Guest Editors:
Anita Milman, Department of Environmental Conservation, University of Massachusetts Amherst, USA and Michael Kiparsky, Wheeler Water Institute, UC Berkeley, USA
INTRODUCTION: Groundwater pumping exceeds naturally occurring recharge in many regions of the world. The resulting impacts to groundwater systems adversely affect human and environmental systems. Climate change adds urgency, as the combination of more extreme flood and drought regimes coupled with intensifying demand further push groundwater resources out of balance. In many or most groundwater basins, some reduction in groundwater extraction will be necessary to reduce outflows from stressed basins. Increasing inflows to these basins through Managed Aquifer Recharge (MAR) is increasingly looked to as a mechanism to help bring aquifers into sustainable balance.
In this special collection, we examine deployment of MAR in examples from around the USA to illustrate the range of institutional approaches used as well as how those relate to the drivers and objectives of MAR. The overarching impetus for this work is the recognition that water managers often anecdotally agree that institutional elements are as important, or more important, than technical challenges to MAR in many cases.
Articles include the Kern Water Bank, Orange County Water District, and Recharge Net Metering in the Pajaro Valley.
Access all articles at the UC Press by clicking here.
MAR is a set of practices and institutions that allows the recharge of water of various types and qualities (surface water, recycled wastewater, and even groundwater from different locations) into a given aquifer. Therefore, it can reduce subsidence (pumping-induced land sinking) damages, prevent saline water intrusion, protect wetland habitat, provide flood protection, and more.
In this work, we examine the role of MAR in the Kings Groundwater Basin. Using several climate-change scenarios, we evaluate how MAR applicability is impacted by possible institutional arrangements and regulatory policy interventions.
Click here to read this paper from the Giannini Foundation of Agricultural Economics, University of California.
As the world population grows, so does the demand for food, putting unprecedented pressure on agricultural lands. At the same time, climate change, soil degradation, and water scarcity mean that productivity of many of these lands is deteriorating. In many desert dryland regions, drinking wells are drying up and the land above them is sinking, soil salinity is increasing, and poor air quality is contributing to health problems in farm communities. “Rewilding” the least productive of these cultivated landscapes offers a sensible way to reverse the damage from intensive agriculture. These ecological restoration efforts can recover natural diversity while guaranteeing the long-term sustainability of the remaining farms and the communities they support.
This accessibly written, groundbreaking contributed volume is the first to examine in detail what it would take to retire eligible farmland and restore functioning natural ecosystems. Rewilding Agricultural Landscapes uses the southern Central Valley of California, which is one of the most productive and important agricultural regions in the world, as a case study for returning a balance to agricultural lands and natural ecosystems. This project—one of the largest rewilding studies of its kind in dryland ecosystems—has shown that rewilding can slow desertification and provide ecosystem services, such as recharged aquifers, cleaner air, and stabilized soils, to nearby farms and communities. Chapters examine what scientists have learned about the natural history of this dryland area, how retired farmland can be successfully restored to its natural wild state, and the socioeconomic and political benefits of doing so. The book concludes with a vision of a region restored to ecological balance and equipped for inevitable climate change, allowing nature and people to prosper. The editors position the book as a case study with a programmatic approach and straightforward lessons that can be applied in similar regions around the world.
The lessons in Rewilding Agricultural Landscapes will be useful to conservation leaders, policymakers, groundwater agencies, and water managers looking for inspiration and practical advice solving the complicated issues of agricultural sustainability and water management.
Click here for more information and to purchase book.
“A groundwater market, which caps total pumping within one or more basins, allocates portions of the total to individual users and allows users to buy and sell groundwater under the total cap, is a promising tool for basins implementing California’s Sustainable Groundwater Management Act (SGMA).
While the benefits of a cap-and-trade system for both groundwater users and regulators are potentially very large, so too are the risks.
An electronic bulletin board that introduces buyers and sellers, like craigslist.org , is not a market. Nor is a sophisticated financial application that matches participants and executes financial transactions. A water market is a complex interaction of individuals and institutions — the product of a large number of people, structures, operational mechanisms and rules. Without careful design, a water market can do harm.. ... ”
Read more from California Agriculture here: The first SGMA groundwater market is trading: The importance of good design and the risks of getting it wrong
Study: Agricultural water use accounting provides path for surface water use solutions:
“Agricultural water demands can conflict with habitat needs in many North Coast watersheds. Understanding different water use patterns can help reduce conflict over limited supplies.
