{"id":21404,"date":"2024-03-25T10:37:00","date_gmt":"2024-03-25T14:37:00","guid":{"rendered":"https:\/\/ncseagrant.ncsu.edu\/coastwatch\/?page_id=19308"},"modified":"2024-08-06T12:20:14","modified_gmt":"2024-08-06T16:20:14","slug":"sunny-with-a-chance-of-floods","status":"publish","type":"post","link":"https:\/\/ncseagrant.ncsu.edu\/coastwatch\/sunny-with-a-chance-of-floods\/","title":{"rendered":"Sunny with a Chance of Floods"},"content":{"rendered":"\n\n\n\n
\n
\n

Researchers and the Carolina Beach community work together to address chronic flooding.<\/p>\n <\/div>\n<\/blockquote>\n\n\n\n

When people see photos of Carolina Beach\u2019s flooded Canal Drive, they might assume those waters lapping against the doorways of a residential neighborhood mean the area had just experienced a severe storm or hurricane. Locals know, however, it is just as likely the deluge was not related to a storm at all but rather an example of \u201cnuisance\u201d flooding.<\/p>\n\n\n\n

\u201cSunny day\u201d flooding \u2014 also called \u201cnuisance,\u201d \u201cking tide,\u201d or \u201chigh tide\u201d flooding \u2014 is one of many challenges climate change poses for coastal communities.<\/p>\n\n\n\n

This event occurs when water levels temporarily exceed an area\u2019s drainage threshold, unrelated to storm surge or riverine influence. As sea levels continue rising, this flooding will happen more often in susceptible locations, including developed areas like Canal Drive.<\/p>\n\n\n\n

In 2021, NOAA reported that high tide flooding happened twice as often as in 2000 \u2014 and that by 2050, some areas could experience up to 75 days of sunny day flooding per year. However, these predictions only reflect ocean drivers and not local factors (such as rain). As such, they may not accurately forecast flooding, and some places do experience more flooding than projections suggest.<\/p>\n\n\n\n

An increase in this sunny day flooding will present even more problems for residents of Carolina Beach, as inundated streets already have forced them to close businesses, adjust routes, or even wade through water to reach their front doors.<\/p>\n\n\n\n

\u201cThe challenges with flooding include trying to mitigate property damage and infrastructure impacts that overwhelm storm drains, deteriorate roads, and monitor saltwater intrusion in town utilities,\u201d says Jeremy Hardison, the planning and development director for Carolina Beach.<\/p>\n\n\n

\n
\n

“Are they going to leave places because climate change is making them so hazardous that they can\u2019t live there anymore?”<\/p>\n <\/div>\n<\/blockquote>\n\n\n\n

Consequently, local leaders and state researchers are committed to bolstering the community\u2019s flood resiliency. A Sea Grant team from North Carolina State University and the University of North Carolina at Chapel Hill have been working alongside Carolina Beach and other communities to document flooding and offer resources to residents through the Sunny Day Flooding Project.<\/p>\n\n\n\n

\"image:<\/a>
High tide flooding has forced Carolina Beach residents to close businesses, adjust their travels, and wade through water to reach their front doors. Credit: Sunny Day Flooding Project.<\/figcaption><\/figure>\n\n\n\n

\u201cMy research originally began around this question of \u2018Are people going to move away?\u2019\u201d says the project\u2019s Miyuki Hino, an environmental social scientist from UNC Chapel Hill. \u201c\u2018Are they going to leave places because climate change is making them so hazardous that they can\u2019t live there anymore?\u2019\u201d<\/p>\n\n\n\n

These questions required measuring the frequency and severity of flooding, which led Hino to Katherine Anarde, a coastal engineer and geomorphologist with NC State.<\/p>\n\n\n\n

\u201cMiyuki\u2019s idea was measuring flooding where people actually live,\u201d says Anarde. \u201cAnd I like tough measurement problems.\u201d<\/p>\n\n\n\n

In Anarde\u2019s previous work, she measured waves during tropical storms, but looking at water levels and flooding in developed landscapes meant finding ways to collect data that would not disrupt residents. They partnered with the town of Carolina Beach to develop a research plan that would work for everyone.<\/p>\n\n\n\n

\"image:<\/a>
Sea level rise exacerbates sunny day flooding \u2014 as do other factors, including inadequate stormwater networks, marsh degradation, precipitation, and even wind. Credit: Sunny Day Flooding Project.<\/figcaption><\/figure>\n\n\n\n

Sensing in Communities<\/h2>\n\n\n\n

Hino says local knowledge is essential in determining where researchers should focus their attention.<\/p>\n\n\n\n

\u201cIn all the places we\u2019ve installed anything, the first thing we\u2019ve done is met with residents and local officials to understand where their problems are,\u201d she says. \u201cBased on their input and the requirements of our sensors, we can work together and figure out what we can monitor and what makes the most sense.\u201d<\/p>\n\n\n\n

