Look to the past to protect our future.

Why are we flooding?

During the last 50 years several events and projects were executed in the watershed that impacted local and regional drainage in the watershed. These include(North to South):

The Red River Navigation project executed in the 1980’s raised pool stages in the Red that impacted Bayou Rapides drainage into the Red River. As a result most of the water from Alexandria and north is draining south eventually ending up in Bayou Courtableau and potentially eventually into the Teche and Vermilion. We have heard reports that Alexandria is considering installing a major pumping system to pump water out of the city into the river.

During the Mississippi river flood of 1973 a drainage gate near Bordelonville LA on Bayou Des Glasises was damaged and subsequently abandoned. This gate drained the bayou into the Atchafalaya river just north of Simmesport LA during low water periods in the Atchafalaya river.  The bayou  has a watershed  of  about 270 square miles. As a result all drainage from this area now drains via the Bayou Des Glasises Diversion Canal in Moureauville LA into the the West Atchafalaya Floodway West Guide Levee Borrow Pit and down to Bayou Courtableau. Our Project Recommendation #3 addresses this deficiency.

Because of these 2 items nearly 100% of the water from the northern part of the watershed now drains into Bayou Courtableau.

The flood gates on Bayou Courtableau  at the West Atchafalaya Floodway West Guide Levee was deemed undersized in the USACE report to the Mississippi River Commission in 2007. This was noted that due to the abandonment of the proposed Eastern Rapides-South Central Avoyelles drainage project it was recommended that these gates be enlarged.

This USACE report to the Mississippi River Commission also noted that a Bayou Cocodrie , Boeuf, and Courtableau drainage project that was authorized in 1941 was only 57% completed by 2007. Our Project Recommendation #1 addresses these deficiencies.

The Teche-Vermilion Fresh Water District (TVFD) project built in the 1980’s now keeps the Bayou Courtableau at a higher level to ensure freshwater flow in the Teche and Vermilion during low water periods to greatly improve water quality and prevent salt water intrusion. The higher water level in Courtableau reduced natural retention in several flood plain areas (lowland swamps) in St. Landry Parish. The original TVFD project did not include any additional controls to quickly lower water levels in Bayou Courtableau when a major rain event threatens the region. Our Project Recommendation #1 also addresses this deficiency.

The Vermilion river has an authorized channel depth of -9 ft below mean low Gulf median (low tide) and an authorized channel width of 100 ft from the Gulf of Mexico to the head of navigation near the US 90 bridge near the Lafayette Airport. A detailed USACE channel survey was executed in May 2017 which illustrated that the river is 100% out of spec for it’s entire length in Lafayette Parish and significantly out of spec for Vermilion Parish north of Perry. This condition greatly hinders river drainage as was noted during the 2016 flood event, where it took 34 days for the river to go below 10’ flood stage at Surrey while at Perry the river got to below flood stage in 4 days and it took 55 days for the river to return to the pre flood stage at Surrey Street. Our Project Recommendation #2 addresses this item.