Groundwater Users Research Articles

Assessing the sustainability of permitted irrigation from groundwater in the Grootfontein-Tsumeb-Otavi Subterranean Water Control Area in Namibia

The sustainable use of groundwater from karst aquifers is key for sustainable development in the Grootfontein-Tsumeb-Otavi Subterranean Water Control Area (GTO-WCA) in Namibia. The ever-increasing demand for groundwater for irrigation purposes in the GTO-WCA and for argumentation purposes to the Central Area of Namibia has put the aquifer under pressure. Proper groundwater management is therefore required to protect this finite resource. This study assessed the sustainability of groundwater use in the GTO-WCA by assessing the behaviour of groundwater users in the GTO-WCA and by assessing the current legislation and regulatory mechanisms followed by authorities in their allocation of groundwater to the users. The results indicate that groundwater use for irrigation has increased above the sustainable safe yield for the aquifers in this area. The paper elaborates on reasons for the current state of affairs and proposes specific management solutions.

Why is state‐centered groundwater governance largely ineffective? A review

AbstractFaced with severe groundwater depletion, many governments have opted to increase the power of the state. Despite calls for more inclusive governance and a role for groundwater users, modes of governance have tended to continue to rely on a diversity of policy tools and state‐run strategies in the attempt to control groundwater (over)abstraction. Yet, around the world, the performance of state‐centered governance has remained dismal. Beyond common difficulties in terms of data and financial or human resources, this article analyzes in greater depth the limited effectiveness of state groundwater policies that has been observed, emphasizing its political ramifications. The various aspects of weak monitoring and enforcement, as well as of the infamous “lack of political will,” are considered from the perspective of the political economy of groundwater economies. Cases of relative success are then used to identify favorable drivers and contexts for effective state‐centered groundwater governance.This article is categorized under: Human Water > Water Governance Engineering Water > Planning Water

Groundwater governance and implementing the conservation policy: the case study of Rafsanjan Plain in Iran

The groundwater system in the Rafsanjan aquifer perpetuated sustainably for decades before 1950s; however, its groundwater resources have been overexploited in the recent decades. In this paper, we aim to investigate the water governance system to understand the reasons behind the ongoing overexploitation. Sustainability processes are considered a policy implementation problematic. As such, we employ the contextual interaction theory as a policy implementation framework to assess the groundwater governance as part of the context for the conservation policy. Data for this qualitative research were gathered from legal texts, articles, technical reports, and multiple interviews with authorities and groundwater users. The assessment results revealed that the poor quality of the governance system is central to the ineffectiveness of the conservation policies. Findings of this paper can be relied on to devise tools to underpin an appropriate context to sustain groundwater resources.

Organic micropollutants in groundwater of India-A review.

Groundwater pollution due to organic micropollutants is a major cause of concern, especially in parts of the world where available water resources are on the decline. India is the largest user of groundwater where the presence of micropollutants in the subsurface environment has been the focus of many researchers. The objective of this study was to provide a detailed review of studies on micropollutants in Indian groundwater and to provide strategies for further work. It is found that the presence of pharmaceuticals, endocrine disrupting compounds, surfactants, phthalates, per- and poly-fluoroalkyl substances, personal care products, artificial sweeteners, and pesticides in groundwater from different parts of India is reported. Pesticides and phthalate concentrations reported exceed the standard guideline values. This review points out the regions where the groundwater is prone to contamination due to micropollutants. An assessment of temporal variation in the concentration of micropollutants in groundwater has been done only by a few researchers. This study highlighted the need for more research on the possible presence of micropollutants in groundwater, especially in the major polluted rivers in cities where more pharmaceuticals, pesticides, and plastic industries are located. PRACTITIONER POINTS: Organic micropollutants were not new contaminants into the environment but the one entered even decades ago which has threatening effect. The number of studies on organic micropollutants in groundwater is lesser than surface water or wastewater. Scarcity on the studies of micropollutants was a result of definite technical lack in its analysis and complexity in sample preparation. Most of the studies done were related to contamination sites and point sources.

