Navigating the Growing Prospects and Growing Pains of Managed Aquifer Recharge

National Ground Water Association (NGWA) | November 7th, 2025

Increasing water demands and declining groundwater levels have led to rising interest in managed aquifer recharge. That interest is growing in the United States—the foc

Increasing water demands and declining groundwater levels have led to rising interest in managed aquifer recharge. That interest is growing in the United States—the focus of this article—and elsewhere. Increasing interest makes sense; managed aquifer recharge can reduce water-supply challenges and provide environmental benefits, sometimes with lower costs than alternative water-management approaches. But managed aquifer recharge also faces growing pains, which will make it difficult for projects to scale up and may limit the benefits provided by those projects that do go forward. Some of the problems arise from the challenges of finding physically suitable locations for managed aquifer recharge; many derive from economics, public policy, and law; and some derive from ways in which managed aquifer recharge could exacerbate traditional equity challenges of water management. But as we explain, there also are potential solutions to these challenges, and the future success of managed aquifer recharge will likely depend on the extent to which these solutions are adopted

Navigating Transformations in 2023: The Metropolitan Water District of Southern California Year in Review

Metropolitan Water District of Southern California (MWD) | April 13th, 2024

Near-term Colorado River Operations Revised Draft Supplemental Environmental Impact Statement

U.S. Bureau of Reclamation (USBR) | October 26th, 2023

Reclamation is proposing to revise the 2007 Interim Guidelines for the operation of Glen Canyon and Hoover Dams beginning in the 2024 operating year to address the potent

Reclamation is proposing to revise the 2007 Interim Guidelines for the operation of Glen Canyon and Hoover Dams beginning in the 2024 operating year to address the potential for continued low-runoff conditions in the Colorado River Basin. The potential impacts of low runoff conditions in the remainder of the interim period (prior to January 1, 2027) pose unacceptable risks to routine operations of Glen Canyon and Hoover Dams; therefore, modified operating guidelines should be expeditiously developed. Due to size, this file has been divided. Part one, Part two.

NEPA and CEQA: Integrating Federal and State Environmental Reviews

U.S. Department of the Interior (DOI) | February 18th, 2014

This handbook provides advisory guidance to Federal, state, and local agencies and others regarding projects that are subject to both the National Environmental Policy Ac

