Attaining Sustainable Urban Watersheds - Urban Watersheds: Geology, Contamination, and Sustainable Development - page 505

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Attaining SustainableUrbanWatersheds
16.1 Introduction
Geological investigations combine scientific observation, analysis, and interpretation.
A by-product of these efforts is a very valuable tool—the geologic map. In many urban
areas, these maps are not of sufficient detail or absent, or if available, are underutilized or
ignored. This often leads to land development without sufficient knowledge of its hydro-
geology, soils, and surface water features, and a diminished ability to foresee the poten-
tial vulnerabilities of the very ground where structures are erected and human activities
occur. This is analogous to taking a trip without a road map—you often get lost.
Once this land has been developed, we assault it with chemicals used in manufacturing,
herbicides and pesticides applied across vast tracts used for agriculture, fertilizers sprayed
or spread on our lawns, and particulates and greenhouse gases emitted from our vehicles.
Many of these substances are harmful to humans and the environment and interact with
the geologic setting into which they are released. These events sound ominous, but with
our knowledge about the properties of these substances we can determine the risks they
pose based on their toxicity, mobility, and persistence. These risk assessments yield valu-
able knowledge about the potential environmental outcomes when chemicals are released
into soil, groundwater, and air.
If we want to reduce this widespread contamination, we need to work fast because
the worldwide rate of urbanization continues to accelerate. Urbanized watersheds have
become the focal point for the excess matter and energy produced by the growing horde
of humans. Rather than accommodating to nature, humans have tried to control it. As a
result, the urban landscape is damaged and needing repair. Remnants of old factories dot
the landscape, groundwater is contaminated or depleted, and any act of precipitation trig-
gers more water pollution.
So now that we are saddled with this mess, everyone is talking about sustainability.
Sustainable urban watersheds might be achieved if we could all get along and stopped
emitting pollution—but how do we get there, given the mishmash of existing institutional
arrangements for managing land, water, and development, and the reality that science-
based planning is not performed at the watershed scale? The Rouge River watershed and
its Rouge River National Wet Weather Demonstration Project (United States Environmental
Protection Agency Grants #XP995743-01, -02, -03, -04, -05, -06, -07, and C-264000-01) is an
example of an attempt to rectify a legacy of neglect and damage caused by 100 years of
urbanization and industrialization. However, here again, the focus is on engineering a
solution to the problem as opposed to reducing the source of the impacts. In this case,
hundreds of millions of dollars have been spent to curb discharges of wastewater from
combined sewer overflows during wet-weather events. Although the goal of the project is
admirable, combined sewer overflows represent a single point source of contamination to
the Rouge River, and all point sources combined represent only 20%-25% of the pollution
problems facing the river.