Hypothetical Urban Aquifer Depletion Report Prepared for the United States Environmental Protection Agency
Jennifer Haus, Department of Global Health
Elizabeth Ziegler, Department of Animal Science
The United States Environmental Protection Agency is investigating the potential future impacts of aquifer depletion and ground water depletion nationally at the environmental and human health levels. We are taking a proactive stance to this issue as EPA environmental analysts and investigating solutions to the problem of aquifer and ground water depletion and steps that the world can take in order to prevent a complete depletion from happening. The agency is also searching for ways to mitigate those impacts through investigation of the uses of land that cause the most intense depletion and encouraging adoption of more sustainable practices for land used in those ways and in some cases the changes in land use style. The way that water rights will be awarded nationally in the present day and into the future is also a matter of concern for the agency, and they are looking for guidance on how those rights should be awarded in terms of the sustainability of groundwater resources. This analysis seeks to provide that guidance through an investigation into the environmental, human health, and economic impacts of aquifer depletion on the major stakeholders at play in water rights contentions. These stakeholders and impacts were determined based upon a literature review completed by the authors that sought to examine each part of this system and how it interacts with other areas. The report is below and a stakeholder roundtable discussion on March 22nd, 2020 will assist in determining the final water rights award breakdown suggestion that the authors will provide to the EPA. Our goal is to cause a shift in order to lower water usage worldwide by presenting our information and possible solutions at the EPA board meeting.
Aquifer from above. (Source: US Department of Interior)
In this paper, we discuss the negative effects of aquifer depletion and ground water depletion in urban and rural areas, and provide potential solutions to these problems. We focus on the systems large-scale farms, subsistence farms, dryland farming, and organic farming. We focused on the overall consumption of water given regional agricultural intensity and its relation to water resource availability in urban and rural areas between different farming systems. We focus on aquifers in Mexico, the United States, Pakistan, and West Bengal. The most significant aquifer included in this paper is the Ogallala aquifer, which lies in the High Plains Region of the United States, which supports around 30% of the irrigation infrastructure in the United States (USDA, 2011). We also view this issue through the lens of the three pillars of sustainability, which are economic, environmental, and social implications. As for solutions, currently we are sitting in a window of opportunity in which there is potential to mitigate future harms using water conservation methods. At the government level, projects like pumping taxes and other economic drivers of conservation can be employed. Additionally the use of models like InSAR in city planning alongside hydrological knowledge can minimize the infrastructural and social issues that may result in city development. All sectors of society and the government must work together to mitigate consequences.
Access to water is essential to life, however, as sea levels rise and climate change causes greater and greater impacts to the water cycle, that access will become even more limited. Water contained in underground aquifers all over the world is being depleted at unsustainable rates and the issue of water scarcity continues to grow. Agriculture is a huge contributor to water consumption, and an abundance of water is required in order to produce enough to feed the world population. Thus, these water resources and their conservation are intimately connected to agricultural practices and have great influence on human health and well being. Ensuring that these water resources are well managed and preserved into the future is of vital importance.
This study seeks to assess the causes of aquifer depletion and its impact on agricultural system, the local and global economies, and human health. It also seeks to make predictions about the future implications if water consumption proceeds at the rate that it is currently at, assess the impacts of different strategies to mitigate that consumption, and increase conservation of water resources in order to increase the global supply. In doing so, it will aim to make a holistic assessment of the importance of groundwater on the global system and analyze the changes necessary to minimize harm in the future.
- Dryland farming: agriculture that is reliant upon weather and seasonal cycles of precipitation and does not employ irrigation
- Irrigation-based farming: farm systems that consistently use water collected from a source other than the rain and which require energy output to employ
- Subsistence farming: agricultural production done to provide food for the individual or household undertaking production activities
- âWindow of opportunityâ: pertains to the time period in which addressing concerns of future water scarcity and making changes is required before the focus of those changes will shift from mitigation to adaptation
- Complete protein: protein source that provides all of the amino acids necessary for absorption and use in the human body without the requirement of pairing with another protein source
- Developmental stunting: used to denote children'sâ physical and psychological growth impairment as a result of inadequate nutrition prenatally, in infancy, and early childhood (sometimes called the first 1000 days of life)
- Lifetime productivity: the amount of economic output that a person will produce over the course of their entire lifetime. This may be quantified in monetary terms (for example: lifetime earnings including all yearly incomes added together and any other increases in wealth through lotteries, gifts, investment successes, and more) or not (for example: subsistence farming), but the combined economic impact associated with the body of work of a person's life is considered in this definition.
