Sea Level Rise (SLR)/Flood

Coastal Flooding Storymap by NOAA

How coastal communities are being impacted by sea level rise and the data that can help

NOAA/NOS, Old Dominion University, ESRI - March 4, 2022

https://storymaps.arcgis.com/stories/4faf6d052c8f41b3b9b99c506642bca5

Why is SLR faster here locally?

Sea level rise is not the same worldwide.  There are different factors that influence that such as proximity to ice sheets, ocean currents and land subsidence.  

• Land subsidence in the region - a major reason being glacial isostatic adjustment.  

• A slackening of the Gulf Stream.  Normally the Gulf Stream “pulls” water away from our coast but now it is slackening due to climate change, and so water is not being pulled away as much, contributing to some of the rise we observe.  

• The melting of ice sheets.  Ice sheets pull water towards them but as they melt, that gravitational pull lessens and freshwater is added to the oceans, which affects the Earth’s gravity and rotation.  This ultimately contributes to higher sea level rise at locations farther away from the ice sheets as compared to locations closer to the ice sheets.  

So putting all of these factors together results in our region having a higher rate of SLR.

"Sussex County contains the flattest land in the state. This  characteristic has led to the saying that the state contains two counties at high tide and three at low." 

- from The History of Sussex County, Delaware  by Harold B. Hancock, printed 1976

U.S. Flood Strategy Shifts to ‘Unavoidable’ Relocation of Entire Neighborhoods

Using tax dollars to move whole communities out of flood zones, an idea long dismissed as radical, is swiftly becoming policy, marking a new and more disruptive phase of climate change.

• 8/26/2020 - Christopher Flavelle 

https://www.nytimes.com/2020/08/26/climate/flooding-relocation-managed-retreat.html?auth=login-google&campaign_id=9&emc=edit_nn_20200827&instance_id=21656&nl=the-morning&regi_id=117831520&section_index=1&section_name=big_story&segment_id=37015&te=1&user_id=55000fa24252e91891d04ca6e56af901 

It is about time we stop building on vulnerable lands in the first place.

The growing power of hurricanes

• 8/27/2020 - New York Times,  David Leonhardt 

https://mail.google.com/mail/u/0/#inbox/FMfcgxwJXfhvtpsngTpLxpXzNgCFKkdJ 

"Hurricane Laura shares something in common with both Hurricane Florence, a 2018 storm that killed 52 Americans, and Hurricane Katrina, which struck Louisiana 15 years ago this week. All three changed from more typical hurricanes into severe ones in just a day or two.

That kind of rapid intensification — to use the scientific term for it — used to be rare. In recent years, it has become more common."

The Category 4 hurricane Laura strengthened from Cat 1 in 1 day - not enough time for warning

 Deadly storm surges of up to 15 feet, the National Hurricane Center warned, is "unsurvivable.” 

Understanding Flood Risk

Helping DE Communities Prepare for Storm Flooding and Sea Level Rise

• Sea Grant Delaware

https://www.deseagrant.org/flood-risk#preparing-for-a-flood 

COASTAL OBSERVER APP

UD and Delaware Sea Grant create app to document current and increasing impacts of weather

https://www.udel.edu/udaily/2020/june/Delaware-Coastal-Communities-Sea-Level-Rise-App/ 

"Coastal Observer was launched at the end of August 2019 and since that time, the app has been growing steadily with hundreds of users posting throughout Delaware and even from surrounding states. "

Tidewater - Documentary Film

Water is rising, land is sinking, military is here to stay. In Hampton Roads, VA, the U.S. military is fighting to save its highest concentration of bases from sea level rise, attempting to solve one of the greatest challenges to our national security and economic prosperity the nation has ever faced.

(free with Amazon Prime)

https://www.amresproject.org/tidewater-film 

Tide rises in the Cape Region - Photos

The season’s first nor’easter, the morning high tide and a nearly full moon Oct 11 put Delaware’s Cape Region’s roads and yards underwater.  

Oct. 11, 2019 

https://www.capegazette.com/article/tide-was-rising-cape-region/190635 

Sea Level Rise.Org

https://sealevelrise.org/

Flooding Has Increased by an Average of 233% in the Last 20 Years

Although the sea level has risen by 6.5 inches since 1950, nearly half of it (3 inches) has occurred in just the last 20 years. This small increase in sea level has caused on average a 233% increase in tidal flooding across the United States. Minor increases of even an inch in the sea level are causing real problems everywhere—from Texas to Florida to New York. Higher seas mean more water and more flooding during high tides, hurricanes, and rainstorms. 

