Posted: 06 December 2006 at 10:53am | IP Logged

Question from: Minnesota Pollution Control Agency (St. Paul, MN)

Are low impact development BMPs, such as rain gardens and green roofs, more effective than stormwater ponds in treating stormwater?

Posted: 06 December 2006 at 10:55am | IP Logged

Reply from Ben Urbonas, Urban Drainage & Flood Control District (Denver, CO):

Hard to answer this since there is very little, almost no data on these LID items.  With time we are hoping the database will have sufficient data, along with reference sites to compare against, to answer this question.

My take on this at this time is that how these practices are applied and what runoff they capture is more important than if they provide better water quality than ponds (which, by the way, can produce excellent water quality). If applied properly, these practices should reduce runoff and, as a result, pollutant loads leaving new development sites. If applied improperly, which I have seen examples of, they are a waste of money and resources. Common sense and good engineering practices cannot be replaced by improper selection of the BMPs used for the problem at hand and their design and application.