- Food security: defined generally here as holding the status of consistently having enough calories and nutritionally complete food to eat. The inverse of this is food insecurity, which is explained in this video: Food Insecurity Explained
A vast literature search was performed to find articles about groundwater depletion and aquifer depletion. Articles that were reviews were not excluded from the search results, but we also took into consideration articles that included experimental studies. Taking the information and results from: location and/or topic specific case studies, data collected by research and government agencies, and ongoing climate, economic, and agricultural knowledge and research. We synthesized our findings to conduct a systems analysis on groundwater and aquifer depletion in urban and rural areas around the globe.
In order to ensure the soundness of our research and the conclusions drawn from it, there was a focus on peer reviewed evidence that has been written by accredited experts in each field and which has been accessed and cited frequently to ensure that the rationale in that research is regarded as sound by those who are more knowledgeable in those fields.
When using the systems lens we make some key assumptions about how different parts interact based upon observation and previous study. These relationships will be explained and sourced, however, as we make predictions about the future, we make the assumption that these relationships will exist as they do today throughout time, which may not necessarily be the case. An example of this would be that caloric deficit in early childhood can cause developmental stunting, which can decrease lifetime productivity and thus a personâs lifetime earnings, perpetuating the cycle of poverty. Each of these relationships has been studied and proven, however future technological advancements and changes to the global economy could change how these variables interact, invalidating the impact that one might have on the next in that cycle.
Results: Case Study Analysis
Current and Anticipated Regional Depletion Rates
Worldwide, major aquifers are being drawn from more intensively than in the past to support agricultural production and human consumption. There are differences both regionally and in terms of the type of activity supported by each system. Observed are the effects that have been observed across four areas with differing land use types: The United States, Pakistan, and West Bengal and Mexico (combined due to situational similarities).
Case Study: Ogallala Aquifer, Western United States
The Ogallala aquifer, located in the high plains region of the United States, is a major water source for irrigation to support the national food production system (USGCRP, 2018). It provides approximately 82% of the drinking water that is consumed in the region, about 175,000 square miles spanning across eight states (USDA, 2011). The US geological survey(depicted in figure 1) tracks aquifer levels and since the beginning of its use for irrigation there have been significant declines in its volume spanning across its entire area (McGuire, 2017). Currently the rate of recharge is not fast enough to keep up with consumption of the water present and major portions are now listed as non-renewable resources (USGCRP, 2018). Depletion is only expected to worsen in this region as production pressures increase and climate change causes increased irrigation requirements in order to support that production (USGCRP, 2018). The current volume is variable across the area of Ogallala and calculations depend upon measures of saturation and thickness, but the general trend in water level since pre-development has been a decline of 15.8 feet on average across its area, mostly due to agricultural consumption and increased population (Mcguire, 2017).
Land use and Agricultural System Impacts with the Ogallala Aquifer
The Ogallala aquifer currently supports about 22,000 square kilometers of agricultural land that it is projected to be too depleted for support in 2100. Of those 22,000 square kilometers, approximately 13% are likely unsuitable for dryland farming (Deines et al. 2020). This will cause shifts in the way that this land is used, likely towards increased urbanization, but it will certainly decrease the amount of productive agricultural land in the United States, negatively impacting the global food supply as the population grows towards 9 billion. A case study regarding the Toluca Valley in Mexico used InSAR modeling and measurements to provide urban planners with the tools for sustainable development, which is promising in looking towards shifts in land use. However the specific study focus area has yet to show improvements in water conservation even with the use of the tool (Castellazzi, 2017). On-farm irrigation reservoirs are another potential solution to the issue, however they can be expensive and difficult to maintain, and thus are unlikely to be adopted in circumstances that are not dire (Yaeger, 2018).
T he Ogallala aquifer specifically supports about 30% of the irrigation infrastructure in the United States (USDA, 2011). Given projections for depletion onwards until 2100, it is estimated that this resource will not be able to support approximately 22,000 square kilometers of currently irrigated lands in the high plains region (Deines, 2020). Additionally, the beef industry is heavily reliant on water drawn from this aquifer both for feed production and water needs of cattle including drinking water and sanitation to minimize the spread of disease (Guerrero, 2010). Given the prevalence of beef calorically in the American diet and its contribution to nutrition as a source of complete protein, decreased production in this sector has the potential to decrease food security in the United States and world wide (Guerrero, 2010). This would impact the development of children and the health of the entire population, leading to worse health outcomes and the associated social and economic issues (US Global Change Research Program, 2018).
