FEATURE: Reactivating our floodplains: A new way forward

Panel of experts discuss how reactivating the floodplains can provide habitat and food for native fish and for migrating birds, and highlights the many projects and opportunities in the Sacramento Valley

Nearly the entire Sacramento Valley floor is part of the historic floodplain that once supported robust fish and wildlife populations.  As the Sacramento Valley was settled and farming began, levees and dams were built to protect people from catastrophic floods; however, the severing the rivers from their floodplains has starved the ecosystem, depriving native fish and wildlife of important habitat.

However, with some modest changes to infrastructure, farmland, wildlife refuges, and the flood bypasses can all be reoperated to mimic the ecosystem processes of the historic floodplains while continuing to provide vital flood protection for Sacramento and other parts of the Valley.  At a panel discussion hosted by Secretary Wade Crowfoot, the panelists discussed how by spreading out and slowing down water across the landscape can provide multiple benefits year-round by allowing farmers to cultivate the land during the spring and summer, and provide habitat for fish and wildlife in the fall and winter months.

So much in water policy in this state can be characterized as conflict: Fish vs. farms, urban vs. rural, north vs. south,” began Secretary Wade Crowfoot.  “One important priority of Governor Newsom is to try to break through that old paradigm and find ways that work across different stakeholder groups – for the environment and for water users.  Finding ways to reactivate the natural floodplain in the Central Valley is one of those win-win solutions.”

Secretary Crowfoot then introduced David Guy, President of the Northern California Water Association who began the presentation.

We’re going to encourage you and ask you to join us in reimagining our water system through some science, through some film, through some water management, and through some ecosystem management, so please join us in reimagining our water system as we think about ways in this new way forward,” Mr. Guy said.

We were encouraged when the Governor called out that we’re going to break down these binaries and this is one of many efforts to do that,” Mr. Guy said. Most recently, we were very encouraged when the Governor signed a budget based on a lot of the work at the Natural Resources Agency to give floodplains a catalyst with basically $100 million of funding to really start moving some of these efforts forward.”

Mr. Guy concluded by acknowledging the many partners that have been involved in the progress of moving the floodplain work forward.


Dr. Jacob Katz is a Senior Scientist with Cal Trout, and he spoke about his research on the benefits of floodplains for salmon.  He began by noting that the Sacramento Valley as it exists today is a tapestry of agricultural production, but before development, it was an incredible mosaic of wetland habitats with different kinds of marsh and emergent wetlands and riparian jungles along the rivers.  It really was one of the world’s great wildlife landscapes where the wetlands really defined the valley.  Before they were the names of counties – Colusa, Butte, Sutter – those were the names of the flood basins, of the ephemeral wetlands that really characterized how the Sacramento Valley worked, he said.

However, that rapidly changed.  What used to be a system that every winter and where the rivers would swell, the water would breach the natural levees and spread out across the different wetlands.  Then 13,000 miles of levees were completed in just a little over a century which was a wholesale alteration to way that water flowed across that landscape, he said.  It was changed from a landscape that used to be about weeks and months of water flowing and spreading across the land, to one in which ubiquitous drainage really had the landscape drying as quickly as possible.

It’s not just every farm field – it’s your backyard, the Safeway parking lot – really the entire human-built landscape is designed to push that water off the landscape as quickly as possible,” Dr. Katz said.  “That fundamental alteration in the natural pattern, the natural process, the natural flow of how water flows across the landscape has had many unintended consequences.”

A few years ago, CalTrout, in partnership with UC Davis for Center for Watershed Sciences and the Department of Water Resources, performed a simple experiment.  They made cages of plastic fence and PVC pipes, attached crab floats to them, and put 10 fish from the Feather River Fish Hatchery in each cage.  They placed the cages in the Sacramento River by the new pumping station for Davis and Woodland.  The fish were each tagged so that their individual growth rates could be tracked.  They placed a similar set of cages and fish about 30 yards away on the other side of the levee in a canal, and another set in a rice field where they spread the water out, mimicking the natural way water would have flowed across the landscape.

What happened? After just three weeks, the fish that were out on the floodplain had grown substantially compared to those in the river or those in the canal,” Dr. Katz said.  “We had 700% greater growth in just three weeks was very clear to see.  Why? In the Sacramento River, there were very few bugs in that water.  In the canal, there were 6 times more, 600 percent more bugs, and that understandably resulted in greater growth.  But on the floodplain, you can’t even see the water.  It’s zooplankton soup; it is liquid protein, it’s energy.  It’s 15,000 percent more food.”

