Tag Archives: sea level rise

Time to Pay Attention to Oxygen for the Bay

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Blocked VDOT roadside ditch flooding adjacent land.

Blocked VDOT roadside ditch flooding adjacent land.

I wrote a report in 2012. If anyone in authority had paid attention then, we’d be seeing results now, instead of looking at more flooded ditches and damaged roads. Expect our TMDL numbers (total maximum daily load) for E. coli levels to stay the same, because the problem is not primarily land-based. It’s VDOT ditch based.

Although nothing about dissolved oxygen levels made it into the final EPA-accepted Water Quality Improvement Plan, there was a recommendation for a Ditch Task Force involving the Virginia Department of Transportation. The intent was to discuss and plan ways to improve the drainage for our state roads. Instead, we have the Middle Peninsula Planning District Commission advocating the creation of a Ditching Authority to charge landowners and counties for VDOT’s failures.

MPPDC is basing its Ditching Authority concept on states and countries which drained wetlands for agricultural purposes–and must continue to drain them to continue farming. Ohio, for example, drained 7.4 million acres of wetlands, and today, 2/3s of their cropland and 500,000 homes depend on that land staying drained. They have a Ditching Authority.

Our drainage problem is rainfall from state roads cannot reach receiving bodies of water because of failed and neglected VDOT maintenance. The cause is not wetland drainage, not agricultural land drainage, not private property drainage, not sea level rise, not land elevation or land subsidence.

Read the report and see for yourself if it makes sense.

Report for Working Groups for the Shellfish TMDL Implementation Plan for the Piankatank River, Gwynns Island and Milford Haven Watersheds, August 27, 2012

submitted by Carol J. Bova

A review of the original Shellfish Sanitation Surveys and outstanding violations for the Piankatank River, Gwynns Island and Milford Haven Watersheds doesn’t document enough ongoing septic system violations to account for the continuing high levels of bacteria in the TMDL waters. From the June 30th report, only Healy Creek had one prior uncorrected septic issue. There were two kitchen deficiencies: one at Healy Creek and one at Edwards Creek.

There are no large agricultural operations, fewer farms than decades ago when the waters were not impaired, and not enough hobby livestock to account for current bacterial impairments. It’s equally unlikely that pets are the main factor, and while wildlife contributes a significant amount, it is not the sole source.

Based on scientific findings over the last six years across the United States, in Canada and in Europe, naturalized E. coli is the most likely major source of the ongoing high bacterial readings.

These studies show E. coli does not require a human or animal host to survive for extended periods in soil, sand, sediments and water. Wind and storms stir up sand and sediment and release bacteria back into the water column. Bottom feeding fish like spot and croaker can take in E. coli while feeding and become carriers. Studies in Michigan show E. coli can survive 5 months in water as long as the temperature is above 39 degrees Fahrenheit. Average water temperatures for the TMDL areas only go below that in January and February and may not go that low in some years. E. coli doesn’t only survive on its own–it can reproduce if it has adequate carbon based nutrients. The presence of muck, which is partially decomposed vegetation, provides that nutrition and shelters E. coli, because no sunlight can get through it. It takes four days of sunlight to kill E. coli.

Part of the key to eliminating E. coli in the TMDL waters is to get the water clear enough to allow sunlight to penetrate. The plan to restore oysters is intended to do that, as well as filter the water, but oysters can’t live in the muck and must be suspended above it. The headwaters and some of the small inlets of the creeks are among the worst areas, with heavy muck, little circulation and probably low levels of dissolved oxygen in the water which must be addressed before oyster placement. Submerged aqueous vegetation will also benefit from more sunlight.

The long-term goal of restoring oysters is solid, but needs to be backed up with a multi-layered approach to cleaning up the waters, with a plan tailored to the characteristics of each TMDL segment. In Queens Creek, for example, at least 3-4 feet of muck exists on the sides of the channel, possibly more in the center. If the channel could be dredged to remove most of that muck, the creek could then be treated with probiotic decomposer bacteria to help break down what remains. This would create a more favorable environment for oysters and other water animals and allow sunlight to reach deeper into the water, killing even more E. coli.

