The sustainability of groundwater and coupled surface-water resources, particularly in California, is a well recognized and urgent concern from local to global scales. Our REU students and exceptionally well-qualified Research Mentors will address knowledge gaps and practical solutions to the global groundwater crisis, with particular emphasis to California’s Sustainable Groundwater Management Act (SGMA).
Groundwater is a fundamental component of the global hydrologic cycle and a vital natural resource. It sustains many rivers, lakes, wetlands, and other groundwater dependent ecosystems, and is a significant source of freshwater for human consumption. Groundwater is also the foundation for irrigated agroecosystems, food production, ecosystem services, energy-extraction and production, and other industries. As a result of this demand, excessive groundwater (over)extraction, particularly in many of the largest and most important food producing aquifer systems in arid and semi-arid regions, has resulted in rapidly declining water levels and substantial loss of storage (Figure 1a), referred to as the global groundwater crisis. Climate variability and change and the associated modifications to the hydrologic cycle are exacerbating concerns over the global groundwater crisis and societal implications.
Figure 1. (a) Groundwater storage declines in several of the world’s major aquifers and food producing regions in mid-latitude arid and semiarid regions. Note that California’s Central Valley aquifer is a hotspot of the global groundwater crisis. (b) The Central Valley and other aquifers in California have some of the greatest groundwater depletion intensities in the U.S. during 2001-2008.
Groundwater overdraft (i.e., pumping that exceeds recharge) in California’s Central Valley aquifer is an often cited example of the global groundwater crisis (Figure 1a). Groundwater is an invaluable resource in California. Compared to California’s snowpack and surface-water reservoirs, groundwater is largely invisible, stored in aquifers below the land surface. Yet, groundwater is the life-blood that quietly drives California’s multi-billion dollar agricultural economy, Silicon Valley, energy production (hydraulic fracturing), supports many groundwater dependent ecosystems, and supplies drinking water to millions of Californians. In fact, California uses more groundwater than any other state and has some of the greatest groundwater depletion intensities (Figure 1b), a trend that increased dramatically during the recent (2012-2016) historic drought, exacerbating the statewide problem of groundwater overdraft. Excessive groundwater extraction has caused overdraft in aquifers across California, which has led to wells failing, seawater intrusion and other water quality degradation, land subsidence (sinking) and related damage to infrastructure, and negative impacts on baseflow to surface water and other groundwater dependent ecosystems. These impacts are often felt the hardest in rural and disadvantaged communities.
The importance of groundwater, overdraft conditions, and historic drought were among the catalysts that enabled California’s landmark legislation called the Sustainable Groundwater Management Act (SGMA) to be signed into law by Governor Brown in 2014. The passage of SGMA and related water legislation prompted some in the local press to refer to 2014 as “The Year of Water” in California, a sentiment supported by the quotes in local newspapers “…2014 is the most significant year for California in a generation…” and “…2014 will be viewed as a critical turning point in California water history.”
SGMA broadly defines groundwater sustainability as avoiding “undesirable results”, which are specified in terms of (i) chronic lowering of water levels, (ii) reduction in storage, (iii) seawater intrusion, (iv) water quality degradation, (v) land subsidence, and (vi) groundwater-surface water interactions. SGMA prioritizes the 515 groundwater basins in the state (Figure 2a) and mandates that Groundwater Sustainability Agencies (GSAs) (Figure 2b) be formed by June 30, 2017. GSAs are required under SGMA to develop Groundwater Sustainability Plans (GSPs) for basins in critical conditions of overdraft by January 31, 2020 and for all other high- and medium-priority basins not currently in overdraft by January 31, 2022. Twenty years after the adoption of the GSPs (2040 and 2042), all high- and medium-priority groundwater basins must achieve sustainability. The GSPs will be based on best available science and existing or new monitoring networks to understand and develop hydrogeologic conceptual models, water budgets (supply and demand), overlying management and legal structures, and description of groundwater conditions (quantity and quality). The GSAs must consider the beneficial uses and users of groundwater, explain their decision-making to the public, and engage with all interested parties, which will include several stakeholder and GSP planning meetings each year in each GSA.
Figure 2. (a) The Department of Water Resources (DWR) prioritization of California’s 515 groundwater basins for SGMA; 127 are high and medium priority. (b) Location of the registered Groundwater Sustainability Agencies (GSAs). The 11 California State University (CSU) campuses with our REU Site Research Mentors (RMs) are shown in white circles.
The overarching goal of the REU Site is to provide genuine research experience and training in groundwater hydrology and related hydrologic sciences and engineering for undergraduate students, particularly women and under-represented minority (URM) students, at an early stage in their careers. Our research program will advance the science of groundwater sustainability and address the global groundwater crisis, with particular focus on SGMA in California. The primary objectives of our REU are:
- To provide junior- and senior-level undergraduates the opportunity to engage in independent research and make original intellectual contributions.
- To provide community based research experience and professional development opportunities that create an engaged workforce in hydrologic sciences and engineering.
- To expand the participation and increase the retention of women and URM students in STEM.
- To integrate cutting-edge research and training about groundwater sustainability science, particularly related to California’s Sustainable Groundwater Management Act (SGMA).
- To provide a framework for productive collaboration between interdisciplinary Research Mentors and undergraduates across the CSU system.
The REU Site has five major activities:
- A week-long, inquiry-based learning orientation that exposes students to the scientific process and fundamental concepts and skills.
- A seven-week independent research experience where students will take primary responsibility for their project, while under their Research Mentor’s guidance and resources.
- A weekly professional development seminar where students engage with professionals to learn about graduate school and careers.
- Social and professional activities to foster a strong cohort experience.
- A community-wide research symposium where REU students will present their research results to the California groundwater community, friends, and family.