The Water Comes Faster, Deeper & Drains Slower … Residents Are Getting Sick And Tired It…
Bayou Pigeon Fire Department - Hwy. 75 Sand Bag Depot
Pictorial Essay Of The Flooding April 2021
Bayou Pigeon,LA. April 2021
Residents on Lower Grand River, Bayou Sorrel, Bayou Pigeon, Pierre Part, Belle River, and Stephenville are getting sick and tired of flooding every time we get a hard rain.
Imagine living with that every heavy rain means that the river is going to rise and spill over it’s banks and flood your yard?
Having to elevate the HVAC, electrical equipment and dealing with sediment and debris laden water.
Spiders and snakes swarm during these floods.
Real estate studies indicate that the price of a residential property located within a flood zone is significantly lower than an otherwise similar house located outside the flood zone. On average, a location that has flooded lowers property value about 8%. If a property is prone to flooding from 15 – 60%
Cost from business interruptions, and on and on.
The Week of 4 / 12 / 2021 Flood waters were moving down Lower Grand River to the Bayou Sorrel, Bayou Pigeon (Iberville Parish). To Belle River (Lower St Martin Parish), and Pierre Part (Western Assumption Parish) and 4 Mile Bayou & Stephenville flooding businesses, residences and camps along the Lower Grand River and distributaries and inundating low lying areas.
There are real Iberville Parish residents and campers dealing with this to often. People in Bayou Sorrel, Bayou Pigeon, Pierre Part, Belle River, and Stephensville are getting sick and tired of flooding every time we get a hard rain.
Hwy. 75 Verrett’s Shipyard @ Jack Millers Landing
Hwy. 75 Verrett’s Shipyard @ Jack Millers Landing
Bayou Sorrel Hwy 75
Bayou Sorrel Hwy 75 @ Pete Kelly’s Crawfish Dock & Bait Shop
Mike U. Hwy 75 Bayou Pigeon …not again…
Hwy 75 No Relief …
Having to Paddle your boat to your door every day, T Lloyd Hebert
Bayou Pigeon Phillips Camp April 2021 Indigo Bayou Area
Camp Sanguine April 2021 Bayou Pigeon ,Indigo Bayou Area
Bayou Pigeon Clay Coleman The Shack April 2021
Bayou Pigeon - The Blanchard Home at Indigo Bayou - April 2021
Bryan Vaughn - Boo’s Campground - Bayou Pigeon Road -April 2021
Vehicle Traffic No Wake Zone Barrier - Some People Won't Listen
St. Joseph Church - Pierre Part, LA. - Bayou Pierre Part
Parker Conrad Flood Control Plan Map c 1980
I Became Aware Of This Parker Conrad Plan /Map For First Time 4 /14 / 2021
I had not seen this map before. In my 10 years of research in writing two books about the Atchafalaya Basin.
The map was posted on facebook, by Mr. Gregory Hedges of Pierre Part, (a fellow alligator hunter), who got it from his dad, Johnson Hedges. Greg posted the map to point out that the overbank flooding that was coming to our area was going to take some time to drain, because it was all the rainfall coming a large area.
In 1979, The Atchafalaya Basin Management Group comprised of the U S. Army Corps of Engineers, Louisiana officials, the federal Department of the Interior and Environmental Protection Agency began a series public meetings to determine how to "Save the Basin" for Wildlife and Fisheries wetlands, Oil & gas industries and and at same time maintain Flood Control.
Parker Conrad, of Conrad Industries that builds tugs, barges, pushboats, liftboats, ferries and many other vessels. Was concerned about how extreme flooding at Morgan City in 1973 and future was threating the economic security of Morgan City.
Mr. Conrad produced his own Flood Control Plan!
I found the map extremely interesting for many reasons and plus the fact I love looking at old maps and pictures from the past.
1. The main reason, it clearly illustrates the boundaries of the Atchafalaya East Watershed and the Lafourche / Terrebonne drainage basin, ie., A Picture Is Worth A Thousand Words.
