n one interesting case in San Diego, a building produced so much roof condensation that water discharged through the parking lot even when it wasn’t raining! The city was concerned about where the water was coming from, but investigations proved it was just natural precipitation, not an illegal discharge.
It’s just as important to know what isn’t stormwater. Common sights like someone washing cars in a parking lot or over-irrigation runoff from landscaping do not qualify. Even permitted actions, like flushing fire sprinkler systems, are categorized as non-stormwater discharges.
Curious to learn more about how to identify natural precipitation versus illicit discharges? Check out the video above to get the full story!
Video Transcript
0:00 Intro
0:02 Stormwater is…
0:36 Stormwater is NOT…
0:00 Intro
What is stormwater?
0:02 Stormwater is…
Stormwater is any natural precipitation. Anything that you get from rain to condensation that accumulates on the roof. We have a project in San Diego that gets a lot of condensation on the roof, and the roof is very slick. Everything runs down the downspouts, and they actually get discharge from their downspouts through the parking lot even when there isn’t rain events.
The city kept inquiring, “Where’s all this water coming from?” and through a lot of investigation, it was coming off the roof and it is natural precipitation. It’s not an illicit discharge. We don’t get a lot of snow here, but snowmelt, etc., etc.
0:36 Stormwater is NOT…
What’s not stormwater is the person in the parking lot cleaning off all the cars, or over-irrigation that’s running over your landscape down your parking lot. You have permitted non-stormwater, which is like your fire sprinkler systems being flushed. Those are permitted discharges, but they’re not stormwater.