Water resource assessment, gaps, and constraints of vegetable production in Robit and Dangishta watersheds, Upper Blue Nile Basin, Ethiopia

The vast majority of farmers in sub-Saharan Africa depend on rainfed agriculture for food production and livelihood. Various factors including but not limited to rainfall variability, land degradation, and low soil fertility constrain agricultural productivity in the region. The objectives of this study were to 1) estimate the water resources potential to sustain small-scale irrigation (SSI) in Ethiopia during the dry season so as to expand food supply by growing vegetables, and 2) understand the gaps and constraints of vegetable production. The case studies were conducted in the Robit and Dangishta watersheds of the Upper Blue Nile Basin, Ethiopia. To document farmers’ cropping practices, field-level data were collected from 36 households who had been cultivating tomato (Solanum lycopersicum L.) and onion (Allium cepa L.) during the dry season (November – April). Two components of the Integrated Decision Support System (IDSS) - the Soil and Water Assessment Tool (SWAT) and Agricultural Policy Environmental eXtender (APEX) – were respectively used to assess impacts of SSI at the watershed and field-scale levels. Results suggest that there is a substantial amount of surface runoff and shallow groundwater recharge at the watershed scale. The field-scale analysis in the Robit watershed indicated that optimal tomato yield could be obtained with 500 mm of water and 200 to 250 kg/ha of urea applied with 50 kg/ha of diammonium phosphate (DAP). In Dangishta, optimum onion yield can be obtained with 400 mm of water and 120 to 180 kg/ha of urea applied with 50 kg/ha of DAP. The field-scale simulation indicated that the average shallow groundwater recharge (after accounting for other groundwater users such as household and livestock use) was not sufficient to meet tomato and onion water demand in the dry season (October to April). The field-scale analysis also indicated that soil evaporation attributed a significant proportion of evapotranspiration (60% for onion and 40% for tomato). Use of mulching or other soil and water conservation interventions could optimize irrigation water for vegetable production by reducing soil evaporation and thereby increasing water availability in the crop root zone.

Groundwater management institutions in the face of rapid urbanization – Results of a framed field experiment in Bengaluru, India

Many aquifers in semi-arid and arid regions with rapid urbanization are over-exploited or even at the point of depletion. Driven by the increased demand for food and other agricultural products, irrigated agriculture constitutes the biggest user of groundwater, and has thus contributed to this critical situation. In this paper, we compare different designs of groundwater management institutions in order to avoid aquifer over-exploitation and ensure secure water sources. We assess externally imposed reward-based and punishment rules as well as communication on their effectiveness to reduce water extraction behavior of groundwater users. Moreover, we evaluate how different user types affect the outcome of these institutional designs. To do so, we conducted a framed field experiment with 600 households along the rural-urban interface of the fast growing city of Bengaluru, India. Results indicate that all treatments can prolong the life of the resource but reward-based and punishment rules seem to be more effective than communication. Moreover, we find that user type behavior identified in the baseline trial is persistent in the treatment trial despite interventions.

Prediction of tunnelling impact on flow rates of adjacent extraction water wells

The decline or drying up of groundwater sources near a tunnel route is damaging to groundwater users. Therefore, forecasting the impact of a tunnel on nearby groundwater sources is a challenging task in tunnel design. In this study, numerical and analytical approaches were applied to the Qomroud water conveyance tunnel (located in Lorestan province, Iran) to assess the impact of tunnelling on the nearby extraction water wells. Using simulation of groundwater-level fluctuation owing to tunnelling, the drawdown at the well locations was determined. From the drawdowns and using Dupuit's equation, the depletion of well flow rates after tunnelling was estimated. To evaluate the results, observed well flow rates before and after tunnelling were compared with the predicted flow rates. The observed and estimated water well flows (before and after tunnelling) showed a regression factor of 0.64, pointing to satisfactory results

Enhancing citizens' sense of personal responsibility and risk perception for promoting public participation in sustainable groundwater resource management in Rayong Groundwater Basin, Thailand

