Is that BMP Working? The Cost of Not Knowing

So you’ve invested in a nice new stormwater BMP. Maybe a standard retention pond, or maybe something fancier, like a green infrastructure installation. The model promised you a 60% reduction in flow to your local waters, so you went ahead and signed on the dotted line.

It’s rained a few times, and you’re feeling pretty good—but do you know if it’s working? Even the most basic stormwater BMPs can cost hundreds of thousands of dollars.  Would you invest that amount again and feel confident you’d achieve the promised results? The problem is, most of us don’t know.

Costs of typical stormwater BMPs (estimates from U.S. EPA)

We keep doing what the models say, yet stormwater remains the only growing source of surface water pollution year after year. Why? What’s going on? Are our projects undersized? Are we lacking in the maintenance department? Maybe the projects just aren’t in the right places?

And herein lies the problem: we are missing DATA!

The most recent ACSE infrastructure report card notes that:

Cities and towns across the country report that complying with federal wastewater and stormwater regulations represents some of their costliest capital infrastructure projects.

And also that:

Data on stormwater infrastructure and CSOs are limited.

What a spot to be in! Communities across the country know that a significant investment is warranted in order to control impacts from stormwater and combined sewage systems, but there is really not much empirical data out there detailing the scale of the problem or confirming the efficiency of designed solutions.

This lack of data on which we therefore cannot base costly decisions was highlighted again in the recently published National State of Stormwater Report, which noted that:

Stormwater managers along with engineers, planners, and designers are still learning how to properly design, review, and approve post-construction stormwater control measures (runoff reduction). These professionals need long-term maintenance and effectiveness data to improve annual reporting as well as tracking and documentation of stormwater control measures.”

Stormwater control projects are everywhere: why don’t we have more data?

The short answer is because we don’t have to. Post-construction monitoring is usually not required for stormwater BMPs, so we usually don’t do it. Monitoring is generally viewed as an expensive and time-consuming undertaking, so managers have taken to trusting models as a basis for making decisions.

The problem is that models are only as good as the numbers you put into them. Without local, empirical data, it’s hard to train a model. And in order to get local, empirical data, you have to monitor. But monitoring is too expensive. (And round and round we go)!

Climate change will make this data gap even harder to ignore.  Every region of the country is expected to see an increased in frequency and intensity of storm events on the coming years. A recent study published in Environmental Research Letters reviewed stormwater design manuals for the lower 48 States and found that some were using out of date data, and that NONE had considered changes due to climate change.

Long story short: The stormwater industry may be shooting itself in the foot by dismissing monitoring as an unnecessary expense.

So here we are. Stormwater is the only growing source of surface water pollution in the U.S., engineering solutions to this problem involve some of the most costly projects many regions undertake, and we’re currently basing these expensive decisions on out-of-date (or nonexistent) data and assumptions. So, maybe the question shouldn’t be whether we can afford to monitor, but whether we can afford NOT to!

What if monitoring did not have to be expensive and time consuming?

Real-time data at your fingertips with StormSensor

At StormSensor, this is the reason we get up every morning (no really, it is—we ♥ data!). We have developed a monitoring network that tracks water depth, velocity, and temperature throughout your stormwater or combined sewage system 24/7. We pair that data with local weather and offer unlimited access via our cloud-based software system. We have priced our network so cost is not a barrier—because we want you to have all the data you need to assess BMPs, prioritize problem areas, and make more informed investment decisions.

Think you can’t afford to keep not monitoring? CONTACT US and let’s talk stormwater!

About the author

Suzie Housely

Talk stormwater with Suzie has over a decade of experience in the Stormwater industry including both government and academic work. She leans on her experience to meaningfully interpret scientific studies and government policies to communicate a practical message. Suzie lives just outside Nashville, TN and gets outside whenever she can to explore nature with her husband and two small children.