocation from among four options that include the current allowable density. This allows the input of scenarios that assume changes in the regulations to increase (or decrease) current densities.

29. Are the “single family residential detached,” “single family residential attached,” and “multifamily residential” settings mutually exclusive (i.e., is it possible to use the residential landuse change to conditions screen to set up all three types of residential land uses for a given target area)?

After careful consideration, these parameters have been subsequently removed from the GUI because the data currently available does not support their use in any of the model components.

Commercial input screen

30. How does one specify a scenario for build-out to maximum allowable commercial density and intensity under existing or modified land development regulations?

Such a build-out scenario would be specified by selecting for development, from the “Change from” screens: (a) all vacant land, (b) zoned for commercial use (other criteria could be specified to further constrain the universe of available commercial land, if so desired), and specifying, under

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

the “Change to” screens, the applicable floor area ratio (including current allowable).

31. How do the magnitude settings work? If the target area is an entire planning unit, where do the new commercial units get assigned under each of the magnitude options? How is the assignment accomplished if the target area is a specified set of property parcels within a planning unit?

Please see #27.

Restoration input screen

32. What is the data source for determining the historic vegetation type?

The data source is the DO7 historical vegetation map. Debbie Peterson (USACE) can provide a copy of the Historical Vegetation Mapping report.

33. What assumptions are made about habitat quality if a parcel/area is designated as “restored”? Is the parcel assumed to have the full complement of plant and animal species immediately? After some specified period of time? Is the parcel assumed to have the full complement of plant and animal species and adequate population sizes regardless of parcel size?

It is assumed that the parcel is restored to the natural state indicated by the historical vegetation map as an end-state condition, 20 years in the case of the CCAM.

Environmental interventions input screens

34. When will sewer infrastructure data be available for use as a criterion in defining available vacant land (paragraph #4, p. 28)?

Unknown.

Scenario Outputs

35. For which impact modules are outputs aggregated by land use category by planning unit (paragraph #1, p. 28) (i.e., land use changes are not defined at any greater level of geographic specificity than the planning unit)?

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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Land use change occurs at the parcel level; however, CCAM results are calculated and reported at the planning unit level.

Scenario Comparisons

36. Explain how “actual intensity of development” calculations (paragraph 3, p. 27) are used in comparing the two test scenarios. I don’t see such a comparison.

These comparisons are part of a series of pre-modeling checks to determine if the user defined scenario is realistic. The user has the option to modify the scenario based upon these checks or to proceed with the current selections. The actual intensity of development calculations were not compared in the test model.

SOCIOECONOMIC MODULE

37. An outcome of the Housing Affordability Index (Table 4.9) is the dichotomy between the economic status of the full-time residents and the part-time residents. This translates into future development being dependent upon investment from outside the area. How does this dichotomy drive changes in land use and impacts on the system?

Since a large proportion of the new development in all urban areas results from investment by “outsiders” who move into an area and create demands for new housing, commercial centers, community facilities, etc., this is not an unusual condition to be found in Monroe County. In the situation expressed in the Florida Keys, it is expected that affluent new residents will purchase the more expensive new housing while the less affluent will purchase older units of more moderate price. Again, the small amount of total population growth will result in a minimal change in land use pattern and individual neighborhood markets.

38. One of the main objectives in the socioeconomic section is to forecast “future land use demand” from an independent population projection. How does this fit with the rest of CCAM? Doesn’t the rest of the model begin with scenario driven land use decisions, which are then used to project population changes?

It is the control value to test the reasonableness of a scenario. See report entitled “Demographic and Economic Analysis of Alternative Development Scenarios in the Florida Keys.” (DO9) This report shows that the residential component of the Smart Growth Scenario IS consistent with independent

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

population projections, but the nonresidential components of this Scenario ARE NOT consistent with demographically driven land use demands for the Smart Growth Scenario.

39. In deriving the independent population projections, what is assumed about land/housing prices? Is “demand” a “demand curve” as economists would understand it or is it instead a prediction about the equilibrium of supply and demand? If it is the latter, what is assumed about “supply” ( i.e., what is assumed about local growth controls and land use policies)?

The demand is expressed in terms of an equilibrium relationship with supply. Both are related to the documented growth trends of the past decade under ROGO. This is a conservative approach that should be consistent with either a continuation of a ROGO-like regulatory system or a lessening of regulations in the future. When land use demands, such as those for hotels or multi-family projects, can be significantly constrained by growth management policies and ordinances, they are identified. See “Demographic and Economic Analysis of Alternative Development Scenarios in the Florida Keys” and “Housing Construction Rates and Prices in the Florida Keys” (both DO9 reports available from D. Peterson) for more detailed discussions of these phenomena.

40. The two IAVs from the socioeconomic module are the Competitive Commerce Index (CCI) and the Affordable Housing Index (AHI). Why wasn’t there an attempt to tie the socioeconomic measures to the results of the PIIP?

The results of the PIIP are tied to all model results through a comparison of model results to people’s ranking of environmental and socioeconomic concerns (Table 4.23, page 108).

41. For the CCI: of all of the socioeconomic measures that could be measured, why the CCI? Why is it so important? Given that it is measured, what is the population profile for which disposable income is calculated? Does it include tourists?

The CCI was used as a means of responding to strip commercial development and the phenomenon of linear trade areas discussed in the report entitled “Socioeconomic Environment of the Florida Keys.” (DO9). The primary purpose of a measure such as the CCI is to identify locations that have the strongest potential for concentrating and managing future commercial development that is consistent with both market conditions and

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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growth management objectives. Simply, the CCI measures indicate the most probable locations of continued commercial development, as well as those that have not expressed a strong trend for these activities in the past.

An income measure is not part of computing the CCI. Instead, retail sales per household or retail GFA per capita are normally used to estimate space demands from the existing resident population. Retail sales per household are derived from the latest Census of Retailing. Tourist expenditures are factored into this average.

