1. RESEARCH POSTER PRESENTATION DESIGN © 2012
www.PosterPresentations.com
Mary Crider, Paul Boynton, Janna Ellis Kepley, Jessica Huffman, Cheng-Tung Liu, Morgan Mooney, Nigel Woodfork
❖ The permitting guidelines for bridge vertical clearance
must be updated to accommodate projected sea level rise
(SLR).
❖ This proactive measure reduces future costs, sustains the
lifespan of fixed bridges and ensures continued safe
navigation for vessels under bridges.
Introduction
❖ Global average temperature has increased 1.4˚F in the
last 100 years and will increase by 2˚-11.5˚F by 2100.
❖ Higher atmospheric temperature drives the melting of land
based ice and thermal expansion which raises sea level.
❖ Projections show that global sea level will rise 2 feet by
2050 and 6.6 feet by 2100.
Sea Level Rise
❖ The Seventh District of the USCG has the authority for
permitting, construction, reconstruction, or alteration of
bridges across navigable waters.
❖ The USCG Bridge Administration Manual only once
mentions rising SLR as a potential factor that could affect
the lifespan of bridge structures.
❖ The 1972 Waterways Safety Act mandates that bridge
clearances must be sufficient to permit safe transit of
vessels expected to use the waterway under normal
conditions.
Figure 1: Photos courtesy of the US Coast Guard.
Coast Guard Bridge Regulation
Economic Impacts
❖ Three-fourths of Florida’s coastal counties generate 79%
of the state’s total annual economy.
❖ Florida accounts for 9% of the US GDP with shipping, at
$66.9 billion in total trade and $28.1 billion in exports.
❖ In 2012, cruise line passengers and crews spent more
than $7 billion in Florida.
➢ Ex: The inability for new cruise ships to fit under the
Sunshine Skyway Bridge due to their increased size
represents $1 billion per year in lost revenue for Port
Tampa Bay.
Vessel-Bridge Impacts
❖ Ex: The Mathews Bridge in Jacksonville was struck by the
USNS 1st LT Harry L Martin in 2013.
➢ Repairing the bridge cost $30 million and took 40 days.
Recommendations
❖ Updating the permitting requirements to account for
projected SLR needs to be a priority.
❖ The permit must require the applicant to account for
projected SLR when determining the clearance of the
bridge.
Arthur R. Marshall Foundation 2014
Bridging the Gap: Sea Level Rise and Navigable Waterways
❖ There are ~35 vessel
collisions reported to the
Coast Guard every day and
these will only increase if
permits are not updated to
account for SLR.
❖ Collisions can reduce the
structural integrity of the
bridge, disrupt motorist and
marine traffic, and damage
the vessel.
Figure 3: Mathews Bridge strike
damage.
Acknowledgements and References provided in handout.
❖ The vertical clearance of fixed bridges will be reduced,
leading to increased risk of vessel protrusions (e.g. masts
and radio antenna) colliding with bridges.
❖ Waterway channel depth may increase, allowing for larger
vessels with deeper drafts.
❖ Waterways that are not navigable at current sea level may
become navigable.
❖ Advanced approval permitting of smaller bridges may
need to become more stringent if previously non-navigable
waterways become navigable due to SLR.
Figure 2: GSLR Scenarios in Feet.
Sea Level Rise Effects on Bridges