PLANNING ANALYSIS
Recently released 2019 sea level rise projections from the South Florida Climate Compact indicate that sea levels are rising faster than previously anticipated. Additionally, as the climate continues to change, Miami Beach expects to see an increase in major rain events which can cause flash flooding. As the City continues to grow, it is important to ensure that new developments are resilient to and able to adapt to sea level rise and climate change.

The attached draft ordinance contains different options to ensure that ground floor commercial uses in different types of buildings are resilient to sea level rise in the near-term and able to adapt to increasing sea level rise with minimal alterations in the long-term. The proposal would also reduce the risks of significant flooding and related damage during major rain events. Standards are provided for three (3) different thresholds in an increasing manor to ensure that the mitigation required is feasible for the type of development being proposed. The proposed ordinance contains four major components as follows:

Minimum Ground Floor Heights
Today, the City of Miami Beach Land Development Regulations (LDRs) provide that height is measured from the Base Flood Elevation (BFE) plus the City of Miami Beach Freeboard. On October 29, 2019, Allan Shulman presented his team’s Historic District Resiliency Guidelines. One of the recommendations in this plan is to require that the height of buildings be measured from the “Design Flood Elevation” (DFE). This term does not change the way the City measures height, but rather provides a catchall term for this measurement. The proposed ordinance therefore proposes to measure building heights from the DFE which is defined as “the BFE plus City of Miami Beach Freeboard...”

Currently, the LDRs require that commercial ground floors have a ceiling elevation of 12 feet above the Future Crown of Road Elevation (5.26’ NGVD). While this provides greater resilience for a building by allowing it to adapt by raising the ground floor in the future, it is an insufficient clearance for the very long term pursuant to the South Florida Climate Compact Unified Sea Level Rise Projects and projected King Tides. The proposed ordinance establishes a “Minimum height of non-residential ground floors.” This requires that the underside of a ceiling of a new development be located at least 12 feet above the DFE. This provides a minimum of an additional 3.74’ of headroom for the ground floor to be raised. This will allow buildings to be resilient for a much longer period.

Existing Building Standards
As existing buildings are renovated, it is important to ensure that improvements are made to those structures so that they are made more resilient to the impacts of sea level rise and major rain events. The Land Development Regulations contain requirements to bring existing non-conforming structures that are being renovated in excess of 50% of the value of the building in conformance with several aspects of the code. For buildings undergoing such a renovation, the proposed ordinance would require improvements to help mitigate against the impacts of sea level rise and climate change. For such buildings, the ordinance proposes the following:

1. To improve a building’s resiliency to sea level rise and major rain events, the proposed ordinance requires that where feasible, the ground floor shall be located at a minimum elevation of one foot (1’) above the highest sidewalk elevation adjacent to the frontage. Ramping and stairs from the sidewalk elevation to the ground floor elevation shall occur inside the property and not encroach into the public sidewalk or setback areas.

2. In order to limit a building’s risk during a major rain events, knee walls should be provided to limit water’s ability to seep into buildings to doorways. Therefore, the proposed ordinance requires that except where there are doors, facades shall have a knee wall with a minimum height of two feet-six inches (2’-6”) above the sidewalk elevation.

3. In order to limit a building’s risk during a major rain events, the proposed ordinance requires that where feasible, ground floors shall utilize flood damage resistant materials for a minimum of 2’ 6” above the floor elevation.

4. Flood panels are useful when there is a predicted hurricane; however, when there is a significant rain event, there is rarely sufficient time to install them. Where buildings are in low-lying areas that necessitate the use of flood panels, it is important that the flood panels that are for doorways be easily accessible so that they can be quickly installed in case of a storm. Therefore, the proposed ordinance requires that flood panels for doorways shall be permanently located next to all doorways.

Because there may be circumstances where such improvements may not be feasible due to the existing nature of the building, the proposed ordinance incorporates a provision that allows the HPB or the DRB, as applicable, to waive the requirements. For example, raising the ground floor may be difficult or unfeasible if there is a historic public interior that has architecturally significant flooring or if there is insufficient headroom. However, the applicant must demonstrate how the development will mitigate against the impacts of sea level rise and storm water.

