New Business and Commission Requests - R9 M
|Honorable Mayor and Members of the City Commission
|Raul J. Aguila, Interim City Manager
|April 21, 2021
|INFRASTRUCTURE AND RESILIENCY ENHANCEMENTS FOR PALM VIEW AREA.
|The Administration recommends that the City Commission discuss the item and provide appropriate policy direction.
On March 18, 2020 the City Commission referred the discussion item to the Land Use and Sustainability Committee (LUSC) and Historic Preservation Board (Item C4 W). On June 30, 2020 the item was deferred to the September 22, 2020 LUSC at the request of Palm View residents.
On September 22, 2020 the LUSC discussion was continued to October 20, 2020. On October 20, 2020 the City consultant, KCI, provided a presentation to the LUSC and the item was discussed. In order to obtain feedback from the Historic Preservation Board (HPB), the item was continued to the November 24, 2020 LUSC meeting.
On November 10, 2020 the HPB discussed the item and provided some preliminary feedback and recommendations. The HPB continued the discussion to their March 8, 2021 meeting.
On November 24, 2020 the LUSC deferred the item to the January 2021 meeting. On January 20, 2021 the LUSC discussed the proposal and continued the item to their March 2021 meeting. The LUSC also referred a separate discussion item to the City Commission, regarding costs and prioritization of the resiliency and infrastructure recommendations set forth in the KCI report.
In 2019, the firm of KCI (formerly Keith & Schnars) was retained by the City to develop a comprehensive 20-year plan for the Palm View neighborhood. KCI has held several public meetings and has received input from key stakeholders, representatives from the Miami-Dade County Property Appraiser’s office, as well as City staff from Planning, Public Works, Environment and Sustainability and the Office of Resiliency.
The final draft of the Palm View Master Plan was presented at a public meeting held on February 18, 2020. A copy of the presentation can be found on the City’s website at the following link: https://www.miamibeachfl.gov/city-hall/planning/studies/ . A copy of the full report is also attached.
The Palm View Neighborhood Study includes an analysis of incremental changes that have occurred in and around the Palm View Neighborhood over the past two decades, discusses the impacts these changes have had on the neighborhood and provides for a series of recommendations. The plan is divided into five chapters as follows:
2. Resiliency Districts & Climate Adaptation.
3. Land Development Requirements.
4. Historic Preservation.
5. Property Sales & Valuation.
Each chapter includes short, mid and long-term recommended strategies intended to increase investment and resiliency within the neighborhood. In summary, the recommendations include improving existing infrastructure, creating a resiliency district, changing allowable land uses and reevaluating the local historic district designation.
It is important to note that while the area could be studied for potential rezoning to allow for new multi-family uses, this option would require an amendment to the City’s Comprehensive Plan and an amendment to the Land Development Regulations. Additionally, voter approval would be for any increase in FAR. Also, modifications to the designation of all or part of the Palm View District would require both legislative action by the City Commission, as well as voter approval.
|PLANNING AND PUBLIC WORKS ANALYSIS
As noted in the attached report prepared by KCI, the City of Miami Beach utilizes a 30-year sea level change (SLC) planning horizon for stormwater. The following is a summary of recent tide and water table fluctuation in the Palm View neighborhood:
• January 2020: The water table adjacent to Collins Canal is 1.7 feet.
• September 2015: King Tide high water elevation at the Collins Canal was 2.1 feet.
• September 2019: Maximum water elevation at the Collins Canal was 2.08 feet.
The neighborhood roadway elevations in Palm View vary from lower than 2 feet to 3.7 feet. The following roadways have elevations that are less than 2 feet:
• Michigan Avenue (17th St – Collins Canal)
• Jefferson Avenue (18th St – Collins Canal)
• 19th Street (Jefferson Ave – Meridian Ave)
The following is a summary of additional infrastructure findings in the KCI report:
• The number of ditch bottom and curb inlets is insufficient, based on the documented nuisance flooding that occurs during typical summer rainfall events.
• Within Palm View, there are 8 foot wide green pervious areas on both sides of the roads (along 19th Street the green strip is 2.5 feet wide).
• Raised D-curbs separate the green pervious areas from the adjacent roadway. These curbs block the path of street stormwater runoff to the pervious areas, preventing them from properly functioning as drainage swales.
• The neighborhood’s stormwater system is an independent gravity-based stormwater system.
• 2 outfalls flow into Collins Canal on the north end of the neighborhood; currently, there are no floodgates on the inlets.
• There will be impacts related to future sea level rise, specifically to the Collins Canal, with a projected sea level rise of 2.58 feet to 6.75 feet by 2060
In order to address nuisance flooding by maximizing existing Infrastructure, short (1-3 years, medium (3-6 years) and long term (6+ years) a number strategies have been recommended by the City’s consultant.
