Terrebonne Parish is located in southeast Louisiana along the Gulf of Mexico. The parish is approximately 2,100 square miles and is the second largest parish in Louisiana. More than 85% of the parish area is made up of water and wetlands. The highest point in Terrebonne Parish is 13 feet above sea level. The map below shows the communities in Terrebonne Parish, its position in the state, and its large expanse of water and wetlands.
The wetlands in Terrebonne Parish include fresh marsh, intermediate brackish marsh, and salt marsh near the coastline. These marshes are intertwined with hundreds of lakes, bays, bayous, and canals. Some of the more notable water bodies within the parish include: Bayou Black, Bayou Dularge, Bayou Grand Caillou, Bayou Petit Caillou, and Bayou Terrebonne. These bayous are significant, as they historically provided the land-building sediment that created the highest areas of the parish. This sediment was deposited during annual flooding cycles of Bayou Lafourche. It is upon these finger-like ridges that all urban and agriculture land exists in the parish today.
Because of the formation of these ridges through alluvial processes, the three-foot contour clearly defines the ridges as the high ground of the parish. Virtually all land areas other than these ridge areas are susceptible to stormwater flooding, riverine flooding, storm surge, or backwater flooding. Flooding is caused by storm surge during tropical events, as well as rain events. Approximately 90% of the parish is considered environmentally sensitive and in the Special Flood Hazard Area. The graphic below depicts the ridges that form the bulk of non-flooding urban and agricultural land in the parish.
Terrebonne Parish has many structures in the Special Flood Hazard Area. Visit maps.lsuagcenter.com/floodmaps to see if your property is in or near a flood hazard area.
Check with Terrebonne Parish Permit Office to learn about flood protection measures for your property.