Urban Runoff and the City of Relations - Politics of Urban Runoff: Nature, Technology, and the Sustainable City - page 18

be achieved through the command and control practices of traditional
engineering. 2 Rather, there was a need to completely rethink the logic
of urban drainage. Using a systems perspective from ecological science,
these practitioners posited that the most effective way to manage urban
runoff was by reducing the volumes generated at the source. Referred to
as Low Impact Development (LID) in North America and Sustainable
Urban Drainage Systems (SUDS) in Northern Europe, source control turns
the urban drainage regime on its head by emphasizing the reduction of
stormwater volumes and cleansing at the point of generation through site
design, infi ltration, and treatment strategies. 3 Where conventional storm-
water management focuses on the symptoms of large stormwater volumes,
source control goes to the root of the problem to address development
patterns and impervious cover that create these large volumes of polluted
water in the fi rst place. 4 LID pioneer Larry Coffman writes that “the
basic goal of LID is to engineer a site with as many small-scale retention,
detention, prevention, and treatment techniques as needed to achieve the
hydrologic functional equivalent to predevelopment conditions.” 5
Proponents of source control advocate for the judicious use of ecologi-
cal science principles rather than physical strategies of conventional engi-
neering. The approach has much in common with the relatively new fi eld
of ecological engineering, which adopts principles of ecological science to
engineering work and shifts the emphasis of stormwater management from
hydraulics to hydrology. 6 Rather than focusing on storage and treatment
of stormwater volumes, source control uses distributed and decentralized
management strategies such as bioswales, pervious paving, green roofs,
and rainwater harvesting to mimic the predevelopment hydrologic cycle as
closely as possible. This approach is promoted as a way not only to reduce
environmental impacts but also to reduce construction and maintenance
costs; it can be understood as a “green governance” approach to urban
runoff issues for which the mantra is “pollution prevention pays.” 7 The
rise of source control as an alternative drainage strategy suggests that
urban water fl ows should not be directed by environmental regulations
focused on water quality and quantity but rather by a systems focus on
the relationship between ecological fl ows and human habitation.
Today, source control represents a small but growing contingent of
stormwater practitioners who are gradually reforming urban runoff prac-
tices to improve environmental quality. Through the implementation of
pilot projects, the retrofi tting of existing networks, and the revision of
municipal codes, source control advocates are updating the Promethean
approach by introducing a variety of new strategies that mimic nature