Wetland Restoration: Using Municipal Wastewater as a Resource

Wetlands are considered one of the most productive ecosystems in the world and they provide numerous beneficial eco-services comparable to those from rainforest and coral reefs. In Louisiana, wetlands not only provide the valuable eco-services, it also serves a very critical function: front line defense against hurricane surge.

After Hurricane Katrina, while repairing and upgrading levee is the top priority, the levee system should be considered the last line of defense against hurricanes. The first line of defense should be the surrounding wetlands. A healthy wetlands system could lower the height of the storm surge when it passes through, absorb storm water to prevent flooding, and stabilize coastal lines. Unfortunately many wetlands have been lost due to various reasons such as pollution, salt water intrusion and erosion. Restoring wetlands often involves complex process and tremendous effort. An innovative wetlands restoration project was conducted in St. Bernard Parish Louisiana utilizing municipal wastewater.

In this project, treated municipal wastewater was diverged to the surrounding wetland after effluents were characterized and nutrient loading rates were calculated. Vegetation diversity was examined; and water quality was also monitored for nutrients contents in the receiving wetlands. Results of study period of one year indicate significant increase in the vegetation diversity and productivity in the receiving wetlands as a possible outcome of nutrients and fresh water content from introduced effluent. Degradation in water quality was not observed. Overall results demonstrated the project being an environmental friendly and cost-effective method to restore wetland.