2. It is easy to see how large this area is and compare to the size of the floodway. That it can capture a lot of rainfall.
I wrote about how this new drainage basin came about in my book,’ Heritage of the Atchafalaya, A Natural and Cultural History of the Atchafalaya Basin. Basically it exist because of the construction the Atchafalaya Floodway.
Before there was an Atchafalaya Floodway
Before the creation of the Atchafalaya Floodway and the USACE became responsible for allocating the waters in the annual flood pulse through the floodway, extreme local rainfall spread out because it had a large area to spread out The water went where it pleased, and people could not do much about it.
There was not the overbank flooding we see today on the lower Grand River.
After reviewing the Parker Conrad map I could easily see it validated the current Bayou Chene Automated Barge Floodgate Structure, project which is under construction to alleviate Backwater Flooding caused by extreme flood conditions occurring inside the Lower Atchafalaya Floodway.
In my online / internet research I quickly realized, that backwater flooding and overbank flooding are different. Both are complicated but overbank flooding appears to me to be more of a complex situation. No kidding...
Let Me explain:
Relative to Backwater flooding, it is COMPLICATED, but the things that are causing the backwater flooding can be separated and dealt with in a systematic and logical way.
Whereas the overbank flooding along Lower Grand River is a little more COMPLEX.
Complex issues are ones in which you can't get a firm handle on the parts /components of situation. There is extraordinarily little order, control, or predictability.
Overbank flooding, you can't control the weather, predict when extreme rain is going to hit and how much it is going to rain.
In my Six Sigma training in an earlier career, I was taught it is best try to 'managed through' complex situations, until you have lots of long-term data to make strategic decisions versus trying to solve it quickly.
Thus, this latest round of exceptional heavy rain this past week (4 14 2021 over 13” in a 3-day period in Southwest Iberville Parish area) That is flooding Bayou Grosse Tete and over bank flooding Lower Grand River with as much as 6 ft rise in some places would have not occurred before the creation of the floodway.
Which begs the question, why is this extreme rainfall and resultant overbank flooding occurring more frequently, often several times in one year.
Is it related to Climate change?
The climate is warming! the climate is cooling! We’re all gonna die!
The answer is...all of the above. Folks just need to chill out and understand that climate’s gonna climate, and there’s not that much we can do about it.
If you really want more information about Climate Change, I suggest you read, “Dark, Cold Years Are Coming, So You’d Better Get Ready”.
file:///C:/Users/clegr/Desktop/Documents/Dark,%20Cold%20Years%20Are%20Coming,%20So%20You%E2%80%99d%20Better%20Get%20Ready%20-%20American%20Thinker.html
Has it more to do with the Atchafalaya Floodway System Than Climate Change?
Without a doubt, high water years in the Floodway and backwater flooding are occurring more often. I can remember my first recall of the back water flooding 50 years ago, 1973 / 74.
May 1973 The Eloyd & Florence Blanchard Home At Indigo Bayou;
Compare to same Picture y 2021 above - Water Level Approximate; No Different Than 50 Years Ago, I.e.., 1973 To April 2021
Those years are still considered highwater markers for flooding along the Lower Grand River.
Just maybe it took the 40 years between 1930’s and 1973 for the manmade changes to the Atchafalaya Basin rivers, streams and landscape to reach an inflection point, severe backwater and over bank flooding.
Personally , I am inclined to believe, that the more frequent high water in the Atchafalaya Basin and subsequent backwater and / or extreme rainfall overbank flooding in the Lower Grand River Drainage Basin is a natural outcrop of exponential growth and progress of mid America and poor or no water / sediment management.
Not the apocalyptic talk of climate change by global warming zealots.
Since 1973, 1974, 1975 there has been back water flooding in years 1979, 1983,1997, 2002, 2008, 2011, 2016, 2017, 2018, 2019.
Overbank Flooding at Bayou Pigeon is not new.
OverBank Flooding at Bayou Pigeon 1974
USACE AeriaL Photo 1974
The Atchafalaya Floodway System Levees
The Atchafalaya Floodway system was designed and built to protect agricultural areas and towns along and in the Mississippi river valley flood plain from flooding by using the flood way when necessary to contain excess floodwaters of the Mississippi and Red Rivers on their way south to the Gulf of Mexico.