Figure 1: Water Level Changes in the High Plains Aquifer from approximately 1950-2015, collected from McGuire, 2017
Case Study: Indus River System, Pakistan
The Indus River System flows throughout the Middle East and is most heavily drawn from in the country of Pakistan to support its agricultural production in the dry climate of the region. This system contributes extensively to the food security of this region and is also facing increasing rates of depletion (Ahmed et al. 2012). Similarly to the Ogallala situation from above, irrigation is a major consumption source (Ahmed et al. 2012). Additionally, a case study on urban developmental impacts on groundwater depletion conducted in Mardan City, Pakistan found that increasing populations and development were also major sources of depletion (Yar, 2020). In this case, the region heavily relies upon the groundwater system to provide for food production, however urbanization is increasingly having an impact on the consumption from this aquifer and is anticipated to increase the human impact on the region and decrease future resource availability (Yar, 2020).
Many health issues are present in Pakistan due to contaminated or scarce water. Drought is already a prevalent issue in this region, and decreased availability of groundwater has the potential to cripple this agricultural system, diminishing productivity and causing food shortages. This is problematic because of the direct human health implications as discussed in the case of the United States, and also because of the social and political unrest in the region which may be worsened if food security is diminished. Water is already a scarce resource and limited access to this aquifer has the potential to increase rates of violent unrest as it has in Syria for the last ten years (United Nations, 2021) and political hostilities as has been the case for the last 100 years pertaining to the Nile river ( Gebrehiwet, 2020). Both of these negatively impact human health through combatant mortality, further limitations to access, and domination by foreign regimes.
Figure 2: A map from Encyclopedia Britannica (2012) displaying the extent of the Indus River System and the land use types within its bounds, along with the geographical borders and population centers throughout the region.
Case Study: Urban Usage, West Bengal and Mexico City
Kolkata and Salt Lake City in West Bengal are two major urban areas which draw heavily from the aquifer that sits beneath them. Currently, these cities are contributing to decreases of approximately 20 centimeters in water level each year (Bardhan, 2016). Given their spatial and temporal situations, there is an expected extraction increase as urban development leads to their expansion and population pressures combine with the potential for successful subsistence agriculture in the region to increase demand for water (Bardhan, 2016). In observing the current situation in Mexico City, which faces a dual issue of water scarcity and frequent flooding caused by land sinkage due to over extraction from the aquifer beneath the city; there is reason for concern for the security of the infrastructure of these cities as this aquifer faces greater depletion in the future (Castellazzi et al. 2018).
The Ogallala aquifer provides 82% of the water used by humans in the eight US states that it serves and in West Bengal, both of these having a major are reliance on groundwater to sustain their populations. Resource scarcity, in these cases especially, has the potential to increase disease morbidity and mortality among these populations if people are forced to decrease hygiene and sanitation practices to save water, allowing for the build up of harmful bacteria, spread of disease among people, and increased exposure to environmental toxins (ex. Pesticides and herbicides on produce), or turn to non-potable resources like potentially contaminated surface water, increasing the incidence of water borne diseases which can also negatively affect childhood development and morbidity (Pruss, 2002).
Figure 3: A map of the groundwater system of western Bengal and the status of the reserve throughout the area. (Bandyopadhyay, 2014)
Aquifers around the world are all being depleted at rates that are unsustainable to keep up with human consumption and population growth into the future. Though irrigation plays a significant role in the consumption of water resources, urban development also places aquifers under stress and depending upon future depletion may lead to human health issues down the road. Those human health issues are spurred on by environmental costs associated with water scarcity as well as diminished production capacities and decreased sanitation. All of these things have negative environmental costs.
Currently we are sitting in a window of opportunity in which there is potential to mitigate future harms using water conservation methods. At the government level, projects like pumping taxes and other economic drivers of conservation can be employed. Additionally the use of models like InSAR in city planning alongside hydrological knowledge can minimize the infrastructural and social issues that may result in city development. All sectors of society and the government must work together to mitigate consequences.
