The California Water Policy Seminar Series, presented by the UC Davis Center for Watershed Sciences and the law school’s California Environmental Law & Policy Center in the spring of 2014, brought together environmental leaders, scientists, agency officials, and others to discuss how water systems can be reconciled to achieve both ecosystem and economic objectives. The series of talks focused on reconciliation ecology, an emerging discipline that is based on the premise that traditional conservation strategies of designating nature reserves and restoration projects will not afford enough protection to present large-scale extinction, and so proposes that human landscapes and ecosystems be reengineered to accommodate both people and wildlife.
In this presentation, Robin Kulakow, executive director of the Yolo Basin Foundation, and Petrea Marchand, a local public policy consultant, join Robyn Suddeth, PhD candidate in hydrologic sciences; William Fleenor, senior researcher; Carson Jeffres, field and lab director; and Richard Howitt, professor emeritus in agricultural and resource economics to discuss the ways to optimize multiple economic and environmental uses of the Yolo Bypass floodway near Sacramento. The panel was moderated by Peter Moyle, a professor of fish biology at UC Davis.
Peter Moyle began by saying that the discussion today would focus on the Yolo Bypass, which could be a great example of reconciliation ecology. “It’s a big issue here in Yolo County, and it’s one that is potentially important for the future in showing the ways flood plains can be used,” he said.
Mr. Moyle then introduced the speakers: Robyn Suddeth, a graduate student in hydrologic sciences at UC Davis will begin with an introduction to the Yolo Bypass. She will be followed by Robin Kulakow from the Yolo Basin Foundation; Petrea Marchand, the Executive Director of the Yolo Natural Heritage Program; Richard Howitt, a professor emeritus of agriculture on the resource economics; Bill Fleenor, senior researcher and engineer with the Center for Watershed Sciences, and Carson Jeffries, senior researcher and fish biologist with UC Davis.
Robyn Suddeth, PhD candidate in hydrologic sciences: An introduction to the Yolo Bypass
The Yolo Bypass a 40 mile segment of a much-larger flood bypass system for the Sacramento River watershed, which serves the primary purpose of providing flood control for the city of Sacramento, began Robyn Suddeth. “It can hold about four times the flow of the Sacramento River,” she said. “It has saved the city of Sacramento from flooding about seven times, maybe eight times by now in the last century.”
She noted the slide that shows both the current configuration of the Yolo Bypass and the way it looked pre-development. “The Bypass sits on what was the historical flood plain for the Sacramento River when it flooded much more often than it does today,” she said. “The Bypass floods one in every two or three years depending on if we’re in a wet year cycle or a dry year cycle. But it used to flood almost annually and the types of flooding that the Bypass would receive were also much more varied than they are today.”
These days, the Bypass only floods when the Sacramento River is very high, she said. “You don’t have the same variety in small to large floods that you once would have had in the more natural system. The natural system also looked very different in terms of the vegetation and typography. It was much more heterogeneous – it had riparian forests, seasonal wetlands, permanent wetlands, and permanent flood plain lakes that no longer exist, as well as a much more dendritic channel structure towards the bottom where it enters the Delta.”
Most of the Yolo Bypass is agricultural, she said. “There are still a lot of wetlands that is heavily managed today. It looks different from what a wetland would have looked like 100 years ago, but there is some purposeful wetlands out there for waterfowl, shorebirds and other critters.”
The Yolo Bypass is important because it’s location at the intersection of the Sacramento River and the Delta is the lowest floodplain in the Sacramento River system before the river empties out into the Delta. “That’s an important place for a lot of fish species and it’s also important in terms of its location along the Pacific Flyway for migrating waterfowl and other bird species in the winter time,” Ms. Suddeth said. “Its location is important for the residents of Sacramento and the surrounding areas for flood control. It’s important right now, politically, because it’s a big player in the Bay Delta Conservation Plan.”
“The Bay Delta Conservation Plan is a plan that’s attempting to figure out ways to mitigate for some of the damage that’s been done with the delta ecosystems by the way that water is being pumped to Southern California for urban and agricultural uses,” she said. “There are a lot of different habitat mitigation components to that really, really big plan, but one of the major ones is restoring fish habitat on the Yolo Bypass. It’s received a lot of attention; it’s in the eyes of the policy makers.”
