We all have a relationship with stormwater.
We route it off our roofs and away from our houses to protect our foundations and the water disappears right? We expect that when we drive on our streets the water will sheet off and go away. Why do we assume these things?
Well, because the way we have interacted with our environment for years is that we are in control. If we want to build something, we build it. If there is water near it, we just direct it to a pipe and pipe it way.
When we all lived with lots of land around us, water already on the ground (in wetland areas or in small streams) and rain water we encountered could easily be moved on the landscape to where it didn’t bother us and would be absorbed and go away. Without us thinking about it, that water and everything it carried along with it, was being filtered by the plants, cleaned by hungry microbes in the soil and trickling down recharging the aquifer and the groundwater that fed the surface streams. The water stayed in the water cycle of the area.
As we moved to villages, cities, suburban neighborhoods, we began to build buildings closer together and covered much of the land surface with nice tidy concrete or asphalt so that it was easier walk or drive (no more muddy horse drawn carriages). The amount of earthen area available to absorb rainwater was reduced significantly. We also modified the soil by scraping away the topsoil — the most absorbent, alive part of the soil horizon.
The engineers (as long ago as the Romans) started to devise ingenious ways to channel, collect, and convey water toward whatever waterway was closest. So the mantra has been for many years — collect it and get it off the site and to the waterway as fast as possible.
So as we develop, the water that cools our streams slowly and naturally, replenish our aquifers, and keeps our groundwater fresh, has diminished. We have begun to see salt water intrusion into our shoreline wells, and most of that useful freshwater is dumped into saltwater — Puget Sound. It also means that when the heavier rains come and rain water overwhelms our engineered collection systems, the water has little pervious surface to be absorbed into and thus flows into our streams and rivers too fast, eroding their banks, causing property damage and silty water conditions. This water also carries a little bit of everything we use on our streets and lawns from Weed and Feed to copper from our brake pads.
Now there is a new idea. Actually it is an old idea that is become new again. Its new name is Low Impact Development or Green Stormwater Infrastructure. Its old name was “water absorbed by the ground!” The new/old idea is to find places to expose the ground, or engineered soil and plant areas to route stormwater.
The plants will use the water and nutrients in the runoff to grow. The areas will provide welcome green spaces (and that wonderful waste product of photosynthesis — oxygen) interspersed between our buildings and our roads. Any additional water not used by the plants will be stored or conveyed slowly, reducing the volumes conveyed and sending cleaner water to the Sound.
Kitsap County is identifying how Green Stormwater Infrastructure can be implemented in Kingston to manage and clean the stormwater. This effort will assist developers build in downtown Kingston and improving the quality of water entering Appletree Cove and our groundwater.
I’m glad what’s old is new again!
Betsy Cooper is a board member and stream monitor at Stillwaters Environmental Education Center.