The Rate of Sea Level Rise Is Accelerating

• 1981-2016    6" rise

• 2017-2030    expected 6" rise

The Essentials of Coastal Ecosystem Conservation

Mangroves and Seagrass: The Future of Blue Carbon Financing

• Alison Reiszadeh - Sep 6, 2020

https://medium.com/climate-conscious/the-essentials-of-coastal-ecosystem-conservation-b8c5a191de71

" . . . the carbon sequestration capacity of mangroves and seagrass is far greater than tropical forests; they are classified as “carbon sinks” (see graph). For example, seagrasses are known as the “lungs of the sea” because one square meter of seagrass can generate 10 litres of oxygen every day through photosynthesis. "

‘Ghost forests’ are spreading across US coastal regions

Encroaching saltwater is turning forests near the coast into haunting landscapes.

BY ELLIE SHECHET APRIL 09, 2021

https://www.popsci.com/story/environment/ghost-forests-east-coast-us/

The area the researchers were studying is protected, which makes the tree deaths all the more nerve-wracking. “We’ve worked really hard through legislation and protection to hold on to these remaining coastal forested wetlands, and now they’re threatened by something that doesn’t respect those boundaries,” says Bernhardt. 

And these results aren’t necessarily unique to North Carolina, says Kirwan. This pattern is being observed all over the U.S. Atlantic coast, particularly in the mid-Atlantic and the Southeast. 

“The findings that they’ve observed historically are only going to intensify,” he said. “In the future, marshes are going to replace coastal forests at ever-faster rates.” The marshes themselves, of course, are not endlessly resilient.

“If there’s not room for the marshes to migrate, if there’s cities or infrastructure in the way, then the ongoing loss of the existing marsh might exceed the ability of marshes to migrate inland.” 

Where should we say Delaware stands on the issue of preservation of the state while its coastline is sinking and new housing developments are going up on every available farmland and up to the edge of every land with coastal view or water access? 

Anyone who refute the idea of rising sea level, would you please explain that somebody made up the story of Smith Island and Tanger Island sinking and disappearing? Sure, they are not in the Atlantic Ocean, but in Chesapeake Bay. Does that make Delaware safe from rising sea level? Delaware sits on the lowest average above-sea-level elevation among 50 states. Yes, lower than City of Houston. The 100-year-weather incidents do not happen every 100 years any more and we hear of the records being broken more often than we should expect.

Just watch what is in discussion by Dirickson Creek in Frankford! Most of the proposed site of Old Mill Landing South and North are not suitable for buildings according to PLUS Review. Some might ask, why do you care while living dozens of miles away. It will affect all Delawareans when these new developments get flooded and exacerbate the situations in surrounding areas. Who will bear the burden of shoring them up or even rescuing them? Definitely not the developers who put them up, nor the land planners and zoning officials who approved them! Is Delaware setting aside the emergency fund for each such risky developments that are approved? Why should Fed even put up a dime from FEMA fund when the states put themselves at risk against warnings? Every state and Fed must ask this question.

Delaware may reek in transfer taxes today by selling out its best asset, the environment, to the developers and landowners who want to cash in while they can. But the public demands answers that will ease their minds and put their trust in the elected officials who are voted into the positions to take the state to the right direction.

The focus of the future revenue source for Delaware, especially Sussex County, must shift from its heavy reliance on transfer taxes to the economic development supported by statewide high speed internet and transportation improvement, including air or rail travel that offers easy connection to the tech hubs outside of the peninsula, among other things.

Eul Lee

Bolsa Chica wetlands face dire threat from sea-level rise

Restoration of Bolsa Chica Wetlands could be erased by the rising ocean

Orange County Register, 4/7/2022

One of the great environmental success stories of the past 30 years has been the resurrection of the Bolsa Chica wetlands. Hundreds of species of birds, reptiles and mammals use the wetlands, an area that once was blighted and slated for development. But a new report says it all could be erased by the rising ocean.

Sea-level rise could wipe out precious habitat at Huntington Beach’s Bolsa Chica wetlands and eventually flood neighborhoods just east of the ecological reserve, according to a new study three years in the making.

But ongoing estuary maintenance and continued improvements — including new levees and elevating some existing wetlands — would preserve and improve existing wildlife ecosystems. Such work also would bolster the buffer that the wetlands provide for adjacent homes against rising seas, the study found.

Because portions of the 1,400-acre wetlands have subsided as a result of decades of oil drilling, there is growing urgency to take action — and the opportunity to provide a model for the state’s other remaining wetlands.