July 28, 2013

Rising Seas Part 1: Sea level, sinking land put Maryland’s waterfront communities at risk

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This is the first in a series about Maryland’s sea level rise put together by the Capital News Service of the University of Maryland Philip Merrill College of Journalism. It was written by graduate and undergraduate student journalists under the direction of experienced editors.

The stories frequently attribute the rising water to “climate change,” which most people believe in but some do not. Whatever the cause, there is no question that the water level in the Chesapeake Bay is getting higher, a combination of the sea rising 3 to 4 millimeters per year and land sinking about 7 millimeters per year. In the past century, sea level rose over 1 foot. Here is what will happen this century to Maryland’s 7,700 miles of coastline.

By Brandon Goldner

Capital News Service

Chesapeake Bay satellite image. Photo by University of Maryland Center for Environmental Science

Photo by University of Maryland Center for Environmental Science

CRISFIELD, MD – Noah Bradshaw knows what the rising waters of the Chesapeake Bay can do to a community.

The 68-year-old city inspector grew up in a house in town that had been moved from nearby Holland Island a century ago.

“Holland Island is gone,” Bradshaw said. “It’s underwater.”

The last house disappeared into the bay two years ago, marking the demise of an island once 5 miles long and home to a fishing community of 300 residents.

Now, rising sea levels and sinking land, the same forces that doomed the island, threaten Crisfield, its seafood industry and its 2,710 residents. And a newly discovered tidal pattern puts them in greater peril than previously known.

“This is our home, and eventually, this will be underwater,” said Bradshaw, a bespectacled, balding man with a white beard. “We know that, because the sea level is rising.”

Scientists say sea levels around the world are rising, that storms are intensifying due to climate change, and that policymakers need to make tough decisions on where to spend limited resources to protect the shoreline and what to let go.

View from Martin State Airport toward the Chesapeake Bay.

View from Martin State Airport toward the Chesapeake Bay. Photo by Crazy Diamond.

Difficult choices

Maryland’s leaders may need to make those difficult choices sooner than other regions.

In his state-of-the-state address this year, Gov. Martin O’Malley warned that Maryland is one of the most vulnerable states in the country to rising sea levels.

Studies show he is right. The Chesapeake Bay is rising at two to three times the rate of worldwide sea levels. It rose more than a foot over the past 100 years and is expected to rise 2 to 5 feet within this century. (See the interactive map at the bottom of the story.)

Property all along Maryland’s meandering shoreline is at risk, from the seaside mansions of Anne Arundel and Talbot counties to the modest cottages of Somerset and Dorchester counties.

Industrial powerhouses like the Port of Baltimore, ecological treasures like Blackwater National Wildlife Refuge and historic sites like the Harriet Tubman monument all lie in the path of rising sea levels.

Lawmakers say they want to protect Maryland’s waterside. But the coastline is 7,700 miles long, according to updated measurements by the Maryland Geological Survey.

Aerial view of Riviera Beach in Anne Arundel County. Photo by add1sun

Aerial view of Riviera Beach in Anne Arundel County. Photo by add1sun

That’s twice previous estimates, because of improved aerial imagery and more complete accounting of coastal inlets.

Not all can be saved. And that is a touchy issue in a state where an estimated 900,000 people — a sixth of the state’s population — live in neighborhoods likely to be affected, a CNS analysis of census and U.S. Geological Survey data found.

The state has adopted measures to protect its own property but ceded the tough decisions about the fate of coastal communities to local officials — questions such as whether and when to build sea barriers, elevate land and buildings, or retreat inland.

Plan? What plan?

Yet when researchers interviewed local officials all along the shoreline for a 2010 study, they found “no explicit plan for the fate of most low-lying coast lands as sea level rises.”

Significant resources are likely to be poured into saving property in some of the bigger cities, such as Baltimore and Annapolis. But shore protection is unlikely along 60% of the Eastern Shore, said the study, which was done for the U.S. Environmental Protection Agency.

Baltimore Inner Harbor (By CaDeltaPhoto)

Baltimore Inner Harbor (By CaDeltaPhoto)

That Eastern Shore stretch is dotted with rural, poorer and less-populated areas. The Maryland Department of Natural Resources offers communities financial assistance for sea-level rise planning through its federally funded CoastSmart Communities program. Just four of 16 coastal counties and the city of Annapolis have taken advantage of the program in the past five years to develop plans or guidance documents.

