Sea-level Rise, Storm Surges, and Delaware’s Resilience Challenge (with a Sandy update)

Posted by on Oct 30, 2012 | 4 comments

$35 million has been spent since early 2011 on beach restoration in Delaware, due to shifting sands from storms. Photo: USACE Philadelphia District.

Update Note, October 30, 2012

With Post-tropical Cyclone Sandy still whirling around somewhere to my west, the article below feels prescient.  It wasn’t of course – there was no advance knowledge of this particular storm – but what just happened with Sandy is well in line with climate change trends.  It had been many decades since a hurricane of this magnitude made landfall in or near Delaware, but the conditions were just right, including record-high late-October ocean temperatures in the high 70s (F) to give the storm extra power as it crossed the coastline.  Had Sandy directly hit Delaware, instead of up the coast in New Jersey/New York, the damage might have been even more dramatic than it was.  As Delaware takes stock in Sandy’s aftermath, and as the destruction of beaches, dune systems, and real estate becomes clear, there will be much opportunity to ponder the issues raised in this article. Planners and community and state leaders need to explore how the impacts of this storm would change with 1 to 3 additional feet of sea level, combined with a more direct hit. As we have learned, this is not implausible, and will likely become the future norm along a path to greater climate change unknowns.  – RM

Original article: Published August 26, 2012

Last week, The News Journal, Delaware’s major newspaper, and the PNC financial services group sponsored a panel discussion and forum in Fenwick Island entitled “Coastline in Crosshairs of Climate Change.”  With a qualified and diverse panel of experts, this event along with three days of special articles in The News Journal appears to have made an important contribution to the public conversation about climate change, rising sea levels, and increases in the damage done by storms.  These topics are on a growing number of minds as research strengthens the case for human-induced climate change, extreme weather events claim larger shares of federal and state budgets, and property owners begin assessing what climate change predictions mean for them and their real estate.

Ocean-centered Tourism     

Most of Delaware is flat, sandy country, with long Delaware Bay and Atlantic Ocean coastlines.  Over 10% (or $6 billion) of the economy of this small, Mid-Atlantic state derives from tourism, and nearly all tourism in Delaware is centered on its beach resorts and the swimming, boating, fishing, and other water sports they offer.  From Cape Henlopen in the north to Fenwick Island in the south, Delaware attracts summer tourists with nearly thirty continuous miles of high-quality ocean beaches, and the Delaware Bay coast, while less developed for tourism, is considerably longer.  Add to these all the bays, inlets, rivers, and creeks, and it is clear that Delaware is both dependent on and exposed to the Atlantic Ocean.

Historic Storms are Instructive

I’ve been visiting the Delaware coast since I was a child, and have relatives who own rental real estate close to the beach in Bethany Beach, South Bethany, and Middlesex Beach.  For locals and absentee property owners alike, the oral tradition surrounding past hurricanes and northeasters is rich, particularly because of the effects that these extreme weather events have had on buildings and infrastructure.  An unnamed hurricane in 1933 broke through the barrier island in Ocean City, Maryland (just south of the Delaware border), creating an ocean inlet to Isle of Wight Bay that was subsequently reinforced with jetties and regularly dredged, and is now regarded as a permanent convenience.  Hurricane Hazel, in 1954, caused much damage across the region.  Hurricane Floyd (1999) and Hurricane Isabel (2003) caused statewide emergencies, flooding, and property damage.

Folks often refer to the devastation caused by the Ash Wednesday Northeaster of 1962, one of the most destructive storms ever to hit the Mid-Atlantic Coast, when many buildings were washed out to sea.  For three days, the coastline was subjected to high winds, rain, and a storm surge that combined with high spring tides to breach dunes and undermine sea walls.  There were numerous deaths in six states and the property damage ran into the hundreds of millions of dollars.  In Delaware, waves more than 40 feet high pounded Rehoboth Beach, destroying the boardwalk and beach houses.  Delaware lost almost all of its sand dunes.

Another famous storm, the “Perfect Storm” of 1991 (on which the movie of the same name is based), was in fact the fusion of a northeaster and the remains of a hurricane.  Most of its effect was felt in Massachusetts and New Jersey, but Delaware sustained much property damage, and tidal records of more than 7 feet were recorded along the southern Delaware Coast.

What makes a big difference is whether a storm’s surge coincides with one or more high tides.  This is when the effective sea level rises the highest, driving ocean water over dunes and into bays and inlets.  Simultaneous high winds send large waves along the raised ocean surface to erode dunes, destroy roads and buildings, and push salt water into regions where it can damage fresh-water or brackish ecosystems.  Meanwhile, rising land-side bodies of water like Rehoboth, Indian River, and Assawoman Bays, which are all connected to the Atlantic, flood the land along their banks and the reinforced canals where so much real estate has been developed.

I was at Bethany Beach in August 2011 when Hurricane Irene was bearing down on the eastern states.  We left Bethany as boardwalk businesses started to cover their windows with plywood and an evacuation of Ocean City was being contemplated.  Ironically, Irene had a much greater impact on Vermont, where I live, whereas it passed Delaware during an unusually low tide, which mitigated the effect of the storm surge.

Sandy Barrier Islands

The entire Atlantic coastline of Delaware (and the longer Delmarva Peninsula coastlines of Maryland and Virginia below it) consists of thin barrier islands made of sand, with brackish bays and wetlands behind them.  Much of this land lies only a few feet above sea level.  Its natural tendency is to move around under the influence of currents, winds, and tides.  The geology of the entire region is dynamic; like Cape Cod and Long Island, the entire Delmarva Peninsula is made of sediment carried down major rivers (especially the Delaware, Susquehanna, and Potomac) during various ice ages, the glaciation having terminated just north of Delaware.

