Natural infrastructure in sustaining global urban freshwater ecosystem services

Nature Portfolio (Springer Nature) | October 21st, 2021

Rapid urbanization throughout the globe increases demand for fresh water and the ecosystem services associated with it. This need is conventionally met through the constr

Rapid urbanization throughout the globe increases demand for fresh water and the ecosystem services associated with it. This need is conventionally met through the construction of infrastructure. Natural infrastructure solutions have increased to provide freshwater ecosystem services, but little global research has examined the intricate relationships between built and natural infrastructure for providing freshwater ecosystem services to cities across the globe. Using network analysis, here we examine the interrelationships between built and natural infrastructure in 2,113 watersheds for 317 cities worldwide, focusing on four key freshwater ecosystem services: freshwater provision, sediment regulation, flood mitigation and hydropower production. Our results indicate that protected wetlands contribute to sustaining freshwater provision to cities. Forest cover in protected areas can improve the capacity of large dams in reducing sediment loads and producing hydropower, but cities mainly depend on reduced impervious surfaces and more green spaces within urban areas for flood mitigation. Improved understandings of the role of natural infrastructure in urban water networks must underpin strategic decision-making to sustainably provide freshwater ecosystem services to global cities.

Navigating a Flood of Information Evaluating and Integrating Climate Science into Groundwater Planning in California

Union of Concerned Scientists | November 1st, 2017

In early 2017, northern California experienced record-setting levels of precipitation. The amount of rain and snow from October 2016 through February 2017 was the greates

In early 2017, northern California experienced record-setting levels of precipitation. The amount of rain and snow from October 2016 through February 2017 was the greatest in the 122 years of California record-keeping. As the reservoir behind Oroville Dam quickly filled to capacity, a torrent of excess water was let out through the main spillway. Shortly thereafter the spillway began to collapse, leading to massive soil erosion and concerns that the erosion could undermine the dam itself. Fears of a catastrophic dam breach led to the evacuation of around 180,000 residents downstream from the dam. While we do not know how much climate change contributed to this particular event, we do know that climate change is making extreme events more common (Black et al. 2016; Mote et al. 2016; Otto 2016). While reports indicate that management failures may have played in an important role in the Oroville disaster, it is also true that this event took place in the context of extreme weather, and that climate change is increasing pressure on structures and communities. This finding is not limited to highprofile infrastructure such as the Oroville Dam. Much of our water infrastructure, management tools, institutions, and planning mechanisms are not designed for the increased magnitude and frequency of such extremes—making the state, its environment, and its water resources vulnerable to the changes we are likely to see in the coming decades. In California, groundwater contributes more than half of the state’s water supply during dry years (DWR 2009). Therefore, understanding the impacts that climate change will have on this critical resource will be of particular importance for the state’s water and food security over the long term. To that end, Governor Jerry Brown issued Executive Order B-30-15 that, along with setting ambitious greenhouse gas reduction targets, requires state agencies take climate change into account in their planning and investment decisions. In addition, California’s Sustainable Groundwater Management Act (SGMA), passed by the legislature in 2014, requires that Groundwater Sustainability Agencies (GSAs) explicitly assess the impacts of climate change and incorporate these assessments into their Groundwater Sustainability Plans (GSPs). Under the legislation, GSAs must develop and implement GSPs to achieve sustainable groundwater management in all high- and medium-priority groundwater basins in the state. Within these plans, GSAs are required to provide “[p]rojected water budget information for population, population growth, climate change, and sea level rise” (CWR 354.18(d)(3)). Additionally, projected water budgets must “identify the uncertainties of these projected water budget components,” including uncertainties in projected hydrology, water demand, and surface water supply resulting from sea level rise, land use changes, population growth, and climate change (CWR 354.18(c)(3)). To meet these regulatory requirements, plans must “rely on the best available information and best available science to quantify the water budget for the basin” (CWR 354.18(e)). Yet, it can be difficult to identify the best approach to incorporating climate change into local plans. The purpose of this white paper is to assist in that challenging task. The consequences of not incorporating climate change into water planning can be severe, leading to unforeseen costs and even threatening lives. It is therefore the intention of this white paper to: • provide water managers and other decision-makers across the state with an overview of climate models, their component parts, and key terminology • provide a framework for evaluating and comparing the various approaches currently employed by the state and federal agencies to incorporating climate change into state-level water planning documents • recommend a four-step process to incorporate future climate projections into local GSPs Recognizing the importance of climate change impacts on the state’s water supply, the California Department of Water Resources (DWR) has devoted a significant amount of time and expertise to integrating climate change into water planning. In 2012, DWR convened the Climate Change Technical Advisory Group (DWR CCTAG) to advise DWR on the scientific aspects of climate change, the impact of climate change on water resources, the use and creation of planning approaches and analytical tools, and the development of adaptation responses. The DWR CCTAG released a report in 2015, Perspectives and Guidance for Climate Change Analysis, which makes several recommendations for future work. One central theme is the need to develop guidance and support for water managers and planners. Factoring climate change into water management decisions requires future projections of how climate change will impact water-relevant factors such as temperature and precipitation—projections that are generally derived from global climate models. However, incorporating climate change into water planning for any given community or groundwater basin can be difficult, not only because of the technical expertise required to do so, but also because the effects of climate change are spatially and temporally variable. Although the scientific community has high confidence in a key set of variables for the planet as a whole, translating global estimates of climate change to specific geographical areas creates uncertainty. Fortunately, there are tools and methods to address uncertainty. As is the case for other natural phenomena that are difficult to predict with precision, such as earthquakes, uncertainty cannot be an excuse for inaction. Scientific and technical tools can substantially assist in creating plans that cope with an uncertain future. This white paper does not directly address the role of hydrologic models themselves, but rather addresses how climate change information can be incorporated into hydrologic models as water managers seek to comply with the requirements of SGMA. The process of incorporating climate change into water management decisions has several steps, starting with running global climate models to produce future climate projections, which are then used as inputs to hydrologic models (Figure 1). We recognize that GSAs are likely to engage at different levels of technical sophistication with climate data and that the majority will seek out the services of technical experts. Ultimately, it is our intent that this white paper equip water managers with sufficient knowledge about climate change projections to understand, evaluate, and direct the work of the technical experts and consultants. Using appropriate climate change information is vital to ensuring that water managers capture potential future water resource conditions. This white paper is organized into three main sections. The first section provides a general overview of climate models, including their strengths and limitations and the type of information they can provide, and describes a framework for incorporating their output into management decisions. The second section addresses how to incorporate climate change into planning involving imported water supplies. The third section turns to planning for local water supplies and proposes a process for incorporating appropriate climate change data into GSPs.

