Mississippi’s Sea Level Is Rising

The sea level around Mississippi is up to 7 inches higher than it was in 1978.¹ This increase is mostly due to Mississippi’s sinking land, and it’s causing major issues. Coastal communities, such as the ones along the Mississippi Sound, are protected by barrier islands that are eroding from sea level rise. As this continues, communities could be threatened.² Ocean water is overflowing more often into the streets during high tides and rain storms. This is not only dangerous for homes, cars, and city infrastructure, but it can also affect drinking water. There are already over 14,000 properties at risk from frequent tidal flooding in Mississippi.³ The state is planning over $1 billion in sea level rise solutions, which include barrier island restoration, dredging, beach renourishment, and hurricane protection.

Sea level rise is speeding up

The sea level around Bay Waveland, Mississippi, has risen by 7 inches since 1978. Its speed of rise has accelerated over the last ten years and it’s now rising by over 1 inch every 2 years.¹ WScientists know this because the sea level is measured every 6 minutes using equipment like satellites, floating buoys off the coast, and tidal gauges to accurately measure the local sea level as it accelerates and changes.⁴

While there are multiple causes for the sea level rise in Mississippi, land sinkage is the main contributor.⁵ The acceleration of sea level rise erodes the shoreline and puts barrier islands at risk. This added to already sinking land can speed up the effects of sea level rise even faster. Click here to learn more about sea level rise.

Most flooding happens in the fall

King tides are unusually high tides that generally occur during a new for full moon, or when the sun, moon, and earth align. In some places, king tides are brought on by changes in the weather and ocean patterns. In places like Bay Waveland, king tides are typically nearly a foot and a half higher than normal tides. Add that to the 7 inches of sea level rise since 1978, and you end up with flooding even on sunny days.¹

Solutions aren’t simple

Rising sea level submerges land and erodes beaches, making the streets and buildings lower to the sea. Erosion of Mississippi’s undeveloped barrier islands leaves inland communities, that are protected by those islands, exposed. This can make solving for sea level rise both complicated and urgent.²

When the ocean rises high enough, high tides cause flooding even on sunny days. Even though the sea level has only risen by around 4 and a half inches, tidal flooding has increased by over 180% in some areas of Mississippi since 2000.⁸

Flooding even when there’s no rain

Drainage systems are designed to channel excess rainwater from the streets and drain it into the sea. But with the pressure from rising sea levels and higher tides, seawater can get pushed into these pipes and spill out into the streets. This causes flooding even on days without rain.

Increased storm surge flooding

Unfortunately, slightly higher sea levels make hurricanes even more damaging. Just a few more inches of sea level rise allow a hurricane to push more water onto the land, even if the hurricane itself doesn’t make landfall.

There’s a lot at risk from sea level rise and flooding in Mississippi, particularly the coastal communities. As the sea level rises, it makes existing coastal flooding more severe and it erodes beaches, eventually submerging wetlands and dry land.¹² Undeveloped barrier islands help protect the coastal communities that sit along the Mississippi Sound. Sea level rise can erode those islands, washing away what little protection there was.¹²

In Bay St. Louis, there are 1,140 residential properties already at risk from repeated tidal flooding, by 2033 that number will increase to 1,237 as sea levels rise. In Gulfport, 306 properties at risk will turn into 420 within 15 years. In Biloxi there are 568 properties at risk, which will become 806. And in Gautier, there are 714 properties at risk, which will increase to 862 by 2033. Click here to explore other coastal areas in Mississippi that are at risk at FloodiQ.com.

What can you do?

Individuals, mayors, legislators, governors, and Congress can work together to build protections before flooding, to build back stronger after flooding, and to create plans that future-proof our communities. Click here to see what solutions can help protect your home or what your community can do.