The core of the floodway are two levees approximately 15 miles apart.
The East Atchafalaya Basin Protection Levee (EABPL). The levee begins at the lower end of the east guide levee of the Morganza Floodway extends southward to and from Morgan City to the Avoca Island Cutoff, and includes the Bayou Boeuf and Bayou Sorrel locks. The length of this system is 106.7 miles.
The West Atchafalaya Basin Protection Levee (WABPL). The levee begins near the town of Hamburg, where it joins the Bayou des Glaises fuse plug levee. It extends in a south and southeasterly direction to the Wax Lake Outlet at the latitude of the East and West Calumet Floodgates and thence eastward through Berwick to the Gulf Intracoastal Waterway. This levee extends 128.7 miles and connects with 3 miles of flood wall along the front of the town of Berwick.
I do not believe the people who created the Atchafalaya Basin Floodway plan and the Floodway itself in the 1930’s at that time considered thought of any consequences regarding natural drainage outside of the new floodway when designing it.
Unintended Consequences - The Lafourche - Terrebonne Drainage Basin
One consequence of landscape change by building the floodway was the creation of a new drainage system, it is now known as the The Lafourche / Terrebonne drainage Basin.
It falls naturally between the Atchafalaya Floodway East Atchafalaya Basin Protection Levee ( EABPL)) and the Mississippi River natural alluvial ridge. It covers an area extending approximately 120 miles from the Mississippi River on the north to the Gulf of Mexico on the south. It varies in width from 18 miles to 70 miles.
Local Rain Fall / Water drainage east of the floodway is totally between the EABPL and Mississippi alluvial ridge levees and has to drain through this area.
I suppose it should have been considered in the design phase how this new drainage basin would interact over time with the Atchafalaya floodway.
Such things as the effects of progress , like new / more impervious surfaces like superhighways, streets and pavement, driveways, house roofs, shopping centers, Malls, etc.!
A significant portion of rainfall in watersheds is absorbed into soils (infiltration), is stored as groundwater, and is slowly discharged to streams through seeps and springs. Flooding is less significant in these conditions because some of the runoff during a storm is absorbed into the ground, thus lessening the amount of runoff into a stream during the storm.
As watersheds are urbanized, much of the vegetation is replaced by impervious surfaces, thus reducing the area where infiltration to groundwater can occur.
When it rains the water no longer seeps into the ground, but now runs off into storm drains and then quickly into local streams / canals.
Couple this with inevitable periodic extreme rain conditions at the same time as the Mississippi River annual flood pulse is passing through the Atchafalaya floodway and it seems like someone should have brought up the question.
Today it is pretty obvious that any extreme flow in the floodway overwhelms the exit of the water in the Lafourche / Terrebonne drainage Basin to the Gulf of Mexico and Slows The Drainage, thus you have extensive back water flooding.
I discuss this Lafourche drainage basin, in my book 'Heritage of the Atchafalaya Basin", on page 101.
USACE Flood Control Strategy / Plan For Entire Mississippi River Valley
USACE Flood Control Plan For Entire Mississippi River Valley
USACE Flood Control Plan For Entire Mississippi River Valley
In Louisiana, besides the Mississippi River, 3 floodways (West Atchafalaya Floodway, Morganza Floodway and the Lower Atchafalaya Floodway) play a vital part of moving annual flood pulse of the Mississippi River Valley through Louisiana to Gulf Of Mexico
Understand the purpose of the USACE and thus the Atchafalaya Floodway is to control what is known as a 1000-year flood in the Mississippi River Valley. Greater than the Great Flood of 1927.
Let’s Talk About About Back Water Flooding & Some Interesting Things About The Parker Conrad Map / Plan, At Least They Are To Me
As I studied the map / plan, I realized, it purports to be an alternative strategy / plan to the USACE ‘Project Flood” plan in the lower Atchafalaya Floodway.