Dorchester County, just north of Crisfield, is among the few. Yet local planners “anticipate that most of the county will not be protected from sea level rise” due to “economic difficulties that the county and its residents are experiencing,” the study said.

“Some of the solutions are very costly or very delicate in terms of making decisions about what areas you’re going to protect and what areas you may not be able to protect,” said Zoe Johnson, climate change director for the Maryland Department of Natural Resources.

“There’s a lot of public and social issues with making those decisions. Not many politicians are ready to take that on.”

Combination of rising water and sinking land

Chesapeake shorelineMaryland’s predicament is due to a troublesome combination of rising water and sinking land.

The land in the Chesapeake region has been sinking over the past 1,000 to 2,000 years, said Raymond G. Najjar Jr., a Pennsylvania State University oceanographer who has studied the impact of climate change on the mid-Atlantic coast.

Called subsidence, the land has sunk 1.3 millimeters each year on average — a trend scientists say is likely to continue at its current rate.

The rise in sea levels is a relatively new phenomenon and part of a global trend. As the earth warms, polar ice caps melt, the volume of water in the oceans expands, and sea levels rise.

Sea levels worldwide rose on average 4 to 8 inches during the 20th century — but more than a foot in the Chesapeake region.

The rate that sea levels are rising appears to be accelerating, Najjar said. The bay is very likely to rise 2 to 5 feet more by the end of this century, according to his and others’ studies. They also predict more intense storms, bigger water surges during storms, and higher high tides.

CNS analyzed the potential impact, using land elevation data from U.S. Geological Survey and population survey data from the U.S. Census. The effect of local man-made structures, such as seawalls, is difficult to determine and not included in the calculations.

The analysis found that if sea levels rose just 2 feet, water would cover roughly 800 square miles, a 12th of the state, inundating part or all of neighborhoods where nearly 900,000 people live.

At an increase of 5 feet, roughly 1,900 square miles would be underwater, reaching into neighborhoods with about 960,000 people and 440,000 homes worth more than $200 million. An estimated 3,700 miles of roads would be underwater.

Already, more than 13 islands in the bay have disappeared.

On the mainland, high tides alone are enough to prevent charter fishing boats from clearing Fishing Creek Bridge on the western shore — and fill roadside ditches in low-lying areas across the bay, such as Somerset County, where Crisfield is located.

“They have this tradition of working with nature and being able to adapt,” said William Nuckols, who co-authored the 2010 EPA report. “Whether they’re able to work with the increased rate that we’re expecting in terms of the changes they may see, that’s a little more of an uncertainty.”


 

  • abby_adams

    So we are experiencing “subsidence” that has gone on for over 1-2 millennia & the water level in the Bay is rising at a faster rate than other sea levels around the world. Since, as we are reminded, the Bay is the final destination point of all waters in the Susquehanna watershed (necessitating the “rain tax” plus additional taxes for cleaning downstream pollution) wouldn’t the inflow from population growth have some impact on the above “normal” sea level increase? Buying into a theory that may or may not prove genuine makes little sense & only excites visions of “Waterworld”. As for those communities who have enjoyed the ambiance of waterfront living, they know or should know the risks. I cannot envision someone living in Cumberland being freaked out abt flooding McMansions along the Severn.

  • craigpurcell

    The Annapolis Markethouse sets about 4′ above MHW and clearly will be impacted by f future flooding & rising sea levels. It is an election year in the Ancient City and this sea level rise issue combined with land subsidence concerns should be front and center especially in the Mayor’s race & Ward One in light of future City Dock Plans, the Fawcetts redo, Height Bulk Ordinance, etc… as well as in Ward 8 generally. Eastport which will definitely be impacted due to its low lying conditions.

    Read the October 2011 ” Regulatory Response to Sea Level Rise and Storm Surge Inundation” report done for the City of Annapolis at link below:

    http://www.dnr.state.md.us/CoastSmart/pdfs/Annapolis_RRSLRnSSI.pdf

    See text below from the report:

    “Ongoing comprehensive and neighborhood planning. The impacts of sea level rise should be incorporated into city planning for areas that may be impacted by coastal flooding. Annapolis already has made progress in this area through the City Dock and Eastport studies and this report. Future planning efforts can continue to evaluate the need and options for protecting historic structures and waterfront areas; identify public utility structures and equipment that may be enda ngered by floods; review needs for drainage and road improvements to allow access to fl ooded areas; and revisit the code sections reviewed in this report.”