42. For the AHI: how will you make predictions of future housing costs given various scenario assumptions? It is clear how the current AHI can be calculated given current data but not how to predict the AHI under various future conditions.

They will not be made. The purpose of the AHI is to identify the areas in which future housing development that is affordable by moderate-income households is more likely to take place. These locations are discussed in “Demographic and Economic Analysis of Alternative Development Scenarios in the Florida Keys” (DO9) in terms of potential residential locations for future labor force. Affordable prices for owner-occupied housing was used in this study because of the previously described difficulty in securing commitments for high percentages of the total County allocation of housing units in a single multi-family project.

These existing conditions, as expressed by the AHI, are considered to be reliable measures of the affordability of individual neighborhoods (Planning Areas). It is well established that residential areas with rapidly increasing housing values are part of the upward trend of a “neighborhood life cycle” and more expensive housing continues to be built within them. Conversely, neighborhoods that have become stable or started to decline in quality and value (but not blighted) will continue this trend and serve as the location for less affluent households. This is typically referred to as the “filter down effect.” Identification of these areas through the model indicates the opportunities for lower cost housing in the future.

43. How does the spatial resolution of the assumptions and analysis of the socioeconomic module fit with the spatial resolution in other modules?

The spatial resolution of socioeconomic and land use conditions is the same as in other modules. All results are aggregated to the planning unit level.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

44. Explain how the constraints imposed by ROGO would affect the time period over which the Smart Growth scenario would be effected (i.e., could it actually be accomplished in 20 years)?

The population required to support the residential component of Smart Growth is consistent with the independently generated 20-year population forecasts by the County and State. This indicates that this portion of the Smart Growth Scenario is achievable within the two decades if the population projections occur.

45. Can you tell us what are the coefficients for the socio-economic module in Table 3.3? There are some fairly acceptable national standards, and it would be good to see what these folks have come up with.

All socioeconomic coefficients for this module were developed from documented conditions in the Florida Keys. There was no need to use coefficients used in other areas or for different purposes.

46. Can you tell us what was the range of parameters that you used to test varying the scale of temporary population (p. 33)?

Yes, this was discussed in the report entitled “Housing Construction Rates and Prices in the Florida Keys” and in the report entitled “Socioeconomic Environment of the Florida Keys.” The seasonal population and functional population, including their bases, are discussed in both of these reports (DO9).

47. Can you share with us the factors that went into the presentations of Tables 3.4-6?

All factors are described in Appendix C. These tables exemplify calculations made in the CCAM.

FISCAL MODULE

48. To what extent does the totality of expenditures incorporate conducting these activities in a hazardous environment, as opposed to ordinary expenses of governmental operation?

The basis used for projecting expenditures were actual current and past year expenditures of the existing governmental entities located in Monroe County. Therefore, by definition, the expenditures are based on the costs of conducting governmental operations in Monroe County.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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49. Is there a factor, even among the unfunded liabilities, that tries to incorporate exposure and risk to hurricane damage as part of the cost of occupying the Keys?

Each of the Governmental Entity’s expenditures includes a risk management component that includes a higher cost (typically based on actual experience) of insurance in Monroe County (high hazard area).

50. Is there a planning option to move development and re-development to areas of lower risk (higher elevations and out of V-zones) to reduce expenditures?

Expenditures were projected based on continuing future governmental operations in the same manner as current operations.

51. There are references to the Monroe County Wastewater and Stormwater Master Plans, especially on p. 40. Can you tell us what these documents have recommended and how they change current conditions?

We understand the Government Study Team provided these documents to the NAS.

HUMAN INFRASTRUCTURE MODULE

52. Does hurricane evacuation take into account the low elevations along U.S. 1 and the effect of flooding on the capacity to handle traffic?

As with other parts of the model, we used State-mandated studies as reference. This includes the Hurricane Evacuation Study and the Stormwater and Wastewater Master Plans. No further assumptions were made on the Hurricane Evacuation component.

53. Would it be possible to relate the elevations of low portions of the highway to recurrence-interval storm flood levels and thereby provide some additional choices to the evacuation scenarios? If so, this same approach could incorporate the effects of SLR in adjusting the effects of recurrence-interval storms and relate the flooding frequencies to populations capable of being evacuated.

See response to Question 52 above.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

54. The discussions associated with the Fiscal Module and the Infrastructure Model in the Test Scenario Results are not well presented (pp. 81–85). There are inconsistencies within the text and the information included in Tables 4.10 and 4.12.

Results of the Fiscal Module are described correctly. Table 4.10 did not include a column to show the % change in current conditions when unfunded liabilities are included.

Table 4.12 is correct—the text associated with it should reflect the change in LOS for many of the planning units. This will be corrected in the revised version of the report.

INTEGRATED WATER MODULE

55. The stormwater runoff model seems to be run with monthly mean rainfall. Is this really correct? Since storm runoff is event driven (hourly-daily), please explain how long-term mean deposition rates can be used to estimate water or pollutant runoff or their impact on the marine module.

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 have 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. Consequently, the CCAM was developed to consider normal seasonal effects in a quasi-steady-state modeling environment, using available data, for planning purposes.

Pollutant discharges to the marine environment from discrete planning units are developed for a steady state—translated as a consistent rainfall input with a consistent discharge output. This approach is coupled with the Groundwater Module approach of a consistent daily discharge of pollutants to the halo zone to generate a continuous pollutant stream entering marine waters.

56. I was surprised to see desalinization excluded from consideration since it is already used in some Caribbean Islands. Have you really looked into this question?

No. This issue has been mentioned sparsely throughout the two years of the study. However, to our knowledge, no serious plans exist for desalination. Neither the Government Study Team, their panels of experts, other

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

State agencies, environmental organizations or the public have pursued this issue.

57. The description about watershed delineation using roads and canals is not at all clear. How did you do this?

Topographic definition in the Florida Keys is very limited, generally to a 5' and sometimes a 10' contour on available mapping. No additional topographic mapping was done for this study. During limited field visits the Project Team Field observed that the roadway system is typically one of the highest topographic features in the general terrain and it was used—in the absence of more accurate information—as “ridges” for the definition of the catchment areas used in CCAM. Similarly, canals provide a good basis for defining interior drainage patterns.