The Yolo Bypass also has many recreational uses such as hunting, birdwatching, or just enjoying the landscape, she said. “There are fish, birds and other critters that don’t get as much play time, such as Swainson’s Hawk and the Giant Garter snake, and I think that Delta smelt could benefit from some types of habitat restorations in the very bottom portions of the Bypass.”
There are a lot of different stakeholders, both human and environmental, that could benefit from this landscape which makes it a great case study for reconciliation, she said. “There are many different fish, bird, and other species that depend on this system, and it’s in a heavily modified human engineered landscape. There is a lot of evidence to suggest that the Yolo Bypass is already somewhat functioning for all of these different fish and bird species while still being agricultural landscape and still functioning for flood control and other human uses. … The question is, can we do a better job of it and make it better for those species?”
The Central Valley Joint Venture is the plan that manages the habitat needs for wintering waterfowl and other bird species as they migrate along the Pacific Flyway, she said. “The Yolo Basin is one of seven basins in the joint venture and is a major player,” she said. “They’ve learned a lot about when the birds are there, when the densities of those populations are highest and when the food supplies are high.”
She presented a slide with two graphics on it, noting that the blue line on the top chart is the energy demand from the birds while the red line represents the supply. “What this graphic is showing is only the supplies that are available if you don’t count agricultural uses, so one of the things that this graphic shows is that rice and other agricultural crops are actually important players as food sources for these birds,” she said.
“There has also been a lot of research in the aquatic ecosystem side of things,” she said, presenting a slide with two graphs on it. “On the top graph, the dark bars are chlorophyll A concentrations in the Yolo Bypass when it’s flooding compared to the mainstem of Sacramento River. It was researched by Lehmann et al in 2007. So you can see primary productivity is much higher in the Bypass when it’s flooding than it is in the river itself and this leads to good things for fish. Chinook salmon take advantage of this as they migrate through the Bypass. They can have much higher growth rates there than they do in the mainstem river.”
“Splittail also come up onto the Bypass to rear and they use it as spawning grounds,” she said. “So it’s already been shown to be valuable for these bird and fish species even as it is today.”
“I wanted to give you a brief understanding of the political realities of where the Bypass is right now,” she said, presenting a table summarizing what the Bay Delta Conservation Plan is proposing for the Yolo Bypass. “When the Sacramento River overflows, there’s a weir at the top called the Fremont Weir, and what the Bay Delta Conservation Plan is proposing is to put a notch in that weir so that more water can come in when the flow in the river is lower; the idea is to increase the frequency of flooding at different times of the year.”
“From March 1st through 23rd, currently 47% of weirs have weir overflow and if they were able to notch it and engineer the system in this way, it would increase to 72% to 81% of weirs where water would be available during that time period,” she said. “They are talking about up to 6,000 CFS and up to 17,000 acres of added extent of flooding than what is currently seen during certain time periods. The bottom of the table shows which fish species they are targeting. And that’s about as detailed as the BDCP gets right now. There isn’t a lot of sort of nuance detail about how they would manage those flows, where it would go – all the sort of moment to moment decision making that would be involved in such a plan.”
“There is a lot of perceived conflict with a plan like this – with the idea of adding more fish habitat on the Bypass,” she said, presenting a slide from various surveys done by experts. “I interviewed a lot of fish biologists and waterfowl and bird ecologists about what those species want in terms of availability and type of habitat that they prefer when they’re using the Yolo Bypass or flood plains in the system.”
“There are some conflicts in terms of timing,” she said. “That’s because for the bird and fish species, habitat is valuable for them all the way through March … but if the plant date is delayed past March, it means their growing season is limited – shorter than it otherwise would be, and they start seeing losses in yield. Because of these losses in yield, there’s losses in revenues and then in profits for these farmers. So there’s that perceived conflict in terms of timing.”
