Concordia Parish, LA
Flood Zones in Concordia Parish, Louisiana: Living Behind the Old River Control Structure
Concordia Parish's hub page mentions the Old River Control Structure -- this page goes further into what that facility actually does, its well-documented 1973 near-failure, and what it means for a buyer evaluating levee-protected farmland in the parish today.
This page covers what's specific to Concordia Parish. For the general explanation, see the national guide.
Why the Old River Control Structure exists
The Mississippi River has a long-documented natural tendency to periodically shift its main course toward a shorter, steeper path to the Gulf of Mexico -- historically, that path has run through what is now the Atchafalaya River basin. Recognizing this risk in the mid-20th century, the US Army Corps of Engineers built the Old River Control Structure in Concordia Parish specifically to manage how much of the Mississippi's flow is allowed to divert into the Atchafalaya, preserving the river's historic main channel past Baton Rouge and New Orleans -- and with it, the shipping, industry, and municipal water supplies that depend on that channel remaining the Mississippi's primary route to the sea.
The structure's importance became starkly visible during major Mississippi River flooding in 1973, when the facility came close to catastrophic failure under flows far beyond what its designers had anticipated. That event is widely documented in the history of American river engineering -- notably as the subject of a well-known essay by writer John McPhee -- and remains a standard case study in flood-control policy discussions about the risks of engineering a major river's course.
What this means for land and flood risk in the parish today
For an ordinary land buyer in Concordia Parish, the Old River Control Structure doesn't create a direct permitting requirement the way, say, a coastal-zone designation would in a coastal parish -- but it is directly relevant context for understanding how the parish's farmland exists in its current form. Much of Concordia Parish's productive Delta farmland sits on the Mississippi River floodplain and depends on a combination of the Old River Control Structure and the parish's local levee system to stay protected from ordinary river flooding.
Practically, this means a buyer should confirm two related things for any specific parcel: its current FEMA flood zone designation, and its relationship to the local levee (land outside the levee -- river batture -- floods regularly as part of normal river hydrology and is treated very differently than protected farmland inside it). The parish's levee district and the US Army Corps of Engineers' Vicksburg District, which administers the Old River Control Structure, are the right sources to confirm both points, along with any levee-district assessments that may apply to protected farmland.
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Connect with a local land specialistSources
- Old River Control Structure — US Army Corps of Engineers, Vicksburg District (accessed 2026-09)
- FEMA Flood Map Service Center — Federal Emergency Management Agency (accessed 2026-09)
- Concordia Parish Police Jury — Concordia Parish Police Jury (accessed 2026-09)
Last reviewed 2026-09