Another Warning of Sea-Level Rise

Ashville Park subdivision in Virginia Beach after Hurricane Matthew. Photo credit: Virginian-Pilot

By 2030, $838 million worth of residential property in Virginia is at risk of being chronically inundated by high tides caused by rising sea levels, directly affecting more than 6,000 people and $8 million in property taxes, according to a new report by the Union for Concerned Scientists. The definition of “chronic” inundation is 26 times per year.

“Sea levels are rising. Tides are inching higher. High-tide floods are becoming more frequent and reaching farther inland. And hundreds of US coastal communities will soon face chronic, disruptive flooding that directly affects people’s homes, lives, and properties,” states the report, ” Underwater: Rising Seas, Chronic Floods, and the Implications for US Coastal Real Estate.” “Yet property values in most coastal real estate markets do not currently reflect this risk. And most homeowners, communities, and investors are not aware of the financial losses they may soon face.”

By the end of the century, the study warns, sea levels could rise by seven feet, exposing 115,000 Virginia homes worth $30 billion to routine flooding.

That’s the worst-case scenario, predicated on the assumptions that global warming-induced sea-level rise is accelerating and that communities are incapable of adapting, and it’s the one highlighted by the report and the Virginian-Pilot coverage of the report. Under the report’s low-rise scenario based on effective global action against climate change, sea levels will rise only a foot and a half, and projected losses would be much smaller.

Scientists skeptical of alarmist global warming scenarios counter that sea levels have been rising steadily by 20 centimeters per century for at least two centuries with no sign of accelerating. The implied sea-level rise globally would be six and a half inches by the end of the century. But the impact varies geographically depending on whether tectonic plates are rising or sinking. In Virginia, the tectonic plate is sinking, suggesting that the impact could be greater locally.

I react negatively to alarmist environmental scenarios, which I think are fed more by wishful thinking that the world is in desperate need of saving. But I don’t dismiss the UCS report out of hand. If these scientists’ worst fears are well founded, Virginia’s coastline could face massive dislocation. Even if the skeptics are right, periodic flooding will get worse — not catastrophically worse but enough to force us to think differently about coastal development.

Given the array of risks, we cannot continue business as usual. I’m not suggesting that it’s time for draconian action, but we can at least stop doing stupid stuff. By “stupid stuff,” I mean we should stop subsidizing coastal development through the National Flood Insurance Program and through implicit promises that state and local government will maintain roads, power lines, water-sewer and beach restoration regardless of cost in the face of increasing floods. Homeowners should bear the costs and risks associated with their decisions to live on or near the water.

Local governments also need to stop zoning for large developments in flood-prone areas. In a separate and unrelated article, the Virginian-Pilot describes the issues surrounding the proposed expansion of the Ashville Park development in Virginia Beach. The developers won zoning approval for the giant, high-quality subdivision more than a decade ago, before periodic flooding became a concern. In 2016 Hurricane Matthew overwhelmed the project’s storm water drainage system, flooding many houses and leaving families stranded for days. Fixes are expected to cost $11 million. The developer will share the cost of the first phase of $2.75 million; the city will cover the rest. Remarkably, the developer claims the right to be able to build up to 400 more houses.

I firmly believe that people should be able to build where they want — as long as they are willing to pay the full cost associated with their location decisions. The problem is not insoluble. Virginia Beach and other coastal localities should establish special tax districts in flood-prone zones, with provisions to expand the geographic scope of those zones as sea levels rise. Property owners in those zones would be assessed a tax surcharge to fund infrastructure projects — storm water drainage systems, flood control berms and dikes, the re-engineering of roads and bridges, whatever — deemed necessary to protect the community. The tax structure should be adjusted to penalize sprawling, low-density housing projects that require greater public investment and reward compact, infrastructure-efficient investment.

The risk of sea-level rise is likely exaggerated, but no one knows for sure. It is not right to transfer that risk — however great or small — from home-owners in flood-prone areas to the tax-paying public. The time to enact reform is now, not when the floods are upon us.

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6 responses to “Another Warning of Sea-Level Rise

  1. Is it fair to transfer the risk to homeowners caused by VDOT’s refusal to maintain its drainage systems that are part of the highway infrastructure? Has SmartScale eliminated availability of funding for routine maintenance and revenue sharing where counties pay half the cost of doing VDOT’s job, or is it a not so subtle push toward devolution to make counties take over road maintenance?

    Virginia Beach and Hampton Roads overall are subsiding from excessive water withdrawal. Land Subsidence and Relative Sea-Level Rise in the Southern Chesapeake Bay Region(USGS Circular 1392) showed half of that area’s sea level rise was subsidence. Allowing land to become and remain saturated also causes subsidence through compaction, and reduces the ability of land to absorb rainfall.

    We may be experiencing a change in weather patterns that will bring more precipitation. That’s not the same as sea level rise. The Commonwealth’s stormwater policies of retaining rainfall on new development sites are making the situation worse. And allowing developers to build more by using mitigation credits from another area, or transfer of development rights, or whatever the current way of avoiding responsibility is, can only make the situation worse.

