Environmental Engineering Reference
In-Depth Information
An old Chinese proverb says a journey of a thousand miles begins with a single step.
This chapter defines that first step. It begins with an overview of the concepts of sus-
tainability and sustainable development and uses them to develop a framework for
undertaking urban watershed management. Next, the principles learned from geological
investigations, contaminant properties, risk assessments, and science-based planning are
applied within this framework. The chapter concludes by demonstrating ways to link this
first step of watershed management with the broader tasks necessary for achieving sus-
tainable urban watersheds.
16.2 Sustainability and Sustainable Development
There is no standard definition for sustainability, and as a result the concept is open to
many interpretations (Bell and Morse 2008). The working definition of sustainability used
so far in this topic was based on a few general principles adopted from Lynam and Herdt
(1989) and Fresco and Kroonenberg (1992): (1) human activities do not inflict excessive
levels of damage upon the environment, (2) society needs to allow the environment to
repair itself from prior damages, and (3) these efforts will help return physical systems to
dynamic equilibrium.
The term sustainable development originated in a 1987 report issued by the U.N. World
Commission on Environment and Development: “development that meets the needs of the
present without compromising the ability of future generations to meet their own needs”
(WECD 1987). This definition is economic based and requires modification to accommodate
the environmental imperatives for attaining sustainable urban watersheds. Specifically,
in urban watersheds, sustainable development encompasses those activities designed to
achieve and maintain dynamic equilibrium within the major physical systems perform-
ing their work in the atmosphere, biosphere, hydrosphere, and lithosphere. A sustainable
urban watershed would have swimmable streams, swimmable lakes, a stable and region-
ally appropriate diversity of plant and animal populations, rehabilitated brownfields that
do not pose a risk to groundwater and surface water, the absence of an urban heat island,
and the absence of any identifiable linkages between its water, soil, and air qualities and
the occurrence of disease in plants, animals, or humans. This is a highly idealized concept
that in reality probably can never be accomplished because of the high financial cost neces-
sary to achieve these goals. However, there is no reason not to do everything in our power,
and within our financial capability, to shoot toward some compromise between the situa-
tion we face today and the idealized watershed.
16.3 A Framework for Beginning Urban Watershed Management
Land is the primary surface component of watersheds, and land-based anthropocentric
activities are the major source of water contamination. In addition, urbanized water-
sheds exhibit a diversity of land uses and landscapes with ensuing high levels of envi-
ronmental damage often present. Given these characteristics and challenges, the first
step of watershed management must accomplish the following tasks: (1) prevent further
 
Search WWH ::




Custom Search