Environmental Engineering Reference
In-Depth Information
3
Sustainab le Water Management
3.1 Introduction
As pointed out in the previous chapter, water is one of the essential ecosystem components
for survival of all living species. The water component of the geoenvironment includes all
rivers, lakes, ponds, inlets, wetlands, estuaries, coastal water, groundwater, and aquifers.
These contribute as inputs to the oceans that make up 70% of the earth's surface water.
Water is required for many needs such as drinking, agriculture, cooking, domestic and
industrial uses, transportation, recreation, electrical power generation, and support for
aquatic life and other wildlife. Among the many underlying reasons for increasing water
shortages are (a) demand in excess of supply, (b) depletion of aquifers, (c) lack of rain and
other forms of precipitation, (d) watershed and water resources mismanagement, and
(e) diversion of rivers. It is noted that irrigation requirements for agriculture are increas-
ing. Estimates indicate that more than 70% of the world's freshwater is utilized for agricul-
tural purposes (Postel, 1999).
The importance of water has been highlighted in the Johannesburg World Summit on
Sustainable Development (WSSD, 2002). “Water and Sanitation” was identiied as one of
their ive thematic areas at WSSD 2002. The quality of water can be, and is, signiicantly
impacted by all the other four thematic areas deined by the WSSD (2002); “Sustenance
and Development,” “Industrialization,” “Urbanization,” and “Resource Exploitation and
Agriculture.” Adequate quantities of good quality water are also essential for health, agri-
culture, energy, and biodiversity. Lack of water and poverty are intimately linked. The dis-
cussion in this chapter will focus on the uses (and misuse) of water in the geoenvironment.
It will also examine some of the main elements required to address, contain, and manage
stressor impacts to water quality as a step toward water management for sustainability of
water resources.
3.1.1 Geoenvironment Sustainable Water Management
Sustainable water management can be deined in a similar manner to the deinition for sus-
tainable development articulated in Section 1.3 in Chapter 1. Accordingly, we can deine
sustainable water management as all the activities associated with usage of water in sup-
port of human needs and aspirations, which must not compromise or reduce the chances
of future generations to exploit the same resource base to obtain similar or greater levels
of yield. In the context of the geoenvironment, with particular focus on geoenvironmental
engineering, we limit ourselves to the receiving waters in the geoenvironment, i.e., all
water forms contained within the land surface, such as rivers, lakes, ponds, and ground-
water (aquifer and soil porewater).
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