Do you know what ecosystem design is and how it can be used to protect coastal areas threatened by flooding or land loss? If you are interested, you might like to know that ecosystem design provides a sound basis for building adaptation into sustainable land-use planning, coastal protection, and education.
Personally, I am attracted to the subject of ecosystem-based adaptation because it is an approach that seeks to protect people and their livelihoods from the effects of climatic events, using the goods and services of natural and productive ecosystems. This approach invites us to consider biodiversity and nature as solutions to the impacts of climate change. If an ecosystem-based approach to adaptation is adopted and actions are taken to restore, maintain, or improve the health of coastal ecosystems, then we also benefit from ecosystem services such as provision of clean water, fertile soil, and food, among others.
Coastal Louisiana, a highly populated area rich with culture and history, is rapidly growing and losing land. This trend holds for Barataria Basin, a basin in Southeastern Louisiana bounded by Bayou Lafourche to the west and the Mississippi River to the east. The basin is hydrologically disconnected due to levees on both boundaries of the basin. The historical connection between the rivers and their floodplains has been disturbed, resulting in a decline of the land building that would have occurred as a natural process of river deltas. The basin faces many issues, such as land loss, salinity intrusion, impaired water quality, and a limited supply of fresh water and sediment. Current mitigation strategies focus on individual projects in isolated areas, but this isolated approach does not allow for the long-term health of the basin because it does not consider the overall system. (To see a list of all projects developed on the Louisiana coast visit Coastal Protection and Restoration Authority’s web page.)
This summer, I interned at the Coastal Ecosystem Design Studio (CEDS) – formerly known as the Coastal Sustainability Studio – with Louisiana State University (LSU). The internship aimed to study settlement, coastal restoration, flood protection, and economic development issues to create innovative solutions for communities in the Barataria Basin within the Mississippi Delta of Louisiana. During the internship, a diverse group of students worked as a team and used the concept of Natural and Nature‑Based Features (NNBF) to study the western portion of the upper and middle Barataria Basin. We proposed designs with a systems thinking approach that considers the health of the entire basin to ensure long-term sustainability.
Our design focused on protecting communities by implementing multiple lines of defense based on building different kinds of nature-based solutions to decrease the likelihood of flooding. The idea was that protection of communities can be achieved by stabilizing, nourishing, and reconnecting the natural system. Stabilizing will prevent further degradation of the system through erosion protection; nourishment will provide a source of fresh water, nutrients, and sediments to help create a self-sustaining, healthy marsh system; and reconnection will restore the hydrology of the system to ensure long-term sustainability, and retain the community’s connection to the marsh by implementing designs that provide recreational opportunities.
We proposed different NNBFs to stabilize, nourish, and reconnect. NNBF’s placed in different marshes with varying grades of degradation could work together to protect the whole system. One of the NBBFs we proposed was to build a horizontal levee instead of a regular levee at the top of the basin. A horizontal levee differs from a regular one because it is short in height, it has a slow slope on which ecosystems could establish and migrate without losing ecosystem services, and it is less expensive to build and maintain. Another advantage of a horizontal levee is that it could be the final destination of discharged treated water, turning this into a wetland assimilation area (see one example in Oro Loma, California). Especially in the Mid-Barataria Basin, which is a system with water and sediment scarcity, the wetland assimilation area would help the natural vegetation to grow, strengthen, and maintain over the long term.
A systems-based approach to design will help encourage long-term sustainability in the whole basin. The future of the south of the basin will have implications on the health of the upper basin. Design interventions should consider the entire system across parishes and different sections of the basin. Systems thinking is an important tool to understand complex problems, and in this case, a problem that involves the lives and livelihoods of the people in the Mississippi River Delta and the survival of the ecosystems that sustain the lives and jobs of those people.
As a personal reflection, this experience has enhanced my knowledge of integrated coastal zone management and the application of systems thinking. It was exciting to study a socio-ecosystem unknown to me, and understand it from different angles such as sediment dynamics, hydrology, marshland ecosystems, and the human populations that inhabit it and their means of subsistence. I hope that the NNBFs that we proposed are up to the challenges that people and ecosystems face.