“You mean… rain?”
Stormwater is a weird word. A conjunction of “storm” and “water” immediately implies that we’re talking about rainfall; however, stormwater is a technical term that is used to describe all rainfall that hits the land surface and begins to flow some other way.
When we talk about stormwater in a technical sense, we usually concern ourselves with the quality or quantity of the stormwater. Land cover is an important part of these concerns. Stormwater flowing off an asphalt parking lot has more quantity compared to stormwater from a natural forest because impervious surfaces prevent it from infiltrating into the ground. Also, parking lots can be covered in small amounts of pollutants, such as oil, trash, and microplastics that are picked up in stormwater and transferred downstream. Comparatively, stormwater runoff from a city park will have less quantity and better quality once it leaves the site.
“Stormwater is rainwater or melted snow that runs off streets, lawns and other sites.” -Environmental Protection Agency
How does this stormwater affect me, personally?
In developed areas, like cities or medieval villages, the flow of stormwater is disrupted in some way. For most cities, stormwater is directed under the ground into storm sewer systems, which convey the water to tidal waterbodies (Tampa Bay) or temporary stormwater management facilities (a pond). Even medieval villages, with their thatched roofs and bare earth roads, dealt with stormwater challenges; likely when it rained roads were washed out and downstream rivers became muddy with sediment.
Quality issues with stormwater are the most apparent to us on a day-to-day basis. With poor management, our waterbodies can show impairment during and after most rain events. Ponds near your home may be murky with sediment, shiny with oil, or covered in algae. Harmful algal blooms, a natural phenomenon exacerbated by human-caused water quality changes, may cause fish to die and beaches to be off-limits. These impacts can be short lived or last for significant periods of time. Even if all stormwater runoff was treated to perfection starting today, poor water quality in waterbodies will still exist and take time and effort to improve.
Water quantity issues, also called flooding, is another common impact to our lives, although this can be rarer or more location specific. For example, during and shortly after a storm, a roadway could have stormwater ponding on its surface, preventing access for hours after the rain. On a more extreme scale, large storms can drop so much rain that rivers flood over their banks and entire city blocks are filled with stormwater, which can cause property damage and spread disease to our community members. Flooding is the most costly natural disaster in this world, and sometimes it is entirely a stormwater management issue.
So, why is this still a problem?
You would think that stormwater management systems, which can include pipes and ponds and medieval roadside ditches, could be sized to prevent all flooding and keep our waterbodies clean. And, you’re right. We can make our pipes bigger and our treatment standards more strict, but not without costs. Bigger pipes and ponds cost exponentially more money to build and reduce the areas available for development. The most common ways to treat stormwater runoff are to let it infiltrate into the ground like it did in undeveloped conditions, which takes area and time. Holding too much stormwater in a pond for too long a time may compromise its ability to reduce flooding. Like the feudal weapon, stormwater management can be doubled-edged.
So, where does this balance lie? How many restrictions on development should we have? How much funding should we allocate for fixing our stormwater management problems?
There likely isn’t one answer to these questions, but the conversations are still worth having.
Welcome to Druid.
“You have to stand up for some things in this world.” -Marjorie Stoneman Douglas
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