Researching citizens' sense of personal responsibility to engage in groundwater resource management, their perception of risks associated with potential threats to groundwater, their degrees of dependence on groundwater resources, and their socioeconomic characteristics, this study aimed to investigate how these variables predict citizens' engagement in groundwater resource management. Participation was divided into three categories: participation in obtaining groundwater information, in developing groundwater policies and strategies, and in implementing those policies. Thailand’s Rayong Groundwater Basin—which currently faces various threats, such as seawater intrusion, erratic rainfall, and intensive use of groundwater for industrialization—was chosen as a case study. Questionnaire surveys were conducted with the participants who were selected based on a purposive method focusing on groundwater users in five sectors: the business and industrial, agricultural, household, environmental, and public organization sectors. The results of multiple regression analyses revealed that the sense of personal responsibility alone could not highly motivate groundwater users to engage in groundwater policy development and implementation. Perceived risks associated with potential threats to groundwater resources significantly influenced participation in developing and implementing groundwater policies. Users' degree of groundwater dependence also influenced their participation in obtaining information relevant to groundwater and in implementing policies. Males were determined to be more engaged in managing groundwater resources, particularly in obtaining information and implementing policies. This study suggests that a sense of personal responsibility and risk perceptions should be promoted together to enhance people’s motivation and enthusiasm for cooperating with organizations responsible for sustainable groundwater management (GM).

Who will think outside the sink? Farmers’ willingness to invest in technologies for groundwater sustainability in Pakistan

Concerns over depleting aquifers tend to recommend water-saving irrigation technologies as a potential solution. This study examines farmers’ enthusiasm towards one of such technologies in four south-western districts of Pakistan. The required information was obtained through a survey questionnaire administered to a sample of 283 groundwater users, and it was analysed descriptively and via an ordinary least squares regression technique. Results indicate that adopting water-saving technologies is less likely in the absence of incentives such as subsidized system installation, a reliable supplier who can provide warranties on the system’s service and spare parts and training the participating farmers. Besides, promoting such technologies would be relatively easier in the southern region due to those farmers’ relatively greater enthusiasm there compared with their northern counterparts. We conclude that promoting technologies such as drip irrigation may continue, but only as the mandatory initial step of a broad-based strategy aimed at nurturing water conservation values at the societal level. Among various possible interventions, enhancing water literacy is extremely important so that farmers discover and correct wasteful aspects inherent in their current irrigation practices, work through options to minimize those wastages, and develop a sense of water conservation as a collective social responsibility.

Groundwater level changes with a focus on agricultural areas in the Mid-Atlantic region of the United States, 2002–2016

Climate change impacts all water sources, including high quality groundwater that supplies agricultural irrigation in many regions of the United States. This study assessed groundwater level changes in the U.S. Mid-Atlantic region with a focus on cultivated areas. Trends of groundwater level were estimated using linear regression, and examined for shallow, medium, and deep depths across physiographic regions of Mid-Atlantic. A hotspot analysis was conducted to identify spatial clusters of wells with rising or declining groundwater levels. In addition, differences in the percentage of cultivated area with declining groundwater between cultivated land categories was examined at the county level. From 2002–2016, the Mid-Atlantic region had an overall decline in groundwater level (0.06 m/yr, 95% CI: 0.03, 0.09) although groundwater changes varied by physiographic regions. The Coastal Plain physiographic region was dominated by declining groundwater wells (48%) and had the most significant groundwater level declines (0.23 m/yr, 95% CI: 0.19, 0.26). Significant groundwater level rises were detected in Southern Virginia adjacent to the Chesapeake Bay (0.92 m/yr on average), which could be due to the cessation of groundwater withdrawal from one of the region's largest groundwater users. In the Mid-Atlantic region, shallow groundwater was found to have slight rising trends (0.08 m, p < 0.05) while deeper groundwater showed distinctive declining trends (1.36 m, p < 0.05) between 2002 and 2016. There were significantly more cultivated areas with declining groundwater levels (88% vs. 35%, p < 0.05) in counties with high percentages of cropland (> 50%) compared to areas covered by less cropland. As climate and human pressures increase, it will be critical to identify and evaluate alternative water sources, such as reclaimed water, to sustain agricultural production and protect groundwater resources.