We’re showing that the system that we have built here in California, that we’ve inherited over the last 100, 150 years, has been squandering this incredible natural wealth,” he continued. “This capacity to make food – those bugs make fish – that has been largely surgically taken out of the system.  Our levees and our drainage system creates food deserts of our rivers.”

One of the reasons for this is residence time.  Dr. Katz explained that the water in the river turns over every couple of seconds; in the canal, every half minute, but in the field, every couple of days.

Residence time of water is the time that it takes to actually build these important food webs and it is absolutely critical,” he said.  “If you’re rapidly pushing the water off the landscape, you don’t have the residence time necessary to make bugs, to make fish, and to make a healthy system.”

The floodplains are essentially the solar panels for the system as a whole; they are the energy source.  He explained that in summer, the plants act as batteries, capturing sunlight and creating sugar, and that sugar is a battery.  In winter, that battery is brought into the system when the rivers spread out, when they slow down.  In the state’s channelized river system, the only sunlight that can come into the system is just between the two banks.

The moment you let the river spread out onto its natural floodplain, you have this much larger surface to capture winter sunlight,” he said.  “Whether it’s summer or winter, the same thing needs to happen.  You need to spread the water out, you need to slow it down, and you need to mimic that natural flood regime.”

It isn’t rocket science but it is physics, Dr. Katz said, noting Albert Einstein had the equation, E=mc2, correlating energy and mass.  “The amount of energy that goes into the river system as a whole is going to have a direct effect on the biomass we get out.  We can’t be surprised if we reduce the floodplain surface by 95%, that we’re reduced to some small fraction of the fish biomass.  That’s the math that we’ve created.

Dr. Katz pointed out that what this means is since we created it, we can un-create it.  We can create a system that reintergrates this fundamental knowledge of physics and biology into how we manage, so sunlight can be trapped by vegetation on the floodplain and by floating algae, it can be turned into food by microbes and bacteria which is then eaten by zooplankton and bugs which make fish, which given a little time, makes bigger fish, which are healthy.  Making fish takes time; it doesn’t happen instantaneously, he said.

It isn’t magic although it might look like it,” Dr. Katz said. “What it is is providing enough time to let nature do its thing, and we have that capacity but we have to design it back into the way we manage our floodplains, our bypasses, and our restoration efforts.”

This is a pivot towards process, he said.  The Sacramento Valley was a mosaic of different floodplains that existed pre-development, but that ground didn’t disappear; on top of it there are the existing ricelands in the Sacramento Valley.  There has been incredible work done over the last 30 years to show that those working lands can make incredible habitat for native species.

We have a chance to do that with fish now,” he said.  “We have a chance to work with the natural processes which create and maintain those diverse habitats and have residence times necessary to create functioning riverine aquatic food webs.  We can spread it, we can slow it, we can sink it back into the ground to recharge critical aquifers and we can grow these food webs which are the fundamental functioning of resilience.  Resilience is about diversity.  It’s right there in the language, don’t put all your eggs in one basket.  That’s what we’ve done with channelizing our entire river system.  Now we have the change to put oxbows, side channels, and floodplains all back into the system.”

Functioning ecosystems create abundance and diversity, and out of that diversity is born resilience, Dr. Katz said.  Ecological resilience then is the very basis of economic resilience.

We can have a system that has abundant fish populations,” he said.  “Endangered fish are not an inevitable consequence of development.  They are a direct consequence of a system built before we really understand how rivers worked or how fish use them.  With that comes this understanding that the similar kind of understanding of natural flow applies to understanding the flow of a fire through forests.  Understanding the flow of grazers across rangelands.  Understanding that we have a real opportunity now to, in California, start working with the actual underlying causes of environmental decline, not just addressing the symptoms.  And that really means that California is really poised to create water solutions that have global impact.”

Roger Cornwell is the manager of River Garden Farms, located near Knights Landing in the Sacramento Valley.  River Garden Farms has long partnered with U.C. Davis, Cal Trout, and many others on projects to benefit birds and salmon.

The ag community really started off in birds and that’s when we really realized that there’s this energetics model that maybe we can apply it to other species,” he said.  “That’s when I met Jacob Katz and a few others, and we started working in that direction.  What we did is we created a simple, animated video that I’m going to play for you that will hopefully bring everything that Jacob was talking about together.


