Scientist Letitia Grenier is coordinating the 2014 update of the 1999 Baylands Ecosystem Habitat Goals. The Goals created a regional vision for restoring 100,000 acres of tidal marsh around San Francisco Bay, an acreage scientists agreed would be big enough to sustain endangered marsh species. Today, climate change and the prospect of a 2-5 foot sea level rise over the course of the next century have changed the environmental context of the Goals, and the prospect of achieving them. Not only will the water be rising, the processes influencing our wetlands will change as we experience new extremes, more frequent storms, and seasonal shifts in when the snow melts and swells runoff. Grenier has been tasked with managing the five science teams working to update the Goals. New sections will describe the evolution of marsh habitats under different climate change and sediment supply scenarios, the terrestrial-estuarine transition zone and the services it provides, risks to wild plants and animals, and carbon sequestration. Grenier is a biologist specializing in landscape-scale planning for restoring natural systems, not to mention a new mom, and formerly led the SF Estuary Institute’s Conservation Ecology Program. The draft goals update has been completed and the final is due out early next year.
What are your basic recommendations in Goals update?
First, we need to get better organized and be more integrated in planning and implementing the revised Goals. We will need regular meetings of agencies that have regulatory authority over how things go down so they can sort out disagreements and be more flexible with permitting projects. Second, we may need to change our policies to adjust to the changing environment. For example, we have a policy around sediment that’s based on way the system worked 20 or 50 years ago, but it’s not necessarily the right policy, environmentally, into the future. Third, we need our own “fire department” to respond to catastrophe. We know something will happen soon, probably a big flood. So our community of stakeholders needs to think through the likely scenarios, be prepared with a plan for what to do, know who to call when the disaster comes, and make sure to get invited to the emergency meetings. Then we can say, “Here’s a plan that could be cheaper for you than throwing up a sea wall, because it incorporates natural processes and is much more likely to produce a good ecological outcome.”
What’s wrong with a big sea wall?
The minute you build that big levee, you’ve got flooding problems on both sides. Big storms will not only affect the water level outside levee, but also inside, by dumping a lot of water that runs off the land and gets stuck behind the levee. From the ecological, and economic, perspective, it’s better and cheaper to have a long sloping levee, buffered by wetlands, than a seawall with deep-water next to it.
With sediment in short supply, how can we build wetlands, let alone levees?
We’ll need the bulldozers and dredges, but we also need to work with the natural forces of the planet, like streams and tides, to move the sediment where we want it to go. If we were allowing our watersheds to work the way they naturally do, instead of through dams and culverts and impermeable surfaces, they’d be delivering more sediment to wetlands, which could help them build up their elevations naturally. We also have all these erosion-control programs to prevent sediment from getting into streams, because it’s important at certain times for fish or water quality. We may need to find creative solutions. And lastly, we need to think about dredging in the Bay and in flood control channels. Sediment is sometimes dredged and dumped in place A instead of place B, because it’s cheaper. With sea level rise, we need to think of sediment as a precious resource that should be managed regionally and strategically. It should be placed in the right spots to preserve our baylands and our low-lying built up areas. We also need to think of the fresh water coming off the land or out of our wastewater pipes as it’s own precious resource. Instead of piping it out into the Bay, maybe we can put it back where it used to go, into the back of a marsh. So every decision we make around retooling an infrastructure project like a bridge, or protecting a wastewater treatment plant that will be below sea level soon, needs to incorporate solutions that think about sediment and water in a new way.
Can our endangered marsh species be as flexible as we’re trying to be?
Maybe, maybe not. One of our bet-hedging tools is to include a lot of variability in restoration projects we design. So then if you’re an animal, and something changes, you can go to a different part of the marsh. If there’s a wet year or a dry year you can stay in the zone that’s comfortable for you. Or if there are lots of different marshes around the Bay, in a good year or a bad year you can reroute yourself. Also, if you have this diverse environment out there, you’re supporting different physical variations, or phenotypes, of your animal. Then if something happens – a bottleneck in the environment, a year with this kind of food or that kind of food, then your phenotype that’s adapted to those conditions, the wetter year, the bigger nut to eat, whatever it is, that one survives. What we want is to promote the greatest genetic and phenotypic variability we can get in our wildlife populations. It’s like having a stock portfolio that’s very broad. No matter what’s up or down, you’ve got everything going on, so you’re going to make some money every year.
Is 100,000 acres of tidal marsh still the magic number?
In terms of where the Goals are going, this project is set up to figure out how to achieve the Goals in the long run. We know they could still be achievable for several decades, and we know we may have to make some big changes to achieve them for the next century. And since we still want to have our wildlife populations, and all the ecosystem services of those wetlands for those decades, our recommendation’s going to be charge on ahead, but do it wisely. Make sure to consider some of the information we’ll be providing in the update about good places to do certain kinds of things, and how to implement projects that will be resilient in the long term.
Will the Goals offer a new prescription for where to build and where to breach?
We’ve discussed where our role stops. We do want to highlight low slope areas around the edges of the Bay and river valleys where marshes can transgress. If you can find them, you should acquire them for the public and preserve them in perpetuity. But we’re not s going to tell people to make room for a setback levee in a specific location by removing houses. We’re trying to present options based on science, like: “If you take this approach you might end up with some wetlands in 2110 that might be a buffer against flooding across the Napa Valley; or if you take this approach with a sea wall, you’re going to have waves that will bounce back and forth, and actually get higher because of geometry, and you’ll have a different kind of risk of flooding behind the sea wall.”
Did we meet the 1999 goal of connecting big expanses of habitat?
We’ve made a great start, but there’s more to do. It’s always easier to get your own restoration project done than to coordinate and connect it to a bunch of other projects. With climate change, we need connectivity even more, not just for the old reasons, but also if conditions change, connected habitats give wildlife a way out. The reality of our urbanized shoreline, however, is that we’ve squeezed nature into too small a space. As sea level rises, there’s going to be this squeeze, and this squeeze is going to create more of a problem with connectivity. If we don’t achieve natural systems that are connected, we might have to expect more intervention – like active translocation or captive breeding.
Do other estuaries have Goals like we do?
Not that I know of, but other estuaries like Washington’s Puget Sound and Maryland’s Chesapeake Bay have thought through a future climate change process. There are differ ent science questions and different ecosystems, but everybody ends up with the same principles. What’s interesting in California is our really strong environmental ethos, which has also resulted in overlapping jurisdictions among our many environmental management agencies. It’s a positive and a negative. It creates a decision-making complexity that can be good, but is also takes more time, like democracy. But it’s nice, because everyone seems to have a shared goal of doing something good for the environment. I don’t get that same feeling from other places. How do you plan for climate change if you’re not allowed to use the word climate change? How do you plan for coastal protection if the government agrees they will protect everyone’s private property on a barrier beach? If you’re going to focus on saving every human structure, are there any resources left to think about doing things in a different way?