“There’s also another nuance in terms of wetland management which is that sure the birds might use it in April and May and shorebirds especially like some habitat later in the year,” she said. “But wetland managers are also farmers in the sense that they want to grow the right type of plant for food supply for the birds the following fall and if there’s water for too long on those landscapes or on those wetland units, then they also face the prospects of those food supplies not being what they otherwise could be. So it’s a very sort of balanced system.” There are also conflicts in that fish want deeper water and waterfowl tend to do better in shallower water, especially for foraging habitat, she added.
There are many questions to be answered, she said. The question that was sent out to the participants asked, can the Yolo Bypass be managed as a reconciled ecosystem and if so,what are the factors that make it possible, difficult, impossible to achieve this as a general goal? And can the perceived tensions among farmers,fisheries managers, flood managers, wildlife managers,and other interests be resolved?
What can be done right away? Can land use be even better integrated?, she added.
A longer term question is that if more water becomes available in winter and spring through the notched weir, how can managers best take advantage of it to maximize benefits to birds and fish while also minimizing cost to farmers and private wetland owners? And are there ways to engineer improvements that further better the system? How much improvement is truly possible and is it worth the cost?
Political questions include should government try and incentivize current land managers to change practices towards a more reconciled bypass and what is the best way to mitigate for any losses to farmers,wetland managers, or duck hunters?, she said.
Robin Kulakow, Executive Director of the Yolo Basin Foundation
“Restoration ecology is already going on in the Yolo Bypass,” began Robin Kulakow. “I work on behalf of the 16,800 acre Yolo Bypass Wildlife Area, and restoration of that area began in 1994. Before that, it was a local effort created the wildlife area … it was the local community felt that it was the right place to restore wetlands.”
Management has evolved to the point where we’re managing very diverse wetland ecosystems, she said. “The management changes every year,” she said. “The habitat that was put in in ’94 has been modified at least several times as people learn more about managing for the wetland species.”
The Yolo Bypass is close to 69,000 acres, and the wildlife area is about 20% of that, she said. “At the wildlife area, we are successfully balancing flood control, agriculture, management of diverse wetland ecosystems, and public uses. We run a large environmental education program. There are probably 30,000 birders that use it every year, and tens of thousands of hunters that use it. It’s a very beloved heavily used place that’s still managing to be a productive ecosystem.”
Ms. Kulakow said that they’ve been working with all the different stakeholders through a group called the Yolo Bypass Working Group. “That group has been meeting continuously since 1997,” she said. “We invite all the different interests – the wetland managers, many of whom are owners of private hunting clubs, managers of the public property, Department of Water Resources, flood control engineers, ecologists, fisheries biologists, and fisheries managers. There are all the regulatory agencies, such as the Sacramento-Yolo Mosquito and Vector Control District. On top of that, now we’re dealing with the Central Valley Regional Water Quality Control Board because of worries about methylation of mercury in wetlands and rice fields.”
“It’s also a huge research resource,” she added. “The agriculture supports 50% of the state budget for management of the wildlife area, in addition to providing very valuable habitat.”
“My point is that once BDCP, the current programmatic plan is approved, and there’s going to be the Yolo Bypass Fish Enhancement Plan,” she said. “All the local interests will be represented there. I feel that we can come up with a plan that meets the needs of the fish.”
“Once we have this detailed fish management plan, it’s really important that a governance structure is created as a result of the planning process, so that all the interests are represented into the future because the ecosystem is going to be changing and there are all these diverse needs,” she said. “If you’re going to create a 60,000-acre working landscape that’s successful, we’re going to need all the people working together for the long-term. I think really the only conflict left at this point is with regulatory agencies.”
Petrea Marchand, public policy consultant
Petrea Marchand began by noting that she has her own consulting firm, and she is the Executive Director of the Yolo Natural Heritage Program, a joint powers agency composed of four cities and Yolo County. “The purpose of that JPA is to develop a county-wide conservation plan to protect 11 endangered and threatened species including the Giant Gartersnake and the Swainson’s Hawk, which are present in the Bypass,” she said. “Separately, I also represent the Yolo County Board of Supervisors in the negotiations on the Bay Delta Conservation Plan.”