From Prevention to Adaptation?

That’s the geology.  But another reality is the way in which humans have developed Delaware’s coast over the past century, and this reality needs the sand to stay where it is.  Hotels, marinas, beach houses, condo developments, retail properties, the public and private beaches themselves, and access roads and utilities reflect an enormous financial investment, and are all predicated on property rights that assume the land will not move.  Local, state, and federal efforts for decades have focused on holding shorelines where they are.  This has included the maintenance of sea walls and “beach replenishment,” where large quantities of sand are dredged up elsewhere and pumped onto eroded beaches.  From Rehoboth to Fenwick Island, a mixture of federal and state funding has seen $35 million spent since early 2011 on beach replenishment.  Visitors quickly notice how much wider the beaches have become, with the appearance of new, grass-planted dunes alongside boardwalks that used to look out directly onto beaches.

Many difficult questions about beach replenishment and the prevention of change are starting to emerge.  First, funds are harder to obtain, as governments cut spending and extreme weather elsewhere competes for resources.  Second, as a consequence, it appears that Delaware is increasing its concentration of coastal defense spending on the affluent Atlantic beach resorts, where property prices and tourism revenues are highest, while Delaware Bay communities are seeing real estate and roads wash away.  One panelist in last Tuesday’s “Coastline in Crosshairs” forum, Colette Croze, gave vivid descriptions of how citizens in her community of Bayview Beach had lost land and been forced to move and raise homes.  The News Journal’s series featured similar situations in Delaware River and Bay locations like Broadkill, Prime Hook, Slaughter Beach, Kitts Hummock, and Bowers Beach.

The forum’s panelists agreed that the resorts would likely continue to enjoy the strongest financial support for preventive beach replenishment measures.  They wondered how long this could go on before a different strategy became unavoidable.  Delaware’s Department of Natural Resources and Environmental Control (DENREC) estimates that ocean levels will rise approximately 1.6 feet by 2050, and is evaluating scenarios of more than twice that.  Such rises combined with more severe storms could make it literally impossible to maintain the built environment, infrastructure, and beaches in their current state.  Assets of substantial economic value are at stake.  How much time do we have?

Addressing Resilience

As I sat behind my father’s house in South Bethany, I watched the water of the canal ripple against the bulkheads that prevent the sandy soil from slumping into the canal.  The canal’s surface lay about three feet below ground level.  In thirty-eight years, on an ordinary day, the average level of the water will close between half and all of that gap, since it’s tidal and connected to the Atlantic through the Ocean City inlet.  High tides and storms will do potentially much more.  What is resilience in a situation like this?  Resilience is the ability to sustain damage and recover quickly and fully.  In the case of Delaware and sea-level rise, this question gets pulled in two directions.  On one hand, storms are short-lived, and resilient buildings and communities are those that are able to provide shelter during storms and ensure human life and safety during the aftermath.  On the other hand, sea-level rise is a gradual, long-term phenomenon that permanently changes conditions, so resilience here must involve the capacity to maintain a certain economy and society as this change unfolds.

Either way, should all buildings be raised up higher, onto pilings?  Should public money be concentrated on for example dikes, artificial islands, or causeways, letting the rest of the land (and what’s on it) swirl back into the natural movements of the sands?  What should the federal and state roles be?  How much will local efforts need to take the lead?

Delaware’s Atlantic coastline has been defined by the tourism of affluent populations in the Washington, Baltimore, Philadelphia, and other urban areas for generations.  Families have acquired beach homes and visited them year after year, driving the local economy through their vacation spending and home maintenance.  A big question is whether these families would continue to vacation along the Delaware Coast as maintenance costs mounted, infrastructure deteriorated, and property values fell.  It seems reasonable to imagine a scenario where strategic investment in land defenses, strategic abandonment of certain infrastructure and property, selected beach replenishment, and letting other areas change with nature’s changes could preserve key property values and maintain the region for beach tourism.  As the old quip goes, “they aren’t making any more coastline.”  While a changing climate may remake beachfronts faster than humans can economically reinforce them, and cause a variety of economic impacts around the region and nation, an important challenge now facing Delaware is how to balance adaptation to the inevitable against efforts to preserve a vital part of the state economy.  Many resilience initiatives will need to start with local actors, but the policy conversation will have to engage the entire Mid-Atlantic region, given the wide geographic spread of people with a stake in the future of the Delaware Coast.

4 Comments

  1. Ralph, nice article. Good to see that Deleware is starting to take a serious look at this issue. I have many friends who are looking at property in Deleware, New Jersey and the Carolinas, and I always tell them “plan for climate change and rising water levels”. It’s surprising how many are starting to listen after the difficult summer people are having. Climate change seems to be becoming “real” for many people after the horrible droughts and storm events taking place.

    This seems like an opportunity for Deleware to lead the way in research and technology to prepare for resilient communities and economies on coastlines. The fact that people of means will be affected is probably one reason why things are moving forward. I’d like to follow this work as it develops. Can you recommend a website I can use to monitor this? Thanks!

  2. I really speculate exactly why you titled this blog, “Sea-level Rise, Storm Surges, and
    Delaware

    • Hello Lynn
      Thanks for your comment, and for following RDI. Can you say more about your speculation? The article related directly to an event organized in Delaware in August to explore the potential consequences of sea-level rise (manifested through, among other things, higher storm surges like the one we saw during Hurricane Sandy two months later).
      Best regards,
      Ralph Meima

  3. Thanks for finally writing about > Sea-level Rise, Storm Surges, and Delaware

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