58. On p.52. Do pollutants from stormwater runoff that enter groundwater reach or not reach the marine module? The report seems to say that sewage that goes into groundwater does reach the coast, but runoff does not? The issue of monthly mean runoff estimates are problematic also.

The flow component (water volume) associated with the stormwater runoff that percolates into the groundwater system underlying the islands is discharged to the halo zone waters adjacent to the receiving water boundary of each catchment. The pollutants contained in the percolated runoff volume are numerically processed by the Groundwater Component, which provides treatment based upon a user manipulated look-up table that assigns a removal coefficient (% mass reduction) for each of the evaluated pollutants, and this coefficient value is consistent with available literature in the Florida Keys.

59. What are the assumed stormwater event mean concentration values used for each land use category (p. 51), and what are the sources upon which these values are based [need full citations]?

Stormwater event mean concentration values used in CCAM are based on an analysis of reported Florida EMC values. The specific EMC values, their variability and their sources are discussed in detail in the Stormwater Component section of the Delivery Order-8 Report.

60. What are the runoff coefficients used for each land use category (p. 51), and what are the sources upon which these values are based [need full citations]?

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

Stormwater runoff coefficient values for specific land uses that are used in CCAM are based on common drainage practices in Florida, and are consistent with the runoff coefficient values in Monroe County’s adopted Stormwater Management Master Plan (CDM, 2001). Specific runoff coefficient values are discussed in detail in the Stormwater Component section of the Delivery Order-8 Report.

61. What assumptions are made about percent impervious surface for different land uses?

Impervious area coefficient values for specific land uses that are used in CCAM are based on common drainage practices in Florida, and are consistent with the runoff coefficient values in Monroe County’s adopted Stormwater Management Master Plan (CDM, 2001). Specific runoff coefficient values are discussed in detail in the Stormwater Component section of the Delivery Order-8 Report.

62. Are these assumptions based on current land development regulations in Monroe County?

The EMC values and the runoff and impervious area coefficient values for specific land uses have been adopted by Monroe County and, based upon limited field visits by the Project Team, are believed to be generally consistent with current land development regulations. However, no detailed study was authorized to field verify runoff and impervious area coefficient values for specific land uses, or to correlate these values with parcels that have been developed in full compliance with current land development regulations.

63. Can these assumptions be modified to simulate the effects of modifying existing land development regulations governing amounts of allowable impervious surface?

Yes.

64. How are EMCs and runoff volumes for different land use types aggregated to calculate area-weighted total loadings within a watershed (p. 51)?

The GIS algorithm aggregates within the individual areas all parcels with like land use codes, to produce a temporary working table of total area by specific land use code.

  • Runoff volumes are calculated for each land use type by multiplying the runoff coefficient value for the land use by the total area of all

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

parcels of the land use type and then multiplying the resultant value by the rainfall depth. The runoff volume generated by each land use type is then summed to produce the total runoff volume generated in the catchment.

  • Pollutant loads are calculated for each land use type by multiplying the EMC value for the land use by the total runoff volume generated by all parcels of the land use type. The pollutant loads generated by each land use type are then summed to produce the total pollutant loads generated in the catchment.

65. Please provide a copy of the look-up table of storm water Best Management Practice (BMP) treatment performance plus formal citations to sources (p. 51). Are these based on actual system performance or on ideal design field tests or bench tests? Are they specifically based on comparable karst bedrock? If not, what were the soils/bedrock conditions for each literature value?

Virtually no structural stormwater BMPs exist in the Florida Keys and no Keys-specific test data has been identified during the development of the CCAM. Consequently, we utilized the BMP treatment performance characteristics from Monroe County’s adopted Stormwater Management Master Plan, which were generally derived from reported literature values from field tests. The look-up table for BMP treatment performance contained the Stormwater Component section of the Delivery Order-8 Report. The impact of karst bedrock on BMP performance was not specifically examined in this work, but may be indirectly reflected in the performance data developed in Florida communities that are underlain by karst formations.

Allocation of discharged storm water pollutant loads

66. How is the location of a parcel taken into consideration in assigning storm water discharges/loadings to surface waters versus ground water (p. 52)?

The catchments used in the CCAM are relatively small, and all catchments have a well-defined interface with the receiving waters. The relative location of a parcel within a given catchment is not considered in assigning stormwater discharges/loadings to surface waters versus groundwater. Consequently, all parcels of a specific land use type are assumed to have the same differential allocation of stormwater discharges/loadings to surface waters versus groundwater.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

67. Are parcel-specific or watershed-specific soils data used (p. 52)? It appears from paragraph #2, p. 53 that such data are not available.

The surface materials in the Florida Keys are not “soil” in the traditional sense, and do not generally function as soils do in terms of water storage or pollutant removal. Detailed soils data is not available in the Florida Keys. No attempt has been made to assign parcel-specific soils characteristics.

68, How do the following wastewater treatment technologies differ (Table 3.12, p. 54):

  • Secondary treatment

  • Advanced secondary treatment

  • Advanced wastewater treatment (AWT)

  • Best available technology (BAT)

The listed general wastewater treatment technologies and associated effluent characteristics standards in Table 3.12 are referenced from Monroe County’s adopted Sanitary Wastewater Master Plan (Master Plan). These treatment technologies and effluent characteristics were evaluated by URS, and subsequently adopted for use in the CCAM, to maintain uniformity with the Master Plan. It should also be noted that these effluent quality standards, set forth by the State, do not specify treatment technologies to be used. Rather, State standards specify effluent quality standards that must be achieved by the treatment process. The general established technology definitions or levels of treatment as defined in the adopted Master Plan are as follows:

  • Secondary Treatment: A biological treatment where organic material in the wastewater is stabilized via biochemical oxidation. Conventional activated-sludge is the most commonly used method of secondary treatment. The effluent characteristics associated with this treatment level listed in the Master Plan are BOD= 20 mg/l, TSS= 20 mg/ l, TN= 20 mg/l, TP= 5 mg/l.

