By: Marcy Williford
Unless you’ve been living under a rock (or in a boat), you’ve probably noticed the tremendous amount of rain we’ve had over the last 6 weeks here in Birmingham, AL. While yes, water is arguably the most important nutrient for any living thing, it is also a pretty important part of a civil engineer’s profession. As Matt Coe mentioned in his blog post “What is a Civil Engineer?,” one very large part of a civil engineer’s job is to design a site not only to function, appeal and provide to a client’s wishes, but also to adapt to the local and even national ordinances, codes and standards. These of which include stormwater quantity and quality management.
Okay, so dig a hole and send the water to it, right? Yep, exactly. But how do you design the water to drain in a way to prevent flooding, reduce stormwater pollution and provide water as a source rather than a waste? Or how about designing it as a functioning system, while ensuring your next-door neighbor isn’t flooding? Well, that’s where a civil engineer comes into play. Our job is to take a site as it comes, accept it for what it is, and design, re-design, and design again to make it the best product it can be. One very important part of that process is considering every drop of water that falls onto our site (or even runs onto our site) and managing this water in a variety of ways to reduce and improve the quality of the runoff. I could talk for days about what all goes into this, but I’ll spare you.
So what do I mean by quantity and quality management? Water quantity involves design which mimics the pre-construction hydrology as closely as possible. This is typically with some type of detention, whether it is above or below ground. Why? To protect your neighbors from seeing more water after your development than they were before. Water quality, on the other hand, comes in many forms and fashions, such as bioswales, green roofs, pervious pavement…the list goes on and on. And the benefits? Healthier natural waters, improved air quality, reduced pollutants. Basically, all-around improved quality of life.
Back to my point: engineering is like a box of chocolates. No two sites are ever the same. The stormwater design of a ½ acre coffee shop in the suburbs and a 100-acre parking lot surrounded by wetlands look pretty different. Geographical location, desired use versus previous use, topography, soil characteristics and size of the site are just a few main players in your design. Even more, there are a variety of ways to interpret the way you manage this water. For example, your coffee shop may need some form or fashion of underground detention whereas your 100-acre parking lot may require 5 detention ponds.
I guess what I’m trying to say is designing stormwater in a way which handles, conforms, and produces the most efficient use of a site means curating a specific design for the site at hand. So many factors present their own challenges and make the site unique. The civil engineer has the humbling job of combining the needs of the client, requirements of the organizations, and existing conditions of the site to ultimately deliver a product that works for everyone involved and continues to keep the public safe. And this is what makes our job so rewarding. To solve problems and provide someone with a place of work, residence, or even just a place to do their grocery shopping. Working as a team with a variety of people with different talents in order to serve a client in the best way possible.