That Sinking Feeling

Land subsidence from over pumping groundwater is a serious problem affecting many parts of the world. This chapter begins with Joseph Poland, the pioneer of land subsidence investigations. The chapter then discusses how drought combined with a lack of groundwater management led to renewed land subsidence in California’s Central Valley. Mexico City, which has one of the most serious urban land subsidence problems in the world, is also discussed. The chapter then moves to success stories in bringing subsidence under control, such as California’s Santa Clara Valley; Houston, Texas; and Bangkok, Thailand.

Who Owns Groundwater?

This chapter discusses the questions of who owns or has a right to use groundwater, how much can they use, where can they use it, and can their water rights be sold? The rules and laws addressing these critical questions have not come easy, and remain highly controversial. This chapter discusses these questions as they have played out in three western states (Texas, New Mexico, and California), as well as Spain and Australia. California’s 2014 Sustainable Groundwater Management Act is used to illustrate many of the challenges.

Not All Aquifers Are Created Equal

This chapter examines how geology and climate create vastly different groundwater situations. Effective management of groundwater depends upon full consideration of these differences. The chapter begins with a distinction between confined and unconfined aquifers and a look at artesian wells, with a focus on Australia’s Great Artesian Basin. The characteristics of different rock types are illustrated by four basic aquifer rock types in sub-Saharan Africa. The chapter then turns to non-renewable aquifers in North Africa and Saudi Arabia. The fast-recharging Edwards Aquifer in Texas then provides a quite different story with its sensitivity to short-term climate variability and concerns about endangered species. The chapter concludes with a discussion of saltwater intrusion in coastal aquifers and the potential of brackish groundwater for water supply.

The World’s Poorest People

By almost any measure sub-Saharan Africa lacks even the most basic infrastructure to meet the needs of the almost one billion people living here. This chapter examines the links among water scarcity, poverty, and disease—and the potential of groundwater for mitigating these problems. The solution involves much more than the all too common approach of drilling a village well, installing a pump, and returning home. The chapter presents instructive stories of individuals who are doing it right, including capacity building.

Beyond Rain

The chapter begins with looking at ways humans have dealt with drought—praying for rain, hiring a rainmaker, or hoping for the best. After World War II, the widespread availability of rural electrification, the deep turbine pump, and center pivot irrigation gave people the option of large-scale use of groundwater. This chapter provides an overview of how groundwater development has radically improved water and food security. The discussion then moves to the growing problems that have resulted from groundwater overuse in places such as the High Plains (Ogallala) Aquifer and the North China Plain. Recently, the GRACE (Gravity Recovery and Climate Experiment) satellites, which can provide precise estimates of changes in groundwater storage over very large areas, have helped draw attention to groundwater depletion around the world.

Pathogens

This chapter examines microbial contamination of groundwater that can threaten drinking water supplies and the importance of proper well construction and protection. Case studies are presented of E. coli poisoning in Walkerton, Ontario and viruses in Wisconsin. The Walkerton incident in 2000 caused Canadian provinces to take a hard look at their drinking water safety through better monitoring, enforcement, training, and source-water protection programs. The Wisconsin case study illustrates the potential for viruses from leaking sewers to contaminant municipal wells.

Nitrate and Aquifer Protection

Nitrate is the most common chemical contaminant in groundwater, affecting both human health and ecosystems. This chapter discusses how nitrate in groundwater has affected the health of the Chesapeake Bay and how it takes decades for changes in farming practices to reverse these trends. The chapter also examines the human health impacts of nitrate in groundwater within poor communities in California’s Central Valley. The chapter concludes with a discussion of source water protection by illustrating the comprehensive program for mapping groundwater protection zones in Denmark.

Arsenic

This chapter begins with what has been called “the largest poisoning of a population in history,” as a result of arsenic poisoning from wells in Bangladesh and West Bengal, India. The chapter then examines the challenges of determining the safe level and standards for arsenic in drinking water. The ongoing challenges of educating homeowners in New Hampshire where high levels of arsenic occur in many private wells are then discussed. The chapter concludes with discussion of other naturally occurring contaminants in drinking water wells, such as fluoride, radon, radium, and uranium.

Streamflow Depletion

Much of the book’s discussion thus far has focused on groundwater depletion. However, as wells continue to pump, the source of water increasingly comes from surface water. This chapter examines how depletion of even a small part of groundwater storage can have large impacts on surface-water resources. Yet despite this critical connection, different laws govern surface water and groundwater. Solving this complex water resource relationship also involves accounting for the delayed effects of pumping on surface-water resources. The ongoing challenges for conjunctive management are illustrated by the South Platte River basin of Colorado, as well as the Arkansas and Republican Rivers.

Arizona

After examining one of the world’s worst case scenarios, the book turns to the state of Arizona that has one of the world’s more progressive groundwater management programs. After years of debate, the federal government eventually agreed to finance the Central Arizona Project to bring Colorado River water to central Arizona, but with a catch—Arizona first had to get their groundwater pumping under control. This chapter presents the historical background and role of key individuals involved in achieving this goal, as well as lessons to be learned from these efforts.