LTC 286-2005 Sunset Harbour Stormwater System
<9 MIAMI BEACH
OFFICE OF THE CITY MANAGER
NO. LTC # 286-2005
LETTER TO COMMISSION
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TO: Mayor David Dermer and Members of the City Commission 0 ';11
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FROM: Jorge M. Gonzalez. City Manage'd r6 1'0 :Tt
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DATE: November 18, 2005 .:::- rn
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SUBJECT: Sunset Harbour Stormwater System (iT') Ul
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On November 10, 2005, at a meeting organized by Mayor David Dermer, City Administration
staff met with representatives of the Sunset Harbour Neighborhood. Commissioner Luis
Garcia attended a portion of the meeting. The following members of the City staff were
present at the meeting:
Robert Middaugh, Assistant City Manager
Fred Beckmann, P.E., Director of Public Works
Femando Vazquez, P.E., City Engineer
John Heffernan, Aide to Mayor Dermer
Representing Sunset Harbour were:
Mario from Joe Allen's Restaurant
Linda Arama-Sunset Harbour North
Dwight Kraai-Sunset Harbour North
Frank Kruszewski- Sunset Harbour South
The meeting was requested by residents concerned with the street flooding in Sunset
Harbour neighborhood. Flooding that has historically occurred in this neighborhood is more
common during the months of April and October which are the months that traditionally have
the highest tides of the year. This past October, in addition to the impacts of Hurricanes
Katrina and Wilma, the tides were the highest experienced in the past few years,
exacerbating the flooding problem. At the meeting City staff reviewed construction to date
and future plans to address the flooding.
The City in 2004 completed the construction of three deep drainage wells at three locations
on Sunset Harbour Drive. The wells were constructed in front of Publix on Sunset Harbour
Drive and West Avenue; adjacent to the Marina at Sunset Harbour Drive and 18th Street;
and at the north-west comer of Sunset Harbour Drive and Dade Boulevard. The system was
designed to operate as a gravity system; however, due to known problems with gravity
drainage wells, the City used the well in front of the Marina as a test site and equipped it with
pumps to make it a more efficient injection well. The structure of the other two wells was
constructed in such a way that they could be retrofitted with pumps in the future for
conversion into injections wells. The injection well at the Marina is working as designed;
however, at times of tidal flooding, the well capacity is exceeded because the pumping
system cannot handle the amount of Bay water that backflows into the pipes and floods the
streets. In addition, the northem seawall along Dade Boulevard has several areas that are
below extraordinary tide elevations, therefore causing additional flooding during very high
tides.
During the meeting, the City presented a plan of action to improve the stormwater drainage
system along Sunset Harbour and also agreed to incorporate into the plan recommendations
made by the residents and business owners attending the meeting. The plan of action
consists of:
1. The City will complete the design and obtain the appropriate permits to install pumps
in the two remaining deep gravity wells in the neighborhood. The retrofit will increase
the discharge capacity for each gravity well from 750 gallons per minute to 4,000
gallons per minute. The conversion of the deep gravity wells into injection wells is
planned to be completed by the end of March 2006.
2. The City will install flow valves in all neighborhood drainage outfalls into Biscayne
Bay. These valves will minimize the Biscayne Bay water backflowing into the
stormwater system which in turn overflows onto the streets during high tidal
conditions. These installations will be somewhat experimental for the City as they
have previously been unused. If successful in averting the tidal flooding, other areas
of the City may also benefit from similar installations. This will also be completed by
March 2006.
3. At the request of the residents the City will make every attempt to minimize the
footprint of the electrical control panels.
4. The City plans to replace the northem seawall along Dade Boulevard to prevent
flooding that currently occurs during very high tides when Bay water flows over the
seawall onto Dade Boulevard and adjacent intersections. This project is currently
under design and is expected to be awarded for construction in 2006. In the
meantime the City will pursue temporary measures such as the installation of sand
bags.
Please feel free to contact me if you have any other concems or questions.
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