Jean Lafitte National Historic Park and Preserve Wetland Restoration

The degradation of spoil banks along decades-old oil and gas canals restores historic marsh hydrology, eradicates invasive species, preserves an important National Park site, and allows future generations to experience Louisiana delta ecology.

South Louisiana is a biologically rich area of swampy bayous and marshes that teems with life and history. Unfortunately, over decades, exploratory access canals were excavated across the region rich, organic soils were piled in long spoil mounds flanking the sides of the new waterways, creating dramatic changes in the hydrology and ecology of the delta. Left to oxidize in the sun, they were colonized by non-native species such as Chinese tallow tree (sapium sebiferum). The mounds also disrupted the surface flow of fresh water across the marshes, resulting in anoxic conditions in many of the canals.

The Barataria Preserve, a 20,000-acre swath of marsh and forest south of New Orleans, is a unique component of our national park system that supplies valuable access and exposure to the Louisiana delta ecology. Biohabitats worked with the National Park Service to repair the industrial damage to the landscape and restore historic marsh ecology. Our approach challenged logistical operations and required floating excavators to remove invasive tree cover and return excavated soil to the canals. In the process we preserved unique specimens and stands of valuable oaks and bald cypress, creating “tree islands” within the marsh. The final grade of the spoil mounds is level with the surrounding marsh, allowing the free movement of surface water and the eventual recolonization of these sites by emergent native vegetation.

Biohabitats completed over four linear miles of marsh restoration within the Preserve and the results were dramatic. Upon the degradation of the spoil mounds, the free movement of fresh water across surface of the marsh was restored and the existing population of Chinese tallow tree eradicated. Native marsh vegetation quickly colonized the former spoil mound sites within months of soil removal.