  • Advanced Secondary Treatment: Typically a more robust biological treatment and including filtration and disinfection providing additional removal of nutrients (i.e., Nitrogen and Phosphorus). Defined in the Master Plan by the effluent characteristics of: BOD= 5 mg/l, TSS= 5 mg/l, TN= 10 mg/l, TP= 1 mg/l.

  • Advanced Wastewater Treatment (AWT): The term advanced wastewater treatment can have many definitions but typically refers to

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

any additional treatment process or systems required beyond conventional secondary treatment to further remove any constituents of concern. Commonly used treatment processes in advanced wastewater treatment to obtain a higher quality effluent include chemical coagulation, flocculation and sedimentation, activated carbon, ion exchange, microfiltration and reverse osmosis. The effluent characteristics listed in the Master Plan for this level of treatment are BOD= 5 mg/l, TSS= 5 mg/l, TN= 3 mg/l, TP= 1 mg/l.

  • Best Available Technology (BAT): Defined in the Master Plan by the effluent limitations of BOD= 10 mg/l, TSS= 10 mg/l, TN= 10 mg/l, TP= 1 mg/l. These statutory effluent standard limitations were set forth by the Florida legislature and are part of a compliance schedule for on-site and community wastewater facilities. The Master Plan recommends adopting BAT standards for Community Wastewater Systems less than or equal to 100,000 gpd and AWT standards for systems greater than 100,000 gallons per day (gpd). The Master Plan recommends On-site Wastewater Nutrient Reduction Systems (OWNRS) as BAT for on-site systems. For community wastewater treatment systems, advanced secondary or AWT would achieve the specified effluent quality standards.

69. What percent of EDUs are served by unknown wastewater treatment systems (p. 55)? Is this information available by planning unit?

The Master Plan, based on Department of Health records, estimates 23,000 private on-site systems exist in the Florida Keys. The Cesspool Identification and Elimination Program identified 7,200 as “unknown systems” and approximately one third of the unknown systems were confirmed as cesspools.

Records did not correlate wastewater treatment or EDU information with specific lots. Although the Master Plan estimates the distribution of total number of permitted systems, ATU’s and unknown systems in Monroe County and within planning units, it does not assign a specific type of wastewater treatment or EDU data to individual parcels. Approximately 80% of its database parcels were incomplete or labeled as “unknown system”. It is clear that 80% of the parcels in Monroe County are not cesspools or illegal systems.

Using the treatment type distribution per planning area in the Master Plan and best engineering practice, the Project Team assigned corresponding treatment systems to every parcel (nearly 80,000 parcels) in the database that was either incomplete (no treatment system designation) or labeled as “unknown system”. Distribution of the type of onsite system to individual parcels was made according to the numbers provided in the Master Plan and

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

per planning unit. As in the Master Plan, cesspools were assigned to the older buildings within the planning unit. Subsequently, EDUs were assigned to parcels using available lot information and water use records. The result of this exercise is that each EDU now has a designated treatment system designation within the database, allowing parcel level analysis of wastewater effluent discharge characteristics and loads.

70. Can you explain the comments in the final paragraph of page 51? If there are no significant BMPs in effect in Monroe County, what did you use to evaluate potential performance? I am particularly interested in local regulation to mandate pervious surfaces for parking lots/space, which might considerably reduce the stormwater management problem.

While there are no significant BMPs in effect in Monroe County, BMPs have been extensively implemented and investigated in other coastal communities in Florida, and BMP performance data has been used as the basis for evaluating potential benefits that might be achieved through retrofitting existing development and requiring effective stormwater management systems and BMP in new development and redevelopment.

Many parking lots in the Florida Keys are unpaved and visual observation of runoff from these unpaved lots indicates typically high level of suspended solids. A number of the demonstration projects proposed in the Stormwater Management Master Plan involve paving of unpaved parking areas at boat ramps. The approach is intended to reduce surface erosion and subsequent transport of the solids into the near-shore waters.

TERRESTRIAL MODULE

71. The decay coefficients in Table 3.17 seem rather arbitrary and are attributed only to Mark Brown as personal communication. Are there any data to support them? If I compare the distance required to reduce the habitat degradation index to 10% of its max. value, the distances seem very short compared with the “impact distances” summarized in Table 3.16. For example, low density residential would drop to 10% in just 38 ft and even a four lane highway or industry would go to 10% in 230 ft while the Spackman and Hughes citation reports a buffer requirement of 490–575 ft for 90–95% of bird species. Perhaps the use of relatively rapid decay coefficients leads to the very modest habitat impacts the model calculates.

The K coefficients are based on the empower density (emergy per time per unit area) and the assumption of a negative exponential decay of empower away from its source to background empower densities. Emergy is

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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Table 3.17 Decay Coefficients by Land Use Type

Land Use Type

Empower Density1 (sej/m2*yr-1)

K Value

Distance to Reduce Impacts to 10%

Low density residential

8.5E+12

0.0645882

35.5

Medium density residential

2.19E+13

0.0250685

92

High density residential

5.49E+13

0.0100000

230

Low intensity commercial

2.88E+13

0.0190625

121

High intensity commercial

3.27E+13

0.0167890

137

Industrial

5.01E+13

0.0109581

210

2-lane highway

3.08E+13

0.0178247

129

4-lane highway

5.02E+13

0.0109363

211

Recreational/Open space

8.3E+12

0.0661446

35

1Empower is Emergy per unit time per unit area. Emergy is quality corrected energy; units are solar emergy joules (abbreviated sej).

quality corrected energy expressed as solar emergy joules (sej). Empower is emergy per time (sej/time) and empower density is emergy per time per unit area (sej/m2*yr-1).