“I dabble a little bit with terrestrial species and a little bit with fish species, but I’m not necessarily on the same side as all of the fish biologists in the room,” she explained. “I come at it from a local perspective. I just want to make that clear that this is my background and professional experience.”
“I also come at this from an interdisciplinary perspective,” she continued. “My educational training is in interdisciplinary problem-solving, so I really believe in bringing together economics, biology, law, and science to solve problems today. I don’t think it’s all about what’s best for the fish or what’s best for the Hawk; it’s about integrating all those together. That’s how I approach this conversation and in particular the question about reconciliation ecology and what factors make it possible and what factors make it difficult.”
Ms. Marchand said she’d start out with the factors that make it difficult. “First, I’d agree with Robin. I think we already have reconciliation ecology in the Bypass. And the question now is not, do we have it? The question is “Can we add to it – Add fish to the species that currently benefit from the Bypass habitat?”
We’re talking about adding something else onto an already existing structure including the agriculture in the Bypass that also provides different species benefits, she said. “The rice provides Giant Garter snake habitat and waterfowl habitat; all of these uses are integrated in a really special way that’s been nationally recognized,” she said. “I think that makes it difficult because there are people who have worked hard to create the reconciled Bypass landscape that we have today and those people are going to fight to keep it that way. That’s just the way people are; that’s the way we operate in this society. So I think that’s going to make it difficult to add the fish habitat on top of the existing uses of Bypass.”
The second factor that makes it difficult is scientific uncertainty, Ms. Marchand pointed out. “It’s both the scientific uncertainty and equally as important, the unwillingness to admit when it’s uncertain,” she said. “Everyone wants to be able to go into a meeting and say this is the way it is – the fish need this, the hawks needs this. Less people are willing to say, ‘You know what? I think they need this, but this is the additional work that we need to do to further understand it and maybe this is the approach we need to take in the face of all that uncertainty.’ Because ultimately a lot of these regulatory agencies need to make really difficult decisions in real time that rely on imperfect science, and so there’s a tendency to overestimate or to overemphasize how certain that science actually is and so that’s one of the major challenges.”
“The last really difficult factor I think for reconciliation ecology is the regulatory agencies themselves,” she said. “There’s been a lot of damage that’s been done to the environmental landscape as a result of human actions over the last 10 or 50 years in California. So it’s natural for regulatory agency biologists to want to ask for as much as they possibly can in programs like the Bay Delta Conservation Plan which is ultimately a permit from these wildlife agencies…. That desire to get whatever they can in a situation like this where they have the regulatory authority limits the amount of flexibility that you have to reach a compromise among all these existing uses in the Yolo Bypass. And so unless staff in the wildlife agencies are willing to say, ‘Yes, we are willing to embrace flexibility, we are willing to understand that maybe we have to flood until March and not until May,’ it’s going to be very difficult to achieve reconciliation ecology or to add another use.”
Despite this, Ms. Marchand still thinks it is possible to add another use in the Bypass. “The best evidence is that Robin Kulakow and the people in the County have done it already,” she said. “One of the factors that make it possible is to create additional benefits for the users that are in the Bypass. Do some things for the wildlife area that make it work better; do some things for the farmers to help the water drain better off their fields or to improve the infrastructure through which they supply water to their fields. Consider those needs at the same time that you’re considering the biological needs of fish.”
Richard Howitt, professor emeritus in agriculture and resource economics at UC Davis
“As a representative of what’s often called the dismal science, I’m going to break with tradition and be optimistic,” began Richard Howitt. “.”
If you’re an ecologist who’s really wants to influence the world, you’re going to have to work with working landscapes, he said. “When Robyn Suddeth was talking about the ducks in the Bypass, did you notice the duck economics she put up there? Did you notice the energy function of the demand for energy and the supply of energy and how they crossed and how later in the year the natural energy was not sufficient to support the Pacific Flyway and they needed to get the energy from some other place. The ducks are concerned with kilo calories as are of course Swainson Hawks and other species.”
