2024 Hurricane Season

[Big Tyme]

Correct but the trend line needs to be based on measurements made with instruments of similar accuracy. If you look at the graph in the original post the difference between the high and low points of temperature is about 2 degrees. An error in reading the temperature buy even 0.2 degree is a 10 percent error. The people publishing this information need to be transparent and tell us the accuracy of their measurements (+ or - so many 0.1ths of a degree) so that an informed decision can be made.

When ever I make a measurement of anything (especially comparative measurements) I always use the same instrument to make the measurement. Whether that be a caliper, mil gauge or total station. Measuring material values versus measuring temperatures and distances are totally different. Temperatures, distances and other environmental and spacial measurements are totally dependent upon the accuracy of the instrument and the precision and training of the operator. Any one or a combination of errors can lead to false readings.

When looking at charts like this always look at the scale of the axes. You can emphasize a difference by adjusting the scale of the axes.

The trend lines are always going up. Instrumentation inaccuracies would happen in BOTH directions. If the trend is increasing, I tend to think that is more accurate than not.

[Big Tyme]

The Houston area has a subsidence district

https://hgsubsidence.org/

They found that all of the industrial plants in the area taking BILLIONS of gallons of ground water a year caused significant subsidence and flooding in the area. They put a surcharge on the water wells that was more than the cost of desalinization of gulf water. The original study was done many years ago and , if I remember correctly, the original surcharge was $3.00 a thousand gallons. You could still pump ground water as long as you wrote a check. It was quickly determined that it was chea6ti desalinate gulf if Mexico water.

After the Kat-Rita event the big question along the coast was "how high is high enough" to rebuild. USGS came through and checked all their benchmarks and found them lower than the published elevations some by as much as 2 feet. That's when it was decided that all future flood elevations were to be established by GPS observations.

It was also found that benchmarks in rice growing areas were one to one and half foot lower than published. They also found that there was some rebound when rice field flooding was over for the year.

We live on a sponge. It get dry we sink it get wet we rise. All in very slow rates but we still move. NOTHING resting on the ground in south Louisiana is stable.

Not arguing about subsidence. California's Central Valley has a crazy amount from groundwater extraction. My point was aquifer depletion is NOT causing the subsidence in SE LA where most land loss is occurring.

[HelmutVII]

I'm not aware of any area where new residential construction doesn't require Base Flood Elevation(BFE) +1 ft for the lowest level. That is the only way you can qualify for flood insurance which is a requirement for any federally backed mortgage (most of them).

Now you can certainly make the argument that BFE+1 is inadequate and I would agree. Latest stats I have is that 25% of all flooded structures are above the BFE+1.

I believe the disclosures to the general public regarding flood threats are misleading. Developers/ Real Estate agents are often times misleading or don't understand. The only thing they are concerned with is you are required to have flood insurance or not.

However there is a massive different in risk between BFE+1 and BFE+3. When I contracted my personal home 14 years ago the number one thing on my list was the BFE. I'm in southern Lafayette Parish near the river with a BFE+20. I've often been asked if I worry about flooding and have to explain no and why. Some have a hard time comprehending that you can be close to the river and much safer from flooding than someone who lives miles away.

Provided they are in a regulated flood zone. There is no requirement for minimum Finished floor or equipment elevations in zone x. Only Zone A, AE & AE FLOODWAY.. That being said, one needs to understand that we're are all in a flood zone, it's just a matter if it's regulated or not.

Having been involved in several flood studies allows me to make several comments,

1). Engineers will spend countless hours arguing over CN values, but I have made the argument that if an area is flooded then the CN goes through the roof because the the ground surface is water.

2) drainage basin areas will vary depending on whether adjacent basins are flooded and the basins communicate with each other.

3). If a ground surface has subsided does the BFE go down with the ground given that the water is on that ground. Fema says no. (Last I checked)

4,) Given that the government has control over the GEOID that is used then they can make water levels higher by adjusting were zero is.

5). I firmly believe that the eventual goal is to make it so expensive to live in a flood zone you will be forced to move.

6). The BFE +1 is from the floodway modeling. By forcing everyone in an A or AE flood zone to be BFE +1 ..... theoretically the natural flood zone could diminish to the flood way if everyone did BFE +1. That is where "No net fill" and "No net rise" comes from.