At the direction of the Land Use and Sustainability Committee (LUSC) the Administration has reviewed the recommendations of the consultant pertaining to resiliency and infrastructure contained in the Palm View report and listed below. Some of the consultant’s recommendations are already in the process of being implemented.
With regard to the recommendations not currently being implemented, the Administration has been following the timelines and recommendations set forth in the attached prioritization scheduled prepared by Jacobs Engineering. In this regard, the Palm View area is located within City Center A (No. 29 on the priority list), Bayshore A (No. 38 on the priority list and Bayshore B (No. 25 on the priority list).
It is vitally important to note that the resiliency and infrastructure recommendations of the consultant are broad and largely aspirational. Additionally, they include complex projects that incorporate various types of infrastructure improvements and require extensive public outreach. Therefore, estimating the exact cost and duration of the applicable tasks can be challenging. However, we can reasonably expect that at number 29 and 38 on the Jacobs priority list, these projects would not begin construction for at least 10 years. This also assumes that the Administration is authorized to initiate the design of two to three neighborhood improvement projects per year, and that it takes approximately two years from initiation to start of construction. Also, all the projects noted on the Jacobs prioritization schedule could be accelerated or delayed, depending on various factors.
The following is a summary of each the consultant’s recommendations pertaining to resiliency and infrastructure, as well as the recommendations of the Administration regarding the current and future implementation status for the work proposed:
Short-Medium Term Strategies (1-6 Years)
1. Provide additional curb or driveway inlets would reduce localize nuisance flooding in areas with missing inlets.
2. Modify D-curbs around roadside green/landscape areas, so that they do not block the path of street stormwater to these areas. Roadside green areas could accommodate some of the street stormwater and reduce standing water after rain events.
3. Provide additional surface storage by creating roadside swales, bio-swales, and similar green infrastructure. For example, existing roadside raised green areas can be graded as shallow swale and street water can be directed to these areas.
4. Establish a schedule to regularly clean the existing drainage conveyance system as siltation clogs pipes and inlets, which impacts the effectiveness of the neighborhood drainage pipe system.
5. Locate new mobile drainage pumps close to the neighborhood outfalls that can assist the master drainage system during heavier storm events by dumping rainwater promptly out of the neighborhood.
6. Identify an appropriate location and design a neighborhood park with a stormwater co-benefit in the neighborhood. The stormwater component shall be designed as blue/green infrastructure that allows for the utilization of the park as water storage and neighborhood activities. The park may include a lined berm for water retention/detention, as well as a natural wetland component.
Unfortunately, during the most severe weather events, when flood mitigation is most needed, temporary measures are often ineffective and unsustainable. The only sustainable approach in the long term is to construct drainage and roadway improvements.
Adding more inlets to a failing system will not prevent flooding, which is why the City intends to upgrade the drainage systems by installing new pipes, more robust pumps stations, and by elevating roads where needed. Additionally, the six short-medium term strategies above would all be included, in some form, as part of the City Center A and Bayshore A/B improvement projects, identified in the Jacobs prioritization list.
Long Term Strategies (6+ Years)
1. Implement City Center basin study recommendations in the Palm View neighborhood area, including the upsizing of some existing pipes and the installation of canal pump station #52.
2. Raise roadway elevations in the neighborhood to mitigate Increase flooding related to sea-level rise. These existing roadway elevations should be raised without causing additional flooding issues to the adjacent residential buildings where feasible. Raising of roadways should be guided by the recommendation of the City's Stormwater Master Plan that is currently being updated to address this issue.
3. As part of the next stormwater master plan, increase the height requirement for the crown of the road so that it is equivalent to the City's stormwater standard for private development where feasible. The neighborhood roadways should be increased in height to prevent flooding at the crown of the road during a 10-year, 24-hour design storm event for 8.75 inches of rainfall.
4. The City should improve its portion of the seawall along the Collins Canal, as well as encourage seawall replacement and maintenance by private property owners to comply with the City's seawall height maximums when they replace existing seawalls.
The City has already begun the seawall improvement project, for those portions of the seawall along Collins Canal that are owned and maintain by the City. With regard to the remainder of the long-term strategies above, they would all be included, in some form, as part of the City Center A and Bayshore A/B improvement projects, identified in the Jacobs prioritization list.
SUPPORTING SURVEY DATA
|The administration recommends that the City Commission discuss the resiliency and infrastructure strategies recommended in the Palm View report, prepared by KCI. At this time, it is further recommended that any additional projects and tasks that are not already in the implementation stage move forward in accordance with the Jacobs prioritization schedule.
|Is this a "Residents Right to Know" item, pursuant to City Code Section 2-14?
|Does this item utilize G.O. Bond Funds?