On this day 14 years ago, on the 29th of August 2005, Hurricane Katrina struck the US Gulf Coast. This should be a time of reflection on the deaths, tragedy, and damage caused by the storm. But this should also be a time to remember what happened, and to learn from it.
Katrina was Category 5 storm, made landfall as a Category 3, and had a massive footprint - satellite imagery before landfall shows the storm taking up over half of the Gulf of Mexico. Almost 1,900 people were killed during this storm, and it was the deadliest hurricane in the era of named storms (only the 1928 Okeechobee storm was deadlier). New Orleans flooded, Gulfport MS was flattened (as well as pretty much all of the Mississippi Gulf Coast), and all told $125 BILLION in damages were caused by Katrina.
Again - 1,826 people killed and $125 billion in damages.
I could write all day about who did what wrong, and go into extreme detail about living in the immediately-after-Katrina shit show that was Louisiana, but I'm not. I rode through the storm like many other people I know, and while my story is nothing compared to most people's, I don't want to dwell on that aspect of it. Yes it was horrifying. Yes the aftermath was tragic and horrible and avoidable. Yes so so many things could have been done differently (basically everything). Many people died and that loss of life is horrible and should be remembered with respect and honor. I want to make sure everyone knows that what I want to talk about in no way diminishes the respect and sadness I have for those who died 14 years ago. I simply want to focus on the future in this editorial, and what we can do to prevent this from happening again.
So, what I really want to talk about is what we, in Louisiana, can do NOW to prevent disasters like this from happening in the future. Other coastal states on the 3 US coasts have their own set of challenges, so I'm going to focus on Louisiana specifically. So today, 14 years later, I want everyone to remember what happened and those who died, and contemplate what a future would look like where this never happens again.
Katrina made landfall in the Buras LA area. That area is essentially a narrow strip of land with the Mississippi River running down the middle. It's the leg of the "birds-foot" part of the delta. There's not much in the way of a the storm there - houses, people, the river, levees, and almost no wetlands.
Wetlands. That's a key component to my op-ed here.
Louisiana is a wetlands rich state. In the early 2000s, before Katrina, researchers had the foresight to begin a progressive and forward looking plan to restore the coast and monitor the coast. The Louisiana Coastal Master Plan is a suite of restoration projects across the coast aimed at offsetting land loss by building new wetlands and by restoring what's still there. In conjunction with that, the Coastwide Reference Monitoring System (CRMS) was born to monitor how well these projects worked, conditions before restoration/construction, and conditions afterwards for 20 years. The first few CRMS sites were launched mere months before Hurricane Katrina.
So, before this disastrous storm that ruined so much, scientists in Louisiana were already looking at the big picture and trying to tackle the disappearing coast problem.
Which is good.
And here we are, 14 years post-Katrina, and many projects in the Coastal Master Plan have been constructed and implemented, and monitoring is continuous and longterm data is being collected. We still have a long way to go with some large cornerstone projects to be built. But bigger picture is that more wetlands = more benefits, for everyone.
Wetlands absorb/reduce storm surge, at a rate something close to 1 foot of surge reduced over every 2-3 miles of marsh. [So, a hypothetical example: If you've got a 10 foot hurricane storm surge, and 30 miles of marsh between the open water and a city, those 30 miles of marsh would reduce all or most of the storm surge so there's limited to no effect of storm surge on the city.]
Wetlands filter out nutrients from the water, trapping them from funneling out into open bodies of water where they could create hypoxic zones, and instead turn them into healthy marsh plants. Plants which in turn help reduce storm surge.
Wetlands capture sediment from the water, and build the marsh height higher over time or build up enough to offset subsidence (natural soil compaction), so that the marsh stays at an adequate height for plants to grow, capture nutrients, grow strong, and again reduce storm surge when the time comes.
