Harnessing Salt Marshes for Cost-Effective Coastal Protection

As coastal communities grapple with rising sea levels and increasingly powerful storms, cost-effective solutions are in high demand. A recent study from MIT reveals that salt marshes provide a highly efficient means of protecting coastlines from storm surges and erosion. The study, led by MIT researchers, found that integrating salt marshes with existing infrastructure, such as seawalls, can significantly reduce construction costs while offering powerful protection against coastal storms.

Salt marshes act as natural barriers, absorbing and dissipating the energy of incoming waves. The research shows that even relatively narrow strips of marshland can reduce the height requirements of seawalls, leading to lower construction and maintenance costs. This finding is particularly relevant in urban coastal areas where space is limited, and building expansive marshes may not be feasible. The study emphasizes that marshes as narrow as tens of meters can still offer substantial protection.

The researchers conducted a benefit-cost analysis, revealing that healthy salt marshes could offset the need for seawalls by up to 1.7 meters in height. This makes the use of salt marshes both environmentally and economically viable. With advancements in drone imaging and machine learning, mapping and evaluating the flood mitigation value of marshes will become more accessible, further promoting the use of nature-based solutions for coastal defence.