The decay coefficients in Table 3.17 in the report were actually carried to 7 significant figures, but for simplicity, rounded off to 2 significant figures in the report, thus the differences in the table below compared to the one in the report. The table below has empower density for each of the land uses. These data are based on studies of urban land uses in Ft. Myers and Gainesville, FL (Brown 1980) Jacksonville, FL (Whitfield, 1994) and additional studies of urban land uses in Gainesville, FL in 1999 (Brown, M.T.; unpublished) The work on empower density and Landscape Development Intensity index of urban land uses is ongoing (Brown et al 1998 and Brown and Tighe, 1989) and we recently have written a working paper describing the LDI (Brown, et al 2002)

The distances described in Table 3.16 range from a modest 25 feet to a maximum of 1,640 feet. These are distances based on a variety of factors and include home ranges, flushing distances, and so forth. Our use of the concept of a relative habitat degradation index was based on loss of habitat values not on home range data or flushing distance. We estimated our decay coefficients based the empower density decay such that the distance where degradation was zero corresponded to the point where the empower density that resulted from a “development source” was equivalent to the empower density of the surrounding natural environment.

References for these data are as follows:

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

Brown, M.T. 1980. Energy basis for hierarchies in urban and regional systems. Ph.D. dissertation, Department of Environmental Engineering Sciences, University of Florida, Gainesville

Brown, M.T. B Vivas, and J. Kasbar. 2002. Landscape Development Intensity Index: a quantitative measure for assessing cumulative impacts of development. Working Paper 02–01. Center for Wetlands, University of Florida, Gainesville. 8 pp

Brown, M.T. , N. Parker, and A. Foley. 1998. Spatial Modeling of Landscape Development Intensity & Water Quality in the St. Marks River Watershed. Final Report to Florida Department of Environmental Protection,. Center for Wetlands, University of Florida, Gainesville 143 pp

Brown, M. T., and R. Tighe. 1989. A Florida Pilot Study for the Evaluation of Created and Restored Wetlands. Final Report to the U.S. Environmental Protection Agency. Center for Wetlands, University of Florida, Gainesville. 51 pp.

Whitfield, D.F. 1994. Energy Basis for Urban Land Use Patterns in Jacksonville, FL. MA Thesis. Department of Landscape Architecture, University of Florida. Gainesville. 259 p.

72. I was not able to ascertain whether the variable of minimum patch size was incorporated in the test scenario results. Does the change of habitat for the seven faunal species (Table 4.22) mean that there are more areas with minimum patch sizes? The text indicates (pp. 97–98) that hammocks smaller than 13 acres are “all edge.” Does the “all edge” classification affect the suitability of habitat for any of the species of concern?

The CCAM evaluates habitat-based variables and species-based variables. Patch size, as discussed in Section 4.2.7, pages 97-98, refers only to habitat. Results show upland habitat fragmentation, and a significantly high proportion of small patches. In the Conclusions (Sect. 5.2, page 110), we state that, because of small patch sizes, “. . . ecological function in upland areas may be depressed in the Florida Keys.”

73, Equation on page 67, is “d” in feet or meters?

d” is the distance from the developed area in feet.

74, Equation on page 68 not clear to me—needs clarification.

The equation should read:

Species Richness Index (including indirect impacts) =

The equation calculates the average number of species per cell, reduced by its % degradation per cell.

75. On page 107, the “Forest Interior Bird” results don’t make sense— clarify—either text is incorrect or Table 4.22 is incorrect.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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Results will be re-run for verification.

76. Also re: page 107—what percentage of the acres of “vacant land’ were in ADID categories used for the Forest Interior Bird habitat use calculations? Can this be broken down by locations? Put results in a table?

This will be included in the revised report.

77. Confusion re: conclusions . . . on page 110 in Section 5.2 it says “The test run of the current conditions scenario show a severe loss of upland habitats in the Florida Keys, as well as further impacts through secondary effects of development. The current distribution of upland habitat patch sizes, in which the vast majority of the patches are small, suggests that ecological functions in upland habitats may be depressed throughout the Florida Keys.” . . . But, in Section 4.2.7 for the results of the Smart Growth run, results indicate either “minimal” or “negligible” change from the current conditions run for the Habitat Impacts element and for the Species Richness elements in this module. The Marsh Rabbit shows a 3.5% reduction in habitat, and there appears to be habitat loss for the White Crowned Pigeon, but the model says nothing more about these levels of change. (The results for the Forest Interior birds were confusing and need clarification, see # 4 above). . . . One would think there would be more than a “negligible” or “minimal” effect with additional growth of 10.2%. If the difference is in the reclassification of vacant lands to habitat as ‘open space,” it is not made clear. If current conditions are so bad that the additional changes with Smart Growth simply can’t make it much worse, then that should be said clearly. Otherwise, if the module can’t pick up a difference it may need to be modified to be more sensitive to such a level of change?

“Severe loss” refers to the loss accrued from historical conditions to current conditions. The additional habitat loss and fragmentation from current conditions to smart growth is small. The small effect of smart growth, despite a 10.2% additional growth, reflects the “smartness” of the scenario in selecting mainly low quality, infill lots for new development.

78. The Land use module does a good job of summarizing results in tables and I’d like to see that used in the Terrestrial Module more effectively. For example, since the majority of population increase in the Smart Growth scenario is on specific locations (e.g., Ocean Reef/PAED 21, Plantation Key, etc.). It would have been very useful to see the relative impacts of the scenario on these specific sites in a tabular form (before and after).

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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Results will be presented by planning unit in the revised report.

Disturbed habitat

79. What criteria are used to define a property parcel as a “disturbed habitat area”—the presence of any exotics or some minimum percent cover of exotics?

The “exotics” ADID classification is used to determine the disturbed habitat portion of a parcel. Only those areas classified as “exotics” in the ADID dataset were defined as disturbed.

80. What is the data source for determining the presence of exotics?

The ADID GIS layer from the Florida Marine Research Institute.

Environmentally sensitive areas

81. What criteria are used to define a property parcel as an “environmentally sensitive area”?

Any of the wetland vegetation types from the ADID data.

