The City of Miami Beach Public Works team currently operates 34 permanent stormwater pumping stations, with more expected to come online in the near future. The Stormwater Master Plan (SMP) includes up to 80 stormwater pumping stations citywide. The initial design of the stations did not include permanent built-in emergency power generators for a variety of reasons: cost, low risk of unplanned power outages, and aesthetics.
Each year in the spring and fall there is an extreme tide season (Spring or King Tide season) which lasts for a period of two (2) to three (3) months. During the fall 2015 King Tide season, the City increased its reliance on temporary portable pumps for mitigation against “sunny day flooding,” or the term used to describe when sea water appears in the streets due to the tidal cycle. Each season thereafter, an increased number of temporary portable pumps have been deployed throughout the City to mitigate the effects of the higher tides.
In October 2016, the impacts of Hurricane Matthew, including the associated power outage, prompted a review of the City’s tolerance for risk concerning generators. Ultimately, in February 2017, that review resulted in the Mayor and Commission directing the Public Works Department to begin procurement of permanently mounted generators for the Sunset Harbour neighborhood’s pumping stations number 2 and 3. Moreover, on August 1, 2017, an extreme weather event occurred which prompted the issuance of an emergency authorization to accelerate the procurement and installation of the Sunset Harbour generators and to develop recommendations for other stormwater pumping stations. The permanently mounted generators have been installed at the two (2) stormwater stations located in the Sunset Harbour neighborhood.
During the most recent King Tide season, the City rented 20 portable emergency generators and 26 portable temporary pumps. Additionally, in other areas that currently have contractors performing work, the City directed those Contractors to install temporary pumps at various costs to those contracts.
ANALYSIS
The cost associated with using temporary portable pumps and generators during the last King Tide cycle was approximately $130,000 per month. The rental of the equipment alone was about $110,000 per month, and the labor required to operate and maintain the equipment was approximately $20,000 per month. Costs associated with the increased use and requests of pumps/generators will continue to increase as higher tides occur during each King Tide season.
Assuming that there will be two (2) months of Spring Tides in the spring and three (3) months of King Tides in the fall, the total annual costs would be approximately $650,000 at the current service level. As sea levels continue to increase, until the permanent solutions are put in place, the costs associated with temporary pumps and generators will continue to increase significantly, and effectiveness will be reduced.
The current stormwater rates do not include components for widespread usage of rental pumps and generators. The use of these pumps is budgeted at $800,000 in FY17/18, but this was funded from cash reserves generated by the rate increases a year ahead of the bond issuance and resulting debt service payments. The long term rate models do not include these expenditures and would result in additional increases required.
A continued reliance on temporary equipment to alleviate flooding will require a source of funding. Until now, the costs have been paid from the stormwater utility’s operations and maintenance fund. The fund, in its current design, is unable to continue this practice into perpetuity without neglecting other obligations. This item is presented for discussion and direction on continuation of the existing temporary pumps and generators as well as potential funding options if continued.