It’s an interesting time to be a stormwater engineer
Ask most environmental engineers why they chose their field and you’ll get an answer along the lines of “I want to help man and nature coexist harmoniously.” With this goal in mind, it has never been a better time to be a stormwater engineer. When many of us more experienced engineers began our careers, the focus of stormwater engineering centered around water quantity and rate, trying to avoid undesirable flooding, with water quality taking a somewhat lower priority. Stormwater facility site designs also tended to be rather segmented and discrete, with each function consigned to its own particular part of the project site.
That was then, and this is now. Water quality in receiving rivers, estuaries, bays and lakes has begun to deteriorate, and developable and re-developable land has become rarer and more expensive. Our water quality has changed, and the way we manage water has had to evolve as well.
I happen to live and work in a state that has been at the forefront of the development of nutrient reduction in stormwater runoff and other non-point sources of pollution. Florida has had to deal with large scale environmental crises related to water quality, including fish kills, algae blooms, eutrophication, sea grass losses, and a severe impact to one of the state’s most vital industries: tourism. All of this has led to new state requirements to reduce nutrients like Nitrogen and Phosphorous listed in the Total Maximum Daily Loads (TMDLs) in the various Basin Management Action Plans (BMAPS).
In response to these new requirements, a whole host of new tools, and redesign of some old tools are being developed, and it’s up to us as stormwater engineers to find new and innovative ways to fit all of the pieces together.
As the use of Geographic Information Software (GIS) explodes, our ability to model existing and proposed conditions paradoxically becomes both easier and more complicated as more parameters are able to be modeled. We’re able to pinpoint discrete features like septic tanks, water wells, and any number of other features that impact surface and groundwater nutrient loads. Using GIS, we can also map larger features like stormwater infrastructure, NEXRAD rainfall data, and most of the physical properties that are inherent in each of these features.
In many cases, we no longer need to spend tedious hours determining runoff curve numbers, or times of concentration. These elements are often performed automatically within modern 1-D and 2-D stormwater models. Coupled with these, nutrient loading models can help us determine base loading to receiving waterbodies, and subsequently determine nutrient load reduction schemes and projects to meet TMDLs and improve water quality.
Best Management Practice (BMP) Tools
In addition to the tried and true methods, we are seeing new takes on alternative stormwater treatment techniques. Treatment trains, where a sequence of stormwater treatments are provided to maximize results, can include green roofs, rainwater harvesting, tree wells, and, more recently, baffle boxes, all of which work together to remove runoff volume, suspended solids, metals, and nutrients from stormwater. Additionally, chemical and biological treatment tools are also being introduced. These include nutrient removing baffle boxes, and alum treatment used for phosphorous removal.
Each of these new stormwater treatment strategies has its own unique costs, benefits and drawbacks. As new treatment methods and technology seemingly spring up overnight, it can start to feel overwhelming. But it’s also fundamentally exciting: now, it’s up to us as stormwater engineers to select and combine the strategies most appropriate for each project. New technologies and methods provide many opportunities to be creative and collaborate with other professionals. Working with landscape architects or urban planners, we can create beautiful public spaces that also serve a vital purpose: together, we can transform that algae-covered wet detention pond into an urban, tree-covered park for our communities to enjoy.
The new and changing regulatory requirements coupled with the harsh demands of economics and public accommodation have created a challenging environment for stormwater engineers. However, as the saying goes, “may you live in interesting times.” For those of us who entered this profession with a desire to enhance the relationship between man and nature, we truly do live in interesting times. Challenge accepted.
Filter by Expertise
QAQC is the “secret ingredient” to success
October 10, 2019
Women in STEM: why does it matter?
September 25, 2019
Mead & Hunt’s Climate Initiative
June 25, 2019