A Global View on Future Major Water Engineering Projects

Klement Tockner, Emily S. Bernhardt, Anna Koska, and Christiane Zarfl

Abstract Human activities have altered how the world functions. During the past decades, we have globally, fundamentally, in the long-term, and in most cases irreversibly modified all spheres of earth. This new epoch, often referred to as the Anthropocene, is just in its early stages. Indeed, there is general agreement that the transformation of our globe takes speed, with consequences that we can hardly imagine but that may threaten our own survival. This goes along with the general idea that major infrastructure projects are a sign of technological progress and believed to stimulate economic development and to improve living conditions for humans. In the present essay, a representative inventory of future major engineering projects, either planned or under construction in aquatic systems worldwide, shows that the rapid transformations of the Anthropocene are particularly evident in the freshwater domain. Worldwide examples of very large dams, major interbasin water-transfer and navigation projects, as well as large-scale restoration schemes, underline the dimensions of and the challenges associated with future megaprojects that will change our freshwater environment. Opportunities to mitigate the consequences of megaprojects based on the lessons learnt from projects in other infrastructure sectors range from ecological engineering to smart water investments that are adjusted to the respective national, social, economic, and environmental conditions.

Keywords Hydropower dams • Interbasin transfer projects • Navigation • Restoration • Biodiversity • Global change • Anthropocene • Terraforming

Introduction

“Welcome to the Anthropocene”, entitled The Economist on 21 May 2011. The Anthropocene indicates a geological epoch that follows the Holocene. Since the beginning of the industrial revolution, human activities have altered how the world functions. We have globally, fundamentally, in the long-term, and in most cases irreversibly modified the geosphere, hydrosphere, atmosphere and particularly the biosphere (Steffen et al. 2011; Rockström et al. 2014). And we are just at the beginning of this new epoch. There is general agreement that the transformation of our globe takes speed, with consequences that may threaten our own survival. Indeed, we are probably not able to imagine, or at least it sounds like science fiction (e.g. Pendell 2010), which alterations we will face in the coming decades to centuries. This includes, for example, the widespread creation of synthetic organisms, the exploitation of the ocean floor, the large-scale loss of coastal areas, the collapse of deltas, and a 4–8 °C warmer globe. We urgently need to understand the future dimension of this epoch and the consequences for the environment and the humans alike. And we need to consider fundamentally new strategies on how to cope with the immense challenges we are facing.

“Terraforming”, i.e. the remaking of the earth surface, is not science fiction. Indeed, it is taking gear too. In China, for example, whole mountain ranges are levelled off to create space for new cities (Li et al. 2009). Mining activities reshape increasingly the earth surface because of an increasing demand for minerals and the concurrent depletion of resources. We dry-up entire river basins, truncate the global fluvial sediment transport, alter the global biogeochemical cycles and transform forests, steppes and deserts for crop and biomass production (e.g. Hooke and Martín-Duque 2012, Table 1). Terraforming not only requires land but also consumes huge amounts of energy and water.

At the same time, our planet is facing a major water crisis. Population growth and economic development are strongly increasing the global freshwater demand, while climate change further exacerbates the uneven distribution of water. The water crisis is spreading through all sectors, from sanitation, drinking water supply, agriculture and energy. Therefore, the signals of the Anthropocene are particularly evident in the freshwater domain (Table 4.1). Nutrient enrichment, exploitation of fossil groundwater reservoirs, fragmentation of river networks, alteration of the flow, sediment and thermal regimes, shrinking deltas and the accelerating erosion of freshwater biodiversity are clear signs of the rapid transformation of aquatic systems.

The water sector represents an immense market and the projected global expen-

diture on water and waste-water services is steadily increasing: from USD 576

Table 4.1 Signs of the Anthropocene in freshwater systems

Pressures

Status and projection

References

Geosphere

Delta regions

Reduced sediment input, increasing subsidence rate, salinisation, sea water rise, demographic pressure (e.g., actually 500 million people live in deltas)

Surface area vulnerable to flooding may increase by 50 % in twenty-first century.

Syvitski et al. (2009) and Giosan et al. (2014)

Several deltas (e.g. Indus, Ganges) are facing complete collapse in near future

Sediment balance

Retention behind dams, land-use change, soil erosion

100 billion metric tons of sediments and 1–3 billion metric tons of C sequestered in reservoirs (status 2005); storage may double within the coming decades due to a boom in dam construction

Syvitski et al. (2005) and Zarfl et al. (2015)

Coastal regions

Nutrient input, climate change

Exponential increase of dead zones (oxygendepleted regions) since the 1960s; today about 400 coastal dead zones cover more than 245,000 km2

Diaz and Rosenberg (2008)

Hydrosphere

River flow

Climate change, water abstraction, land-use change, damming, interbasin transfer

Increase in extreme events, rapid expansion of temporary streams, widespread change of flow regimes

Nilsson et al. (2005), Vörösmarty et al. (2010), and Acuña et al. (2014)

Groundwater

Exploitation for irrigation, demographic development, climate change, pollution

From 1960 until today, groundwater depletion increased from 126 ± 32 to 283 ± 40 km3 a−1 (India, USA, Pakistan, China and India jointly share 71 % of global groundwater withdrawal)

Giordano (2009) and Wada et al. (2010)

Water quality

Urbanisation, agriculture intensification, industry, synthetic substances

Worldwide contamination of freshwater systems with thousands of industrial and natural chemical compounds, eutrophication

Camargo and Alonso (2006), Schwarzenbach et al. (2006), and Vörösmarty et al. (2010)

Biosphere

Biodiversity

Habitat degradation, flow regulation, pollution, climate change, invasion

10–20,000 freshwater species are estimated extinct or imperiled;

Strayer (2006) and WWF (2014)

Freshwater vertebrate populations declined by 73 % between 1970 and today;

63 % of all freshwater megafauna species listed as threatened

Ecological novelty

Species invasion, novel stressors

Faunal homogenisation, emerging pathogens, GMOs and synthetic organisms

Jeschke et al. (2013)

Atmosphere

Global carbon cycle

Pollution, habitat degradation, damming

Increased greenhouse gas emissions from near-natural, altered, and artificial freshwaters

Wehrli (2011), Raymond

et al. (2013) and Zarfl et al. (2015)

billion in 2006, to USD 772 billion in 2015, to USD 1,038 billion in 2025 (Ashley and Cashman 2006). And the projected expenditure on water infrastructure as percentage of GDP will increase too, from 0.75 % in 2015 to more than 1 % in 2025. These values do not include the major water engineering projects that are either planned or under construction. For example, the construction of 3,700 future hydropower dams may require an investment of about USD 2 trillion, excluding operation costs as well as the costs caused by social and environmental damages (Zarfl et al. 2015). A primary challenge in designing and operating major water infrastructure projects will be to balance the economic benefits while preventing social costs and the loss of natural ecosystem services.

In this chapter, we provide a comprehensive albeit in no case complete inventory of future major engineering projects, so-called megaprojects, that are either planned or under construction in freshwater systems worldwide. We focus on very large dams, major interbasin water-transfer and navigation projects, as well as on largescale restoration schemes. The main goal is to raise awareness about the dimension of and the challenges associated with future megaprojects. We discuss opportunities to mitigate the consequences of megaprojects based on the lessons learnt from projects in other infrastructure sectors.

 
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