2019 Mississippi River

[HelmutVII]

Helmut, what would happen should the tropical depression drop significant precipitation on any area of the Mississippi?

Rainfall here in Louisiana really won't affect the water levels all that much because the we don't drain all that much into the Mississippi or Atchafalaya. . I think the main reason why the Corps has decided to wait is because this system could cause an increase in surface water levels due to storm surge. That is depending on where it make s landfall. The water levels in the lower Atchafalaya are really high due to high flows from the red river and normal diversion from the Mississippi, Storm surge would make that worse causing more flooding than anticipated. Best to wait until this thing passes. Hope it passes to the east to get a strong north wind to reduce water levels. It's all about slope of the energy grade line. Lower water levels at the downstream end increase the conveyance. The channel could be a mile deep and it would still flow the same amount of water with the same water surface elevation.

[billbeck451]

how is the water in the Henderson area, I know it was high earlier during the spring, but haven't heard anything lately

[CharlieK]

how is the water in the Henderson area, I know it was high earlier during the spring, but haven't heard anything lately

I think the official St. Martin parish term for it is "high high"

[HelmutVII]

I think the official St. Martin parish term for it is "high high"

And that is why they are not too happy about opening Morganza.

[Ragin4U]

I think the official St. Martin parish term for it is "high high"

Nice

[mahtoo]

I think the official St. Martin parish term for it is "high high"

For those not familiar with this area:

The Henderson Control Structure is located in the borrow canal along the West Atchafalaya Basin Protection Levee, south of the pontoon bridge. I believe the top of the structure gates is somewhere around elevation 9.0. Water stage in Henderson will rise any time the river stage at Butte LaRose is 9.0 and rising. Water enters the WABPL borrow canal through the Butte LaRose Canal and backs up into Henderson Lake. The juncture of the Atchafalaya R and the Butte LaRose Canal is just south of the Butte LaRose public boat landing. The canal runs south from there and then west to the WABPL borrow canal and then into the lake.

[HelmutVII]

For those not familiar with this area:

The Henderson Control Structure is located in the borrow canal along the West Atchafalaya Basin Protection Levee, south of the pontoon bridge. I believe the top of the structure gates is somewhere around elevation 9.0. Water stage in Henderson will rise any time the river stage at Butte LaRose is 9.0 and rising. Water enters the WABPL borrow canal through the Butte LaRose Canal and backs up into Henderson Lake. The juncture of the Atchafalaya R and the Butte LaRose Canal is just south of the Butte LaRose public boat landing. The canal runs south from there and then west to the WABPL borrow canal and then into the lake.

I suspect the pontoon bridge is still closed. Is that correct?

[mahtoo]

I haven't been there to look around but I would guess you are correct.

[mahtoo]

____. Is this dude wrong about this? Helmut? matoo?

BWK's description of allowing excess water to drain from the Butte LaRose area is confusing, at least to me. If he referring to the Atchafalaya River area at Butte LaRose, then I say he is wrong. If he is really referring to the Henderson Lake area that is a different story. That area can only be drained when the river level is lower than the top of the Henderson Control Structure gates, which I said in a previous post is around elevation 9.0. If the river level is higher than the structure elevation, water will flow into the lake no matter if gates are open or not.

Opening of the gates when river levels are low is coordinated amongst many.....St. Martin Parish, Henderson Town officials, LDWF, USACE, etc. Locals whose business interests depend on sufficient water levels to remain open would certainly have had objections to draining the lake area months in advance of a possible high river situation. Besides, IMO the Henderson watershed area is not sufficient to provide enough capacity to affect Atchafalaya River levels. Again , IMO.

I am trying to get river stage info for Butte LaRose for the last 6 months. Since we have been in a high water situation for so long, it would surprise me if river stages were at or lower than elevation 9.0 for a sufficient length of time to allow for much drainage of Henderson Lake. If/when I get that info I will share it. Maybe someone else will have better luck finding info for more than the last 2 months.

Others asked earlier today about water levels in Henderson Lake and about the pontoon bridge. I took a ride out there today.

Pontoon bridge is closed and will apparently remain so for a while. There is hardly any current at all at the pontoon bridge. Could not read the gage that is located in the borrow canal. Hidden from view. The bottom of the gage just north of the bridge is at elevation 20.0 Water elevation is approximately 2 feet below that, maybe 2.5 feet, which puts the water elevation at approx 17.5 to 18.0

There is a slight current at the Henderson Control Structure 2 miles to the south of the bridge. The entire structure is under water. Didn't look around much. I believe I would have disturbed a couple that were there for a rendezvous.

Several of the private boat landings are still open for business but parking is at a premium.

Water is at or near the flood side toe in many areas along the levee.

[Bandwagon King]

My question is was the river ever below 9 foot of elevation any time from January thru March. If so, why was the upper Atchafalaya not drained then in preparation fro the coming floods which were obvious to me as a casual observer? I knew then when I saw the level int he lake we were going to have this problem & I thought to start a thread then. But I knew I would be met with at least as much, or more criticism for daring to speak up against fearless leader. So I figured, why bother. In time he would have enough rope to hang himself. Now the stage is set. I have a house on the Amite as well as Lafayette. I know river levels were way down in January. That's the only reason my house didn't get water in it during the last rain. But I was concerned having to fight the water coming in from the Bonne Carrie to take out the water fast enough. The bottom line is IF the water level had been allowed to evacuate the upper Atchafalaya basing EARLIER. there would be a place for the water which is coming down now to go & thereby alleviate a large part of the coming water which is still due to hit which can't be released now because it has nowhere to go. Do you get that?