Using small aeration units attached to private docks to provide additional oxygenation has been tried in Maryland. William Wolinski of Talbot County Maryland Dept. of Public Works stated the aeration used there from May through October created ‘oxygen sanctuaries’ for fish and other creatures and allowed positive bacterial action to break down sludgy sediment. A simple unit costs about $500-$600 and covers 1/4 acre placed at a 4′ depth according to one manufacturer. Any aeration provided will improve the action of probiotic bacteria in decomposing muck sediments.

Before any direct action is taken in TMDL creek headwaters and inlets, the Virginia Department of Transportation roadside ditches and related outfall ditches leading to those waters must be cleaned, pipe blockages cleared and overgrown vegetation removed to allow clean rainwater to reach the waterways. Currently, the water in outfall ditches is deoxygenated by decaying plant matter and has little to no flow except during storm events. Major storms flush the stagnant water into areas leading to the headwaters, and the load of rotting vegetation and silt with it adds to the mucky sediment already present.

The Virginia Department of Transportation should be named a stakeholder in the TMDL Implementation Plan for low dissolved oxygen levels in water in ditches which connect to TMDL waters. Credit trading should not be an option because the actions required to improve oxygenation fall within normal roadside maintenance and budget. DCR and DEQ staff can support citizen requests for a VDOT 5-year plan for roadside and outfall ditch maintenance to provide an outlet to an adequate receiving channel and body of water as required by VDOT Drainage Manual policies. This will allow clean, oxygenated rainwater to reach TMDL waters, giving other measures a better chance of success.

New Point Comfort Development Company’s Plans: A Mathews Resort – But Only On Paper

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The last post showed this Wetlands Watch slide used in a Middle Peninsula Planning District Commission presentation.

It’s true you’ll find water and some marshes today where the lots were shown on a 1904 Mathews County subdivision map near the lighthouse. But what the MPPDC/Wetlands Watch slide doesn’t say is the development company planned to fill in the tidal marshes and bring in sand to create beaches. The New Point Comfort Lighthouse site online says that the enormous cost to carry out that plan is what caused the company to go out of business the following year.

New Point Comfort Development Company Subdivision Plan – 1904

 

So what happened to the tidal marshes, sandbars and shoaled areas that existed in 1904 and earlier? And what about the photos and stories of people a generation or two ago who went to sandy beaches at New Point for picnics and outings?

Sand moves with the wind and waves. It is washed away, and bars and beaches reform at another place if there’s enough material available. But major storms can play havoc with that process. The Office of Naval Research describes one kind of current along the coast called the Longshore Current, how it moves, and how it can cause powerful and dangerous rip currents.

There’s an animation of the wave action that can produce sandbars on ONR’s educational Science and Technology Focus website at: http://www.onr.navy.mil/focus/ocean/motion/currents2.htm

With hurricanes and some other storms, the low pressure system increases the speed of longshore currents and height of waves. When these stronger longshore currents produce rip currents, they excavate channels through sandbars. The sand then accumulates in a quieter areas forming new bars. In this way, depending on the number and types of storms, and the intervals between storms, sandbars appear to migrate. When sand is exposed and dry, the wind then moves it to build up beaches–or blow them away. Beaches can only build up when dry sand is available. If the angle of a beach changes, so that the sand remains wet, the beach will not grow and can be diminished by wave action or the effects of storms.

The Chesapeake – Potomac Hurricane of August 23rd, 1933 and the one that hit on September 16th, 1933  ripped through the area around New Point Comfort, leaving two separate islands we see today. But the New Point Comfort Lighthouse withstood the tremendous winds and rain and waves, and isn’t that the story that really matters?

 

The Shoreline’s Moved 1/2 Mile–if Sandbars Count as Shoreline

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The shoreline that moved was mostly sandbars washed away by storms and waves.

This slide was used in a Middle Peninsula Planning District presentation at a  Virginia Coastal Partners Workshop in 2010.  An eye-catching headline, a dramatic image, a subhead intended to reinforce an idea. Wetlands Watch supplied MPPDC with the image, and both organizations used the same picture in separate presentations at the same workshop.

Wetlands Watch used the line, “Climate Change Impacts Can be Seen in Virginia” along with “From 1885 to now–the shoreline has moved 1/2 mile.” The banner across the center of the MPPDC slide says: “THIS PROVES NOTHING!!” To which I can definitely say, You’re right!  This doesn’t prove any sea level rise; it doesn’t prove climate change; and there’s a lot more to this story.