“But there’s another predator in this working ecology and it’s called people,” he said. “And in this particular case, it’s farmers and if the farmers have the right ecological incentives, which is money, they will plant rice and the rice will generate the energy for the ducks. Why is this going to work here? Because we have a fantastic serendipitous situation. I think it’s serendipitous, because not only do ducks like rice, but fish like rice too. And this was an absolute eye-opener for me.”
“If you provide the correct incentives for the big predator in the system, they will provide open space for flood control,” he said. “Remember, it’s primarily flood control and that’s where the big dollars are. So the last thing you want is a reversion to natural habitat of cotton woods and other things because that would completely undermine the central purpose of the flood plain, the Yolo Bypass flood control. There’s a second economic sense, and that is farming. … What we’re trying to do is we’ve already got the bird relationship and now we’re trying to build the fish relationship on it.”
Mr. Howitt said he was not minimizing the problems of reluctantly moving regulators. “But we’ve got to be looking at this as a complete working ecology with a bunch of species in there, and if we can find that sweet spot of interdependence between the species that doesn’t trash one species ecologist, so we’re not trashing the farmers, we’re not trashing the duck hunters, we’re not trashing the ducks, and we’re not trashing the salmon – then we have what ecologists and economists would call a Pareto Optimal; we have those trade-offs.”
“I would encourage you to think of the trade-off functions for all those species,” he said, noting that there are tradeoffs between ducks and fish for water depth, and timing and fish for farming. “I think it’s fascinating, I think it’s the future of the majority of ecology, and I think in this case, certainly, despite the problems, it’s going to work.”
Bill Fleenor, senior researcher at UC Davis
“I’m an engineer,” began Bill Fleenor. “Engineering is very simply the application of scientific and economic principles to the solution of societal needs and morays. And so from a pure engineering standpoint, this is a simple problem. Every engineering thing is a simple problem because people come to you and say, “Here are the economic constraints. Here are the political constraints. Here are the environmental constraints,” and we have this beautiful landscape on which to solve these types of problems. Now, do we know the answer a priori? No, it takes a quite a bit of work.”
Mr. Fleenor explained that the Bypass originally was a very natural bypass type of system, but with hydraulic mining and the filling up the sediment, we caused it to flood in different ways and eventually created it as an unnatural Bypass system by building the Fremont Weir. “One of the things that BDCP wants to do is notch that Weir to get water into it more often. Some people may not know it, but the Weir was originally built with a notch, and we went in and filled it in all up to the same level because we didn’t like how often it flooded. We weren’t giving due consideration to things other than what we personally wanted to do. Hence some of that had to do with agriculture, and agriculture is very important. … The Bypass accounts for quite a bit of Yolo County agricultural income, and even in really dry years, the Bypass can nearly always be farmed reasonably because of its proximity to water so it becomes even more valuable at that time.”
“One reason the notch was done away with before was because the water was coming on, but it wasn’t giving us the types of benefits that we were really after because we found that we were stranding a lot of fish,” he said. “We still do strand a lot of fish. When we have a pretty good flood, you’ll see DWR assign people out there in boats and they’ll try to capture particularly some of the bigger sturgeon who are endangered and return them to the channels, but trapping fish in that manner is not a good thing ecologically.”
“So we have to find ways to get the water on and off,” he continued. “Agriculture needs water off so they can maximize their income, their profits, and their produce. We don’t like to pay more at the store either. And, of course, we need certain depths and durations for the benefit of fish and fowl. So it’s a combination of those things that is our chore then to go out and see what we can find and do, and keep it flexible enough because we don’t expect everybody’s science to be a 100% correct up front including our own. As hydraulic modelers, we expect to have a certain amount of error in there as well.”
Mr. Fleenor explained that they are looking at dams for the toe drains that drain on the east side all the way down to the river, and by putting in simple bladder dams, which are fairly inexpensive and quite controllable, we can see what kind of water we can get on different parts of the land and get off, thereby benefiting fish and fowl, and not doing too much damage to agriculture, he said. “We can do these examinations with a hydraulic model, pretty cheaply, especially compared to what it would take to put in something and then take it out,” he said. “We can play these little what-ifs scenarios and get a fairly decent handle on these things well. While scientist, fish people and bird people and others managing it … What is the best way to get these things accomplished?”