    I’ve pointed out before, when neighborhoods at higher elevations in an area are flooded and lower ones aren’t, it’s drainage that doesn’t work, not sea level rise impacts. You can’t fix what you won’t acknowledge.

    By the way, the tide gauges are still recording 3 to 6 mm a year (1 to 2 feet in a century) Check out the trends based on actual NOAA measurements.

    • Cjbova, I completely agree with you, the Mobjack Bay/Hampton Roads area already has a severe subsidance problem independent of global warming concerns. As the USGS explains in great detail, and I’ve tried to summarize below, there are several factors involved: [BTW, your link above doesn’t work; use this one for USGS Circular 1392: https://pubs.usgs.gov/circ/1392/pdf/circ1392.pdf ]

      (a) Geologically speaking, the continental crust — from the Fall Line to the edge of the continental shelf under the ocean — is still sinking slowly from the last time it was uplifted (when the Atlantic Ocean last was closed, before Pangaea split up about 240 million years ago). This sinking is mainly due to elasticity in the mantle below the east edge of North America but also reflects the weight of undersea deposits which continue to accumulate on the continental shelf.

      (b) The weight of the glaciers covering North America until about 18,000 years ago caused the continental crust to sink downward into the mantle, creating at the surface a huge depressed region (the water filled depressions we still see today such as the Great Lakes and Hudson’s Bay are visible remnants). South of the glaciated area, the displaced mantle resisted being squished sideways and pushed the crust upwards; this upward motion extended across what is now the mid-Atlantic region. With the ice now gone, the continent is still recovering by rising in the glaciated areas and sinking in the area beyond the ice that had been uplifted. This elastic movement contributes to the sinking of the Tidewater Virginia surface today.

      (c) The surface of Tidewater Virginia is sinking faster than it should in certain areas due to rapid depletion of water below the surface; according to the USGS this is worst around West Point, VA and Franklin, VA due to high levels of extraction for drinking water and industrial purposes there, but affects the entire Tidewater region. Mobjack Bay happens to be within an ancient (35 m.y. old) meteor crater so the subsurface aquifers are structured somewhat differently; there the sinking due to hydrology is less rapid than in other parts of the region but continuing compaction of the rubble within the crater may partially offset this.

      So Tidewater Virginia is already sinking. Global Warming merely makes the situation worse. How much worse remains to be seen; but in any event the notion that nothing is going to happen to sea levels around Hampton Roads is already demonstrably false.

    • drippert beneath his Remembering Tim Kaine’s Caribbean Vacation post, comments that the “grass roots journalism” that replaces MSM news “will be a labor of love run by people who willing to work for little personal compensation based on a desire to see the truth told in America again.”

      Cjbova’s and acbar’s comments above are sure proof of drippert’s observation.

  2. It’s not only the sea coming ashore like Hurricane Sandy did – which not only wiped out many private property but did billions of dollars of damage to public infrastructure, tunnels, etc.

    I do not think it is smart to look at this in terms of whether it is “exaggerated” or not when actual events are occurring already – and the flood insurance program is in big trouble because of so many folks making claims and others still wanting to stem future losses by getting more subsidized insurance.

    Here’s the answer to the “exaggeration” idea. Suppose we repeal the Flood Insurance program all together and let private sector insurance handle that “exaggeration” question. What would private sector insurance do with these “flood prone” properties? My guess is that the premiums .. if you could actually get coverage would be greatly “exaggerated” AND you could not blame it on government or “activists” – just plain old economic realities.

  3. Sea level rise may be exaggerated, but there is also reason to be concerned that temperature and sea level rise will be much higher than predicted by current models. The last time we had CO2 levels as high as we are facing now, there were no humans on the planet, temperatures were ~9-15 degrees hotter, and sea level was ~130 feet higher than today.

    Source: a very recent article over at Ars https://arstechnica.com/science/2018/06/are-past-climates-telling-us-were-missing-something/

    To quote: “Consequently, sea levels rose by a whopping 40 meters or so (~130 feet). To put that in perspective, Mid-Miocene-like sea levels today would draw a new US Atlantic coast roughly along Interstate 95 through Philadelphia, Baltimore, Richmond and Fayetteville, North Carolina, inundating the New York-New Jersey-Connecticut metro area, Boston, most of Florida, and the coastal Gulf of Mexico. Similar things would happen across densely populated lowland areas around the globe, home to a quarter of the world’s people.”

    …This may also just be fear mongering, but the research is good. The geological record may be a much more concrete view of where we’re headed than our predictive models today. If so, we’re in for some very big changes — even if we manage to slow things down.

    Which is to say: we should absolutely not be subsidizing risky coastal developments.

    (One point of disagreement with the article: recent satellite data shows that sea level rise is accelerating, not steady-state: https://arstechnica.com/science/2018/02/yes-sea-level-rise-really-is-accelerating/)

  4. Check out the film Tidewater on PBS. That should give pause for thought in certain areas.

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