An interview with...

Ramona Swenson
Project Ecologist, Cosumnes Preserve

 

Why of all the rivers in the Valley did the Cosumnes -- and only the Cosumnes -- avoid damming?

Good question. Actually someone, for a Masters, looked at it and I think there were four different crusades to try to dam the Cosumnes and for a variety of reasons it just happened to get away from those efforts. One of them was when San Francisco was looking for a water source and some people were vying to propose the Cosumnes as opposed to the Tuolumne as a water source for the city. Fortunately for the Cosumnes -- but not the Hecheche -- this area was not dammed. But there have been several efforts to try to dam the Cosumnes. One thing is that the watershed isn't as large as some of the surrounding watersheds, which go up higher into the Sierra. So there may be less production out of this watershed than say the Mokolmne to the south, the American River to the north.

Could you describe the spot we're standing in now, and has it changed much in recent years?

Yes, this is Wood Duck Slough, and we're standing amid some of the best remaining forest that we have in the lower Cosumnes. The forest is about 100 years old and chances are it was probably cleared maybe in the last century. This channel here may have actually been part of the main stem of the Cosumnes at one point, but the way these rivers move across the lower floodplain, this channel was probably abandoned for the main channel now that it's further over that way. So as the river moves across the floodplain, you'll have new channels being created old ones left, and forests left behind.

When was this preserve first proposed and planned?

The Nature Conservancy got involved here in 1984; that's when we first identified an opportunity to protect one of these last remaining stands of bottomland Valley Oak forests that live around streams. So we protected a small stand along one of the sloughs, and later returned in 1987 after some of our scoping efforts -- when we were looking for where in the Central Valley are there some of the last remaining forests left -- and that's when we found that the Cosumnes actually had some of the best intact. So we really got efforts started then, in 1987, with a bunch of partners. The Cosumnes Preserve was actually dedicated 15 years ago in 1987, and together with eight other organizations -- state, federal, and local agencies as well as private groups like Dicks Unlimited -- we've been engaged in doing land protection and restoration.

You mentioned the large number of partners who work with the Nature Conservancy on the Cosumnes project; is that a benefit, or does working with so many different agencies create any problems?

The partnership here at the Cosumnes has been tremendous. It's given us more leverage to accomplish more than we could have done on our own. And you know, people come with different needs. I mean, the missions of each agency can be different. But just to rattle off, we've got Bureau of Land Management, which is really doing a lot of work here; they have supplied the building as well as the preserve manager. Ducks Unlimited was an early partner; they're particularly interested in waterfowl and wetland protection. California Department of Fish and Game, Sacramento County Parks, Department of Water Resources, State Lands Commission…all have taken a role here, and bring their strengths and interests in trying to protect this river. We all have in common the desire to protect riparian forest, the natural river system, the wetlands that surround it. And each brings kind of a different skill set; some better in land management, others in water resource management. Everyone's worked here really well, and I think it's become a showcase for how agencies and partnerships can be done, both with agencies and state groups and private NGOs, but also with the community. We depend a lot on working with the local farmers and agricultural community to try to come up with protection schemes that also fit well into the local economy, and help support some of the agriculture that's actually become habitat for many of our species of interest.

How has it been working with the farmers you have here on the Preserve?

One of the things that's been to our benefit in teaming up with agriculture here is we both see kind of a common threat from increasing urban pressure coming from the north. They're trying to maintain their livelihood and maintain farming; we're trying to protect habitat for wildlife. And in many cases we've found that we have common needs, and common threats. So in situations like that, we've worked to try to help insure that agriculture can stay in place where it provides habitat values, and working with them either through conservation easements to prevent development from going in in the future, while helping support their current farming operations. We're looking for opportunities to team up in ways that are innovative. We have an organic rice operation here, an independent operator -- Living Farms -- that does rice farming during the summer, and in the wintertime those fields actually become great habitat for waterfowl and cranes. Similarly, we've embarked on Staten Island in the Delta. We've purchased the island and we're going to maintain it in farming, because the corn and wheat operations there have been managed in such a way by the farm managers that it provides great habitat for wintering waterfowl and cranes. So we've found ways to team up that have been very beneficial. Similarly with ranching and range issues, some of our goals to try to maintain these grasslands and cut back the weeds. We work with them to try to come up with grazing levels that meet their needs for looking for forage, and ours for maintaining these grasslands.

How exactly do your farming easements work?