Determination of groundwater sustainable yield using a numerical modelling approach for the Table Mountain Group sandstone aquifer, Rawsonville, South Africa

Sustainable yield is defined as the amount of groundwater abstraction that can be maintained for an indefinite time without causing unacceptable environmental, economic and social consequences. It is usually determined by monitoring the water-table depth, without the need for costly pumping exercises and subsequent deterioration of the groundwater and ecological environment. Groundwater numerical modelling provides an effective way to determine the yield by analysing the responding water levels to various pumping scenarios. In this study, the natural flow system and flow with pumping scenarios were simulated using FEFLOW for the fractured-rock aquifer in Table Mountain Group, South Africa. Results for different pumping rates show the distinct impact of groundwater abstraction on hydraulic head, which indicates that long-term abstraction slowly increases the well drawdown, but it would stabilize at a level that is dependent on pumping rate and induced recharge. To estimate the aquifer sustainable yield, a relationship between simulated drawdown and pumping rate was established, namely an exponential function with parameters that may change value between sites. This empirical relation, derived from this site-specific study, provides an option for informed decision-making. The issue of how to sustainably abstract groundwater might rely on a compromise between the groundwater user and the governmental authority.

Spatial Groundwater Management: A Dynamic Game Framework and Application to California

The design of policies and institutions to promote the sustainable management of groundwater resources for use in agriculture is both a long-term and short-term challenge in California and globally. When designing groundwater management policies, it is important to account for spatial externalities that may lead groundwater users to behave non-cooperatively. Spatial externalities arise because groundwater users face a common pool resource problem: because farmers are sharing the aquifer with other farmers, other farmers’ pumping affects their extraction cost and the amount of water they have available to pump. In this paper, we present a dynamic game framework for analyzing spatial groundwater management. In particular, we characterize the Markov perfect equilibrium resulting from non-cooperative behavior, and compare it with the socially optimal coordinated solution. In order to analyze the benefits from internalizing spatial externalities in California, we calibrate our dynamic game framework to California, and conduct a numerical analysis to calculate the deadweight loss arising from non-cooperative behavior. Results show that the inefficiencies arising from spatial externalities are driven by higher returns on crops, electricity input prices, whether the crop is an annual crop versus a perennial, the level of the groundwater stock, the climate of the region, and the adjustment costs of fallowing production. We find that the benefits from coordinated management in California are particularly high when crop prices are high.

Groundwater Depletion and Associated CO2 Emissions in India

AbstractIndia, the world's largest groundwater user, withdraws about 230‐billion‐m3 groundwater annually for irrigation. Excessive groundwater pumping in India leads to rapid groundwater depletion and CO2 emissions. Here using multiple data sources (observation wells and Gravity Recovery Climate Experiment) to estimate groundwater depletion in India, as well as the associated chemistry and the pumping energy requirements, we provide the first estimate of the potential CO2 emissions due to bicarbonate extraction (CO2 release due to lowering of groundwater table) and groundwater pumping. We show that combined annual CO2 release due to bicarbonate extraction and pumping in India is approximately 32.01–131.74 million tons (31.29–131.02 million tons for pumping and 0.72 million tons for bicarbonate). The total estimated groundwater depletion in India is in the range of 122 to 199 billion m3 from the observation wells (1996–2016) and Gravity Recovery Climate Experiment (2002–2016). The CO2 emissions due to bicarbonate (~0.72 million tons/year) are dominated by those due to groundwater pumping (31.29–131.02 million tons/year) in India. However, the total (pumping and bicarbonate) estimated annual CO2 emission from groundwater is less than 2–7% of the total (annual) CO2 emission from India. Based on our unique data set collected from more than 500 farmers in Punjab, we show that a low‐cost intervention for irrigation scheduling based on soil moisture information can provide a sustainable solution by reducing groundwater pumping and CO2 emissions. The environmental problem of groundwater depletion in India is much more serious than the associated CO2 emissions, and hence, there is an urgent need for a regulation of groundwater use.