And that's just the wetlands themselves! You can read my piece about the whole suite of ecosystem services wetlands provide: Taming the Mississippi, Part 3: Wetland Values
There's many complex interactions in storm surge, wetlands, wave dynamics, hydrology, and all these interconnected things but the main point is - wetlands are valuable and provide protection/assistance against a variety of issues (storm surge, nitrification, sedimentation).
Basically, wetlands are awesome.
So to bring this full circle, more wetlands = less problems. So if there had been a healthier and larger marsh ecosystem between Katrina storm surge and people/cities, then storm surge would have been reduced. Houses could have been spared, levees maybe not topped/breached, and on a larger scale - maybe the storm surge that broke the levees in New Orleans wouldn't have been as stressed by a smaller storm surge that had been reduced by these wetlands that don't exist anymore.
It's a hypothetical, but maybe.
If we create, build, and restore our wetlands we help protect ourselves and the people/places we love from future storm related tragedy.
It's not going to solve all our problems, but it will help with some.
We need to be PROACTIVE, instead of REACTIVE. It's hard to think about spending so much money to solve a massive problem that might only actually come to fruition once every 100 years, but it's cheaper than $125+ billion dollars in damages potentially every few years.
Living shorelines has become a bit of a buzzword the last few years, but what it really means is what I'm suggesting - natural habitat used as a buffer between nature and people. NOAA has a great website about living shorelines HERE. I'm just suggesting we use a much bigger scale of living shoreline in Louisiana and every other wetland heavy coastal state.
Louisiana specifically got into this bind in the first place for a few reasons, but the 2 big ones are:
- people isolated the river from the wetlands it built, so the wetlands are disconnected and no longer get the totally natural yearly floods and flushes of water, sediment, and nutrients that historically sustained them.
- oil & gas exploration in the early 20th century dug canals and pipelines criss-crossing across the marshes, which allowed saltwater to intrude further than it had before, fragmented the marsh and made more miles of shoreline available for erosion, and destroyed the wetlands in the path of the canal or pipeline.
And now, we have fragmented marshes that don't regularly and naturally get the nutrients and sediments they need to sustain their existence. We're in a bind. The Coastal Master Plan is a massive plan to use engineering to:
- replicate the natural processes in some ways (sediment diversions),
- to repair the damage in some marshes (marsh rejuvenation projects),
- build new marsh in replacement (dredge and fill marsh construction projects),
- restore and reconnect how water flows and moves in an area (hydrologic restoration projects), and
- provide shoreline protection to abate erosion (like rock wave barriers).
It's not perfect. Nothing is ever perfect in the world of science and wetlands restoration. We have to balance the big picture vs the smaller scale needs of the individual. Without wetlands, we're all doomed, so doing anything is better than doing nothing. And building more wetlands only has positive impacts - it helps us save money on damages in future hurricanes by protecting us better. It helps us protect people and structures. It helps us by capturing carbon and acting as a sink in the face of climate change, which is a different conversation but still important.
On a smaller more individual or city-wide scale, we can do things to help prepare us for future hurricanes. We can storm proof better. We can build houses and buildings stronger and to higher standards (which is more expensive in the front end, but less expensive in the long run). And a really contentious one - we can move inland from the most perilous locations to some to more protected places (we can have many long debates about the pros/cons of this one, about the ties and merits of home, so we'll save that debate for later, but it is an option though not a good one).
The Coastal Master Plan isn't perfect - nothing of a scale that large is perfect. But the big picture idea to build wetlands because they are a valuable ecosystem and because we need their protection is the key idea. So the details of the plan may not be perfect and may not suite every single need in every single area, but we need wetland restoration and we have to do what we can. I personally think having a comprehensive strategy is amazingly progressive, and I'm glad that we have a plan and are doing everything we can to make it work.
So it's the best we can do without just letting the river run free.
But that's a whole other conversation.
REFERENCES:
CPRA: 2017 Coastal Master Plan
CWPPRA: Information about all the projects in the Coastal Master Plan
CRMS: Wetlands monitoring information and public data
Among the Ruins of Mexico Beach Stands One House, Built ‘for the Big One’ NY Times, Oct 2018
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