As California ponders its long-term water supply challenges, one solution getting increased attention is Sierra Nevada meadow restoration.
Those high-mountain meadows historically acted as sponges, capturing spring snowmelt to recharge groundwater and provide vital wildlife habitat, then discharging it slowly in late summer and fall to keep streams flowing until winter storms returned.
But, starting in the late 1800s, that function has been degraded by rural development, road building and livestock grazing. Many mountain meadows have been cut by deep channels that allow snowmelt and storm flows to run off too quickly, and the opportunity to recharge soils and groundwater have been lost.
Now, however, the benefits of meadow restoration have been embraced, and many new projects are being funded. One of the leaders in this field is American Rivers, a nonprofit conservation group that began working on meadow restoration in 2010. It recently was awarded three state grants of about $670,000 for meadow restoration projects in the Sierra Nevada, out of eight projects in total that received grants in a new wave of state funding for this work. Water Deeply recently spoke with Luke Hunt, director of headwaters conservation at American Rivers, to learn more about this work.
Water Deeply: Is this round of grant funding a new thing in meadow restoration?
Luke Hunt: This is really brand new. It all really stems from meadow restoration being called out in the California Water Plan and, specifically, in the Governor’s Water Action Plan. The water action plan has been driving a bunch of Proposition 1 (water bond) investments as well as other investments.
Last year, there was a sizable award from the Department of Fish and Wildlife from cap and trade (greenhouse gas mitigation) funds. In this case, the cap and trade funds were going toward watershed restoration that would improve carbon storage in soils. It’s not totally known what the net effect of meadow restoration on greenhouse gas emissions is, but there was about $6 million that funded 10 or so projects. That was the very first big investment in meadow restoration and it came from the state. In the last two years, things have really changed.
Water Deeply: Why did American Rivers get involved in meadow restoration?
Hunt: Meadows are one place where restoration is really obvious. You walk onto the spongy soils of the meadow and the connection is really clear between meadow health, water storage and streamflow – and the connection between meadow health and river health. You can feel it under your feet – a healthy meadow is really spongy.
We see it as sort of a gateway to looking at the larger watershed. So what we want to do is leverage the momentum we’re building around some of these meadow restoration projects and take a larger watershed approach and look at things like forest roads that also have significant impacts. Not only are these connections clear, but also making a change over a relatively small acreage has a big watershed benefit. And not only for water quality and water supply, but also for species like Yosemite toad and Eagle Lake rainbow trout. Those are two species that will benefit from these most recent grants.
Water Deeply: How did meadows become degraded?
Hunt: The short answer is historic land use practices. Shortly after the Gold Rush, people moved into the meadows of the Sierra with their livestock and did a number of things. They ditched meadows, they built roads through them and did other things that changed the water courses.
The reason they ditched these meadow is they were a place where they had a homestead, and they wanted to be able to use the meadow. They wanted to get the cows on there early in the season, so they wanted to dry out the meadows. So they would ditch it. These would be hand-dug ditches on the order of a couple feet deep. And they would straighten out the stream channels. Then erosion in these ditches would eventually create a ditch that was maybe 8 feet [2.5m] deep and maybe 50 feet [15m] wide. This then acts like a French drain to drain the surrounding water table down to that downcut elevation.
Meadows are floodplains. What they naturally do is, during spring snowmelt, the energy of a whole lot of water flowing down is dispersed over the whole meadow surface. When you carved a ditch or if intense overgrazing has compacted the soils and allowed the banks to become destabilized, once the channel gets big enough that it can hold more of the floodwater, then instead of the energy dissipating over the whole floodplain, it’s concentrated in the channel. That leads to a feedback where there’s more erosion and incision of the stream channel, which causes even more erosion. It leaves the natural floodplain perched high.
So in some of these meadows, they used to flood annually or every few years, and now they won’t even flood during a 500-year storm because the channel has been cut so deep. It’s one of those things that won’t correct itself even in places that haven’t been grazed in 30 years.
Water Deeply: Why is it important to restore meadows?
Hunt: Meadows are well known to be hotspots for biodiversity. So the species benefits of restoring these areas are really large.
They are also able to maintain cool, flowing streams up high in the Sierra. Those stream temperatures and summer streamflows are going to be under pressure with climate change. As more winter storms fall as rain instead of snow because of climate change, we need to be able to maintain this water in the upper watershed not only for people and for water supply, but also for all the habitat benefits and for healthy forests.
Water Deeply: What work has been done so far?
Hunt: A lot has been done already in terms of finding best practices. Meadow restoration started in the 1930s and 40s. The Conservation Corps would go out and fill some of these gullies with brush dams and check dams, and they would clear encroaching conifers from a meadow.
Water Deeply: How much work is still left to do?
Hunt: Well, the U.S. Forest Service estimated in 2015 that more than half of all meadows on Forest Service land are degraded with eroded channels. That amounts to 110,000 acres [44,515 hectares] of degraded meadow, and restoring all of them would result in 35,000 acre-feet [43.2 million cubic meters] of increased groundwater storage. About 60 percent of meadows in the Sierra are on Forest Service lands. The rest are largely private or in national parks.
In the past, so many people have been working in isolation. Now, in the last five years, it’s become more of a coordinated movement – less about the Forest Service acting independently – and now there’s more transfer of knowledge. That’s really going to make meadow restoration a lot more of an effective process and a lot more of a better investment as well.
Water Deeply: What are the water supply benefits?
Hunt: Timing is the key one. Where a channel has been eroded into the meadow, the water quickly drains out of the upper watershed, out of the rivers, over the dams and out to the ocean. But when the floodplain is engaged and the meadows can soak up this water, it provides flows for later on in the season, and that’s really what California needs.
In one meadow we studied (Indian Valley in Alpine County, part of Mokelumne River watershed), in September the meadow provides the same amount of flow after restoration as the whole watershed above. The meadow doubles the flow and it’s a relatively small creek.
What meadows do is they keep these small tributary streams flowing longer and at higher flows as we go through our annual drought. Essentially what happens is, you trade lower streamflows in winter for higher flows later in the summer.
Water Deeply: What are your plans to expand meadow restoration?
Hunt: What we would like to see happen is to have a solid queue of projects coming forward. What that means to us is, in places in the Sierra where there aren’t projects happening, to build support and capacity to do projects in those areas. So we’ll continue to do pilot projects in places where we think demonstrating success will lead to more projects on the ground.
We’re also looking at expand into other places across the nation, probably first in the Rockies and Cascades where American Rivers has significant capacity.
Water Deeply: What can people do to help?
Hunt: Well, we can thank everyone for passing the water bond (Proposition 1 in 2014). Another thing is to support the corporate and water agency financing of these upper watershed places.
Also, people can help get the world out more about the importance of meadow restoration and watershed condition to the health and prosperity of Californians. The Sierra Nevada watersheds provide enormous benefits to the people of California. But the big missing link is that the bulk of the people of California don’t live in the Sierra Nevada. So it’s investing outside of where they live that’s really important.
The best investment you can make for California’s overall prosperity is to invest in the health of our natural watersheds.
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