LID. In Beyonce’s world, it probably stands for Lovely Irresistible Denim. But in our world, it stands for Low Impact Development. It was the subject of an all-day seminar I co-presented in Florida last week with a college professor of mine. And no, it’s not just for the single ladies…
I was in the first class that then-Professor Don Carpenter taught at Lawrence Tech in Southfield, MI. Hydraulic Engineering. Don was a doctorate student at that big university up the road (the one that loves Wolverines – the animal, not the mutant) and we were a little leery of having a new prof teach a senior level course. I look back on it and laugh, because now-Doctor Don Carpenter has quite the impressive resume of accomplishments – Founder and Director of the Great Lakes Stormwater Management Institute, extensive research on bioretention and green roofs, significant contributor to the Michigan LID Manual, and presenter at many national conferences.
So when he asked me to join him in presenting a LID seminar, I of course said absolutely! I mean, who wouldn’t want the opportunity to show their college professor they really were paying attention all those years ago! Maybe it was the case studies I had from some Florida LID projects. Or maybe he felt he needed a Gator to help increase attendance…at any rate, I was glad he asked.
Low Impact Development is a design methodology to managing stormwater runoff using a more naturalized approach. Using more of what we call “green” systems (that promote infiltration, evapotranspiration, and reuse) and less of what we call “grey” systems (that put the water in a pipe and fire it downstream at a high volume and velocity.)
Our audience consisted of architects, landscape architects, and engineers. Which meant trying to give a broad enough overview of topics that they could all understand, while also doing some deep dives into subjects important to each of them. It was a lot of information in 7 hours, especially since some of the topics could be their own 7-hour seminar!
One area I focused on was the Cost of LID. There are a lot of misconceptions that more sustainable stormwater management means higher costs. Studies have largely proven the opposite is true, like this one where total capital cost savings ranged from 15% to 80%. Using LID, from both an initial capital cost and ongoing maintenance cost standpoint, is MORE economical that conventional systems.
Let’s think about it:
- - Less pavement, curb, and concrete pipes (replaced by bioswales and porous pavements)
- - Reduced detention basin and smaller pipe sizes (from infiltration, green roofs, and cisterns)
- - Less site prep, grading, and fill material (from having a more compact site with more natural areas)
- - Reduced landscape materials (by preserving existing trees and vegetated areas)
On top of the capital and maintenance savings are some additional benefits that have been difficult to quantify, but only add to the worth of using LID. These include increased land values and sale prices, increased aesthetics, improved livability, additional recreation opportunities, and most importantly a cleaner environment. Most developers are selling residential lots faster when they have implemented LID on their project.
It all adds up…