Navigating Groundwater-Surface Water Interactions under the Sustainable Groundwater Management Act

Center for Law, Energy, and the Environment (CLEE) | March 28th, 2018

California’s Sustainable Groundwater Management Act (SGMA), passed in 2014, recognizes and addresses connections between surface water and groundwater. The st

California’s Sustainable Groundwater Management Act (SGMA), passed in 2014, recognizes and addresses connections between surface water and groundwater. The statute is California’s first statewide law to explicitly reflect the fact that surface water and groundwater are frequently interconnected and that groundwater management can impact groundwater-dependent ecosystems, surface water flows, and the beneficial uses of those flows. As such, SGMA partially remedies the historically problematic practice of treating groundwater and surface water as legally distinct resources. SGMA requires groundwater sustainability agencies (GSAs) to manage groundwater to avoid six undesirable results, including significant and unreasonable adverse impacts on beneficial uses of surface water. While this aspect of SGMA is clearly important, significant uncertainties exist regarding how GSAs will actually define and achieve this goal. Addressing SGMA’s requirements for groundwater-surface water interactions will be difficult. Defining the issues at stake in any given basin, let alone successfully balancing the range of uncertainties and potentially conficting interests, will pose challenges for many GSAs. No clear, pre-defned formula exists to guide GSAs in determining what significant and unreasonable depletions of interconnected surface water will be, or whether planned actions will sufficiently avoid them. Yet they are required to do so. Many GSAs will face pressure to aggressively address impacts on surface water in their basin. Many will face equal or greater pressure not to draw the line. Nevertheless, it will fall to the GSAs to make a determination, and to defend it in their groundwater sustainability plans (GSPs). Therefore, GSAs will likely take on some level of risk—of successful political opposition to their GSP, of successful legal challenges to their GSP, of their GSP performing ineffectively, or of all of these outcomes. Given the aggressive timeline inherent to SGMA, addressing this risk early will be crucial for preserving management options. Challenges and risk are not the whole story, however. The process of addressing groundwater-surface water interactions also ofders GSAs an opportunity to help communities and other stakeholders resolve, or avoid, difficult conflicts, and to do so in lasting ways. While California law has only recently begun to seriously address conflicts between surface and groundwater uses, those conflicts have been occurring for decades, and in some places for over a century. SGMA, in other words, did not create conflict between groundwater pumping and beneficial uses of surface water; instead it created an opportunity—as well as an obligation—to respond to those challenges. Embracing that opportunity will not be easy, but GSAs that take SGMA as an opportunity to resolve longstanding issues can do lasting good. The research presented here examines some of the legal and institutional questions that will inevitably arise as GSAs seek to address groundwater-surface water interactions under SGMA. The core goal of this report is to help parties identify and address these questions, and ultimately to let GSAs and stakeholders manage groundwater-surface water interactions proactively and effectively.

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.