Water resource availability contributes to human health in two major ways: food security and water borne diseases (CDC, 2020). Aquifer depletion has the greatest impact on resources available for irrigation and food production, and thus in terms of human health, it is mostly connected to food security. The agricultural systems of the United States and Pakistan are heavily reliant on Ogallala and the Indus River System, and if depletion progresses as it is currently, there is the potential for extreme changes in these agricultural systems and how land is allocated in these nations and surrounding regions. Pertaining to urban areas, the major issue at play is water safety. Thanks in large part to public health and infrastructural advancements in the last century, the prevalence of water borne diseases in urban areas has decreased significantly, (Esrey et al. 1991) however, the scarcity of clean and drinkable water has the potential to unravel all of that. It is often assumed that should groundwater resources become depleted, there will be a shift to dryland crop production. (Deines et. al, 2020). Because of climatic impacts on the weather system and global temperature rise, it is increasingly likely that this shift will become either very difficult or impossible in many areas.
Economic implications are intimately connected to each of the aforementioned sectors. Human health challenges including increased disease prevalence, developmental stunting, violence, and political upheaval all have potential to shorten life and sap people's energy, both of which decrease lifetime productivity. Additionally, in terms of disease and violence, medical care is an economic cost that is transferred to the individual and the government under which that individual is a citizen. Repairing infrastructure that contributes to those human health issues also brings about costs at the governmental level. More specifically pertaining to aquifer depletion, conservation within certain windows of opportunity can provide economic benefits in allowing farmers to better respond to the risks presented by water scarcity and a changing climate (Foster et al. 2017). The up front economic costs of this conservation can be mitigated through the use of regulations like pumping taxes in Finney County, Kansas, which was shown to increase well water levels over time, agricultural production capabilities, and profitability (Rad et al. 2020).
Explore the concept map below for a visual depiction of these relationships:
Figure 4: Concept map showing the relationship between the three pillars of sustainability and how they relate to groundwater and aquifer depletion. Created by author Jennifer Haus for use on this webpage.
Implications for Policy Makers
The implications of this research include the ability to create a tailored approach to mitigate the trends that we are seeing today and the use of modeling technology for the benefit of human health and safety into the future. Given the findings here and the powers allotted to this agency, our apportionment recommendations are as follows:
- Educational outreach to farmers about the economic and environmental protections benefits of adopting conservation-based practices and how to begin that process
- Research and Development of technologies to mitigate and adapt to water scarcity
- Stipends for the implementation of techniques to mitigate depletion at the individual, production, and community levels in the Ogallala region
- Infrastructural updates to ensure efficiency of water extraction and movement and safety/sanitation in the event of a natural disaster
Prioritized in this order(from greatest extraction allowances to least)
- Those using water for drinking and sanitation given the proportion of extraction currently being used for human consumption
- Farming operations in places where water is scarce and dryland farming is not a possibility
- Farming and industrial operations with high sanitation requirements for safety reasons
- Farming operations with high water requirements given the type of production that are reliant on the climate of the region otherwise
- Farming and industrial operations that are in the process of implementing conservation techniques whose water usage is on the decline
- Farming and industrial operations that historically have minimal to average amounts of water wasted
- Farming operations with average amounts of water waste historically
- Farming operations with high amounts of water waste historically
- Industrial operations that require water but have histories of high waste
- Community entities that do not require water but that improve the health and well being of those in the region
Given the extent of depletion, it is our recommendation that rights should not be allocated to those who have historically overdrawn and have not taken steps towards conservation, those whose purpose for extraction is decoration, and those that do not require water and for whom its extraction does not improve human, animal, or ecosystem health and functioning.
These recommendations along with stakeholder opinions on them and needs voiced in the March 22nd roundtable should inform the final decisions by this agency about the allocation of this increasingly scarce resource as it considers how it will impact generations to come.
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About the Authors
Both researchers working on this study are undergraduate college students at the University of Wisconsin focusing on agricultural and human health topics in our studies. Jennifer has previously studied the economic side of this issue with respect to the Mexico City water crisis specifically, and has baseline geological knowledge of how the water table functions, however, geological intricacies and advanced economic reasoning skills are not an area of expertise. Elizabeth is an Animal Science major with a certificate in Food Systems that focuses on agriculture as a business and has acquired knowledge about the backgrounds of agriculture and its processes, but has not looked in depth at groundwater depletion and its effects on sustainability.