1. Defining Level of Service based on Dynamic
Environmental, Economic, and Social
Challenges within the Barrier Island
Community of Miami Beach May 2013
Jason A. Johnson, P.E.‐
Senior Project
Manager/Principal
Engineer

2. City of Miami Beach Stormwater Conditions
• Land area is 7 square miles
• Population of ~88,000
• Highly urbanized
• Low and relatively flat terrain
• Limited pervious area
– Existing development
– New construction
• Tidal constraints and backflow
• High groundwater table
• Aging infrastructure
in corrosive conditions
City of Miami Beach Stormwater Management Master Plan

3. Stormwater Management Master Plan
City of Miami Beach Stormwater Management Master Plan

4. Stormwater Basics
City of Miami Beach Stormwater Management Master Plan
When the sea level rises:
Water flows more slowly or even
flows from the Bay to the streets
Storm water flows to catch basins
Through large pipes
Outfalls into Biscayne Bay

5. Stormwater Management Master Plan
The previous City Stormwater
Management Master Plan was
developed in 1997.
Old Plan determined needs by:
– water quality
– flooding potential
– citizen complaints
– City staff ranking
New Plan determined needs by:
– City‐wide model analysis
– Water quality
– Incorporates sea‐level rise
projections
City of Miami Beach Stormwater Management Master Plan

6. Rainfall Inundation Mapping
6 inch rainfall event flooding with
tidal elevation of 0.67 ft NAVD up
from ‐0.9 ft NAVD normal tide
condition
City of Miami Beach Stormwater Management Master Plan

7. Two Sea Level Related Questions
What is the present sea level?
How fast is it rising?
City of Miami Beach Stormwater Management Master Plan

8. Incorporating Sea‐Level Rise into
Stormwater Planning
• Evaluate current tidal guidelines and requirements by other
Government agencies:
• Evaluate 20 year projections for sea level rise
– Use local data, when possible (i.e. Virginia Key)
– Sensitivity analysis to tidal and rainfall conditions
– Adaptability to varied sea‐level rise projections (i.e. USACE
guidance document)
City of Miami Beach Stormwater Management Master Plan
Federal
• USACE
• NOAA
• USGS
• FEMA
State of Florida
• SFWMD
• FDEP
• FDOT
• Miami‐Dade County

9. City of Miami Beach Stormwater Management Master Plan
0.51
0.67
0.84
0.16
0.36
0.29
0
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9
1980 1985 1990 1995 2000 2005 2010 2015 2020 2025 2030
Mean High Water (ft NAVD)
Year
USACE NRC Curve I (Low)
USACE NRC Curve II (Intermediate)
USACE NRC Curve III (High)
Virginia Key Tidal Data
NOAA Epoch Annualized Virginia Key
NOAA Data (1996‐2011)
USACE curves are based on the Engineering Circular EC 1165‐2‐212, published on October 1, 2011 and expires September 30, 2013.
Historic and Projected Mean High Water Levels at
Virginia Key

10. City of Miami Beach Stormwater Management Master Plan
Historic and Projected Mean High Water Levels at
Virginia Key

11. Recommendations from SWMMP Related to
Sea‐Level Rise
• Monitor and participate in future regional recommendations
related to sea level rise
• Follow USACE Civil Works and FEMA guidance in planning
and design
• Monitor pending IPCC recommendations regarding sea‐level rise
that are scheduled to be released to the public within the next
three years
• Review tidal data in intervals and adapt the SWMMP as
appropriate
City of Miami Beach Stormwater Management Master Plan