The USACE Atchafalaya Basin Flood Control plan passes a the largest portion of the water diverted (30 / 70) from the Mississippi River into the Atchafalaya Floodway through The Atchafalaya River main Channel at Morgan city. A lesser portion of the flow through the Wax Lake Outlet. This has been the plan since the 1960’s.
The Parker Conrad plan validates that the back water flooding that was occurring in the lower Lafourche-Terrebonne drainage basin above Morgan City was related to any extreme conditions in the annual flood pulse passing through Morgan City.
The problem is there has been an extreme annual flood pulse, 1973, 1974, 1975, 1979, 1983,1997, 2002, 2008, 2011, 2016, 2017, 2018, 2019.
The Parker Conrad plan recognized in 1980 that something had changed … sedimentation had changed the hydrology of Atchafalaya River Basin and the annual flood pulse was extreme most of the time, ‘too much water, too fast and staying to long’.
Why wasn’t The Parker Conrad plan given more consideration than it received in 1980. One reason could be, at the time it was as 'mind boggling' as the first plan was to create the Atchafalaya Floodway in the first place in 1928 / 29.
His plan called for blocking / controlling the annual flood pulse through the Atchafalaya River at Morgan City with a Lock & Dam structure, and diverting the entire flow of the Atchafalaya River through the Wax Lake Outlet.
Mind Boggling proposals of the Parker Conrad plan :
This plan recognized / devised a plan for the Backwater flooding in the Lafourche / Terrebonne drainage basin over 40 years ago!
The map identifies the bottleneck causing the Backwater flooding problem, ie., the Avoca Island Cutoff at confluence with Atchafalaya River below Morgan City.
Parker Conrad plan - A Bigger Outlet to the Gulf at Wax Lake
In the bottom left hand corner of the map, it shows a proposed spillway two miles wide, with plans to carry 100 % of Atchafalaya river flow under normal, I assume that means including annual flood pulse conditions.
Background info on The Wax Lake Outlet
Wax Lake was a lake in St. Mary Parish, Louisiana that was converted into an outlet channel, the Wax Lake outlet, to divert water from the Atchafalaya River to the Gulf of Mexico.
The Wax Lake Channel was created by the United States Army Corps of Engineers in 1942 to divert 30 percent of the flow from the Atchafalaya River to the Gulf of Mexico and reduce flood stages at Morgan City, Louisiana. The channel is approximately 15 miles long that begins at Six Mile Lake (and the "Charenton Drainage and Navigation Canal", that began at Bayou Teche in Baldwin, LA.
The Avoca Island Cutoff / Bayou Chene area, has been a major conduit for this backwater flooding.
Back water flooding through Bayou Chene is enhanced & facilitated by a navigation channel maintained 20 ft deep and 400 ft wide.
Avoca Island / Bayou Chene Channel
2021 - Current Project At Avoca Island Cutoff / Bayou Chene To Reduce Backwater Flooding
Gov. John Bel Edwards Announced in 2020 Construction will start on Permanent Floodgate at Bayou Chene in St. Mary Parish. The projection is underway at the time of this writing.
High water events in the Atchafalaya Basin, have precipitated backwater flooding in the parishes of St. Mary, Terrebonne, Lafourche, St. Martin, Assumption.
The Louisiana Coastal Protection and Restoration Authority (CPRA) and St. Mary Parish Levee District (SMLD) are overseeing construction of the automated barge floodgate.
Diagram of Backwater flow through Avoca Island Cutoff / Bayou Chene
Artist Illustration Completed Automated Barge Floodgate
Diagram of water flow to gulf when Automated Barge flood control structure is closed
The flood pulse eventually reaches Lake Palourde and is diverted through Amelia and Bayou L’ourse and out to Bayou Black and the Gulf of Mexico.
Problem Solved For Bayou Sorrel, Bayou Pigeon, Likely Not
Problem #1 Water / Sediment Management...
Lower Grand River in Iberville and Iberia parish have experienced rapid and substantial amounts of sediment deposition since the 1960's. Particularly between the Bayou Sorrel Locks & Belle River.
