August 31, 2020 | Water in the West | News
Over the next 20 years, San Joaquin Valley farmers may need to temporarily fallow or permanently retire over half a million acres of cropland as California pushes towards sustainable groundwater use. But, according to new research led by Stanford University and The Nature Conservancy, using an informed approach to land management that engages and compensates landowners for dedicating land to habitat can spur recovery of biodiversity in local ecosystems and provide other environmental benefits for people. While California’s San Joaquin Valley produces crops totaling over $35 billion a year on five million acres of land, expanding irrigated agriculture has led to significant challenges such as groundwater overdraft and drinking water contamination, along with major losses of biodiversity and habitat. Implementation of the Sustainable Groundwater Management Act (SGMA) – which limits groundwater withdrawal to bring water use into balance with supplies in California – provides an opportunity for conservation actors to work with farmers and re-envision the balance between agricultural and natural land.
Below, the paper’s lead authors, Benjamin Bryant and Rodd Kelsey, discuss their research examining how conservation planning can guide the land use change being driven by SGMA to achieve multiple benefits, such as recovery of natural communities and resilient agricultural production. Bryant is a joint researcher with Stanford’s Water in the West program and the Natural Capital Project. Kelsey is an associate director for the Water Program at The Nature Conservancy in California.
What is multi-benefit landscape planning and how can it be applied to help a stressed landscape?
Bryant: The key idea behind multi-benefit planning is an awareness that actions we take in landscapes can affect multiple outcomes that people care about. These outcomes include crop yields, flood protection, groundwater recharge or endangered species protection. By considering all of the potential benefits and impacts – and how protecting or restoring nature can enhance them – it’s possible to create solutions that are overall more beneficial. In our study, we examine how land fallowing to reduce water use (something that needs to happen anyway), can be anticipated and shaped through collaboration between stakeholders. We look at how this can be done in a way that also makes it easier to create beneficial habitat for many of the endangered and threatened species native to the valley, while creating other benefits for people and minimizing additional economic impacts on the farming economy. The same types of questions can be asked in other contexts as well, such as managing forests for wildfire resilience while also aiming to benefit our water supply and store carbon.
What are the opportunities and challenges SGMA presents in realizing multi-benefit outcomes in the San Joaquin Valley?
Kelsey: Reaching sustainable use of water by implementing SGMA is going to fundamentally change the valley, one way or the other. This once in a life-time transformation creates the opportunity to proactively and collaboratively use landscape-scale, multi-benefit planning to help valley residents create a future with the most benefits possible at the least cost. Importantly, the impacts and benefits of change will vary among groups and communities in the valley. That’s why quantifying the many benefits that are possible is so important, in order to identify the ways that we as a society can invest in the changes and benefits necessary to make nature, farmers and communities in the valley more resilient and sustainable. Planning by local Groundwater Sustainability Agencies is already underway, but full implementation of SGMA does not need to happen until 2040, creating both opportunity and challenge. On the one hand, it gives the community time to incorporate collaborative, multi-benefit planning into the process to get the best outcomes. On the other hand, local and uncoordinated planning, along with failure to genuinely engage the full diversity of voices in the valley, would rapidly close opportunities for coordinated, landscape-scale change with the greatest potential for human and nature benefits.
How can the conservation community engage with farmers and potentially compensate them as a way to mitigate the immediate impacts of SGMA?
Kelsey: The conservation community has a vital role to play facilitating successful implementation of SGMA and ensuring that both nature and people get the water they need. We can help take advantage of this change to create a more healthy, vibrant California. First, by helping implement the kind of multi-benefit planning illustrated in this study and using the results in collaboration with state and local agencies, we can help guide regional planning to create the best outcomes. Also, by quantifying tangible benefits – like greenhouse gas reduction and water quality improvements – the conservation community can advance policies and funding programs that help pay for land retirement and restoration in order to create those benefits. While this study demonstrates what’s possible, it will be important for these kinds of approaches to be applied collaboratively with local agencies, valley communities and farmers to do more comprehensive accounting and planning for the many benefits and costs that will come with remaking the valley’s landscape. For example, The Nature Conservancy and Audubon California are currently working with a local agency in the valley to apply the results of this study and other information to design a program for retiring irrigated land and restoring it either to upland habitat for imperiled species or multi-benefit recharge basins that increase water supply and provide wetland habitat. This kind of direct partnership in the early days of implementing SGMA will be essential.
How do the analytic tools developed in your research help improve planning for habitat restoration in San Joaquin Valley?
Bryant: Our study links a couple of common approaches in a new way that is informative not only for planning, but also for stakeholder engagement and communication. Instead of comparing potential land management actions within the current landscape, we look ahead to the major impending land use change driven by SGMA and examine how land management could change in the future. This helps conservation organizations see where and what types of engagement will be most useful. Places with high potential value for wildlife that overlap with water constraints are likely to require farmers to retire some land, creating interest in alternative uses that can soften the impact. This could include payments for habitat. In other areas, there may be opportunities to coordinate the location of habitat and agriculture as the valley changes, by working on water trades to prevent retirement in one place and directing it to areas that are more valuable for habitat. In our analysis, we found that there are a couple key portions of the valley that are likely to see significant retirement and also have very good potential to create beneficial habitat, because they are in places that are close to existing nature reserves and also are suitable for multiple threatened species. The other benefits of carefully planned restoration we examined were reductions in excess nitrogen fertilizer that end up in the air and groundwater (both of which are causing significant health problems for people in the valley) and carbon storage in the soil and vegetation of restored natural lands. Highlighting these other benefits that people get from restoration helps identify compensation opportunities for farmers, such as payments for carbon storage as part of climate change programs.
Can this approach be applied to other landscapes?
Bryant: Yes! Besides informing efforts in the San Joaquin Valley, a big goal of this study is that it motivates and demonstrates how others can apply a similar approach in other landscapes. Water stress and other types of land degradation are big issues in many parts of the world, and are generally going to get worse with climate change. So we hope places facing similar circumstances can utilize the methods we demonstrate here. It may take some work depending on how much data is available, but each step of the analysis can be adjusted for the models and data that exist. Ultimately, the process involves getting numbers for different key attributes, and these can be estimated with whatever tools or expertise can be assembled. The existing work could also be readily used to zoom in and refine the analysis for subregions of the San Joaquin Valley, where stakeholders might want to use local knowledge to incorporate new or additional information about natural assets, or updated estimates of water availability and fallowing needs. The computer code and data we used is in a public repository and we encourage others to pick it up!
Bryant is also an economist with the Millennium Challenge Corporation. Additional authors include Adrian Vogl, lead scientist, Natural Capital Project; Stacie Wolny, senior GIS analyst, Natural Capital Project; Duncan MacEwan, managing partner, ERA Economics; Paul Selmants, research ecologist, U.S. Geological Survey; Tanushree Biswas, spatial data scientist, The Nature Conservancy; and H. Scott Butterfield, senior scientist, The Nature Conservancy. Primary project funding was provided by a 2017 Science Catalyst Fund grant from The Nature Conservancy, California, the Ishiyama Foundation and the USGS Biological Carbon Sequestration Program.