Through the provision of drinking and agricultural irrigation water, groundwater resources fundamentally underpin the existence of modern human society across large regions of the world. Despite this, decades of unsustainable exploitation have led to acute degradation of groundwater quantity and quality, creating pressing challenges that society must address if we are to maintain viable access to this crucial resource for future generations. Taking stock of the current situation, in this contribution we begin by reviewing some of the major global groundwater resource pressures, before exploring a range of technological, engineering, societal and nature-based solutions to address these challenges. We look at examples of emerging groundwater resource threats and potential innovative solutions to tackle them, before concluding with a forward look at future research opportunities that can ultimately enhance our management of this vital resource.

Water recreation is valuable to people, and its value can be affected by changes in water quality. This paper presents the results of a revealed preference survey to elicit coastal New England, USA, residents’ values for water recreation and water quality. We combined the survey responses with a comprehensive data set of coastal attributes, including in-water and remotely sensed water quality metrics. Using a travel cost model framework, we found water clarity and the bacterial conditions of coastal waters to be practical water quality inputs to economic analysis, available at appropriate scales, and meaningful to people and their behavior. Changes in clarity and bacterial conditions affected trip values, with a $4.5 change for a meter in clarity in Secchi depth and $0.08 for a one-unit bacteria change in colony-forming units per 100 ml. We demonstrate the large potential value of improving water quality through welfare analysis scenarios for Narragansett Bay, Rhode Island, and Cape Cod, Massachusetts, USA. The paper discusses lessons for improving the policy relevance and applicability of water quality valuation studies through improved water quality data collection, combined with the application of scalable analysis tools for valuation.

We investigate the effect of water quality on the educational outcomes of children aged 8–11 in 39 districts in five states in the Ganges Basin of India. Using data from the Centre for Pollution Control Board of India and the Indian Human Development Survey (IHDS) 2011–12, we study the effect of water quality in the Ganges Basin on the performance in three test scores. Our evidence suggests that faecal coliform levels in water sources above safety thresholds negatively affect reading and writing test scores. The effects of Nitrate-N and Nitrite-N in the water appear to be weaker compared to those of faecal coliform. The results establish that water pollution caused by excessive presence of faecal coliform is an important environmental factor in determining educational outcomes of children. High levels of faecal coliform in the water could be lowering cognitive abilities of the pollution-affected children through the channel of waterborne diseases.

Anthropogenic nutrient loading from land use, especially agriculture, is a major threat to waterbodies worldwide. Efforts to govern nutrient pollution are increasingly based on simulation modeling for research, evaluation, and regulation. This study develops a novel approach to simulate nutrient losses from agriculture applied to the Lake Champlain basin in the US state of Vermont. The Vermont Phosphorus-Index—a farm-based empirical model regularly used for site evaluation—is scaled up to the basin level with high-resolution geographic data and probabilistic estimation of unknown parameters and management practices. Results are comparable with analyses using more data and computationally intensive tools. Important insights into basin-wide management include: (1) nutrient-management planning can significantly reduce P losses in a livestock-agriculture-dominated watershed by re-distributing manure applications from areas of high loss to low loss; (2) hotspot identification from geographic data alone may be deeply complicated by high underlying heterogeneity of soil phosphorus; and (3) probabilistic modeling using simple, field-scale models is a potentially useful complement to complex watershed process models. Findings suggest that currently available best-management practices will likely be insufficient to reach reduction targets in the most impaired sub-watersheds. Reductions of agricultural land use and herd size, particularly in intensive dairy operations, may be necessary.

We develop a theoretical framework and present a corresponding empirical analysis of the Food and Drug Administration’s irrigation water quality regulatory standard under the Food Safety Modernization Act using lettuce as a case study. We develop a stochastic price endogenous partial equilibrium model with recourse to examine the standard’s efficacy under various scenarios of foodborne illness severity, standard implementation, demand response to foodborne outbreaks, and irrigation costs. The stringency of regulation is evaluated with endogenous producer response to regulatory requirements and corresponding implications for economic surplus. The baseline results show that in the case of the lettuce market, the proposed microbial irrigation water quality regulation in the Food Safety Modernization Act (FSMA) is not cost effective relative to the existing Leafy-Greens Marketing Agreements relying on water treatment for mitigation of microbial contamination. However, FSMA can be cost effective if water treatment is sufficiently expensive.

Governments need tools to analyze trade-offs for freshwater policy, yet valuation estimates from the literature can be difficult to deploy in a policy setting. Obstacles to benefit transfer include (i) difficulties in scaling up local estimates, (ii) water quality attributes that cannot be linked to policy, and (iii) surveys positing large, unrealistic water quality changes. Focusing on freshwater rivers and streams in New Zealand, we develop and implement a nationwide discrete choice stated preference study aimed at future benefit transfer. The stated provision mechanism and environmental commodity being valued are specified at the regional council level, which is the administrative unit for policy implementation. The survey is administered on a national scale with three attributes – nutrients, water clarity, and E. coli levels – which were chosen to align with government policy levers and salience to the public. Estimation results demonstrate positive and significant willingness to pay values for improvements in each attribute, with magnitudes that are comparable to a recent referendum vote on a water quality tax. To illustrate the utility of our study, we apply the results to a recent policy analyzed by New Zealand’s Ministry for the Environment and estimate nationwide annual benefits of NZ $115 million ($77 million USD).

Protected areas (PAs) represent a powerful refuge for maintaining and safeguarding biodiversity. Generally, PAs are delineated to protect terrestrial taxa, providing incidental protection to the aquatic ecosystems within their borders. Here, we compare water quality within PAs and non-PAs in southern Brazil, encompassing remnants of the Atlantic Forest biome, to assess whether PAs serve as a buffer from external pressures for aquatic ecosystems within their boundaries. In addition to physicochemical and microbiological water parameters, we analysed 147 pesticide and 31 pharmaceutical compounds in water samples from 33 sites within and outside PAs. The water quality did not differ between PAs and non-PAs but indicated clear pollution from sewage discharges. We found 19 pesticides and five pharmaceuticals in streams within the study area. We detected pesticides in all sampling sites, with the herbicide 2,4-dichlorophenoxyacetic acid present in 91% of them. Our data show that PAs are insufficient means to mitigate the impacts stemming from their catchments, and the running water that reaches their domains already shows signs of anthropogenic interference, which may affect aquatic biodiversity. Protection and management measures require consideration of the whole watershed to protect freshwater habitats and biota.

This paper analyzes public willingness to support farmer adoption of best management practices in Oklahoma’s Fort Cobb Watershed, a multiuse area for agriculture, residential water provision, and recreation. The study uses Oklahoma’s Meso-Scale Integrated Sociogeographic Network survey to conduct a contingent valuation analysis of a hypothetical, one-time tax that would support farmer adoption of pasture and riparian buffer management practices. Respondent heterogeneity is modeled using beta-binomial regression. Public support for the hypothetical program is stronger for the tandem implementation of riparian buffer establishment and pasture expansion (willingness to pay [WTP] = $290) and riparian buffer establishment (WTP = $317).

Due to COVID-19, many households faced hardships in the spring of 2020 – unemployment, an uncertain economic future, forced separation, and more. At the same time, the number of people who participated in outdoor recreation in many areas increased, as it was one of the few activities still permitted. How these experiences affect the public’s willingness to pay (WTP) for environmental public goods is unknown. During the early months of the pandemic, we conducted a stated preference survey to value statewide water quality improvements in Delaware. While a majority of participants report experiencing hardship of some sort (economic, emotional, etc.), mean household WTP declined by only 7 % by May 2020.