The Mayor of Tangier Island is Right

By Carol J. Bova

(Originally posted as a response to James A. Bacon’s blog, “Does “Ooker” Estridge Know Something the Experts Don’t” on Bacon’s Rebellion about sea level rise impacting Tangier Island in the Chesapeake Bay. Tangier Island is losing about 16 feet a year on its western side and 3 on the eastern.)

“Ooker” Estridge is right that Tangier Island’s problem is erosion, and he’s got hard science behind that statement. While sea level rise is a long-term issue and increased monitoring of local impacts is important, that’s not why Tangier Island is endangered. Lewisetta is the nearest tide gauge and not out in the Bay, but the local sea level trend is 1.7 ft in 100 years, which is less than a quarter inch per year. So there’s more in play there.

“Storms provide the greatest source of coastal change on barrier islands due to storm surge and strong waves. Surging water and stronger waves can erode barrier island beaches and, if the surge is high enough, result in overwash, breaching, or back bay flooding… .” (U S Army Corps of Engineers, North Atlantic Coast Comprehensive Study: Resilient Adaptation to Increasing Risk. January 2015.)

Tangier Island is a barrier island, and like all barrier islands and barrier beaches, it’s made up of sand-sized sediment that is deposited, moved, and reformed by wind and waves. Political positions about sea level rise have ignored the reality of longshore transport of sediment (also called longshore drift). If the sand supply is not maintained, the island erodes to the point where it is inundated by the tides. No one realized in the 1700s how fragile these bodies are, or that it wasn’t a good idea to build on them.

NOAA relates the story of Tucker Island in New Jersey, settled in 1735, and how attempts to stop longshore transport of sand using jetties in 1924 eventually caused the loss of that barrier island.

We have the same problem on the Chesapeake Bay coastline in Mathews County where we’ve just about lost Rigby Island, another barrier island, and have a breach in the Winter Harbor barrier beach caused by a nor’easter in 1978.  Beach replenishment could repair it and restore the protective function of the barrier beach against storm surge flooding, but the Virginia Institute of Marine Science and the Corps of Engineers chose instead to only supplement the tiger beetle habitat below the breach, allowing the breach to continue to widen.

The Virginia Department of Transportation helped create the problem by removing 5-7 feet of sand from the beaches to the north of Winter Harbor in the 1930s and 1940s to use to build roads in two counties. (This was confirmed by a memo in VDOT’s files.)

The Corps of Engineers also helped create the problem by working with the County to open a channel directly from Garden Creek to the Bay. The jetties they built to keep the channel open failed, but they also prevented the movement of sand southward to the Winter Harbor barrier beach leading to its breach.

Wetlands Watch joined with the Middle Peninsula Planning District Commission (MPPDC) in blaming sea level rise for the loss of the barrier beach and barrier island around the New Point Comfort Lighthouse in the NOAA grant-funded MPPDC Climate Change Adaptation Phase 2 report and repeated the claim in the 2011 Phase 3 report with slides implying sea level rise causes the lighthouse to be left on a tiny island. One has picture of the lighthouse in 1885 and “today” with the caption, “shoreline has moved 1/2 mile.” Another says, “TODAY – 5 ft water covers more than 1,000 plated subdivision lots.”

 

 

 

 

 

 

 

 



The platted subdivision only existed on paper because the project failed financially in 1905. Much of the barrier island and barrier beach were lost in the 1933 August and September hurricanes, and the rest lost through longshore transport after that.

The reports include those slides and a mocking cartoon about the “Coconut Telegraph,” alluding to person-to-person communication between Mathews citizens, as part of Power Point presentations made throughout Virginia and in other areas on sea level rise by MPPDC Executive Director, Lewie Lawrence.

 

 

 

 

 

 

 

 

 

When local observations are ignored in favor of political positions, everyone loses. Tax money is spent on the wrong responses and real problems get worse because they’re not acknowledged.

People who come from generations who’ve lived in the same place may not have the university degrees, but they have knowledge that could benefit the universities and government agencies who disregard them.

In the http://www.nad.usace.army.mil/Portals/40/docs/NACCS/NACCS_main_report.pdf”Hurricane Sandy report, the Corps of Engineers places barrier island and barrier beach preservation among the highest Coastal Storm Risk Management and Resilience measures, short of removing buildings from the coast.

 

 

 

 

 

 

 

 

 

 

 

 

 

 



Too bad no one considered this kind of replenishment for Tangier Island while there was a better chance of saving it.

 

Beavers Love BMPs
(Big Messy Projects)

By G. C. Morrow

Wards Corner Outfall Beaver Dam

Wards Corner Outfall Beaver Dam

I decided to look at previous projects to see if I could find a pattern in their failures. It is extremely hard to conceive that these projects with their half million plus engineering budgets fail so miserably at their purpose. At first glance, it appears that the engineers are attempting to move their drainage conveyances to more accessible locations, but even the greenest of engineers should know better than to try to drain water uphill.  (G. C. Morrow, June 15, 2016)http://insidethecrater.com/714-2

Most of the environmental and pollution problems we are facing in stormwater management can be traced to very simple explanations and solutions. I warned in 2016, “South of Wards Corner, there are three outfalls much lower in elevation than the one at Wards Corner, and they are necessary to handle several hundred acres of stream flow, as well as roadside drainage.”

Beavers are drawn to the sound of water whose flow is disrupted. They have invaded the Wards Corner outfall, as well as two unmaintained neighboring outfalls.

I saw three dams at Wards Corner this week. At one place, the dam filled the outfall to the top, about 6-8 feet deep. Water was overflowing next to a 36-inch pipe and cut through the earth surrounding the pipe to create a spillway. This eroded soil is going downstream into the marsh.

Similar erosion has occurred around the 36-inch pipe at the start of the outfall off the shoulder of route 198. Old-fashioned concrete endwalls would have prevented the erosion at both locations, but today, only cosmetic plastic endwalls are used–and this project didn’t even use those.

We won’t know until the dams are cleared exactly how the beavers managed to block the flow so well. If the outfall had functioned properly, draining within 2-3 days after rainfall, there shouldn’t have been enough water to attract beavers in the first place, especially since the outfall is uphill of most of the area it’s supposed to drain.

A large number of saplings, stripped of their bark, are lined up on the banks near the dam, ready to be used to enlarge or repair it. The beavers will continue to stop the water as long as it’s moving slowly enough for them to harness it to float the saplings into place.

It appears that using rock checkdams to slow down the water flow in a rural environment is not the right answer. Putting the drainage in the right place might have been a better idea.

Makes you wonder why the state spent $1.6 million to cause perpetual flooding of downstream locations. A much smaller amount could have restored the outfall to Stutts Creek behind the high school, and cleared or even replaced the pipes in the VDOT easement along the football field. Doing that would have conveyed the water from Route 198 to the creek and not let it flood the school and park properties. Now, the county is being asked to fund half the cost of the restoration through revenue sharing or continue to suffer the damage of its property. It may be that VDOT’s failure to maintain an outfall inventory meant the designers didn’t know about the existing outfalls.

At some point, VDOT designers and engineers have to use real world considerations and get away from their laptop configurations. Overbuilding to create a new construction project, instead of developing a simpler restoration of existing structures, is not a better value-based decision in the long run, even if federal money is involved. And that era may be ending soon.

 

The following pictures are taken at the shoulder on Route 198 looking toward the area with the beaver dam showing the progressive erosion.

Wards Corner 2012

Wards Corner 2012

2013--eroded area 4-feet wide

2013–eroded area 4-feet wide

2014

2014

2015

2015

2016

2016