Within a century, scientists predict that king tides will add 2 to 12 feet (0.6 to 3.6 meters) more water to coastal areas as sea levels rise. King tides brought some very high waters these last months to coastal areas of the US and the world.
The term (king tide) is a non-scientific term used to explain exceptionally high tides called perigean spring tides. They occur during a new or full moon when the moon is in alignment with the sun AND in its closest point in orbit to the Earth (perigee), resulting in the greatest gravitational pull.
Tides high enough to flood cities used to be relatively rare, occurring every two to three decades. Now, though, they happen with increasing regularity and it’s common to see flooded streets, parks and waterfront yards on areas surrounded by canals and rivers.
A most notorious occurrence was in Venice, Italy, that because of its tourism attractions “flooded” (pun intended) social networks with pictures of tourists standing on waist high waters. Of the top 10 tides in Venice’s history, half have taken place in the past two decades, and the most recent top five flood event occurred just last year and this last November 2019. The causes of the tidal peaks are the movement and phase of the moon, wind strengths and direction as well as rain level and, the much maligned rising sea-levels. Venice was affected by all these together. Call it a perfect storm!
The city of Venice installed gangways for pedestrians to use, but in the 2018 floods these had to be removed as the water exceeded the raised walkways. Other cities around the world also struggle with rising waters such as Miami and Fort Lauderdale, and have installed pump systems and seawalls to deal with the short term effects of high tides.
Issues with high waters around the world and how they are dealing with the problem
In Jakarta, the capital and largest city of Indonesia, the government has found that the existing embankment on the northern coast of Jakarta, was in critical condition and in urgent need of reinforcement. The project involved 120 kilometers of embankment, and even though it’s several times taller than the maximum tidal height, it has become innefective because of the rapid subsiding which can reach up to 25 centimeters per year.
In New Jersey, the Jacques Cousteau National Estuarine Research Reserve, launched a citizen science project called “Capture the King Tide” to encourage people to snap pictures of the king tide event and upload them to a Facebook page, as a way to document these higher-than-normal tides.
In Miami in 2019, King Tides were expected between August 29 – September 3, September 26 – October 3, October 25 – October 31 and November 24 toNovember 28. Coastal and low-lying areas may have increased flooding due to ground saturation caused by recent excessive rains, and using caution is advised when traveling through these areas.
Most king tide impacts are experienced by coastal property owners and those living in very low-lying areas near other water bodies. To PREPARE for a king tide, one should consider the following options to protect your properties.
- Move your vehicles to higher ground BEFORE a king tide event
- Keep sandbags on-hand
- Consider obtaining an elevation certificate from a licensed surveyor. This helps lower your flood insurance costs.Review your flood insurance policy, or consider acquiring flood insurance, if you are not required to carry it by your mortgage company.
- Study the elevation of the areas around your property and identify alternative routes to avoid driving through floods in the case of a king tide event
- Remove waste carts and recycling bins from the curb as soon as possible when you are expecting a king tide event
To PROTECT yourself and your loved ones during or after a king tide, there are a few precautions citizens can take:
- Do not walk through flood water if possible. This can be a health and/or safety issue
- If you do need to walk through flooded waters, practice good hygiene and wash your hands, clothes, and pets as soon as possible
- Do not drive through flood waters if possible. This can be dangerous to you, and can damage your vehicle
- Be aware of the new tidal range, and practice safe boating when traveling under a bridge. Check the tides before leaving the dock.
- During king tide events, closely monitor your waste carts and recycling bins, and remove them from the curb as soon as possible as soon as they are emptied. If your property experiences flooding, consider storing your containers in a secure location until the next scheduled pick-up day.
When the water is reaching your property, what are the immediate actions one can take
Conventional sandbags are heavy enough that it might discourage you from getting them and placing them on your front door. But if you have one that is flat and expandable bags, you can set them out as a precaution and if it doesn’t rain or the water never reaches it, you just pick them up and store them again.
Flood Avert is a company that makes bags that are filled with a polymer, a water absorbing polymer very much like the polymers you find in diapers that hold water. And they are ideal solutions for homeowners that don’t want to deal with the bulky sandbags.
The Flood Avert bags don’t stay flat for long. Water makes them swell up and hold back water like a normal sandbag. They cost more up front than regular bags but regular sandbags can cost much more than you’d think on the long run.
To avoid the heartache and tragedy of losing home goods and sentimental items, homeowners use zip lock bags but those can break open and tear and that is not ideal. Another simple, and highly-practical bag is a better way to protect your personal belongings that are left behind during natural disasters. SAVD Floodbags, an australian company created by Michael Valentine, offers bags that are tested to protect and save your belongings, and keep them floating inside a reinforced plastic bag in case your property floods.
FloodStop Barriers protecting properties where the waters rise
Floodstop barrier is a rapidly deployable flood barrier. Each section (pod) is 24″ tall and 48″ (3.9 foot) in length and the Pods are easily connected together using the weighted universal key, creating a flexible flood barrier of any length. Flood Stop Barrier from Benson, MN, protects any opening from flood waters. They are Rapidly deployable flood defence systems that can be assembled by one person. They are proven temporary protective systems.
A garage door on its own can only do so much to protect the interior of your garage from the elements. Whether it’s a one-car residential garage or a large-scale commercial garage, keeping everything inside of it protected is what a garage is for; but gaps between the floor and the garage door can create serious problems for property owners. Garadry’s flexible vinyl garage door seals are made of durable and flexible vinyl material, which is superior to rubber because it will not rot or decay over time.
The award-winning NOAQ Tubewall is a temporary flood barrier that is lightweight, flexible and quickly deployed, making it ideal as a flood barrier for fast response to flood threats. The Tubewall consists of air inflated tube sections that are interconnected by zips to form a continuous protective flood barrier. Each tube includes a skirt which lies on the ground on the flood side. When flood water covers the skirt, the water’s own weight squeezes the skirt against the ground forming a seal. The friction of the weighted skirt against the ground anchors the entire Tubewall.
Coastal Risk is a company with a track record of flood and climate risk analysis at an individual property level. Basically, they do Flood and Climate Risk Assessments, for Residential or Commercial properties and are based out of South Florida.
One of their services aims to help commercial real estate investors and owners make their high value properties more resilient to future climate impacts through “Flood Protection as a Service” – a 6 step process of risk identification, needs analysis, adaptation actions, insurance premium reductions, bank financing and ongoing maintenance.
Official sources to deal with the king tide in your city
The Southeast Florida Regional Climate Change Compact is a decade-old partnership between Broward, Miami-Dade, Monroe, and Palm Beach counties, to work collaboratively to reduce regional greenhouse gas emissions, implement adaptation strategies, and build climate resilience within their own communities and across the Southeast Florida region.
Town of Surfside, FL, preparation article
Miami Beach also has a resource website that gather information on what the city is doing againsta the problem. They predict water pumps, dune restorations and public seawall improvements are ongoing to make the City more resilient to sea level rise and climate change.
The website has an elevation calculator and details the city’s resilience strategy.
The city of Fort Lauderdale also has a large website with information.