re: Back flooding and built up neighborhoods

Again, so much misinformation. First you use Houston as an example, which does not require detention or fill mitigation. So it doesn't compare with our area unless you are talking about outlying areas that do not require those things. I would agree with you that development without detention and fill mitigation does increase flooding. Their point about wetlands doesn't translate here either. A 404 permit from the Corps mitigating your wetlands impact is required to get a development permit in Baton Rouge and surrounding areas. Does everybody play nice? No, just like in any profession, there are some bad apples. However, most developers generally follow the rules if they want to continue developing.

Then you say detention ponds don't work. Don't know what you are basing that on since you make no argument, just a blanket statement. Then you talk about silt filling them up, which if you are talking about dry detention ponds then that could be an issue but most likely you are talking about wet retention ponds where it doesn't matter. A wet retention pond only relies on the volume from the normal pool to the top bank. So silt would have to fill from the bottom all the way above the normal water surface and create dry land in the pond. I have never seen that happen in my 20 years of engineering. A dry detention pond would need silt removed after construction if it was deposited on the bottom since dry detention volume is from the dry bottom up to the top bank.

Don't you think engineers take land use into account when designing infrastructure? A runoff rate is calculated based on the land as it exists before it is developed. That takes into account the land cover, soil type, slope, etc. Then there is a runoff rate associated with developed land taking into account land use, percentage of impervious area, slope, etc. The difference is the runoff is what must be stored in the pond and released at the undeveloped rate. I'm sure you realized all that though.

Finally, most of those two articles are high on environmental and political hyperbole and low on actual technical information. Yes, stormwater measures like Baton Rouge and surrounding areas have would have lessened the flooding in Houston but much less than they want you to believe. 50" of rain is going to flood a large part of the city no matter how much stormwater mitigation you do.

Talking about 2 different concepts. Flood mitigation requires them to not fill the land to take away flood storage. That is different than everyday rain drainage. They are not allowed to redirect drainage or block runoff that formerly flowed thru their development. If your development drains to theirs, they had to account for it in the design. The Parish is who insures that happens on the local level so you have to ask them to insure it is corrected.

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e added dirt doesn't impede the flow of water it is of no concern.

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It often does. While they arent damming off any canals or anything, some developments span a large low area, basically damming off a wide shallow ditch.