Study: Sediment, Tidal Marshes Are Key To Protecting Bay Area From Rising Sea Levels

Scientists warn that sea level rise is a problem that cannot be ignored. But a new study says the secret to protecting the Bay Area may rest with something that is currently being thrown away. John Ramos reports. (4/13/21)

Video Transcript

- New at six, scientists say sea level rise is a problem that cannot be ignored. KPIX5's John Ramos reports a new study says the secret to protecting the Bay Area may lie in something that is currently being thrown away.

JOHN RAMOS: As sea level rises, it's going to be important to raise the level of the shoreline to protect the things we've built. But where's the material for that going to come from? It turns out, it's been here all along. The San Francisco will spend billions of dollars over the next 30 years to build up a few miles of seawall along the Embarcadero to protect it from rising seas, but, the rest of the Bay Area may have something that may work even better, tidal marshes.

LETITIA GRENIER: We are so lucky in the Bay Area that we have these tidal marshes. We have this option, if we choose to take it.

JOHN RAMOS: Dr. Leticia Grenier, senior scientist with the San Francisco Estuary institute, says shoreline marshes are a natural form of sea wall that grow higher as the water level rises. Each high tide deposits a new layer of sediment to the marsh. The more mud washed into the marshes, the faster and higher they will grow.

- These wetlands can actually grow vertically to keep up with the water as long as they have enough mud to do that.

JOHN RAMOS: The Institute released a study today saying the amount of mud needed to protect the Bay Area would fill 48 million dump trucks, enough to circle the equator 10 times over.

- That's what the report was about. We said to ourselves, OK, well, how much do we really need? And where can it come from? And the great news is, we actually have enough mud.

JOHN RAMOS: They recommend that sediment already being dredged from the Bay every day be used for this purpose. Right now, the Army Corps of Engineers pays to have the mud hauled far away and dumped, but, David Lewis, with the conservation group, Save the Bay, says the challenge will be to convince the government to pay a little more to use the mud as a valuable resource instead of just throwing it away.

DAVID LEWIS: If the Army Corps of Engineers would change their policies, we could promote this reuse and have it be affordable and really protect the Bay Area and the Bay from sea level rise.

JOHN RAMOS: The clock is ticking. Scientists say spending the next 10 to 15 years growing the marshes could prevent billions of dollars of damage in the decades to follow. In the East Bay, John Ramos, KPIX5.