Competition for shrinking window of low salinity groundwater

Groundwater resources are being stressed from the top down and bottom up. Declining water tables and near-surface contamination are driving groundwater users to construct deeper wells in many US aquifer systems. This has been a successful short-term mitigation measure where deep groundwater is fresh and free of contaminants. Nevertheless, vertical salinity profiles are not well-constrained at continental-scales. In many regions, oil and gas activities use pore spaces for energy production and waste disposal. Here we quantify depths that aquifer systems transition from fresh-to-brackish and where oil and gas activities are widespread in sedimentary basins across the United States. Fresh-brackish transitions occur at relatively shallow depths of just a few hundred meters, particularly in eastern US basins. We conclude that fresh groundwater is less abundant in several key US basins than previously thought; therefore drilling deeper wells to access fresh groundwater resources is not feasible extensively across the continent. Our findings illustrate that groundwater stores are being depleted not only by excessive withdrawals, but due to injection, and potentially contamination, from the oil and gas industry in areas of deep fresh and brackish groundwater.

Protecting groundwater levels and ecosystems with simple management approaches

Groundwater quantity is often managed using simple tools. The most common are (1) basin or sub-basin scale volumetric allocations, usually based on either historic use or estimates of recharge, (2) trigger-level management which regulates use according to observations of groundwater level, and (3) buffer zones, which control the location of wells, particularly around groundwater-dependent ecosystems (GDEs). The volumetric approach limits the long-term impact of abstraction and provides a stable, secure supply for groundwater users. However, this approach does not consider the spatial distribution of recharge and discharge, and so is poor at protecting GDEs. Buffer zones provide an effective means of limiting the short-term impact of abstraction on GDEs, and can also be used to shift impact from high to low priority GDEs. However, buffer zones mostly delay the impacts of abstraction on groundwater level and flow, and are less effective for managing long-term impacts. Groundwater response triggers aim to directly control groundwater levels, although the success of this approach is highly dependent on the location of the observation well, and the trigger value. This makes its successful implementation extremely difficult. Used alone, none of these approaches will successfully protect the environment. In combination, they can provide reasonable protection for ecosystems and reliability of groundwater supply for users.

Comparing Alternative Policies for Modification of Energy Subsidies: The Case of Groundwater Pumping for Irrigation

The present paper studies the effects of alternative modifications of a subsidy for electricity used to pump groundwater on the behavior of profit maximizing groundwater users. It proposes a stylized model for groundwater extraction, and then numerically derives general results by simulation. The model is applied to aquifers in Leon, Guanajuato, Mexico and Kern County, California. The performance of two traditional policy intervention measures—subsidy elimination and reduction—are compared to a new, innovative modification policy, namely, decoupling the subsidy from the electricity bill; this policy is arguably more politically acceptable. The results of extensive simulations suggest that the rate of aquifer water extraction, and the consequent level of water in the aquifer, can be improved significantly by changing the subsidy structure.

English

This article examines conflicts and or disputes attributed to ineffectiveness of groundwater governance. The study adopted sequential exploratory research design. A random sample of 90 water users was involved in the survey. The key informants and focus group discussions were used to collect qualitative data. Content analysis was used to analyze qualitative data. Frequency and percentage distribution of the responses were computed by using Statistical Package for the Social Sciences (SPSS). The results show that 43 (47.7%) of the sample experienced groundwater disputes, between and or among water users themselves, or between groundwater governance structures, at least in the previous five years since 2013. This is attributed to poor governance and failure of the actors in abiding to the guidelines of the Water Resource Management Acts of 2009 (WRMA), particularly lack of transparency, destruction of water pumps and unequal distribution of water among groundwater users. Some disputes were resolved successfully at water users&rsquo; level, while those occurred between governance structures were difficult to resolve. The article concludes that there was poor groundwater governance and therefore disputes occurred. The disputes could develop into conflicts if continue unabated. Therefore, the article recommends strengthening of groundwater governance in abiding to the Acts. It also recommends a comprehensive governance structural arrangement, formal and informal institutions to enhance groundwater governance, specifically resolving groundwater disputes to avoid conflicts in future.&nbsp;&nbsp;&nbsp; &nbsp; Key words: Groundwater, disputes, conflicts, governance, structures, Tanzania.

Groundwater use and diarrhoea in urban Nepal: novel application of a geostatistical interpolation technique linking environmental and epidemiologic survey data.

