Completed Stormwater and NIP Related Studies
The City of Miami Beach (City) has completed several studies over the last five years; these include the Road Elevation Strategy and Neighborhood Project Prioritization, Blue-Green Stormwater Infrastructure, Stormwater Facilities Plan, Seawall Prioritization Plan, Basin Drainage Reports for the Flood Mitigation Study, and the latest 20-Year Stormwater Needs Analysis—completed in June 2022 according to Sections 403.9301 and 403.9302, Florida Statutes.
Stormwater Master Plan Update and Financial Feasibility Study
The City’s current approved Stormwater Master Plan is over 11 years old, and thus staff is in the process of completing a new Stormwater Master Plan, with the goal of incorporating all these recent studies into a 2023 City-wide Stormwater Master Plan and Capital Improvement Plan, which will help the City guide its stormwater program for the next 10 years, with longer term consideration and guidance through the next several decades.
This project began on October 14, 2022 and the goal of this project is to develop a Capital Improvement Plan to help implement drainage improvements for critical areas, as well as incorporate the long term plan for NIPs, with stormwater improvements, road elevation strategy as well as incorporate Blue-Green Stormwater Infrastructure as part of future projects. The Master Plan will look at the possibility of fast-tracking and prioritizing smaller-scale critical-needs improvements that could be a complementary part of a planned Neighborhood Improvement Project but where implementation could be expedited ahead of a scheduled Neighborhood Improvement Project. Figure 1 presents a summary of the ongoing analysis of areas that experience recurring flooding. The Consultant will be assessing the City and its infrastructure to recommend the critical areas that require improvements and could significantly benefit from smaller scale upgrades. The resulting Capital Improvement Plan and the associated funding will be presented to the community and to Commission for review, input and ultimate adoption and implementation.
In the meantime, the City continues to deploy temporary pumps and use vacuum trucks to alleviate flooding to the extent possible. The Public Works team is committed to meeting or exceeding system maintenance goals so the existing drainage system works as best as it can.
Furthermore, the Public Works Department engaged GovRates, Inc. to update the prior Stormwater Rate Study, which was completed in 2017. The aim of the updated stormwater rate study is to evaluate the current financial position of the Enterprise Fund, and to develop a funding plan for operational expenses and capital improvement needs. Since NIPs are partially funded also by water and sewer funds, another analysis related to those rates is also underway. Upon completion, the updated rate study will provide the City with funding and rate scenarios that are useful tools in determining which variables need to be adjusted or changes that need to be implemented to achieve the desired financial results.
in parallel, the Administration continues to work on the execution of previously approved NIPs, including the following:
- Indian Creek Drive (roadway and drainage portions completed, seawall construction is ongoing and reaching completion in 2023)
- West Avenue Phase II (construction of North Segment scheduled to start April 2023)
- First Street (detailed design phase ongoing)
- North Shore D – North Beach Town Center (currently in design procurement, following execution of $10 M grant agreement)
2022 King Tides and Completed Resilience Projects
Figure 2 provides tide elevation and rainfall data during fall king tides of 2022. It illustrates how the highest tides generally approached elevation of 2.0 ft, with an extreme high tide in early November with minimal surge impact from Hurricane Ian. Figure 3 provides a map of the City showing roadway elevations. This map shows that significant areas within the City currently have elevations lower than 2.0 ft. These generally suffer some level of flooding regularly during king tides, and the flooding can be exacerbated by the combination of heavy rainfall during the extreme high tides. Road raising is a critical tool in our toolbox to address climate change and sea level rise, which will ultimately bring higher king tides and more frequent, heavier rainfall events. The implementation of the Neighborhood Improvement Projects, with road raising, robust stormwater collection, water quality treatment and pumping stations, along with the needed water and sewer infrastructure replacement, are key to mitigate these future conditions.
Areas that have already undergone this type of improvements, such as Sunset Harbour and Indian Creek avoided 49 days of flooding in the period of September 1st to November 30th, 2022.