Once the research team determines a location, they collect data, maintain the sensors, and ensure the accessibility of the information they gather.<\/p>\n\n\n\n

\u201cOur original approach was Let\u2019s try to get everything in real-time, so we don\u2019t lose data<\/em>,\u201d Anarde explains. \u201cAnd what we found is that these communities really like the real-time data and camera images. So, as we\u2019ve expanded, it\u2019s been more than just monitoring flooding, but actually serving as a hazard communication platform.\u201d<\/p>\n\n\n\n

They deployed sensors that measure current water levels and take photos of the area, which assist in long-term data collection and monitoring of conditions. This enables residents to prepare for flooding by viewing real-time data as water levels rise, while also documenting information that will inform a path toward realistic and sustainable long-term solutions.<\/p>\n\n\n\n

The cameras transmit photos every six minutes. However, once floodwaters reach a certain level, the sensors go offline temporarily.<\/p>\n\n\n\n

\u201cIf the sensor is underwater, we lose communication with it,\u201d says Anarde. \u201cSo you might be on the web app and see that there\u2019s no data, but once the water goes down, we\u2019ll start to get that data again and fill in the gaps.\u201d<\/p>\n\n\n\n

Sensors still provide information about rising waters before contact is lost, though, and the team works to send out flood warning emails for each community they cover.<\/p>\n\n\n

\n
\n

“Every storm drain brings its own challenges \u2014 and eels”<\/p>\n <\/div>\n<\/blockquote>\n\n\n\n

Sometimes, floods bring more than a disruption to coverage.<\/p>\n\n\n\n

Anarde recalls one surprise when she was checking a sensor. \u201cOne time, we saw a dead eel attached to the end of one of our sensors,\u201d she says. \u201cEvery storm drain brings its own challenges \u2014 and eels.\u201d<\/p>\n\n\n\n

\"image:<\/a>
The Sunny Day Flooding Project provides residents with real-time images, such as this king tide flooding in Beaufort. Credit: Sunny Day Flooding Project.<\/figcaption><\/figure>\n\n\n\n

Same Ingredients, Different Recipe<\/h2>\n\n\n\n

Sea level rise exacerbates sunny day flooding, as do other factors like inadequate stormwater networks, marsh degradation, precipitation, and riverine discharge.<\/p>\n\n\n\n

And wind.<\/p>\n\n\n\n

\u201cI was really surprised how much wind matters,\u201d says Anarde. \u201cWe found that wind is often the driver of unexpected flood events in this region. It pushes water into this narrow bay behind Carolina Beach, and that piling up of water overtops the low-lying shorelines and pushes water up through the stormwater network.\u201d<\/p>\n\n\n\n

Stormwater systems themselves can also influence flooding. Duckbill valves \u2014 backflow prevention devices in the drains \u2014 require cleaning and maintenance every few months to work correctly. Additionally, groundwater can enter these systems, leaving very little room for excess rainwater to be stored.<\/p>\n\n\n\n

The Cape Fear\u2019s riverine influence was surprisingly less influential than tides, rainfall, wind, and stormwater systems. However, the degree to which each factor plays a role varies by location.<\/p>\n\n\n\n

\u201cIt\u2019s not that the ingredients are necessarily different everywhere,\u201d says Anarde. \u201cIt seems like the ingredients are consistent across communities. It\u2019s the recipe.\u201d<\/p>\n\n\n\n

This means that a solution to chronic flooding is not one-size-fits all, and afflicted communities must tailor a response to their unique \u201crecipe\u201d of factors.<\/p>\n\n\n\n

\"image:<\/a>
High-tide flooding in Davis. Credit: Sunny Day Flooding Project.<\/figcaption><\/figure>\n\n\n\n

One-Size Doesn’t Fit All<\/h2>\n\n\n\n

To Hino and Anarde, the disruptions that locals report to their daily routines point to the often-neglected impacts of climate change.<\/p>\n\n\n\n

Most people are aware of increasing storm severity, but fewer consider situations such as sunny day flooding in coastal communities or other effects on quality of life.<\/p>\n\n\n\n

\u201cThose types of impacts represent one of the real hallmarks of climate change,\u201d says Hino.<\/p>\n\n\n\n

Problems with nuisance flooding also extend beyond Carolina Beach. \u201cWe\u2019ve had people reach out to us from up and down the East Coast, in New Jersey, New York, Maryland, Virginia, and the Gulf,\u201d she says. \u201cIt\u2019s a widespread problem, but the solutions will be very local.\u201d<\/p>\n\n\n\n

Just as the causes differ by location, strategies, and solutions for one community might not work for another. Furthermore, changes often require altering the landscape or existing infrastructure.<\/p>\n\n\n\n