This handbook provides advisory guidance to Federal, state, and local agencies and others regarding projects that are subject to both the National Environmental Policy Act (NEPA) and the California Environmental Quality Act (CEQA). Once President Nixon signed NEPA on January 1, 1970, and California Governor Reagan followed suit signing CEQA into law on September 18 of the same year, these laws expressly required the incorporation of environmental values into governmental decision making. Those statutes require Federal, state, and local agencies to analyze and disclose the potential environmental impacts of their decisions, and, in the case of CEQA, to minimize significant adverse environmental effects to the extent feasible. NEPA was codified under Title 42 of the United States Code, in section 4331 et seq. (42 U.S.C. § 4331 et seq.). Under NEPA, Congress established the White House Council on Environmental Quality (CEQ) to ensure that Federal agencies meet their obligations of the Act. CEQ’s Regulations for Implementing the Procedural Provisions of NEPA (hereinafter CEQ NEPA Regulations) are in Title 40 of Code of Federal Regulations section 1500 et seq. (40 C.F.R. § 1500 et seq.). In California, CEQA was codified under Division 13 of California’s Public Resources Code, in sections 21000 et seq. (Cal. Pub. Resources Code, § 21000 et seq.). The Guidelines for Implementation of the California Environmental Quality Act are in Title 14 of California’s Code of Regulations, section 15000 et seq. (Cal. Code Regs., tit. 14, § 15000 et seq.; hereafter CEQA Guidelines). NEPA and CEQA are similar, both in intent and in the review process (the analyses, public engagement, and document preparation) that they dictate. Importantly, both statutes encourage a joint Federal and state review where a project requires both Federal and state approvals. Indeed, in such cases, a joint review process can avoid redundancy, improve efficiency and interagency cooperation, and be easier for applicants and citizens to navigate. Despite the similarities between NEPA and CEQA, there are several differences that require careful coordination between the Federal and state agencies responsible for complying with NEPA and CEQA. Conflict arising from these differences can create unnecessary delay, confusion, and legal vulnerability. Federal, state and local agencies have cooperated in the environmental review of projects ranging from infrastructure to renewable energy permitting. As the state and Federal governments pursue shared goals, there will be a continued need for an efficient, transparent environmental review process that meets the requirements of both NEPA and CEQA. Recognizing the importance of implementing NEPA and CEQA efficiently and effectively, the CEQ and the California Governor’s Office of Planning and Research (OPR) developed this handbook to provide advisory guidance on conducting joint NEPA and CEQA review processes. The CEQ oversees Federal agency implementation of NEPA, which includes writing the CEQ NEPA Regulations1 and preparing guidance and handbooks for Federal agencies. OPR plays several roles in the administration of CEQA, including developing the CEQA Guidelines in coordination with the California Natural Resources Agency, providing technical assistance to state and local agencies, and coordinating state level review of CEQA documents. The purpose of this handbook is to provide practitioners with an overview of the NEPA and CEQA processes, and to provide practical suggestions on developing a single environmental review process that can meet the requirements of both statutes. This handbook contains three main sections. First is a “Question and Answer” section that addresses the key similarities and differences between NEPA and CEQA. This section compares each law’s requirements or common practices, and identifies possible strategies for meeting the requirements of both laws. These strategies are not meant to prescribe methods that agencies must use; rather, this handbook provides suggestions that will help agencies identify and think through potential issues. Indeed, developing a common understanding of the NEPA and CEQA review processes and their differences at the beginning of a joint review process may be among the most important ways to conduct an efficient and effective review process. Second, this handbook provides a framework for a Memorandum of Understanding (MOU) between two or more agencies entering a joint NEPA/CEQA review process. MOUs can clarify responsibilities and avoid potential conflicts. The MOU framework in this handbook highlights a number of issues that agencies can consider before embarking on their joint effort. This handbook is not intended to replace or replicate any existing MOUs; rather, it raises topics agencies might consider incorporating into their own MOUs. Much like the Q&A document, a key goal of this framework is to encourage state and Federal agencies to consider and resolve potential challenges common to joint NEPA/CEQA review processes in order to avoid complications late in the review process. Finally, the third section addresses the California Energy Commission (CEC) licensing process for decisions on thermal power plants 50 megawatts and larger. This licensing process is a certified regulatory program under CEQA and therefore the process and documents prepared by the CEC serve as the functional equivalent of a CEQA review (CEQA Guidelines, § 15251, subd. (j)). As noted above, this handbook is advisory and does not supplant the administrative regulations set forth in the CEQA Guidelines, or the CEQ NEPA Regulations. Agencies conducting an environmental review must also take into account any additional requirements or time periods established in an individual agency’s administrative regulations or procedures implementing NEPA and CEQA, which could prescribe additional or more stringent requirements than the CEQ NEPA Regulations and the CEQA Guidelines.

New Stone Water District GSA Groundwater Sustainability Plan

New Stone Water District (NSWD) | September 23rd, 2019

New Stone Water District Revised Groundwater Sustainability Plan

New Stone Water District (NSWD) | March 20th, 2023

Nitrogen Fertilizer Loading to Groundwater in the Central Valley

University of California, Davis (UC Davis) | October 31st, 2017

Nitrate‐nitrogen is the most common pollutant found in the Central Valley aquifer system of California. This project provides a long‐term assessment of past and curr

Nitrate‐nitrogen is the most common pollutant found in the Central Valley aquifer system of California. This project provides a long‐term assessment of past and current potential nitrogen loading to groundwater on irrigated and natural lands across the entire Central Valley of California using a nitrogen mass balance approach; assesses the long‐term implications for groundwater quality in the Central Valley (Sacramento Valley, San Joaquin Valley, and Tulare Lake Basin); evaluates potential best management practices to reduce groundwater nitrogen loading from irrigated lands; and provides a planning tool to better understand local and regional groundwater quality response to specific best management practices and policy/regulatory actions. The project complements other work to assess the vulnerability of Central Valley groundwater to nitrate contamination, sources of nitrate in groundwater, and how to reduce source loading.