82. What is the data source for defining environmentally sensitive areas?

The Florida Marine Research Institute’s Advanced Identification of Wetlands GIS layer.

Undisturbed habitat

83, What criteria are used to define “at least 10 acres of contiguous undisturbed habitat”? Must the 10 acres be within a single property parcel, or can the 10 acres be constructed by aggregating multiple property parcels?

This criterion is based on current Monroe County regulations related to vegetative community connectivity. The 10 acres can be aggregated from areas of undisturbed habitat on multiple, contiguous parcels.

84. What vegetative cover types are used to define “undisturbed habitat”?

Any ADID vegetation type other than “developed” or “exotic.”

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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85. What is the data source for defining undisturbed habitat?

The Florida Marine Research Institute’s Advanced Identification of Wetlands GIS layer.

86. Has any use been made of the State Game and Freshwater Fish Commission’s 1994 report, “Closing the GAPs,” to identify important habitat areas?

We used the updated (2000) version of the study extensively. We used their methods to develop habitat models for seven species. The habitat richness map and index were created using their approach and species selected from their study.

QUALITY OF LIFE

87. The quality of life section is so vague that I have no idea how it was developed and calculated. Can you give us a better description of this component? For example, how were the values in Table 3.21 calculated and how were they used “to help determine the components of each module, and the end points . . . quality of life issues.”? (p. 70).

The PIIP (prepared by another contractor) describes the methods by which the seventeen criteria or parameters were ranked. In the test CCAM, we looked at the sign (+ or -) of the change in each parameter based on the results of the model.

We understand the PIIP has been provided to the NAS.

SCENARIO SELECTION PROCESS

88. What are the implications of changing a land use category to “open space” (Table 4.1, p. 73)? Does this preclude future development of all kinds? Does it require public acquisition?

The underlying assumption is that public acquisition is involved, and that these lands would be preserved for conservation (i.e., undeveloped) in perpetuity.

89. What is a “red flag” wetland (Table 4.1, p. 73)

Definition taken from the Florida Keys Advance Identification of Wetlands (ADID) Project Technical Summary Document, 1998: “Red flag wetlands were those that clearly exhibited a high level of integrity in community

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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structure, size, landscape position and other features.” Monroe County has imposed strict limits for development in these wetlands.

90. How are lands listed for CARL acquisition treated?

For the Smart Growth scenario, all vacant land (according to the parcel data) within a CARL boundary were selected and converted to open space, with the exception of Ocean Reef Club.

91. Explain the extent to which the “Smart Growth” scenario differs from a scenario that would represent build-out in conformance with the current future land use element of the Monroe County comprehensive plan and applicable land development regulations.

The “Smart Growth” scenario, developed by local planners, assumes extensive public acquisition of vacant land for conservation purposes and a heavy emphasis on redevelopment and infill, which local regulations have not explicitly or particularly favored until recently. Therefore, a build-out scenario would result in significant additional growth as compared to smart growth.

Publicly owned conservation areas

92. What criteria are used to define these—CARL lands already acquired?

The PC Code, in conjunction with both ownership and zoning data in the Taxroll, was used to identify publicly owned conservation areas.

93. What assumptions are made about habitat type and quality of these areas?

No assumptions are made about the habitat type or quality of the publicly owned areas. Information regarding the habitat type for a particular area is derived from the ADID dataset in the terrestrial module.

Subdivisions

94. Is the percent of subdivision development based on the number of individual parcels developed or on the percent of allowable density that has been built?

The percentage is calculated from the number of parcels developed within the subdivision.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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95. When a partially developed subdivision is included as “vacant land” is it only the vacant portion of the subdivision that is included in the scenario?

Yes, only vacant lands become developed.

96. How are property parcels that are more than 300 feet from US 1 included in a scenario?

Proximity to US 1 is used as a suitability criterion and as an option in the GUI. Regarding the suitability analysis, vacant parcels close or adjacent to US 1 are more suitable for commercial development than those that are not. The final model will have a GUI option allowing the user to choose parcels without regard to distance from US 1.

Residential land use input screen

97. Why are parcels < 5000 sq. ft. considered substandard (Table 4.1, p. 73)?

See response to (23) above. In order to input the Smart Growth scenario into the model, the team had to interpret to some extent the use of the term “substandard,” the criteria for consideration were primarily suggested by the local planners.

98. Why are structures < 1200 sq. ft. considered substandard (Table 4.1, p. 73)?

See response to (23) and (97) above.

99. How are structures 5 years old or less included in a scenario?

Structures less than 5 years old would generally be considered less likely candidates for redevelopment. Such structures would be included in the scenario by not checking the option to select land according to age of structure. The final model will have a GUI option to disregard the age of structure in the residential change from conditions.

Commercial land use input screen

100. How are structures 20 years old or less included in a scenario?

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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The age of the structure is only a factor in a redevelopment scenario. This criterion was recommended to the contractor for redevelopment scenarios by local planners, based upon their experience in the Florida Keys. If warranted, alternatives to the age of structure may be added to the GUI in the final model.

101. Why are commercial parcels developed at < 19% FAR considered “blighted” (Table 4.1, p. 73)?

The under-development/under-utilization criterion is not used by itself in this scenario to indicate blight, but as one of several conditions, which together constitute substandard conditions or likely candidates for redevelopment.

102. Why are commercial structures assessed at < 33% of the land value considered “blighted” (Table 4.1, p. 73)?

See response to 101.

103. Why are commercial structures > 20 years old considered “blighted” (Table 4.1, p. 73)?

See response to 101.

104. Why are commercial structures < 1200 sq. ft. considered “blighted” (Table 4.1, p. 73)?

See response to 101.

Parameter settings for the two scenarios presented in the draft report

105. How was the “Current Conditions” scenario defined?

The PC code from the current Monroe County Property Appraiser’s Office was used to define current conditions land use.

