Dredge the Vermilion Issues Flood Threat Assessment

May 18, 2021 | Uncategorized

Dredge the Vermilion

5/17/2021 7pm

Dredge the Vermilion issues our flood threat assessment as HIGH 

  • High Water Levels and Flows from the northern part of the watershed are putting pressure on the southern part of the watershed where water levels are also high, in some cases, over flood stage .
  • The drains in the southern part of the watershed have a number of issues that decreases their efficiency resulting in slow overall drainage .
  • Southerly and East winds for the last 48 hours are causing higher than desired tides that slow drainage.
  • All Flood Gates are open fully except the Lower Henderson Lock where only one of two gates are open due to an equipment failure.
  • Teche Vermilion Freshwater District is not pumping any water into the system
  • The National Weather Service was predicting a crest of 12′ at Surrey but the level as exceeded that forecast reading 12.6 at 6:15pm
  • As of about 6pm the National Weather Service was reporting slightly more than 2′ of rain at the Lafayette Regional Airport.
  • Rainfall in Lake Charles today is being reported as greater than 12″.
  • Levels in the Vermilion River from LA733 to Perry are favorable but the level at Surrey is cause for concern.
  • Existing high water levels over the entire region add risk if a large rain event (5” or greater) should happen.
  • Please check KATC channel 3 Rob Perillo as he is issuing frequent updates. Here is the link to his Facebook Page  (3) rob perillo chief meteorologist katc – Search Results | Facebook
𝐀𝐛𝐨𝐮𝐭 𝐃𝐫𝐞𝐝𝐠𝐞 𝐭𝐡𝐞 𝐕𝐞𝐫𝐦𝐢𝐥𝐢𝐨𝐧
Dredge the Vermilion (DTV) is a non-profit setup to inform the public about the need to identify and to perform regional drainage projects in the Teche-Vermilion watershed.
The board of DTV are all citizen volunteers with varying backgrounds from engineering, business owners, business management, medical, and legal.
If you wish to help with our efforts please like and share our posts on Facebook(search “Dredge the Vermilion”) and please see our website at www.dredgethevermilion.org if you would like to make a donation. All donations help fund our website, Facebook and other marketing efforts, public outreach, and research.
Below is much detail regarding the situation as it stood yesterday evening before this system moved into the area.

Comments, detail, and data on current levels, flows, and such for some of our main drains in the Watershed.

Bayou Courtableau at Washington LA St Landry parish is at 25.20 and falling slowly Flood Stage is 28 Flow is 4190 cfs  which is 253% of the mean flow for this date.

Bayou Des Glasises  Diversion Canal at Moreauville LA Avoyelles parish is at 11.64 and falling Flood Stage None Flow is 1550 cfs  which is 280% of the mean flow for this date.

Bayou Teche north of the Keystone Dam near St Martinville LA is at 11.10 and falling slowly Flood Stage None Flow is 1180 cfs   No mean flow for this date available.

Bayou Teche near Jeanerette LA is at 3.37 and is beginning to follow the tide  Flood Stage Flow is 982 cfs  which is 189% of the mean flow for this date.

The Vermilion River at Surrey Street  in Lafayette LA Lafayette parish is at 11.72 and falling slowly Flood Stage is 10 Flow is 2890 cfs  which is 307% of the mean flow for this date.

The Vermilion River at LA733 (E Broussard Road)  in Lafayette parish 7.02 and is beginning to follow the tide  Flood Stage is 7 No Flow Data available

The Vermilion River at Perry  near Abbeville LA Vermilion parish 6.52 and following the tide slowly Flood Stage is 9 Flow is 2270 cfs  which is 192% of the mean flow for this date.

The tide at Cypremort Point in St Mary Parish is at 3.03 at high tide and has been trending higher the last 4 days

 

The gauge at Bayou Courtableau in Washington measures most of the water from the northwestern part of the watershed.

The gauge at Bayou Des Glasises Diversion Canal in Moreauville measures most of the water from the northeastern part of the watershed. Note this  canal joins Bayou Courtableau just north of the West Atchafalaya Floodway West Guide Levee(aka “Henderson Levee”) just north of US190.

These two tributaries are the main drains in the northern part of the watershed. The water from these drains flows into the Atchafalaya River or the Gulf of Mexico:

  1. The West Atchafalaya Floodway through the USACE operated gates in the West Guide Levee. These gates are wide open. This water ends up in Lake Henderson and Lake Pelba  where the water level is 17.27 and falling very slowly. This water drains into the Atchafalaya river south of Butte Larose. The water level at the bridge leading to Butte Larose  is 16.54.  South of the bridge is the lower Henderson Lake Locks where one side of the structure is open and the other side is broken closed.  The water level in the Atchafalaya river at Butte Larose is 15.33.
  2. Some of the water that arrives at the above USACE gates flows over 2-  500’ overflow weirs if water levels are greater than 18’. Currently the level is   18.86 and is falling. Water that flows over the weirs goes to Bayou Amy and down to Catahoula and eventually ends up in Lakes Dauterive and Fausse Pointe. Lake Fausse Pointe is at 3.54 and steady which is a pretty high level. The lake complex drains back into the Bayou Teche and eventually out into the GOM at Jaws Bay south of Baldwin LA.

For the Vermilion River the water from this drains flows into the Intercoastal Waterway , Vermilion Bay, then into the Gulf of Mexico:

  1. Water from Courtableau in Port Barre flows into Bayou Teche . The level in the Teche at Port Barre is 19.87 which is high but falling slowly. Bayou Teche is connected to the Vermilion River in Arnaudville.
  2. The level at Surrey Street is currently 11.72 and falling slowly.  This is 1.72 feet above flood stage. This level is of concern should a large rain event happen. The slow fall is due to backfilling from the north and shoals in the river in Lafayette proper that slow drainage.
  3. The levels south of Lafayette (LA733 and Perry) are much less concerning.
  4. Tides are trending up for the last 4 days which is a concern.