Virginia Institute of Marine Science (VIMS) did a site assessment of the New Point Comfort Lighthouse in 2008, and they noted that “erosion has always been an issue at the New Point Comfort.” The lighthouse was built on a peninsula connected to the mainland by a sandbar. Between the time the lighthouse was built in 1804 and 1832, immense areas of sand had been moved by storms, waves and wind. What follows here is the story of what was done to try to protect the lighthouse during those years, not from rising water levels, but from the relentless scouring of sand from the lighthouse island by waves and wind and storms.

The keeper reported after the Great Coastal Hurricane of 1806 that “a considerable part of the beach washed away & one of the landmarks <indicating the boundaries> was washed up, that was at the distance of 45 feet, when the public land was laid out from highwater mark.”(Candace Clifford, New Point Comfort Light Station – Historical Documentation, 2001) “This hurricane, due to its slow movement and consequent erosion of the coastline completed the formation of Willoughby Spit. A seawall built to prevent further erosion at Smith Point Lighthouse was damaged.” (http://www.hpc.ncep.noaa.gov/research/roth/vaerly19hur.htm)

In 1814, the first report of the extensive damage the British did to the lighthouse in the War of 1812 suggested the lighthouse should be destroyed if the war continued because it was being used as a watchtower, and “the water already washes its base and in a few years will undermine it.” (Clifford, 2001 quoting from the National Archives.) That advice was not followed and in 1815, the original builder recommended 156 pilings of 12-14 ft be sunk 5-6 ft in the sand, and another 100 opposite the house to protect it.

A year later, sand had begun to collect around the pilings and the lighthouse was considered secure. Unfortunately, by 1822, those pilings had rotted in the ground. A stone wall was then approved in 1825, and still more repairs and additional work were done in 1832.

The National Archives holds a request for a boat in 1839 because, “There is now two miles of water communication necessary where until lately there was a ford at low tide.”  In 1846, the keeper reported the “publick buildings were completely surrounded by tidewater.” (Candace Clifford, 2001)

The lighthouse was put out of commission during the War Between the States in 1861, restored in 1865, and once again, a boat was requested for the keeper in 1866. Sand moved and shoals formed in the decades that followed, and gales and hurricanes moved and changed them as they always have. But that’s a function of weather, normal, ordinary weather–capricious and unpredictable, not because of climate change.

The next post will take a look at what happened to the 1904 1,000 lot subdivision of the New Point Comfort Development Company. Or, perhaps more accurately, what didn’t happen.

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Below is a detail from NOAA Nautical Chart 12238, showing water depth in feet in 2009 around New Point Comfort Lighthouse island. (Green areas are marshes.) One small area to the northwest, between the lighthouse and the shoreline is 5 ft as the MPPDC/Wetlands Watch slide said, but north, past a marshy area, it’s 1 ft; to the northeast, 1/2 ft, and east-northeast, 2 ft.

 

The New Point Comfort Lighthouse

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New Point Comfort Lighthouse, date unknown, possibly late 1800’s

 

The New Point Comfort Lighthouse is on an island off the southern tip of Mathews County. It’s the 3rd oldest lighthouse surviving in the Bay, the 10th oldest in the Country, and it’s on the National Register of Historic Places. Efforts are underway to preserve it for the future. (Photo courtesy of the U.S. Coast Guard and the National Archives.)

There’s a great video and a lot of information here: http://www.newpointcomfortlighthouse.org/

There’s also a concise and well-written history on the Lighthouse Digest site:  http://www.lhdigest.com/Digest/StoryPage.cfm?StoryKey=2304

Photo on Ten Mile Hill shows the effect of liquifaction where the intense shaking caused the water to rise and mix with the sand, forming a craterlet with puddled water at the bottom after the shaking stopped.

The lighthouse was completed in 1804, and has survived a number of storms, the War of 1812, and the Charleston Earthquake of August 31, 1886, which shook seven states from South Carolina to New York. Aftershocks  continued for days afterwards, but the lighthouse withstood them all.

(Photo courtesy of U.S. Geological Survey; Photo by C.C. Jones, September 1886. Plate 20, U.S. Geological Survey Annual Report 9, 1887-88)

Currently, the lighthouse is being used as an example of the imminent danger from sea level rise caused by global warming. My next post is going to show why that’s not quite the case.