What we do with a conservation easement is that we buy the development rights in perpetuity, and we put certain restrictions on the land use there. So what we can do is ensure than an area that's open agriculture does not later become house, or more intensive land uses that may be incompatible with wildlife. And as respect, we pay the landowner - a willing seller - the fair market value for that value of his land that he's giving up. And what this does is for farmers who may need some money in the current situation, it helps give them a financial boost. And many of these farmers really do want to maintain farming in the family, or into perpetuity, and don't want to see this landscape become just subdivisions.

Is the development that is going on in this area having any impact on the quality of the water in the Cosumnes?

What we've seen is that development, in addition to locking up land, can have effects on the hydrology here. We're discovering that a lot of the groundwater use by depleting the groundwater tables can actually affect the stream flows. Groundwater has been used extensively in this watershed for agriculture, and depletion did start kind of in the 1940s. But it's been exacerbated as more straws go into the aquifer, with people putting in wells and new developments coming on line, looking for water sources. So what that means is the Cosumnes River, which is undammed - that has a natural flow pattern - in the winter, high flows with the rains. And in the summer it goes intermittent at times. What we see is that it stays dry longer, and perhaps for a broader region than it used to historically. And that can affect the fish, such as Chinook salmon, which use it -- and potentially affect the forest here. By having lower water tables, we believe that it could make it more difficult for young forests to get established and persist.

Could you tell us about the accidental forest, and how it was discovered?

Yeah, in sort of the principles of trying to do restoration here, one thought is go out and…"You want more forest, plant more trees." But we also took a lesson from nature in a field that we'll go to, where we discovered that if we can restore the natural flooding process - reconnect the river to its flood plain - the river can actually do some of the planting and re-creation of forest. So what happened on one of these fields is that a levee breached in storms in 1985 or 1986. The farmer didn't remove all the sand and twigs and stuff that came off the river - he just fixed his levee, continued farming around that area. And what came up was this wonderful cottonwood and willow forest - on its own! And we looked at that patch and it gave us this idea that if we can maybe remove levees in certain places and allow the waters to come back, we could create new forests. And so that inspired us to actually start breaching levees on the lower preserve here. 25:39 One incidental benefit - folks thought at first the idea of, "Let's create forest," but not surprisingly it had other benefits as well. And this breaching, which allowed floodwaters to come over in the wintertime actually created great fish habitat for our salmon and other native species. So that was another bonus, the idea that if you restore these natural processes they can have a greater benefit than just us trying to very - you know, control and manipulate, just by maybe restricted planting. So trying to breach the river's levees at certain points, it's something we're looking to replicate along the river, and it's also an lesson we've been exporting to other people who are managing rivers.

Was there a lot of resistance to the idea of purposely breaching the levees?

Well, one's neighbors do get nervous when you say you want to take down levees, and when this was proposed in 1995 we did do some hydrologic studies to try to demonstrate that we would not be increasing the flood stage in the river. And actually, it makes sense. I mean, by opening up the floodplain, we actually create -- increase the capacity for holding floodwaters. So that instead of trying to confine it to a narrow stream channel, we can actually spread it out over the broader floodplain and perhaps reduce flood levels. So it's something that as we move forward and try to look at other places to breach levees, we need to do that modeling to kind of make sure that we're not going to have other unintended consequences for our neighbors.

Does this preserve have broader benefits for the Central Valley as a whole?

One of the things that the Central Valley -- you know, it's a really special place and one of its hallmarks were these extensive streamside forests that used to cover the Valley floor, extend for maybe a mile or more from the river. This natural jewel here - just look around - of this beautiful forest provides habitat for so many different species of birds and animals is something that we have only a tiny fraction left. Sp protecting a place like this preserves that natural treasure of the Central Valley. In addition to that we have a lot of - it's a training ground for people looking to learn, how do we preserve and restore natural systems here? So we have a lot of researchers from UC Davis. We also have a lot of people at agencies and efforts like CalFed learning from what we're doing here. And finally the more enjoyable aspect is that it's a great place for the public to come. We have school trips come here all the time. We have about 4,000 students from the Elk Grove and Galt school districts coming here and learning about nature in their backyard, the place that they live near. And also people coming out just to enjoy hiking and bird watching and canoeing. So it's kind of a respite for people who live in the area to see what wild California used to be like - and that it's still here.

How did the Native Americans along the region interact with the river before the area was settled by Europeans?