Short Frontage Standards
The City has seen several infill buildings with ground floor commercial uses that have been developed in recent years which are adjacent to existing and historic buildings which are built at lower elevations. These buildings typically have a frontage that is less than 150 feet long. While it is important to make sure that the new buildings are resilient and able to adapt, it is also important to ensure that those buildings are compatible with the surrounding built environment. In such a situation, there are many features that can be incorporated into the building that will allow it to be more resilient and able to adapt to sea level rise in the future, while remaining compatible with the built environment.

In order to allow buildings to be more resilient and adaptable, the following requirements are incorporated into the draft ordinance, in addition to those required for existing buildings:

1. To improve a building’s resiliency to sea level rise and major rain events, the ground floor should be located higher than the sidewalk elevation. Because access ramps and steps consume large areas, it is suggested that the floor be at least two (2) steps (14 inches) above the sidewalk elevation. Therefore, the proposed ordinance requires that the ground floor shall be located a minimum of fourteen inches (14”) above the highest sidewalk elevation adjacent to the frontage. Ramping and stairs from the sidewalk elevation to the ground floor elevation shall occur within the property and shall not encroach into the public sidewalk or setback areas.

2. Ground floor setbacks must be wide enough to allow for wider pedestrian circulation paths and sufficient landscaped areas and facilitate the ability to adapt in the future as rights of way are raised to mitigate against the impacts of sea level rise. Landscape areas should be larger in order to help drain and treat stormwater. As a result, the proposed ordinance proposes that there should be a minimum of 15 feet from the back of the curb of the roadway, to provide for a ten (10) foot wide sidewalk Circulation Zone that includes a five (5) foot wide Clear Pedestrian Path, and a five (5) foot wide landscape area.

3. There are developments that have multiple frontages; this presents an opportunity to provide additional mitigation measures. The proposed ordinance requires that for developments that have multiple frontages and one frontage is greater than 150 feet, the development shall follow the more stringent standards for buildings with long frontages, which are described below.

The Historic Preservation Board (HPB) or the Design Review Board (DRB), as applicable, is able to waive the requirements if implementing them is unfeasible; however, the applicant is required to demonstrate how the development will mitigate against the impacts of sea level rise and stormwater.

Long Frontage Standards
The City has several examples of new commercial and mixed-use development which have raised the public sidewalks adjacent to their properties in order to facilitate incorporating higher ground floor elevation. These projects tend to have frontages that are longer than 150 feet. The majority are located on or near commercial sections of Alton Road. The sidewalks are generally being raised to the Future Crown of Road Elevation as designated in the City’s Stormwater Master Plan which is currently set at 5.26’ NGVD (3.7’ NAVD)

The Planning Department has analyzed how those buildings and sidewalks are being developed and how transitions between lower and higher sidewalk levels are occurring. Since uniform standards do not exist, each sidewalk is being developed in a different fashion. Each example that was analyzed has both positive and negative aspects. The proposed ordinance consolidates the positive aspects of each example into uniform sidewalk and ground floor commercial standards that can be followed by future projects.

Below is a description of some of the major sites that were analyzed, including positive and negative aspects. Photos and a more detailed description are available in the attached PowerPoint presentation.

• 709 Alton Road (Baptist Urgent Care) – This development contains raised sidewalks. A very positive aspect is that the ground floor façade is setback, allowing for a wider pedestrian circulation area. The landscape transition area between the raised sidewalk and the lower parallel parking is wide enough for the landscaping to succeed. However, no access is provided to the vehicles from the sidewalk, leading to people walking through and damaging the landscaping to access the sidewalk, or alternatively, dangerously walking along the edge of travel lanes to get to access points at the corners of the block. The transition area to one of the lower level adjacent sidewalks exceeds 5% and therefore necessitating that handrails being placed in public rights of way.

• 1212 Lincoln Road – This development contains raised sidewalks. A very positive aspect is that the ground floor façade is setback to allow for wider pedestrian circulation areas and future outdoor cafes. Transitions to lower adjacent sidewalks are gradual and therefore do not require handrails being placed in public rights of way. However, the landscape transition area between the raised sidewalk and the lower parallel parking is narrow, and the landscaping has struggled to survive. The landscape transition area has areas with steps to allow direct access to on-street parallel parking; however, they are insufficient to provide access to the entire row of parallel parking and they are placed in locations where access can be blocked by parked vehicles.