This is a very complex issue involving engineering, politics and government agencies each with their own agenda. I am certain it won't get solved any time soon.

[CajunVic]

so keep your flood insurance no matter what?

[Turbine]

I have never heard of inland aquifer depletion as a cause of coastal subsidence. The fact is that because of the unconsolidated nature of the sediment, the weight of the overlying sediment compacts what is under, hence subsidence, especially with no replenishment from floods.
In this case, 'blaming humans' is 100% on target. The only feasible way to keep up with land loss, probably way too late to reverse it, is sediment redistribution from levee breaks like the Wax Lake Outlet project.
This is a cool project but like all the solutions, very expensive. https://www.fisheries.noaa.gov/featu...n-noaa-funding

It is established fact that Louisiana is sliding into the gulf. There are hundreds of documented landslides due to the jello that is sediment built.

Don't think of it as subsidence directly above an aquifer.

Aquifer depletion causes an underground valley of sorts affecting the adjacent jelllo structure with the force of gravity.

It is silly to think the jello can only slide south when subsidence to the north has its own pull.

Erosion is not the only culprit.

[BabbForHeisman]

so keep your flood insurance no matter what?

At the current price point, yes. But if it keeps going up…

[zephyr]

And ZERO requirements are being placed on many developments to require proper elevation of those new homes... so the brand-new ones will flood just as the old ones are flooding now.

This is false

[facelessjonmoon]

And ZERO requirements are being placed on many developments to require proper elevation of those new homes... so the brand-new ones will flood just as the old ones are flooding now.

I don’t think this is accurate based on my experience

[ZoomZoom]

And ZERO requirements are being placed on many developments to require proper elevation of those new homes. so the brand-new ones will flood just as the old ones are flooding now.

Uh, no. In fact, regulations is a root problem causing concern. Once where water filled rice fields, there are tons upon tons of dirt brought in to elevate home sites to meet FEMA requirements. The rice field owner has every right to do what he wants with his land, but there is the classic butterfly effect that comes with it.

Local governments have a responsibility to their citizens to adhere to the FEMA regulations. There’s a direct impact on insurance rates with failure to do so. The days of a person telling the local administrator “Cher, mais ya know my momma’s and dems house never floods” are gone. Yes, the preceding statement isn’t a joke, really was happening a decade or so back (not in Lafayette parish).

And sediment of things have consequences. How about building a home in a flood zone, rightfully shooting an elevation line off a LADOTD marker, pouring a slab, pass inspection. Between this and final inspection the state replaces the marker with one 3” higher (the old mark allegedly sunk). Which fails the final inspection. Yeah, that’s no joke either.

[HelmutVII]

Uh, no. In fact, regulations is a root problem causing concern. Once where water filled rice fields, there are tons upon tons of dirt brought in to elevate home sites to meet FEMA requirements. The rice field owner has every right to do what he wants with his land, but there is the classic butterfly effect that comes with it.

Local governments have a responsibility to their citizens to adhere to the FEMA regulations. There’s a direct impact on insurance rates with failure to do so. The days of a person telling the local administrator “Cher, mais ya know my momma’s and dems house never floods” are gone. Yes, the preceding statement isn’t a joke, really was happening a decade or so back (not in Lafayette parish).

And sediment of things have consequences. How about building a home in a flood zone, rightfully shooting an elevation line off a LADOTD marker, pouring a slab, pass inspection. Between this and final inspection the state replaces the marker with one 3” higher (the old mark allegedly sunk). Which fails the final inspection. Yeah, that’s no joke either.

Or doing a Flood elevation certificate for a new home. Then years later after new flood maps with a higher BFE AND BFE +1 requirements the home owner wants to add on to the home at the same elevation. Not going to happen. Try explaining that to a client. Especially when he saysI never flooded.

[CajunVic]

govt regulation at any level is fraught with constant issues, gaps, inaccuracies, over limitations, contradictions . . . which is why, in ALL instances, less is better than more

[Big Tyme]

govt regulation at any level is fraught with constant issues, gaps, inaccuracies, over limitations, contradictions . . . which is why, in ALL instances, less is better than more

ALL generalizations are worthless.
Info on subsidies.
https://arstechnica.com/science/2024...all-subsidies/