106. Were existing land uses assigned parcel by parcel?

Yes, using the PC code from the Monroe County Property Appraiser’s tax roll.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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107. How was the “Smart Growth” scenario defined?

The “Smart Growth” scenario was developed by the local planners after a series of working sessions with the study team. The scenario was discussed at this workshop with the other local planners, who agreed it was one plausible vision for the future development of the Florida Keys.

108. How was vacant land defined for this scenario?

Vacant lands are all lands with a tax roll PC code of 00, 10, 40, or 70.

109. What is meant by “habitat lands” in the section entitled “Maximum protection of conservation lands” (pp. 71–72) and by “habitat polygons” in Table 4.1 (p. 73)?

Habitat lands include all areas with upland or wetland vegetation cover. This does not include exotics.

110. How were the new park sites selected on Big Pine and Sugarloaf Keys (p. 72)?

It is assumed that the conversion of vacant land to open space will result in the creation of the parks.

111. How were the 3,000 dwelling units allocated to subdivisions with 75% or greater development to simulate “a random lottery system” (p. 72 and Table 4.1, p. 73)?

The queries to find parcels that met these criteria resulted in less than 3,000 units. Therefore, all of those parcels were developed in this scenario. Otherwise, the units are allocated based on the parcel’s suitability for development.

112. What type of residential development is assumed to occur under “current zoning restrictions” in redeveloped trailer parks and on substandard residential lots (p. 72 and Table 4.1, p. 73)?

The smart growth scenario referred to substandard structures, not necessarily substandard lots. The replacement development complies with the current zoning.

113. How was commercial redevelopment assigned to 25% of the “blighted” commercial parcels among the planning units (p. 72)?

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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The commercial redevelopment criteria resulted in a very small number of eligible parcels to be redeveloped. Therefore, all parcels that met the criteria were redeveloped in this scenario.

114. How did the redeveloped commercial use differ from the existing use besides application of default stormwater and wastewater management— maximum allowable FAR? (Table 4.1, p. 73)?

Yes, maximum FAR and stormwater and wastewater treatment.

115. How was the 700,000 square feet of new/expanded commercial development allocated among the planning units, i.e., if all other conditions are equal, how is it decided in which planning unit to place a given amount of new commercial development? (p. 72 and Table 4.1, p. 73)

The commercial development element of the smart growth scenario provided specific criteria that defined the selection of the vacant commercial lands. These criteria provide the constraints for available land in each planning unit. Parcels are chosen randomly from within this selected set for each planning unit.

116. What methods of stormwater management for existing industrial and marine sites and county owned buildings are considered to be “consistent with current regulations” (p. 72)? How realistic are these for existing development retrofits, e.g., is there land available upon which to construct the systems?

A variety of structural and non-structural BMPs have been implemented in other coastal communities in Florida to treat stormwater originating from existing industrial and marine sites and county owned buildings, and there is no reason to believe that these BMPs would not perform equally well in the Florida Keys. Some of the potentially implementable controls include:

Structural Controls

Non-Structural Controls

Perimeter Swales

Porous Pavement

Contained Constructed Wetland Systems

Periodic Sweeping

Detention Ponds with Skimmers

 

Retention Ponds with Skimmers

 

Pre-Treatment Ponds Connected to Wetlands

 

Sedimentation Vaults

 

Treatment Vaults

 

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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In the general scheme of overall environmental management in the Florida Keys, we believe that these controls are realistic for existing development retrofits. Several of the demonstration projects proposed in the Stormwater Management Master Plan involve retrofitting existing areas and illustrate that water quality management can be achieved at reasonable costs.

117. How were the blighted individual industrial and marine sites selected to accomplish the specified 50% retrofitting, i.e., how was it decided which of the blighted sites should be retrofitted (Table 4.1, p. 73)?

Due to the small number of parcels meeting these criteria, all areas that met the blighted industrial and marine sites were selected.

118. What form of landscaping is assumed for retrofitted industrial and marine sites, county owned buildings, and US 1 (p. 72)?

The use of maintained landscaped area—essentially a shallow intermittent pond area—for attenuating and treating stormwater runoff relies upon two design concepts:

  • Depression Storage is used to attenuate flows to reduce discharge rates and allow sedimentation to reduce suspended solids concentrations prior to discharge to receiving waters.

  • Planted areas in dry ponds, preferably sod in the central portions of the depression areas, can provide limited benefits in terms of reduction of fine solids, fixation of metals, sorption of oils/greases on vegetative surfaces, and bio-fixation of nutrients.

The surficial deposits and underlying geology of most of the Florida Keys prevent the maintenance of a wet pond system, thereby generally precluding the use of a littoral shelf. Similarly, the lack of real “soils” also precludes filtration of finer particles and binding of metals in the soils matrix, which benefits much of the peninsular portion of the State.

119. What specific stormwater management techniques are assumed to be used as a result of implementing the Stormwater Master Plan for all state and county highways and new developments (pp. 72, 86)?

The Stormwater Management Master Plan suggests that the retrofitting process be accomplished through a large number of small projects over a continuing long-term implementation process. Specific management techniques are discussed in some detail in the Stormwater Management Master Plan

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

The demonstration projects discussed in the Stormwater Management Master Plan generally focus on retrofitting existing areas, but the techniques can be used equally well in new development and redevelopment, often at lower overall costs, and illustrate that water quality management can be achieved at reasonable costs.

120. What are the “default” stormwater treatment methods referred to in Table 4.1 (p. 73)?

On-site retention of stormwaters.

121. What are the “default” wastewater treatment methods referred to in Table 4.1 (p. 73)?

The treatment methods referenced to as “default” in Table 4.1 of the Delivery Order-11 draft report are the treatment methods and standards recommended for implementation in Monroe County’s adopted Master Plan. The Master Plan specifies treatment levels according to the existing/proposed WWTP’s location and size.

122. Which “default” wastewater management technology is assumed to be used in place of existing cesspits (p. 72 and Table 4.1, p. 74)?

