Note to Reader:
An article written by Florida-based Lisa Nisenson, a prominent member of the Rainwater-in-Context Initiative, was the catalyst for an exchange of Canadian and American perspectives on What Are the Shortcomings with Low Impact Design (LID)?
Extracted below is the perspective on LID as provided by Colorado-based Paul Crabtree, leader of the Rainwater-in-Context Initiative, after he had reflected on a commentary by Jim Dumont on the view from British Columbia.
Jim Dumont is also a member of the Rainwater-in-Context Initiative. His commentary was written to provide relevant context for an upcoming seminar on Sustainable Rainwater Management (September 2013). A respected water resources and infrastructure practitioner, Jim Dumont is the Engineering Applications Authority for the Partnership for Water Sustainability in British Columbia.
Rainwater in Context
“Rainwater-in-Context unites New Urbanism, rainwater / stormwater and watershed management, Smart Growth, water reuse, low impact, Light Imprint, and other sustainable practices toward a holistic approach to rainwater that utilizes the rural-to-urban transect and Charter for the New Urbanism,” explains Paul Crabtree.
“LID attempts to manage stormwater quality by using on-site design techniques (such as bio-swales and pervious pavers). The primary concern with LID is its origin in managing water in auto-centric development,” states Tom Low, author of the Light Imprint Handbook and member of the Rainwater-in-Context leadership.
What About the Stream?
“If the sole objective of LID is quality of the runoff, then the vision of the stream and its health are secondary and must be assumed to be entirely related to quality,” wrote Jim Dumont in his commentary.
“What ever happened to looking at the stream to determine what is happening and to identify its needs and to identify ways to keep it healthy? I believe that the approach of focussing on water quality is short-sighted and will prove to be only a part of the solution. It seems that everyone has forgotten the pioneering work of Richard Horner and Chris May in the late 1990s in Washington State (scroll down to graphic).”
“They found that habitat protection and maintenance of the hydrologic regime is much more critical that water quality in headwater streams.”
Mimic the Water Balance: Can the United States Learn from British Columbia?
“The Canadians do appear to be ahead of the US in this field because the US EPA took a really bad approach to LID that was based on the premise that enforcing every site to the same standard would somehow fix the problems of water quality in the US,” commented Paul Crabtree.
“The USA EPA approach has done some good, but has several crippling drawbacks: a) analysis of the stream/watershed is not part of the protocol: b) sprawl and greenfield development are incentivized since compliance is easier for those development types: c) the regulations became enormously cumbersome (100’s of pages long) because the premise was arbitrary, not based on good science, and required tremendous negotiations in order to achieve passage: and d) the resultant implementation is usually an expensive quagmire that is hated by all except those who are profiting from it.”
“In a heavily built up area, water quality protection would be a worthwhile objective as the habitat would already be damaged. Undisturbed headwater streams require erosion protection and maintenance of the hydrologic regime – that means water balance first, and protection of water quality second,” concluded Jim Dumont.
To Learn More:
To read the complete article posted on the Convening for Action community-of-interest, click on What Are the Shortcomings with Low Impact Design (LID)?