The next speaker was Meghan Hertel with Audubon California.  “My job is to lift your eyes up from the river and streams to overhead to talk a little bit about birds, and why the Central Valley matters for birds and why it is imperative that we work with landowners and find solutions that work for birds and people in this place we call home.”

Much like salmon, there are many birds that migrate that rely on the Central Valley, some flying thousands of miles along the Pacific Flyway, so what we do here in the Central Valley really matters, she said.  These birds are flying thousands of miles, linking across countries and across hemispheres, from neotropical migrants that are coming here in spring and summer to breed to the phenomenal numbers of wintering waterbirds that come to stay the winter or to rest and refuel before continuing their long journey.

She presented a picture of the Aleutian goose, which at one point in time was actually thought to be extinct; however, they found a small number breeding on the Aluetian Islands off of Alaska.  Efforts to reduce predators, both in their breeding grounds as well as in their wintering grounds in the Central Valley, have led to a full recovery of the species.

This is one of the few species that’s actually been removed from the endangered species list,” said Ms. Hertel.  “That’s because we were able to do work both where they breed but also here in the Central Valley, and a lot of that work revolves around partnering with landowners to protect and enhance their winter habitat.”

Development of the Central Valley has fully changed what birds, fish, and people see, losing 90 to 95% of floodplains, riverside forests and wetlands, and all in less than 200 years.  But even so, if you go out to the Yolo Bypass in fall or winter, you could still see phenomenal numbers of birds, she pointed out. Historically it would have been 20 to 40 million waterfowl; it’s now between 5 and 7 million.

The reason we have these high numbers of birds still is both that we’ve protected the last remaining wetlands, public and private wetlands, and that we’ve partnered with farmers to create surrogate habitat that mimics what the habitat was historically,” said Ms. Hertel.

She presented a map showing the remaining public and private wetlands, noting that rice grounds are shown in green.

These birds are coming here and are really relying on those last remnant wetlands that we have but also on the habitat in the rice fields,” she said.  “Two-thirds of waterfowl diet is coming from rice fields.  Some of the highest densities of wintering waterfowl in the world we have here in the valley.  Actually the rice ground is designated as a site of hemispheric importance for shorebirds.”

Audubon and their many partners have been working with rice growers for more than a decade.

The way we work with them is we talk about what the birds need, we come up with ways they can manage their land and water to benefit birds, we go out and study and test it, and when we prove that it works for the birds and the farmers, we work with agencies to try and take them to scale,” Ms. Hertel said.  “These practices can be really simple.  It’s something like holding water longer in your field in the spring to benefit shorebirds.  Making the water be 2 inches instead of 6 inches so you’re benefitting a different type of bird.  This is not rocket science, but these are simple things we can do on the landscape to benefit birds.”

She concluded with a ‘birds-eye view’ of the flooded rice fields, which look to the birds like the wetland or floodplain habitat they evolved with.  “Water choices in California are not always easy.  We’re certainly going to have to make some hard decisions coming up, but birds and fish evolved together and there are opportunities to partner with landowners to think about ways to mimic that and recreate it.”


Lewis Bair is an engineer and the manager of Reclamation District 108; he likes to ‘build stuff’ as he puts it, and he next discussed projects underway or planned in the Sacramento Valley.

He began by noting that RD 108 is located in the middle of the floodplains.  “We’re a reclamation district because we built levees, so we created some of this problem that we’re talking about right now,” he said.  “But I think what is exciting is that we see ways in which we can go forward with modernizing that infrastructure so it still works for farms but it also works for the environment.”

For a long time, they were burning the rice straw at the end of the growing season, but when that stopped, there was incredible success when they started flooding rice fields.  Having experienced that, folks in the Sacramento Valley have come together with a ‘let’s just fix it’ approach, Mr. Bair said.

During the recent drought, a comprehensive salmon recovery plan for the Sacramento Valley was developed under the leadership of David Guy and the Northern California Water Association.   That plan targets activities in three areas: the upper Sacramento River, the mainstem of the Sacramento River, and the floodplains.  Mr. Bair discussed projects in each of those areas.

Upper Sacramento River

On the upper Sacramento River, salmon are cutoff from their original spawning grounds by Shasta Dam, so they have ongoing and active projects supported by the Central Valley Project Improvement Act.  There are spawning gravel projects, side channel projects, and in-river habitat projects which are all activities that have been engaged by Sac River Settlement Contractors and others.