BackgroundGroundwater is a common domestic water source in developing countries, but is persistently contaminated with enteropathogens. However, studies on determinants of diarrhoea have predominantly focused on piped water. This study examines the relationship between groundwater microbial quality and household diarrhoea occurrence (HDO).MethodsConsidering it as a proxy of enteropathogens, this study analysed Escherichia coli concentrations in groundwater wells. Ordinary kriging, a geostatistical technique in geographic information systems, was used to interpolate the E. coli concentration to survey points that had secondary survey data (n=942). The relationship between E. coli and HDO using simple and multivariate statistical analyses in SPSS was analysed.ResultsA total of 77% of households used groundwater. One-third of households were without piped-water access (PWA), and these households were significantly more likely to use groundwater than those with PWA. Of the 87 households that reported HDO, 77% were groundwater users. Of the groundwater users, the households with HDO consumed groundwater with significantly higher E. coli concentrations than the households without HDO. Of the households without PWA, the increase in the E. coli concentration increased the odds of HDO (adjusted odds ratio=3.15; 95% CI=1.07–9.22).ConclusionIt is suggested that the groundwater microbial quality is a risk factor for HDO and illustrates this by an application of an interpolation technique relevant for developing countries.

Effectiveness of groundwater governance structures and institutions in Tanzania

This paper examines effectiveness of groundwater governance structures and institutions in Mbarali District, Mbeya Region. The paper adopts exploratory sequential research design to collect quantitative and qualitative data. A random sample of 90 groundwater users with 50% women was involved in the survey. Descriptive statistics, Kruskal–Wallis H test and Mann–Whitney U test were used to compare the differences in responses between groups, while qualitative data were subjected to content analysis. The results show that the Village Councils and Community Water Supply Organizations (COWSOs) were effective in governing groundwater. The results also show statistical significant difference on the overall extent of effectiveness of the Village Councils in governing groundwater between villages (P = 0.0001), yet there was no significant difference (P > 0.05) between male and female responses on the effectiveness of Village Councils, village water committees and COWSOs. The Mann–Whitney U test showed statistical significant difference between male and female responses on effectiveness of formal and informal institutions (P = 0.0001), such that informal institutions were effective relative to formal institutions. The Kruskal–Wallis H test also showed statistical significant difference (P ≤ 0.05) on the extent of effectiveness of formal institutions, norms and values between low, medium and high categories. The paper concludes that COWSOs were more effective in governing groundwater than other groundwater governance structures. Similarly, norms and values were more effective than formal institutions. The paper recommends sensitization and awareness creation on formal institutions so that they can influence water users’ behaviour to govern groundwater.

Chronic groundwater decline: A multi-decadal analysis of groundwater trends under extreme climate cycles

Chronic groundwater decline is a concern in many of the world’s major agricultural areas. However, a general lack of accurate long-term in situ measurement of groundwater depth and analysis of trends prevents understanding of the dynamics of these systems at landscape scales. This is particularly worrying in the context of future climate uncertainties. This study examines long‐term groundwater responses to climate variability in a major agricultural production landscape in southern Queensland, Australia. Based on records for 381 groundwater bores, we used a modified Mann-Kendall non-parametric test and Sen’s slope estimator to determine groundwater trends across a 26-year period (1989–2015) and in distinct wet and dry climatic phases. Comparison of trends between climatic phases showed groundwater level recovery during wet phases was insufficient to offset the decline in groundwater level from the previous dry phase. Across the entire 26-year sampling period, groundwater bore levels (all bores) showed an overall significant declining trend (p < 0.05) of an average 0.06 m year−1. Fifty-one bores (20%) exhibited significant declining groundwater levels (p < 0.05), 25 bores (10%) exhibited significant rising groundwater levels (p < 0.05), and 175 bores (70%) exhibited no significant change in groundwater levels (p > 0.05). Spatially, both declining and rising bores were highly clustered. We conclude that over 1989–2015 there is a significant net decline in groundwater levels driven by a smaller subset of highly responsive bores in high irrigation areas within the catchment. Despite a number of targeted policy interventions, chronic groundwater decline remains evident in the catchment. We argue that this is likely to continue and to occur more widely under potential climate change and that policy makers, groundwater users and managers need to engage in planning to ensure the sustainability of this vital resource.