Forget Stormwater, It's All About Rainwater!

By Steve Benz posted on Thu, 2009-07-16 16:44 , 531 reads, 0 comments

 Forget Stormwater, It's All About Rainwater!

Low Impact Development- It's not business as usual for stormwater engineers

 

 

Low Impact Development (LID) is the latest buzz term in the world of land development. According to the Low Impact Development Center, " Low Impact Development is a new, comprehensive land planning and engineering design approach with a goal of maintaining and enhancing the pre-development hydrologic regime of urban and developing watersheds."

 

When you think of LID, you probably think of practices like permeable pavement, green roofs, infiltration landscapes and biofilters. Most of these elements are adept at managing small volumes of rainfall, yet don't hold up to the peak rate, low frequency, high-intensity event "design storm" methodologies that stormwater engineers use. Yet, intuitively we understand that LID practices are good for the environment.  Trouble is, the traditional peak rate "design storm" hydrologic design methods in use today do not generally recognize the intrinsic value of LID practices.

 

There's a fundamental disconnect between the way we look at the goals of stormwater management today and the broader issue of environmental sustainability.  The design storm approach evaluates the effects of flooding, resulting in application of Best Management Practices that protect downstream systems by regulating and detaining peak rates of discharge from a developed site. The methodology focuses on high-intensity, infrequent rainfall events.

 

The attached article appeared in the May/June edition of Storm Water Solutions.