\u201cOne of the big challenges in adapting to climate change is that it involves many other changes,\u201d Hino says. \u201cAnd the ways that people are going to be comfortable with their communities changing are going to be very different place to place.\u201d<\/p>\n\n\n\n

\"image:<\/a>
Carolina Beach flooding. Credit: Sunny Day Flooding Project.<\/figcaption><\/figure>\n\n\n\n

Resiliency in Carolina Beach<\/h2>\n\n\n\n

Anarde, Hino, and NC State Ph.D. student Thomas Thelen surveyed Carolina Beach residents earlier this year about chronic flooding, hoping to see its influences on daily life and gauge support for potential flood mitigation strategies, such as raising bulkheads and roadways. Thelen has led the development of a high-resolution flood model for Carolina Beach, which the team will combine with information from survey responses.<\/p>\n\n\n

\n
\n

“As physical scientists, we typically come up with all these brilliant engineering solutions that may or may not have local support”<\/p>\n <\/div>\n<\/blockquote>\n\n\n\n

\u201cWhat we\u2019re going to do with that information is try to model some of the strategies \u2014 alongside future scenarios of sea level rise\u2014 to see how good the different approaches are at managing each of these ingredients of flooding,\u201d Anarde says. \u201cWith that, we can start a conversation between community members and the town government on what sequence of flood mitigation strategies may be most desired.\u201d<\/p>\n\n\n\n

Anarde notes a tendency for this process to work in reverse.<\/p>\n\n\n\n

\u201cAs physical scientists, we typically come up with all these brilliant engineering solutions that may or may not have local support,\u201d she says. \u201cWe\u2019re trying to get a sense of what the communities are interested in even doing first.\u201d<\/p>\n\n\n\n

The team\u2019s decision to place Carolina Beach and its needs first is at the heart of finding and implementing solutions for the different recipes that result in sunny day flooding \u2014 regardless of the approach the town chooses.<\/p>\n\n\n\n

\u201cThese are places that are trying to find solutions,\u201d says Hino, emphasizing the resiliency of Carolina Beach. \u201cThey\u2019re taking these steps to come up with a path forward that works well for them and their residents. They\u2019re not unique in the problems they face, and there will be more and more towns with this problem.\u201d<\/p>\n\n\n\n

\"image:<\/a>
High-tide and wind-driven flooding in Carolina Beach. Credit: Sunny Day Flooding Project.<\/figcaption><\/figure>\n\n\n\n

The Path Forward<\/h2>\n\n\n\n

In addition to Carolina Beach, the Sunny Day Flooding Project currently has systems in place in North Carolina at Beaufort, Down East, and New Bern. Additionally, the team is in the early stages of planning to expand its research to Hawaii, another area facing sunny day flooding.<\/p>\n\n\n\n

Moving forward, they hope to turn their attention to more rural areas along our state\u2019s Inner Banks, noting that research on the severity of the problem is lacking in these areas. With North Carolina\u2019s vast networks of river basins and estuaries, many communities farther inland from the coast are also becoming more susceptible to chronic flooding.<\/p>\n\n\n\n

\u201cIt\u2019s important that we turn our eyes towards these areas and focus our efforts on more rural spaces that are underserved by our monitoring networks to try and understand what\u2019s happening there,\u201d says Anarde. \u201cNot just flooding, but also other impacts from sea level rise, such as saltwater intrusion and marsh migration. The burden on these communities is largely unknown.\u201d<\/p>\n\n\n

\n
\n

“In the background are these slow-moving changes that also have a meaningful effect on the people who live there.\u201d<\/p>\n <\/div>\n<\/blockquote>\n\n\n\n

Climate change also is more likely to have a more detrimental socioeconomic impact in rural areas, where residents have fewer resources and often find it more difficult to recover from major flooding events. Climate change\u2019s \u201cminor\u201d but more frequent impacts, such as sunny day flooding, add additional weight to an already unwieldy load.<\/p>\n\n\n\n

\u201cWe can\u2019t just focus on the hurricanes,\u201d Hino says. \u201cWe can\u2019t just focus on these big, catastrophic events. They’re important, of course, and we can\u2019t ignore them. But in the background are these slow-moving changes that also have a meaningful effect on the people who live there.\u201d<\/p>\n\n\n

\n\n\n\n
\"logo:<\/a><\/figure>\n\n\n\n

Safety Tips and Resources for Sunny Day Flooding<\/h2>\n\n\n\n

Waterfront properties and low-lying roadways are most likely to experience tidal or \u201csunny day\u201d floods. If you encounter tidal floodwater, minimize or avoid contact with it.<\/p>\n\n\n\n

Because floodwaters from tidal or storm flooding may contain biological and chemical contaminants, the CDC suggests the following:<\/p>\n\n\n\n