In-river projects

An in-river project is the Bullock Bend project, which began with a field that was actually inside an oxbow.  Westervelt designed a project where they degraded the farm field so it would be flooded more frequently, and now it’s a backwater on the Sacramento River that’s frequently inundated, providing habitat and primary production for outmigrating salmon on the Sacramento River.

Mr. Bair said there’s another opportunity for in-river projects.  About half of the 550,000 acres of rice that’s planted in the Sacramento Valley is flooded each winter; the current practice right now is to flood it and hold the water all winter, so there’s no exchanging of that water.  The food production takes about a month of residence time in the field to develop so the idea is to hold it for a month and then discharge the enriched water to the river and bring in new water.

We exchange that for some new water and we can do that two or three times a winter,” he said.  “If you can imagine a tapestry of that happening in the Sacramento Valley, you could have this constant food supply for the mainstem of the Sacramento River and we think it has real opportunity to affect those in-river fish.”

He presented a map of the Sacramento Valley, noting that the blue shaded areas are essentially the areas that still get wet.  Parts of the floodplain still exist, although some of it doesn’t have access for juvenile salmon and some of it has access but only infrequently.

This is what I think of this as our low handing fruit where we could engage the existing infrastructure and really try to make this landscape work for us,” said Mr. Bair.

He started by explaining how the Sacramento River system works.  In the northern Sacramento Valley, the Sacramento River normally flows within its banks.  But as it fills up, it has to get to fairly high flows before it starts overtopping the weir structures, and when it does, it goes from almost no flow to very high flow in the bypasses.

The first weir to be overtopped is the Tisdale Weir, which is basically just a lowered levee section that is several hundred yards wide.  Once the Sacramento River flows over 20,000 cfs, water starts to spill into the Tisdale Bypass and then into the Sutter Bypass downstream.  About 12,500 acres are inundated when that happens.

The next weir to be overtopped is the Colusa Weir, then the Moulton Weir, and further up at the top of the Butte Sink, there are other places where water spills out where the infrastructure could be modernized to spill more frequently, Mr. Bair said.

The solution is to put a notch in the weir that lowers the elevation of the weir for a small section as shown in the diagram below.  This will allow smaller, more frequent lower flows to enter the bypass and create that floodplain habitat.

He presented a graphic to illustrate the difference such a modification could make.  In 2003 and 2004, water flowed over the Tisdale Bypass for 41 days; if the notch had been in the weir, the water would have flowed into the bypass for 91 days.  The notch could be gated and be lowered after December 1st when the farm season has ended to allow the water and juvenile fish to enter the bypass, and then raised when it’s time to prepare for the next growing season.

He presented a graphic, noting that the green line is the water surface elevation of the river, the top yellow line is the actual elevation of the weir today, and the red line is the bottom of the notch.  Whenever the green line passes the red line, the water starts to flow; however, today, it would have to reach the yellow line at the top.

This simple project could have a dramatic impact on 12,500 acres,” Mr. Bair said.  “The high flows can be used for recruiting the juveniles and getting lots of juveniles on, and then you can use the lower notch flows for keeping that floodplain going, to drive that habitat while the juveniles are rearing.”

So my message is simply, let’s get to work,” he said.  “I represent farmers and water users, they are ready to partner with folks like yourselves at the agencies and the NGO partners to get some of this stuff done, so let’s not waste any more time.”

Roger Cornwell noted that all the speakers on the panel are all from very different backgrounds.  “I farm, Lewis is an engineer that runs the water district, and then we have Meghan who is with a conservation organization about birds, and then Jacob Katz, as well as Virginia, but we’ve worked hard to build some trust.  It took a lot for all of us to come out of our silos.”

He noted that it was the drought that really spurred the farmers to look at what changes they could make to help improve salmon.  “This momentum just keeps going and getting bigger and it’s carrying us to somewhere new every time.


Virginia Getz, manager of conservation programs for Ducks Unlimited, then discussed several success stories of multi-benefit restoration projects that reconnect the water and the land.

Reactivating the floodplain and reconnecting the water to the land requires a comprehensive approach and improvements are needed from the top of the system on the upper rivers down to the bottom of the system in the San Francisco Bay,” she said.

