AND STURDY LEVEES, BUT THERE IS A NEW DESIGN THAT'S TAKING SHAPE , AND SPENCER CHRISTIAN IS BACK WITH THIS NEW TECHNOLOGY. SPENCER. OKAY, LARRY AND DION, INCREASINGLY A NATURE BASED DESIGN IS PROVIDING AN ALTERNATIVE TO ALTERNATIVE TO THE TYPICAL LEVEE, ONE WITH SIGNIFICANT BENEFITS IN THE FACE OF SEA LEVEL RISE. >> WE QUITE LITERALLY MEAN THE TRANSITION BETWEEN TWO TYPES OF HABITATS. >> WHEN WE FIRST MET JESSIE OLSON, SHE WAS IN THE MIDDLE OF A MULTIYEAR PROJECT CREATING WHAT'S KNOWN AS A HORIZONTAL LEVEE ALONGSIDE A NEWLY OPENED TIDAL MARSH IN MENLO PARK. JOINING WITH VOLUNTEERS AND COLLEAGUES FROM SAVE THE BAY, THE TEAM INSTALLED HUNDREDS OF PLANTS THAT WILL HELP CLEAN THE BAY WATERS AS THE TIDES SURGE IN AND OUT. >> A HORIZONTAL LEVEE IS NOT WHAT YOU THINK OF WHEN YOU THINK OF A TRADITIONAL HARDENED LEVEE. IT'S A GENTLY SLOPING LEVEE THAT COMES OUT INTO THE BAY. >> THE NEW TIDAL MARSH WAS CREATED FROM A FORMER SALT POND SEVERAL MONTHS AGO, WHEN CREWS BROKE OPEN A TRADITIONAL LEVEE TO LET BAY WATERS IN AND IT'S GREEN HORIZONTAL EDGE COULD BE CRITICAL IN KEEPING IT HEALTHY IN THE FACE OF SEA LEVEL RISE. THAT'S BECAUSE THE SLOPING STRIP ACTS AS A STEPLADDER, GIVING THE MARSHY AREA ROOM TO EXPAND. AS WATER LEVELS RISE, IT'S POSSIBLE FOR TIDAL MARSH TO GET DROWNED OUT IF IT CAN'T KEEP UP PACE WITH THE RATE OF SEA LEVEL RISE, AND PROVIDING THESE HORIZONTAL LEVEE SPACES GIVES THEM SOMEWHERE TO GROW UPWARD AND CONTINUE TO PROVIDE THAT IMPORTANT HABITAT. AND THAT LIST OF OPPORTUNITIES IS GROWING, INCLUDING SECTIONS OF THE SAN FRANCISCO BAY SHORELINE THAT SERVE A CRITICAL FUNCTION HOUSING MANY OF THE BAY AREA'S BIGGEST WASTEWATER TREATMENT PLANTS. WE TOURED SEVERAL FACILITIES THAT ARE NOW PREPARING TO SPEND HUNDREDS OF MILLIONS OF DOLLARS ON UPGRADES TO MEET THE TIGHTER STATE WATER QUALITY REGULATIONS FOR WHAT'S DISCHARGED INTO SAN FRANCISCO BAY PROJECTS ALSO SET TO INCLUDE HORIZONTAL LEVEES. >> YEAH, SO THAT IS A PART OF WHAT WE CALL HARBOR MARSH IN PALO ALTO. >> SENIOR ENGINEER SAMANTHA ENGLISH SHOWED US A MARSH AREA NEXT TO THE WATER QUALITY CONTROL PLANT. THAT'S WHERE THE DISTRICT IS PLANNING TO CONSTRUCT A HORIZONTAL LEVEE PROTOTYPE DESIGNED TO FIGHT EROSION AND POTENTIALLY HELP ADD TO THE WASTEWATER PURIFICATION CYCLE AND TREAT, WASTEWATER A LITTLE BIT MORE, AND REMOVE MORE NUTRIENTS AND REMOVE MORE CONTAMINANTS OF EMERGING CONCERN ACROSS THE BAY. >> AT THE AURA LOMA WASTEWATER TREATMENT PLANT IN SAN LORENZO, VOLUNTEERS FROM SAVE THE BAY AND OTHER GROUPS HAVE HELPED TO GREEN YET ANOTHER EXPERIMENTAL LEVEE PROJECT, AGAIN USING MARSH PLANTS TO HELP ABSORB MATERIALS FROM THE WASTEWATER. LAURIE ANTONIO IS EXECUTIVE DIRECTOR OF THE BAY AREA CLEAN WATER AGENCY. >> OUR VISION FOR OUR REGION OVER THE LONG TERM IS THAT WHEN WE DO NUTRIENT REDUCTIONS, WE ALSO GET MULTIPLE BENEFITS. SO IF WE'RE GOING TO SPEND THESE FUNDS, WE WANT TO GET THE BIGGEST BANG FOR OUR BUCK THAT WE CAN FOR JESSE OLSON, THE ADOPTION OF HORIZONTAL LEVEES IS A FORCE MULTIPLIER, ADDING NEW OPPORTUNITIES AS THE BAY AREA RACES AGAINST THE CLOCK TO RESTORE THOUSANDS OF ACRES OF TIDAL MARSH AROUND THE SAN FRANCISCO BAY IN THE UPCOMING DECADES. >> YES. >> NATURE BASED SOLUTIONS. HORIZONTAL LEVEES THESE THESE TIDAL MARSH RESTORATION PROJECTS, THEY ARE A MAJOR ANSWER TO HOW THE BAY IS COMBATING CLIMATE CHANGE AND SEA LEVEL RISE. >> A MORE SUSTAINABLE FUTURE ROLLING OUT BEFORE OUR EYES ON OUR OWN BAY AREA SHORELINE SUPPORTERS ALSO ARGUE THAT THE HORIZONTAL LEVEES ARE A COMPARATIVE BARGAIN, WITH SAN FRANCISCO BAY PROJECTED TO RISE BY SEVERAL FEET IN THE NEXT FEW DECADES. THE COST ESTIMATE TO PROTECT THE