“It’s an optimization problem of a very large magnitude and, there is no question we can solve it, but the question is, what’s the best solution for the minimum amount of money and the best outcome which is what society is looking for – society being you and I who are paying taxes?,” concluded Mr. Fleenor.
Carson Jeffries, field and lab director at UC Davis
“Lastly, it boils down to the fish,” began Carson Jeffries. “I’ll start with a little history and how we got to where the work that we are doing now began. Ted Summer [another fish biologist] was finding that, during those wet flood years when the Yolo Bypass would flood naturally, fish that were leaving the Bypass, were larger than fish that were just going down the river channel. And so, that ended up in this big cascade of research that’s happened over the last 15 years, not only on the Yolo Bypass, but more natural systems such as the Cosumnes River down south of Sacramento. A lot of research went into looking at what made a flood plain beneficial for salmon, what was the food web that happened, and what were the physical processes that ultimately led to fish growing faster on a flood plain than in the river.”
“So we started looking at the Yolo Bypass,” he said, “looking if we could essentially mimic those processes on a managed system like rice fields on the Yolo Bypass. A rice field is a wetland in some sense, but it’s not a flood plain. We use it as a flood Bypass on the Yolo Bypass, but when you think of what at the salmon habitat during it’s out migration should look like, a rice field isn’t the first thing that comes to mind.”
“Part of that is that the Yolo Bypass doesn’t always flood in coordination, or at least reach a high enough magnitude to flood every year at the right time for fish, and so if you want to manage for a threatened species like Chinook salmon in Central Valley, what you need is water out there most years at the time that coordinates with their life history. So we were thinking about how can we do this and we saw essentially a bunch of rice fields on the Bypass.”
The first year, we literally just put some juvenile salmon onto a five-acre rice field, just to see how they grew, he said. “We found that those fish grew faster than any other observed growth rates in the Central Valley either river or flood plain. And so we started asking the questions of what is it about a rice field that makes it interesting and makes it a good habitat? … So we went out and started actually asking those questions. What are the actual processes that we know happen on a natural flood plain and can we essentially mimic those on the habitats that exist on the Yolo Bypass?”
“We looked at fallow fields, disc fields, and standing rice stubble, and it turned out that the key to making the floodplain happen is that you have to have a robust food source in conditions that are conducive to growth,” he said. “One of the things that we found is that disced rice fields turn out to be the fastest growing salmon habitat on the Bypass. It’s essentially a muddy substrate that has just been tilled, we pour water on it and it’s the fastest growing salmon that we’ve seen in the Central Valley.”
He said it’s very counter-intuitive for ecologists, particularly restoration ecologists, because a rice field is quite unlike a natural flood plain, but as it turns out, flooded under normal conditions as farmers like to do to help decompose their rice, ends up being the situation where the best growing habitat is also the best farming habitat, he explained.
“The flexibility is the thing that’s currently missing right now,” he said. “Particularly between wet years and dry years, and having hard dates on management for species in a climate that doesn’t have hard dates on it. During dry years, there’s no way you could keep fish in a habitat that’s flooded late into the season because it’s too warm. During wet years, if it’s wet anyway, there’s no way that they can start their farming. And so, having that flexibility built in to this reconciled ecosystem and agrosystem is really where we find the benefit from having agriculture management and putting those ecological processes and overlaying them on top of each other.”
Peter Moyle asked the panelists that if the notch was put in Fremont Weir, what would be the operating rules or restrictions you would want to see put in place?
Robbyn Suddeth: “It depends on the year and the timing that water is available as the time of year that the river would be high enough to actually have water come through that notch will vary from year to year. I think that you’d have to have some governmental structure set up that goes through some of the different scenarios and different possible years that might occur, and have an agreement there already set up between the farmers and the different users on the Bypass to know, in this type of year we’ll allow water to come through at this time for this long, and to have an idea of how you would manage those flows. Same for a dry year versus a wet year.”