Napa Plant Site Restoration

The Napa Plant Site Project restored about 1135 acres that were formerly in salt pond production by breaching the dike and restoring tidal influence to those areas.  The $13.4 million project was funded by a variety of different public and private entities.  The Napa Plant Site Project is only one of many that are underway or planned in San Pablo Bay.

Prior to the project, the land was a rather inhospitable environment for both fish and wildlife.  Tidal influence to the area was established by lowering the internal levees on the former salt ponds and then breaching the dike in several places where historic slough channels existed.

Restoring the tidal connection to the land provided better habitat and more food for fish, for waterfowl, and a variety of special status species including salmon, snowy plover, Ridgeway’s rail, and salt marsh harvest mouse,” Ms. Getz said.

Cougar Wetlands Restoration

On the Cosumnes River, the Cougar Wetlands Restoration Project was recently which restored about 154 acres of floodplain habitat for fish and a variety of other species.  The project was funded by multiple partners and agencies.

They reconnected fresh water to this floodplain by breaching the dike and constructed a series of swales on the interior of the property to help convey freshwater into the site when the tide is up and the river level is high, and then help convey water back out of the site as the tide goes down and the river level drops.

Fish now have access to the floodplain in this area,” said Ms. Getz.  “This area is producing invertebrates which provide food for fish, waterfowl, and a whole bunch of other species, and it’s providing food that not only can be consumed on the site, but that also is conveyed back out to the river daily as the tide goes down and the river level drops.”

Butte Creek Fish Passage Improvement Project

The Butte Creek Fish Passage Improvement project might be the greatest success story to date for multi-benefit floodplain restoration work, she said.   It demonstrates how a group of diverse stakeholders including state and federal resource agencies, water districts, farmers, private duck club owners, and NGOs came together to tackle the project to make safe fish passage along Butte Creek, a tributary to the Sacramento River.

The project allowed the system to continue to function for agricultural supply and drainage, flood control, and to support about 12,000 acres of privately owned wetlands in the Butte Sink which provides some of the most important waterfowl habitat, not just in the Sacramento Valley but in the entire Pacific Flyway.

The project removed several dams on Butte Creek and installed many high-tech fish-friendly structures to ensure safe passage for spring run salmon.  It resulted in restoration of the spring run from about 200 fish to more than 20,000 fish, so it is truly a win for all interests.

These are just a few examples of what’s already been accomplished and what we can accomplish at an even greater scale moving forward,” said Ms. Getz.  “Through partnering, we could deliver these types of projects on the Sacramento River floodplain and provide multiple benefits and multiple land and water uses.”


Chuck Bonham, Director of the Department of Fish and Wildlife, then gave some concluding remarks.  “What we have left today is nothing compared to what we once had,” he said.  “When I was in a prior job at Trout Unlimited, we boiled our work down to four goals:  Protect the most important places, reconnect them, restore landscapes with private landowners because the fact is that most of the plants and animals are on private property, and sustain that work with a movement.  People.  We have to put people into it.”

When I look out here, I see the beginning of the movement of floodplain fatties,” Director Bonham continued.  “I would argue the most amazing journey in the natural world is that of a salmon.  They are born in a river, they swim out that river, they spend time in an ocean, and then magically, something goes off in their makeup and they swim back to the very same spot where they were born to start the cycle again.  If that doesn’t give you hope, solace, satisfaction in these desperate times, I don’t know what will.”

I read an article a while ago by a reporter at the Washington Post interviewed a guy named Mike McHenry.  He was a biologist for a tribe in the Elwha basin on the Olympic Peninsula where we’ve had one of the most accomplished and successful dam removals occur in the nation.  He told the reporter, when he got into fisheries biology, he didn’t expect to be working with bulldozers and excavators.  But along his journey, he realized if you want nature back, sometimes you have to go big.”

We’ve lost so much, I would submit, we have to go big,” Director Bonham said.  “We can do this.  We can bring the salmon back, we can recreate this lost habitat.  California is asking us to get that done, and in the immortal words of Dr. Suess, ‘unless someone like you cares a whole heckuva lot, nothing’s going to get better, it’s not.’  It’s easy to say what you’re against, it’s easy to find the reasons to say no.”

I know what I’m for.  I’m for floodplain fatties.  I’m for reconnecting nature and giving it a chance to roam.”

For more information …

Explore floodplain restoration at the California Water Library

Click here to view these documents full screen.


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