Rain (stormwater) collected on the parking lots and roofs are gravity fed into a treatment wetland where the pollutants are filtered. The treatment pond in Ku’ wah-dah-wilth is named Too-mahnocks, meaning “tule” or “bulrush” in the Yurok language. The pond naturally improves the quality of stormwater by filtering sediments and other pollutants that are carried to the wetland with runoff from the roofs and parking lots.
After entering the wetland rainfall runoff slows down and moves around plants. This allows sediment in the water to fall to the wetland floor. Nutrients from fertilizers, and other sources, dissolve in the water and are absorbed by plant roots and microorganisms living on plants and in the soil.
Wetland plants such as tule, which is the tall reed-like plants growing around the edges of the wetland, creates a mesh of thick plant material that filters the water. Tule plants have stems that look like sponges inside. This characteristic allows oxygen to be transferred from the air to the roots that are under water. Tule is used by local tribes to make traditional sleeping and sitting mats.
The Too-mahnocks Pond showing open water in the center of pond for waterfowl and Tule growing around the edges
[click photo to enlarge]