By the end of September 2020, both Coon and Martin Lakes will have new treatment of stormwater before that water reaches the lake. Two stormwater ponds at Martin Lake are being renovated. One new rain garden at Coon Lake is being constructed.
The two stormwater ponds already exist on the shores of Martin Lake at 228th Place and 230th Avenue (see map). Like a full vacuum cleaner bag, they have captured as much sediment and nutrients as is possible. To call them "ponds" today seems generous. Each will be made deeper than the original design, like replacing an old, full vacuum cleaner bag with an empty, bigger bag. Pollutant removal will be more than 50% greater than when the ponds were originally designed and new. Water reaches the ponds by pipes that capture water from several acres of surrounding neighborhood, including roads.
The rain garden at Coon Lake will capture curbside water that today is piped to Coon Lake without treatment. The curb will be cut creating entrances to the approximately 1 ft deep basin. Sandy soils allow quick infiltration of the water. A special underdrain ensures no standing water. Native plants create a garden appearance. The owner of the property on Channel Lake has agreed to maintain the garden.
Images show project locations and condition of the stormwater ponds before renovation.