We measured on-farm crop water use and conducted grower interviews to estimate the agricultural water demand in the upper Russian River and Navarro River watersheds. Annual agricultural water demand was less than 11% in the Russian River, and 2% in Navarro River, of the total annual discharge in each watershed. However, because demands are concentrated in the dry season when instream flows are at a minimum, these relatively small amounts can represent a significant constraint to stream habitat conditions.
We have shared our study results in broad basin and community water resource planning efforts, including flow management of the Russian and Navarro rivers and implementation of the Sustainable Groundwater Management Act in the Ukiah Basin.
Findings and recommendations from this study have influenced on-the-ground solutions to meet water demand in these watersheds, including construction of off-stream wintertime storage capacity to replace summertime stream diversions, and use of a municipal recycled water conveyance system as a replacement for summer diversions.”
Read the study from California Agriculture here: Study: Agricultural water use accounting provides path for surface water use solutions
“In California, the amount of water exiting aquifers under the state’s most productive farming region far surpasses the amount of water trickling back in. That rampant overdraft has caused land across much of the region to sink like a squeezed out sponge, permanently depleting groundwater storage capacity and damaging infrastructure.
The trend – and a 2014 mandate for sustainable groundwater management in the state – has ignited interest in replenishing aquifers in California’s Central Valley through managed flooding of the ground above them. … ”
Read more from Stanford News here: Stanford study offers a way to map where flooded fields best replenish groundwater
From Environmental Monitor:
“In drought-stressed areas like California where every drop in the aquifer counts, seismic noise may be the key to monitoring water. Harvard University PhD student and principal investigator Tim Clements spoke to EM about this recent work, and how it might be a game changer for water watchers across the country.
“The inspiration for this research was the historic drought in California from 2011 to 2017,” explains Clements. “This was the driest period in recorded history in the state. We started this research after California had implemented the first mandatory water restrictions in state history in 2015.” … “
Read more from Environmental Monitor here: Tracking aquifer water with seismic noise
From California Agriculture:
“In California’s semi-arid climate, replenishment of groundwater aquifers relies on precipitation and runoff during the winter season. However, climate projections suggest more frequent droughts and fewer years with above-normal precipitation, which may increase demand on groundwater resources and the need to recharge groundwater basins. Using historical daily streamflow data, we developed a spatial index and rating system of high-magnitude streamflow availability for groundwater recharge, STARR, in the Central Valley.
We found that watersheds with excellent and good availability of excess surface water are primarily in the Sacramento River Basin and northern San Joaquin Valley. STARR is available as a web tool and can guide water managers on where and when excess surface water is available and, with other web tools, help sustainable groundwater agencies develop plans to balance water demand and aquifer recharge. However, infrastructure is needed to transport the water, and also changes to the current legal restrictions on use of such water. … “
Continue reading from California Agriculture here: Streamflow availability ratings identify surface water sources for groundwater recharge in the Central Valley
From the Giannini Foundation of Agricultural Economics, University of California:
Groundwater markets offer a cost-effective means of meeting management goals under the 2014 Sustainable Groundwater Management Act. Using data from the Coachella Valley groundwater basin, we quantify the economic impacts of trade in one of California’s most important agricultural regions. Facilitating groundwater trade under a mandatory basin-wide “cap” on pumping will reduce disruptions to the local economy and keep land in production, relative to a scenario where trade is prohibited.
From the Northern California Water Association Blog:
Sacramento Area Council of Government (SACOG)’s Sustainable Water Management Strategies for Specialty Crop Expansion in the Sacramento Valley examined scenarios to consider optimal locations for strategic flooding of cropland to maximize groundwater infiltration and improve water supply reliability for continued specialty crop production and related economic activities.
The work completed has identified attributes in our region’s open space land that facilitate infiltration and those that limit groundwater recharge potential. The project also examined ways these flooding scenarios may provide habitat benefits. The project included a contractual study component to complement RUCS staff work and build upon in-kind services from industry stakeholders, including specialty crop stakeholders, and water resource managers. The contractual work provided technical support and subject-area expertise in groundwater recharge science. This included the collection of environmental data to underpin scenario analysis and enhance the RUCS toolkit; including regional water balances and other factors that impact recharge (e.g. soil type permeability).
Click here to continue reading at the Northern California Water Association blog.
