2018: The year of Stormwater!
As I reflect on 2018, one word that comes to mind is stormwater (and not just because I’m a stormwater professional). 2018 was one of the wettest years on record, particularly in the Eastern and Midwestern U.S., where over 25 cities set new records for rainfall. Meteorologists at weather.com tracked FIVE (!!) 1/1000-year events in 2018. However, it’s important to note that these large events were not the only contributing factors to record-setting annual rain totals. For example, Wilmington, NC, was effected by Hurricane Florence, but even excluding the totals from that event, the city still set precipitation records in 2018. This map from NOAA shows the national deviation from average precipitation in 2018; as you can see, most regions east of the Rocky Mountains had a very wet year.
2018 U.S. Departure from Average Rain Totals
Once all that rain hits the ground it becomes…stormwater! So, not surprisingly, 2018 was also a year of record flooding. Extreme rain events led to flooding in many regions east of the Rocky Mountains, including Louisville, KY, the Carolina’s, and the Mid-Atlantic states. Elliott City, MD, experienced historic flooding this year and experts blame not only the rain but increased impervious surfaces due to unchecked urban sprawl for exacerbating the problem.
Flooding in Elliott City, MD. (Source: Slate)
Those historic flood waters pick up pollution as they flow, and receding water in the streets means increased pollution to receiving waters, and ultimately bays and oceans. This non-point source pollution from stormwater is the leading source of oceanic dead zones. The U.S. is home to the second largest oceanic dead zone on Earth, located in the Gulf of Mexico which receives runoff water from 41% of the Country through the Mississippi River Watershed. 2018 measurements showed that the dead zone actually shrunk significantly to just a third the size of the record-setting expanse it reached in July 2017. But don’t fly that “mission accomplished” banner just yet. Regional experts credit strong summer winds, not source controls, for lessening the impact of the dead zone this year by pushing the high-nutrient, low oxygen water east and dispersing it more than normal.
The extent of the Gulf of Mexico Dead Zone (Source: Iowa State University)
Overall, was this just an extreme year or are we seeing climate change in action? Meteorologist Steve Bowen has a great response to this question (paraphrased here): We cannot say that climate change “caused” record setting rains or flooding any more than we can say steroid use “caused” a record setting homerun streak, but we can say that they likely played a role.
What do you think? How did weather in your region stack up this year?
Regardless, at StormSensor, we think 2019 should be the year of the (monitored!) stormwater BMP.