Research
Finds Dramatic Increase in Flooding on Coastal Roads
University of New Hampshire
High
tide floods, or so-called “nuisance flooding,” that happen along shore roadways
during seasonal high tides or minor wind events are occurring far more
frequently than ever before.
Researchers
at the University of New Hampshire have found that in the past 20 years roads
along the East Coast have experienced a 90 percent increase in flooding – often
making the roads in these communities impassable, causing delays, as well as
stress, and impacting transportation of goods and services.
“This could be just the beginning of impact on these areas,” said Jennifer Jacobs, professor of civil and environmental engineering. “With the continued rise in sea levels, nuisance-flood frequency is projected to grow and the effect on the physical roads and the people that live along the coastline is concerning.”
In
their study,
recently published in the journal Transportation Research Record, the
researchers found that tidal nuisance flooding threatens over 7,500 miles of
roadways along the entire East Coast, with over 400 miles of that being
interstate roads.
They estimate that this causes over 100 million hours of delays each year for drivers on those roads and that number could rise to more than 3.4 billion hours by 2100.
By the middle of the century (2056 –2065), they predict nuisance flooding could occur almost daily at specific sites along the shores of Connecticut, New Jersey, Maryland, the District of Columbia, North Carolina, and Florida under an intermediate sea-level-rise scenario.
They estimate that this causes over 100 million hours of delays each year for drivers on those roads and that number could rise to more than 3.4 billion hours by 2100.
By the middle of the century (2056 –2065), they predict nuisance flooding could occur almost daily at specific sites along the shores of Connecticut, New Jersey, Maryland, the District of Columbia, North Carolina, and Florida under an intermediate sea-level-rise scenario.
“As
tidal coastal flooding increases in the coming years, there will also be issues
with the transportation infrastructure,” said Jacobs. “We’ve already seen
billions of dollars in damage to coastal roadways from recent hurricanes. In
the future, with rising sea levels, we expect to see more frequent issues, more
damage, and impact to roadways even farther inland.”
Researchers
note that these impacts are not limited to storm events. They say that critical
transportation infrastructure is at risk from sea level rise alone; which
numerous transportation agencies project to be between one to eight feet, along
the U.S. Atlantic and Gulf Coasts.
The
researchers say that the goal of this study is to better understand the type
and extent of roadway infrastructures that are vulnerable to high tide flooding
and the transportation impacts now and in the future due to sea level rise.
This study focuses on the East Coast of the United States and includes all
coastal states from Maine to Florida, including the Gulf Coast of Florida and
Key West.
Vulnerable
roads were identified using data from the Federal Highway Administration’s
Highway Performance Monitoring System and National Oceanic and Atmospheric
Administration’s Center for Operational Oceanographic Products and Services.
They looked at flood frequency maps, tidal gauge historic observations, and future projections of annual minor tidal flood frequencies and durations.
They looked at flood frequency maps, tidal gauge historic observations, and future projections of annual minor tidal flood frequencies and durations.
This
research was funded by U.S. National Science Foundation research grant
(CBET-1231326).