Terrebonne Levee & Conservation District Provides Flood Control Structures Overview

Angela Hidalgo, the Terrebonne Levee & Conservation District Executive Director, provided an overview of the flood control structures’ operations at this week’s Terrebonne Parish Council meeting.

She started by outlining the district’s infrastructure, which spans 98 miles of levee, with 80 miles within Terrebonne Parish. The district encompasses 14 navigable floodgates, two navigable lock structures, the under-construction HNC Lock Complex, and eleven environmental control structures with Sluice Gates within the Parish. Closures are necessary due to regular monthly maintenance, tropical systems, non-tropical events such as elevated water levels or high winds, and lock complex operations. Hidalgo emphasized all closures are scheduled around suitable tides and weather conditions. The district also alerts the U.S. Coast Guard and mariners through notifications and text alerts.

She shared that monthly maintenance is crucial for ensuring proper operations and identifying necessary repairs. These closures typically last less than a day. She also noted fewer maintenance closures during the winter due to low tide levels, which can limit gate operational capabilities.

In the case of tropical systems, complete closures are implemented when a named storm is present in the Gulf of Mexico, and water levels reach 2.5′ of elevated tides. Road gates are the last to be closed, only if deemed necessary. She noted that gates can only be reopened once water levels have equalized and it is safe to do so.

For non-tropical elevated water levels, closures are generally prompted by weather fronts or prolonged southern winds leading to high tides. Due to their orientation, closures tend to occur more often on the east side of the Parish, particularly in Montegut, Chauvin, and Cocodrie.

Hidalgo also provided updates on the three lock complexes at the council meeting. The Boudreaux Canal Lock is currently operated in conjunction with the D-67 pump station at the direction of the Terrebonne Parish Consolidated Government (TPCG). The Upper Little Caillou Structure in Bourg must be closed to manage the gate effectively. Moreover, the Bayou Terrebonne Lock is operated to facilitate marine navigation and provide a safe harbor. Regarding the HNC Lock, which is undergoing construction until 2028, the Phase 2 groundbreaking ceremony is scheduled for Wednesday, August 7, at 10:00 a.m.

Hidalgo explained the typical sequence for a closure of the entire system, which usually takes 24 hours. The closing typically happens in the following order:

1. Close water control structures
2. Close non-essential, less navigable floodgates
   1. Humble, Placid, Bush, Upper Little Caillou, Grand Bayou, BGC, and Lower Dularge
3. The remaining of the floodgates are closed
   1. Cocodrie, PAC, Boudreaux Canal Locks, Bayou Terrebonne Locks, Falgout, HNC “Bubba Dove”
4. Close road gates if needed

The reopening typically reverses the order of closing.

To sign up for alerts, visit www.tlcd.org/mobile. The website also offers a view of floodgate status and an interactive map that shows gate locations along with their status.

© Terrebonne Levee & Conservation District