Every aspect of coastal infrastructure will be impacted by sea level rise; and the sheer size of the problem is difficult to comprehend. We can’t just turn
Venice, California into Venice, Italy; but there are things we can do to protect our coastal communities and infrastructure.
There are several places in the world where canals, not roads, represent the
main thoroughfares — where front doors and shop entrances lead to boat slips and
bridges, rather than driveways and parking lots. Venice, Italy, of course, comes to
mind; along with Vietnam’s Hội An and Russia’s St. Petersburg,
among other picturesque spots.
Denizens of these localities have adapted their transport, commerce, emergency
services, policing and firefighting to these conditions; and go happily about
their watercourses with little regard for their odd circumstances.
The rest of us have neither the inclination nor the aquatic wherewithal to
navigate our towns, cities and hour-long commutes from the suburbs by water.
Yet, that is just what many of us will need to do when the predictions of
today’s climatologists come to pass — a rise of between two and six
feet
is projected this century.
The current projected rise will have massive, devastating and planet-wide
consequences. Two to three hundred million people are expected to be refugees
of
flooding
and inundation — as the 90 percent of humanity living along the coastlines
around the globe are assailed by rising tides, persistent flooding and
unmanageable storm surge. Even non-coastal areas and low-lying riverine
communities are expected to flood
regularly.
We normally think of this in terms of the number of dwellings that will be
washed away and those made homeless thereby. Goodness knows that’s tragic
enough, but our entire coastal infrastructure — not just individual holdings —
are going to take a beating. A Stanford University
study
recently sounded the alarm about Northern California’s highway system: “the
domino effect of flooding … is going to require a redesign of transportation
systems as sea levels, storm surges and flooding worsen over the next thirty
years. Otherwise, more extreme weather conditions could paralyze road
transportation.” Yikes.
Many coastal cities have airports located as near as possible to the waterfront,
with runways often just above the waves; and Resource Watch
found
that just one meter (3.28 ft) of rise (MSL), a conservative estimate, would
drown approximately 80 airports worldwide. Indeed, Boston and San
Francisco have erected
seawalls
in the last few years.
So far, this is all civilian stuff; but imagine a naval base immobilized by too
much water. That’s what is now happening in Virginia at Naval Station
Norfolk.
“The entry road swamps. Connecting roads become impassable. Crossing from one
side of the base to the other becomes impossible. Dockside, floodwaters overtop
the concrete piers, shorting power hookups to the mighty ships that are docked
in the world’s largest naval base … all it takes to cause such disarray these
days is a full moon, which triggers exceptionally high tides,” notes National
Geographic.
As sea levels continue to rise, the base is expected to “flood 280 times a
year.” A 2016
report
showed 18 other military installations around the United States that were at
risk due to climate change impacts.
Homes and schools can be moved, though with much disruption — but a naval base
is much harder. And then there are the critical situations we don’t even see.
Water resources may need to be rethought — as rising volumes of saltwater
infiltrating traditionally fresh groundwater supplies could make many aquifers
and drinking-water sources unusable without desalination. As the National
Environmental Education Foundation
reported
this year: “The amount of saltwater infiltrating the (Biscayne) groundwater
aquifer will increase, which can make the water too salty for human
consumption.”
Less obvious but no less critical are the underground conduits: water, electric.
Two years ago, researchers performed a risk assessment for fiber optic
cable in the US and found
that more than 4,000 miles (6,437 kilometers) of the stuff was at risk,
especially around some of the larger cities such as New York City and
Miami: “While the standard buried fiber conduits are designed to be water-
and weather-resistant, most of the deployed conduits are not designed to be
under water permanently,” as they would likely be under NOAA sea level rise
(SLR) projections. Given the importance of connectivity — especially in
emergencies — this is yet another significant risk.
Then there’s the problem of
salt: “Sea level
rise is not just a problem of water … imagine if saltwater flooded a farmer's
field, or a coastal forest. Not only does the area have to survive flooding, but
also a drenching in salt water that can kill plants and irreversibly alter soil
chemistry. Saltwater flooding can mean death for these ecosystems. Already
scientists have seen stands of ‘ghost forests’ where once-healthy trees were
killed by saltwater flooding, and farmers' fields are being converted to tidal
marsh and salt flats.”
Every aspect of coastal infrastructure will be impacted by sea level rise; and
the sheer size of the problem is difficult to comprehend. Infrastructure is
built locally, designed to last over time based on the conditions that obtain at
the time.
Yet, how many communities have the resources to relocate their homes,
businesses, roads, schools and emergency services; protect their farmlands, and
raise their bridges and seawalls — in short, change their infrastructure from
top to bottom?
We can’t turn Venice, California — which is at serious risk of
inundation
— into Venice, Italy; but there are things we can do to protect the people, and
the infrastructure, therein.
It turns out there are three main strategies, which we’ll cover in a future article.
Published Dec 22, 2020 7am EST / 4am PST / 12pm GMT / 1pm CET