The “default” wastewater management technology the Wastewater Component uses to replace existing on-site systems located in lower density areas of the Keys is the On-site Nutrient Reduction Systems (OWNRS) as prescribed in the adopted Master Plan.

123. What other wastewater management changes are assumed to be accomplished through “full implementation” of the Wastewater Master Plan (p. 72)? Are these the changes summarized on p. 86? If so, why are some upgraded existing and new WWTPs assumed to be BAT versus AWT?

Other changes that are incorporated in the Wastewater Component include the following “upgrades” recommended in the County’s Master Plan:

  • Existing on-site systems located in lower density areas of the Keys be replaced or upgraded with On-site Nutrient Reduction Systems (OWNRS).

  • Development of “community” wastewater collection and treatment systems for 12 specific service areas

  • Development of “regional” wastewater collection and treatment systems for 5 specific service areas

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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  • WWTPs with design flows less than or equal to 100,000 gpd are converted to systems that will achieve BAT standards for effluent discharges

  • WWTPs with design flows greater than 100,000 gpd are converted to treatment systems that will achieve AWT treatment standards for effluent discharges

124. How do assumptions about water conservation affect scenario outputs (p. 72)?—Reduced wastewater loadings? Other impacts?

Implementation of water conservation measures are directly factored into the consumption rates for EDUs, which in turn produce reductions in accumulated flows by planning unit which impacts aggregate demand, thereby eliminating/delaying expansion of wellfield and water treatment capacities. Similarly, the reduction in potable water demands at the planning unit level directly reduces the cumulative flow rates in the FKAA pipeline, thereby eliminating/delaying expansion of supply pipeline and pumping capacities.

In a parallel consideration, reduction of potable water flow will reduce wastewater generation rates. Water conservation measures are expected to occur in the form of more efficient toilets and low-flow showerheads, which reduces the volume of wastewater but tends to increase the concentration of pollutants. We anticipate that water conservation measures should have virtually no effect upon the net pollutant load.

TEST SCENARIO RESULTS

125. I am confused about Table 4.12. This table compares LOS along Rt. 1 under current conditions and with the smart growth scenario. The last sentence on p. 84 concludes that “The LOS remains unchanged in the Smart Growth scenario for all planning units except Plantation Key.” However, it seems to me that 21 out of 26 units show a decline in LOS between current conditions and smart growth. And Plantation Key drops from C to F, not D to F as stated in the text. What am I missing? This point comes up again on p. 85, Part 2, because LOS interacts with hurricane evacuation and you have assumed no change in LOS despite the fact that Table 4.12 seems to show a large number of declines, some quite severe (e.g., Upper Matecumbe goes from A to D).

These results came out of the computer late in the document production process and the text was not edited to reflect the corrected results. The table is correct. The text is not.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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126. How do you relate the Test Scenario Results on page 74, which indicate there is an increase in non-residential development of 550 acres under the smart growth scenario and 5.9 million sq. ft. on p. 78, with the narrative on p 72 that only 700,000 sq. ft. will be permitted on vacant land and effectively no increase in redeveloped lands?

In our continuing efforts to test the model, we found that an incorrect selection statement was made in the smart growth scenario, by which all vacant non-residential lots were selected for development.

127. How is it possible (p. 74) that “Vacant land residential is the second largest land use” in the Smart Growth scenario?

The smart growth scenario resulted in very little development throughout the Keys; therefore, leaving many of the vacant parcels undeveloped.

128. On p. 81, the Housing Affordability Index discussion indicates that most of the planning areas have income levels well below what will be needed to purchase housing. That’s important, but how relevant is this to likely economic conditions of the Keys? If there is an emphasis on tourism and hotel employment, workers in those industries (who are essential and may well be transient) are unlikely to consider buying property. Beyond housing purchase, what is the situation regarding the affordability of renting apartments and houses, and are there any initiatives on the part of the hotel industry to provide housing for their workers?

The primary purpose of the Housing Affordability Index is to identify potential locations for housing that is affordable by moderate-income households.

ADDITIONAL CCAM QUESTIONS 1/2/02

These questions deal almost exclusively with the Integrated Water Model.

SECTION 3.5

129. P. 45. Use of Central Values. Does this imply that the median concentration, etc., has been used? Or is the mean used? Although it would not seem reasonable to take the maximum or a high percentile from such a range, neither does use of the median or mean seem like a very conservative assumption. The 10th and 90th percentiles are listed along with

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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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:

  1. Rainfall locations analyzed.

  2. Availability of hourly and daily data.

  3. Any statistical comparisons made.

  4. 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

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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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

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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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+

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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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).

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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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.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

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.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

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?

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

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

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

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.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

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

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
×

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.

Suggested Citation:"Appendix D Detailed Comments and Questions." National Research Council. 2002. A Review of the Florida Keys Carrying Capacity Study. Washington, DC: The National Academies Press. doi: 10.17226/10316.
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A Review of the Florida Keys Carrying Capacity Study Get This Book
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Nearly thirty years ago the Florida Keys were designated as an Area of Critical State Concern. The state recognized that Monroe County contained many valuable natural, environmental, historical, and economic resources that required thoughtful management. In 1996, as a result of many years of discussion, negotiation, and litigation, the Florida Administration Commission issued an Executive Order requiring the preparation of a "carrying capacity analysis" for the Florida Keys. To fulfill this requirement, the U.S. Army Corps of Engineers and the Florida Department of Community Affairs jointly sponsored the Florida Keys Carrying Capacity Study (FKCCS). The key component of this study is a carrying capacity analysis model (CCAM) that provides a technical tool for state and local jurisdictions to "determine the ability of the Florida Keys ecosystem, and the various segments thereof, to withstand all impacts of additional land development activities."

This National Research Council (NRC) report provides a critical review of the Florida Keys Carrying Capacity Study: Test Carrying Capacity Analysis Model, First Draft, hereafter referred to as the Draft CCAM. This independent review offers critical commentary in order to assist the sponsors and contractors in making final adjustments to their report and the Carrying Capacity Analysis Model.

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