Severely aggraded and silted up areas of the Lower Grand River channel are holding back the water flow especially around the Bayou Pigeon Pontoon Swing bridge.
Dredging and channelization of Lower Grand River has not occurred since the 1920’s. In fact it may have not been dredged for over 100 years.
Note the dates and depths of the dredging.
Documentation of last dredging in Lower Grand river
Barge Traffic on Lower Grand River at Bayou Pigeon c 1950's or early 60's
Some local residents say that since the Grand River at Bayou Pigeon is no longer part of the Alternate route of the Intracoastal waterway, ie, since the Bayou Sorrel Lock. The lack of barge traffic does not help scour to keep channel open anymore.
Problem #2 - The Pontoon Swing Bridges On Lower Grand River
The Bayou Sorrel pontoon-style bridge, built in 1964, carries La. 75 over Upper Grand River and Bayou Sorrel in Iberville Parish.
Lower Grand River Bridge, Bridge Recall # 054480 constructed in 1957 /58 opened in 1959. Carries traffic from Louisiana Hwy. 75 to Highway LA 997) over Bayou Pigeon/Lower Grand River, Plaquemine, Iberville Parish, LA
When the Lower Grand River water level gets high, the bridge master pumps water into the Bridge barge to lower it into the water column so it is level enough for vehicular traffic to cross; otherwise the bridge would be too high above the ramps. As a result the sunken bridge restricts the water flow even more, and especially at a time when maximum drainage flow is needed to allow the floodwater to drain downstream.
It has been said that the water level elevation on the north side of the Bayou Sorrel Pontoon Bridge and the south side of the bayou Pigeon Pontoon Bridge is as much as 11”.
If that difference can be validated, it means they are an significant impediment to rapid drainage.
Which begs the question why the bridges can’t be in open position in the wee hours in the morning 11 PM to 4 AM except in cases of emergency. There is essentially no barge traffic in The lower Grand river below the Bayou Sorrel lock
Note: There are pontoon bridges at Belle River and Pierre Part.
Problem# 3 - Lock Structures
Bayou Sorrell Lock on Lower Grand River
Bayou Sorrel Lock & Dam
Lock structures have guidelines by water stages on when they cannot allow Boat traffic or leave open the lock gates. Boat traffic is ceased at 6.5 ft at the Bayou Sorrel Lock gauge.
Even though boat traffic is stopped the lock gates remains closed. You would think opening the lock gates, that it would let some of the high water into the Atchafalaya Floodway, where there are no residents.
I presume the USACE has data to say the flood pulse flow inside floodway would overwhelm the Lower Grand River flow and cause back water flow.
An alternative proposal is a large volume pump station somewhere north of Bayou Sorrel lock to pump water over the levee into the Atchafalaya Basin during extreme rainfall and overbank flooding. ( probably the most effective cost technology)
“Which brings to this point”
Will the Bayou Chene Automated Barge Flood Gate alleviate all, most or some of the extreme Rain Water over bank flooding below Jack Millers Landing , through Bayou Sorrel, Bayou Pigeon?
Without addressing Water / Sediment management and the pontoon bridges situation and not being able to move some of the high water out of Lower Grand River to the Atchafalaya Floodway.
I think the answer is at best some relief and most likely very little to none.
The water will still go out very slow. Even if the annual Atchafalaya Flood Pulse is average.
Just saying … We are still screwed !
Overbank Flooding Is An Economic Threat To Iberville Parish
Overbank flooding is a threat to the sustainability and growth of the entire Lower Grand River corridor. The Bayou Pigeon Heritage Association is a voice for our local community we are pushing for flood protection that is critical to our survival and that will help us continue to improve our community and the ‘Down the Bayou’ part of Iberville Parish.
Iberville Parish - The Eastern Gateway To The Atchafalaya
Bayou Pigeon is the center point in the between I 10 and HWY 90
Bayou Pigeon The Only Authentic Cajun Community In Iberville Parish
Aim Straight
Cliff LeGrange
