Page 52 - Green Builder Sept-Oct 2016

Resilient Housing

BUILDINGS AND SYSTEMS THAT ARE READY FOR ANYTHING

Housing Solutions to
Rising Sea Levels

Climate change requires developers to get creative to protect buildings from flooding.

BBY LAURA TAM CREDIT: GREG HENSHALL/FEMA, FLICKR
Y 2050, the Union of Concerned
Scientists expects sea levels to rise
6 to 16 inches above current averages.
Many are already preparing for the
rise. Following are four ways housing
developers and communities can reduce the risk
of flooding, despite rising levels.

ELEVATED DEVELOPMENT Above the flood. Elevated houses on the Bolivar Peninsula in Texas
survived Hurricane Ike’s 20-foot storm surge with minimal
What it is: Raising the height of land or existing development and damage. Homes that were not elevated in this area no longer exist.
protecting it with coastal armoring.
it may be a good tool for retrofitting certain low-lying infrastructure,
New fill is a strategy being used by the Netherlands to expand and such as airports.
elevate land for settlement. In other locations, elevated development
would more likely be confined to elevating existing fill land and Disadvantages: It’s a short-term strategy. Elevated development,
protecting it with armoring. The elevation could also be used to unless it only consists of stilts directly over water, also alters the
protect infrastructure such as airports, roads or railways. characteristics of shorelines. It also will need protection, just like low-
lying development. Its advantage is merely that it is not threatened
Examples by sea level rise for a longer time.

Treasure Island Master Plan, which would elevate the building Unknowns: No one knows if higher land or structures will
pad for the island’s proposed developed area, and concentrate support high-density, transit-oriented new development. Elevated
development there. The plan also calls for protecting the buildings new development in areas close to shorelines could be a good
with a levee and a wide setback. strategy to accommodate growth without worsening sprawl. This is
particularly true if constructed near existing transit or built densely
Elevated houses in post-Katrina New Orleans. New Orleans enough to fund the creation of new transit—similar to the plan for
actually requires new or rehabilitated housing in levee-protected Treasure Island. However, if low-density development is allowed
areas to be elevated either 3 feet above grade, or to the base flood to proceed along the shoreline, it could increase global warming
elevation established by the FEMA, whichever is higher. emissions and may not warrant expensive protection measures in
the future.
Boardwalks and pole houses. Some boardwalk-type communities
are built on poles over tidal salt marshes with a predictable tidal range.

The Good, the Bad and the Unknown

Advantages: This strategy allows structures to be built on an
encroaching shoreline or in a vulnerable area with a low risk of
flooding. Although it is probably only cost effective for new buildings,

50 GREEN BUILDER September/October 2016 www.greenbuildermedia.com