Sea level rise mitigation is simply any investments made into minimizing the damage caused by rising sea levels. Other examples include raising facilities above sea level, building flood barriers, and moving facilities away from the shore.

The 2019 City of San Diego State Lands Sea Level Rise Vulnerability Assessment indicates that 300+ acres of state-granted lands are vulnerable to sea level rise through 2100. Restoring wetlands can serve as a cost-effective measure to mitigate the damages from sea-level rise relative to other options such as sea walls.

We aren’t able to confidently estimate an annual value because the City’s vulnerability assessment isn’t spatially indexed (meaning we don’t know where the liabilities are located) and that much of the damage will be caused by storm surge events. Furthermore, storm surge events aren’t consistent across years, both in their frequency and intensity. Coupling these two problems together means that we can’t confidently determine the annual damages avoided by restoring the marsh.

Wetlands act as a buffer against sea level rise by decreasing the size and power of incoming water. They also act as sponges by absorbing excess water. In fact, a single acre of wetland can store 1-1.5 million gallons of flood water!