Re: OT: Mississippi River Aquapocalypse 2019
Quote:
Originally Posted by
ZoomZoom
The end result of dredging is some "poor" landowner will be paid to receive the spoils. The contractor sells the sinkers, and people like me are amused by the number of stolen vehicles that will be recovered.
Went to the meeing at the southside library last night discussing drainage. The Youngsville situation was brought up and the fact a lot of the water east of 90 drains thru Youngsville. Additionally, Vermilion Parish is allegedly against dredging the river.
Allegedly the big problem we have in Lafayette is these rentention ponds that are built are for a 5 year flood event, not 100 year.
I use the word "allegedly" since these were mostly politicians speaking, abet one engineer with hydrological experience.
Who said that runoff east of 90 drains through Youngsville? Were they sober?
Re: OT: Mississippi River Aquapocalypse 2019
Quote:
Originally Posted by
HelmutVII
No. If you have a glass that's half full and you want to put more water in it where is is going to go? The top half right. It's all about water SURFACE elevation. Not depth of flow.
I think NAVD88 at LA 733 is zero. Not much slope to get things moving. As you say dredging isn't the answer.
Years ago Houston was talking about potentially putting thrusters in Buffalo Bayou in order to try and increase velocity. Never happened but it was a thought at the time.
Re: OT: Mississippi River Aquapocalypse 2019
Regional retention/detention is likely the answer.
Re: OT: Mississippi River Aquapocalypse 2019
Quote:
Originally Posted by
Cajun90
I think NAVD88 at LA 733 is zero. Not much slope to get things moving. As you say dredging isn't the answer.
Years ago Houston was talking about potentially putting thrusters in Buffalo Bayou in order to try and increase velocity. Never happened but it was a thought at the time.
If you go here
https://waterdata.usgs.gov/la/nwis/uv?site_no=07386940
and select gauge height you will see that the water level is reported and displayed every fifteen minutes or so. Select "graph" as the option and select "gauge height". during periods of low flow (no rain) you will see the water level varies and has "about" two highs and two lows a day. the past few days the water level has been bouncing back and forth around elevation 4.0 NAVD88. The highs and lows correspond to the high and low tides. The gauge is at about Mile 45 of the river. That means there is 4.0 feet of fall in the water surface in 45.0 miles. (that is not much at all). That means the bottom of the river is below sea level. The water below elevation 0.0 (give or take) CANNOT move as fast as the water above elevation 0.0 because that is the level of the Gulf of Mexico. When water levels get low velocities get low and the water starts to drop its silt. When water levels get high velocities increase and the bottom of the river is scoured (to a degree). Basically, any portion of the conveyance area of the river that is below elevation 0.00 NAVD88 is useless as a conveyance for water. Trust me on this.
Re: OT: Mississippi River Aquapocalypse 2019
Quote:
Originally Posted by
HelmutVII
Basically, any portion of the conveyance area of the river that is below elevation 0.00 NAVD88 is useless as a conveyance for water. Trust me on this.
Yes and I'm pretty sure most of the population in the area doesn't understand this concept. Its time for people in this area to start understanding their risk better and realize that little to nothing is going to happen to significantly change flood levels. Retention areas would help but were talking about some rather large lakes to be of any signifigance. These small attempts when they build a neighborhood to do retention ponds are not much more than a false sense of security.
The real answer in my opinion.... build higher.
Re: OT: Mississippi River Aquapocalypse 2019
Quote:
Originally Posted by
HelmutVII
Who said that runoff east of 90 drains through Youngsville? Were they sober?
Forgot the name, on Ritter's staff at Youngsville. Supposedly all the swamp area near airport and south goes thru Youngsville.
One of those "had to be there" to get the full experience. Was suppose to be about drainage, but was 50/50 political. I'd go into more detail but don't want to go there, but I left disappointed overall.
I must admit, I enjoyed the "altar call" where one lady announced her candidacy for city council after multiple calls for people to run for office.
Re: OT: Mississippi River Aquapocalypse 2019
Quote:
Originally Posted by
ZoomZoom
Forgot the name, on Ritter's staff at Youngsville. Supposedly all the swamp area near airport and south goes thru Youngsville.
One of those "had to be there" to get the full experience. Was suppose to be about drainage, but was 50/50 political. I'd go into more detail but don't want to go there, but I left disappointed overall.
I must admit, I enjoyed the "altar call" where one lady announced her candidacy for city council after multiple calls for people to run for office.
Ooooohhhhhh mmmmmyyyyyy. Most of the area East of highway 90 is much lower than the area. West of 90. That is the Coteau Ridge. Sigh.
Re: OT: Mississippi River Aquapocalypse 2019
Quote:
Originally Posted by
CajunRebel
This is just a shot in the dark, but instead of draining South & West, would it be possible for at least some of this water to be diverted East into the Long Bridge swamp where no one will ever build anything? It seems like that area could be a perfect retention pond.
I would agree but the info given the other night the rentention ponds we have are not what we need long term, not deep enough. I'm sure Mr. Environmental would be first in line filing suit if a wetland was disturbed, that is, unless he can make a buck. I started to be a jerk and ask where would anyone want to put an area retention pond just because NIMBY would have made it interesting. But I didn't.
Re: OT: Mississippi River Aquapocalypse 2019
Quote:
Originally Posted by
ZoomZoom
I would agree but the info given the other night the rentention ponds we have are not what we need long term, not deep enough. I'm sure Mr. Environmental would be first in line filing suit if a wetland was disturbed, that is, unless he can make a buck. I started to be a jerk and ask where would anyone want to put an area retention pond just because NIMBY would have made it interesting. But I didn't.
.........Story in the DA about the threat of flooding in NO if a cat 4 would hit.......also about danger of the levees failing from under......basis is that the Miss River is still very high and all you stat guys would love the juxtapositions!!!