• 1045 5th Street (Target) – This development contains raised sidewalks. However, the pedestrian circulation paths are somewhat narrow and broken up by planters. Because there are minimal landscape transition areas between the raised sidewalk and the vehicle travel lanes, handrails are necessitated along the edge of the raised sidewalks. Because the location of building entrances was not considered prior to the design of the raised sidewalk, ADA access requirements necessitate the use of awkward steps and switchback ramps with handrails to transition between the raised sidewalk elevation and the adjacent lower sidewalk elevations. One positive aspect is that trees are planted in raised planters that will allow the trees to survive sea level rise and future roadway adaptation.

In addition to the requirements for existing buildings and buildings with short frontages, and based on the analysis of the various sites, the following best practices for developments with raised sidewalks have been identified and incorporated into the draft ordinance for developments that have a frontage that is longer than 150 feet:

1. Developments with longer frontages have an easier ability to raise sidewalks and provide transitions to areas with lower elevations. Because these buildings are larger there is a bigger area that can facilitate sea level rise mitigation. Therefore, the proposed ordinance requires that, with the exception of transition areas, the sidewalk must be raised at a minimum to the future crown of road elevation (5.26’ NGVD).

2. Ground floor setbacks are to allow for a wider pedestrian circulation zone and sufficient landscape transition areas between the raised sidewalks and lower level roadways. Landscape transition areas must be sufficiently wide to allow trees to thrive and eliminate the need for handrails along the edge of the circulation zone. As a result, the proposed ordinance proposes that there should be a minimum of 15 feet from the back of the curb of the roadway, to provide for a ten (10) foot wide sidewalk circulation zone that includes a five (5) foot wide clear pedestrian path, and a five (5) foot wide landscape transition area between the raised sidewalk and the lower vehicular roadway.

3. As sea levels rise, the fresh water source required for trees to survive will diminish. Additionally, as roads are raised, it is important that trees will not be impacted. Therefore, it is important that trees be planted at higher elevations so that they will be resilient. As a result, the proposed ordinance requires that trees be planted in raised planters or stabilized planting areas with a minimum elevation of the future crown of road.

4. The sidewalk transitions between higher and lower elevations should be designed to minimize impacts to pedestrian comfort and safety. Low slopes on transitions between raised sidewalks and lower sidewalk elevations should be provided. This should be considered before entry points into a building are sited to remove the need for steps and the use of minimize handrails. Generally, this necessitates that slopes of less than five (5%) percent be provided so that ADA access can be maintained. Therefore, the proposed ordinance requires that the use of switchbacks, and handrails be prohibited in parallel transition areas.

5. In order to improve safety for those parallel parking and minimize impacts to landscaping, developments must provide properly placed access steps where there is lower elevation parallel parking adjacent to a raised sidewalk. Therefore, the proposed ordinance requires that steps that are no wider than 36 inches be placed between every two parking spaces where parallel parking exists.

6. Because the sidewalk is being raised, there are opportunities to raise the ground floor even further than what is typically done, providing for resilience to sea level rise for a longer time frame. Therefore, the proposed ordinance requires that the ground floor elevations be located a minimum of 14 inches above the raised sidewalk elevation.

7. Because the sidewalk is raised, knee walls can be measured from a higher elevation, improving the building’s resilience to major rain events. Therefore, the proposed ordinance requires that except where there are doors, facades shall have a knee wall with a minimum height of two feet-six inches (2’-6”) above the raised sidewalk elevation.

As with the short frontage standards, the HPB or the DRB will have the ability to waive standards, provided that the applicant provides measures to mitigate against sea level rise and storm water.

SUMMARY

The building, planning and public works departments have all coordinated input into this proposal. The administration beleives that achieves a balanced approach to shoring up and better protecting new commercial construction. The proposal may have an impact on the maintenance and liability of public sidewalks, and additional policy direction may be required as the ordinance moves forward.