Background

Vulnerability to water shortages is already acute in many regions of California during drought events. Climate change including higher temperatures and more extreme droughts, coupled with claims to water by more diverse interests, will exacerbate this vulnerability. Our projects focus on approaches to achieving water supply security and sustainability for the state's communities.

THE LINKAGES BETWEEN GROUNDWATER DROUGHT AND CLIMATE CHANGE:

Groundwater is a critical resource in California, providing approximately forty percent of the state’s water supply and significantly more during dry years. This project is documenting and assessing the critical issues and relationships between groundwater and drought under climate change. Our goal is to summarize both what is understood and important information gaps, and we will provide recommendations for future policies that can support sustainable groundwater management under drought conditions. 

ANALYSIS OF THE IMPACT OF FUTURE CLIMATE CHANGES AND LAND USE/LAND COVER SHIFTS  ON WATER SUPPLY SECURITY AND SUSTAINABILITY

Global scale projections of land use change have been an important component of climate change research, however, their utility at local to regional scales is often limited. Climate change data at local scales relevant to land use decisionmaking is also incomplete. These are significant research gaps, as local decisions about land-use activities and land-cover (LULC), including agricultural and municipal development, are localized in nature and require accurate climate and land use data if land and resource managers are to effectively adapt to impending climate change and plan for alleviating community vulnerability.This project will examine how climate and LULC trends will impact the vulnerability of communities in the understudied Central Coast region of the state, including disadvantaged communities in the Salinas Valley.

ANALYSIS OF INSTITUTIONS TO GOVERN THE GROUNDWATER COMMONS: Adjudicated groundwater basins and special act districts.

Court-adjudicated basins - where water users turn to the court to define and assign private property rights over groundwater and to oversee the rules governing basin management, and legislatively created special act districts - that allow for enhanced local regulation of groundwater, are two major institutional arrangements to manage groundwater in California. The adjudicated basins and special act districts encompass major municipal and agricultural areas in the state. In 2014, the Sustainable Groundwater Management Act (SGMA), established new requirements for 127 basins in, or vulnerable to, overdraft to develop sustainable management programs with increased state oversight. But SGMA exempted all adjudicated basins and SGMA provided all special act districts with the right to be the exclusive local agencies within their statutory boundaries, and the option to be the sole GSA in their service area. Most special act districts have opted to be the sole GSA for their service area and are currently working on their groundwater sustainability plans.

In 2016, our research team completed a detailed evaluation for the SWRCB of all the current adjudicated basins and all special act districts. We continue to analyze these and other groundwater basins to illuminate the comparative advantages of particular institutional arrangements with respect to sustainable groundwater management.

LOCAL DROUGHT RESERVES:

Traditional drought adaptation strategies typically focus on monitoring weather conditions, generating surface and groundwater data, and implementing water shortage contingency plans after a drought occurs. Desalination, recycled water, new surface storage facilities, and increased water use efficiency are commonly proposed approaches for balancing supply and demand during a drought.

While these strategies can be effective, they may also lead to pernicious unintended consequences. An increase in groundwater supply during a dry period can prompt growth during subsequent normal periods which increase future water requirements. Moreover, long-term demand reduction can result in a hardening of demand-side conservation capabilities during a future drought. This results in an increase of a region’s vulnerability to future water shortages.

We are exploring a proactive approach to increase a community’s resilience to future prolonged droughts - the establishment and maintenance of local strategic groundwater reserves. This includes case studies of individual management approaches to develop and sustain such reserves. If, as projected by DWR, improvements to groundwater management are key strategies to generate more water to meet California’s growing demand, then it is critical that incentives be created to protect the quality and quantity of this water for future generations and to maintain a reserve for a long-term drought.