Robin Kulakow: “The point of conflict is March, early March. And the farmers, if they’re going optimize their yields, they need the flooding to stop because the Bypass needs to drain and then the heavy clay soils have to be dried out enough to be plowed. The same goes for managed wetlands. You need to be able to start drawing down the water in early March so that the nutritious wetland plants that the birds rely on when they show up in large numbers in the fall and winter, they need to germinate in the early spring. The later you wait, the more weed species come in and less nutritious the wetland plants are.”
Bill Fleenor: “I’m an engineer, so it’s all about control. It’s a matter of whether we can control that, but still find ways to not entrap the fish, not impound the fish, and also to find ways to get the fish through passage. I think through passage is also a key element of this. There are some questions in that regard that we do not have final answers.”
Carson Jeffries: “In dry years, you can’t have fish out there anyway. In wet years, if you have a really wet March, you’re not going to be able to disc it anyway and work the ground. If you have flooding in a March, then it’s going to be good habitat. So you have to be able to work within that environmental framework and climate conditions.”
Peter Moyle: “I agree with Carson, but I’d be a little bit more definitive in the beginning, because we don’t know so much. And so I would limit it to 4,000 acres, I would end flooding March 1st unless there are some of these conditions that Carson was talking about. And I would implement an aggressive, adaptive management program that relies heavily on research from UC Davis.”
Richard Howitt:“I don’t have much to add. March 15, wet years, extend the natural flooding by a couple of weeks or more and have a simple non-governmental organized rule that people can rely on. Just March 15, wet years, that’s it. that’s probably about the best trade-off.”
Robin Kulakow on mosquitos: An audience member asked about mosquito abatement. “The most powerful agency out in the Bypass is the Mosquito District. They can tell you to drain and you have to, and they can tell you that you can’t flood up till November 1st because of mosquitoes, depending on weather conditions of that year. They can tell you just wait till October or November 1st first, and you’ve missed a large part of that migratory bird season. … Having flooding stop sometime in March fits the needs of the mosquito district also because they need the ponds to start drying down as the weather warms up, and they don’t like to have a lot of the weedy vegetation that sprouts with later flooding.”
Petrea Marchand on how the Central Valley Flood Protection Plan fits in: “In my role, I’m working for the Yolo County Board of supervisors and I’m also involved in the implementation of the Central Valley Flood Protection Plan. One of the major proposals is expansion of the Yolo Bypass, because the Yolo Bypass is the cornerstone of the Sacramento River Flood Control project system. And they can’t fix the other parts of the flood control system until they expand the capacity of the Yolo Bypass, so that is an ongoing effort. And the integration that’s proposed is actually a very complicated one, because the all the federal agencies that are involved have to decide now whether or not they’re going to notch the Fremont Weir or are they going to wait and integrate that enhanced flood plain habitat into the expanded Yolo Bypass? There is a timing issue there. Regardless, you’re absolutely correct, the Central Valley Flood Protection Act does require all new flood protection projects to be multi-benefit. So there’s also some potential for there to be two separate fish projects that happen in the Yolo Bypass.”
Patrea Marchand on notching the Fremont Weir: “That’s one of the biggest difficulties, in terms of reconciling better habitat for fish and the bypass, because it doesn’t seem that anyone has the direct answer to the question yet of how best to actually attract fish to the bypass if there was a notch there. There is a lot of debate about whether a good number of fish would even enter the bypass in that scenario. … I’ve sat through a number of meetings with the wildlife agencies where they are trying to build models that demonstrate how many fish would make it onto the bypass through different sizes of notches. There are a lot of different proposals for how big it should be, how long it should be, and how deep it should be. My impression – and I am not a scientist – is that there is enough uncertainty that people don’t really know how many fish would make it on. That is then complicated by the fact that the fish they really want on the flood plain – the endangered winter-run and spring-run salmon – are so few in numbers that it makes even more challenging to figure out how many will actually make it onto the flood plain. That’s one of those issues that I wish people were just really upfront about. We need to learn a lot more, and we need to do a lot of studies after we build the notch to figure out what works and what doesn’t.”