The Miwok Indians were the Native Americans in this area and some of the natural resources that they probably could have taken advantage of would have salmon in the river. The word Cosumnes means "people of the salmon," so fisheries here. Collecting plant materials, There's some native sedges here, something called "basket sedge" that they would collect the roots from and use to weave baskets. Lots of plant material that they could have collected from the acorns; I suspect they probably used those as well. And probably timed their movements with the seasons depending on the floods and moving to high ground in the wintertime and closer to the river, I suspect, during the summer.

In the 19th century, what kind of impact might agriculture and mining have had on the river?

The Cosumnes doesn't have a major dam on it, like any of the other rivers. That said, it's not an unaltered system. Levees have been built along it. They straightjacket it so instead of moving freely across the Valley floor, it's in a single channel now, and that's had a profound effect on what these streamside communities looked like. Instead of natural flooding and ebb flows that create new forest and also create broad wetlands in the winter that provide fish habitat, it's now confined to a single channel. So what we've probably seen is that over time as more people have been here and the river's been locked in place and land's been cleared for agriculture, that we've lost some of these broader forests and also wetlands that used to be here.

The Cosumnes has still its natural sort of hydrologic pattern intact of high flows and low flows. Probably it still has some inputs from the surrounding land uses; water that flows off of here. So we have water treatment plants along the tributaries further upstream that could be contributing materials to the water. We also have the surrounding agriculture that could have some farm runoff. An interesting thing on the Cosumnes is that there's even -- just the land it flows through, it picks up materials from that such as metals and nitrates. So, you know, chances are the water quality's probably not as good as it used to be, but I don't think it's severely impaired.

The surface flows of a stream are interconnected with the underlying groundwater table to varying degrees. What we see here in the Cosumnes, which unlike some of the other surrounding rivers, there's not that much snowmelt in the contribution to flows. So during the summer, the flows actually become discontinuous and the river dries up in some sections, and the water table is not connected to the riverbed in those places. What we have seen is that period of disconnection and the extent of it along the river has probably been prolonged by increased groundwater use, both for agriculture and now growing from development. So modeling of the stream flows and also the groundwater situation by these folks at UC Davis have suggested to us that the increasing depletion is going to be - create a problem both for fish that want to migrate upstream in the fall, and potentially also for the riparian forest. Maybe not so much for the tall older trees that are established, but perhaps for younger trees that need to have soil moisture in order to get established earlier in their lives.

Is the Cosumnes a viable river to support the kind of growth we're expecting in this region?

The Cosumnes in terms of its water resources is probably already over-tapped, over-allocated. There's more people wanting to use the water than…can be sustainable for the river system over the long term. And it's going to only get worse as more straws are put into the aquifer, and there's more people here using. That's of great concern for us as we move into the future, because what the Nature Conservancy and our partners we've done here is we've successfully protected the land itself from maybe being converted to houses. But we may not have secured the water resources that it needs in the long term. So if we're going to hope to try to maintain this river system and the resources around it, we've got to come to a better balance between consumptive water use for housing or agriculture and also the needs for this natural system. So that's going to be a challenge as we move into the future. 8:35

Although you've been successful in protecting the land right around this portion of the river, is there a chance that developers could move to another area that could still have an impact on the Preserve - if they were to build upstream, for instance?

Well, you never relax your guard entirely. One of the things in terms of land use planning…right now these areas are not zoned for development, but that could change if Sacramento County or San Joaquin County change their general plans. Elk Grove right now is trying to come up with the city documents and some of their visions include the area between Elk Grove right down to the river as potential for development. So there is concern still for protecting this into the future here. And as you indicated, upstream and downstream there could be increasing uses that affect the river down here. So it's something that we try to keep in mind, and our goal is to try to protect things long into the future. So we want to ensure that we maintain the natural water processes that are so valuable here.

Do you see the Preserve expanding even further?

What we see is that the Preserve of lands that we protected along the river corridor principally from the Delta upstream to near Highway 99 -- we'd like to finish acquisitions along there. That's an area where the stream elevations and the floodplain are appropriate for restoring natural flooding. As you move further upstream, the river's more incised, so we don't think that we'll be doing much more land acquisition up there. But what we'd like to do is work more closely with other partners and other forums who are trying to ensure conservation - be it working with the Army Corps of Engineers to try to look for methods of doing non-structural flood protection that creates habitat. Working with the county and their water forum to look at groundwater use, and transitioning lands to other resource agencies and partners, such as the Department of Fish and Game, Bureau of Land Management, county parks, for long term management and stewardship.

Presentation also made possible by a grant from
the Great Valley Center