Nonstationarity in the global terrestrial water cycle and its interlinkages in the Anthropocene

National Academy of Sciences (NAS) | October 28th, 2024

Climate change and human activities alter the global freshwater cycle, causing nonstationary processes as its distribution shifting over time, yet a comprehensive underst

Climate change and human activities alter the global freshwater cycle, causing nonstationary processes as its distribution shifting over time, yet a comprehensive understanding of these changes remains elusive. Here, we develop a remote sensing–informed terrestrial reanalysis and assess the nonstationarity of and interconnections among global water cycle components from 2003 to 2020. We highlight 20 hotspot regions where terrestrial water storage exhibits strong nonstationarity, impacting 35% of the global population and 45% of the area covered by irrigated agriculture. Emerging long-term trends dominate the most often (48.2%), followed by seasonal shifts (32.8%) and changes in extremes (19%). Notably, in mid-latitudes, this encompasses 34% of Asia and 27% of North America. The patterns of nonstationarity and their dominant types differ across other water cycle components, including precipitation, evapotranspiration, runoff, and gross primary production. These differences also manifest uniquely across hotspot regions, illustrating the intricate ways in which each component responds to climate change and human water management. Our findings emphasize the importance of considering nonstationarity when assessing water cycle information toward the development of strategies for sustainable water resource usage, enhancing resilience to extreme events, and effectively addressing other challenges associated with climate change. Click here for a plain language summary from NASA.

North American Subbasin Groundwater Sustainability Plan

Sacramento Groundwater Authority | December 15th, 2021

In 2014, the Sustainable Groundwater Management Act (SGMA) was signed by the Governor of the state of California, setting the framework for local agencies to sustainably

In 2014, the Sustainable Groundwater Management Act (SGMA) was signed by the Governor of the state of California, setting the framework for local agencies to sustainably manage California’s groundwater basins. To avoid potential State intervention, SGMA requires groundwater basins/subbasins designated by the California Department of Water Resources (DWR) as medium- or high-priority to follow four basic steps: 1) form a Groundwater Sustainability Agency (GSA); 2) develop and adopt a Groundwater Sustainability Plan (GSP or Plan); 3) implement the Plan to achieve a sustainability goal and avoid undesirable results within 20 years; and 4) report the implementation activities to the DWR to document whether the sustainability goal and the avoidance of undesirable results is being achieved. Ultimately, five GSAs were formed to manage groundwater in the North American Subbasin (NASb or Subbasin), completing Step 1. This GSP and adoption by each GSA will complete Step 2. This GSP will be assessed every 5 years, with amendments as needed to ensure the Plan is meeting its sustainability goal. This GSP is a framework to provide for the sustainability of the NASb of the Sacramento Valley Groundwater Basin for the next 20 years. The NASb, designated as subbasin No. 5-021.64 by the DWR, is bounded on the north by the Bear River, on the south by the American River, to the west by the Feather and Sacramento rivers, and on the east by the Sierra Nevada foothills. The NASb was designated by DWR as a high priority subbasin and therefore the formation of GSAs and the completion of a GSP is required to avoid potential State Water Resources Control Board (SWRCB) intervention. Surrounding subbasins were also designated as medium- or high-priority and are required to comply with SGMA. Groundwater is a critical resource to the Subbasin’s community, economy, and environment by providing an average of 280,000 acre-feet per year (AFY) for public and agricultural supply or just under 50 percent of total water supply. Agencies in the NASb have been actively managing groundwater for decades and have achieved positive groundwater management results. Groundwater levels within the Subbasin have been relatively stable for decades and have shown the ability to recover after periods of prolonged pumping and droughts. The passage of SGMA created an opportunity for a cooperative endeavor to develop a single GSP for the entire NASb. Beginning in January 2017, representatives of local agencies began coordination meetings that ultimately led to agreement to form five GSAs to cover the entirety of the Subbasin, while ensuring broad representation of the various stakeholder interests throughout the parts of the three counties comprising the NASb. Due to size, this file has been divided. Part 1, Part 2, Part 3, Part 4, Part 5, Part 6, Part 7, Part 8, Part 9

North Coast Hydrologic Region Groundwater Update

California Department of Water Resources (DWR) | April 1st, 2015

The primary goal of the North Coast Hydrologic Region (North Coast region) groundwater update is to expand information about region-specific groundwater conditions for Ca

The primary goal of the North Coast Hydrologic Region (North Coast region) groundwater update is to expand information about region-specific groundwater conditions for California Water Plan Update 2013, and to guide more informed groundwater management actions and policies. A second goal is to steadily improve the quality of groundwater information in future California Water Plan (CWP) updates to a level that will enable regional water management groups (RWMGs) to accurately evaluate their groundwater resources and implement management strategies that can meet local and regional water resource objectives in the context of broader statewide objectives. The final goal is to identify data gaps and groundwater management challenges that will guide prioritizing of future data collection and funding opportunities relevant to the region. This regional groundwater update is not intended to provide a comprehensive and detailed examination of local groundwater conditions, or be a substitute for local studies and analysis. Nonetheless, where information is readily available, this update does report some aspects of the regional groundwater conditions in greater detail.