The hyporheic zone is where groundwater and surface water interact below the stream bed. In a healthy river, it’s where microbes and tiny invertebrates filter pollutants, cycle plant matter and form the base of the food chain. 

In 2015 Seattle Public Utilities inoculated newly restored stream beds of Thornton Creek with hyporheic material gathered from Cedar River tributaries in an attempt to jumpstart the process. (https://www.seattletimes.com/s...)

This confirmed my belief in the power of small things…including small brush strokes.