SPOKANE, Wash. — Manito Park’s Mirror Pond is set to be rehabilitated in late fall.
Many people have noticed that the pond looks green. The city of Spokane says it’s because of planktonic algae.
The bottom of the pond builds up with broken down organic material loaded nitrogen and phosphorous, which the city says is great food for algae. The pond is shallow and there’s not enough water above the pond floor to filter out light, which helps grow algae blooms.
The city said the algae blooms are not harmful in small amounts, but large blooms can harm wildlife.
The city of Spokane said they are taking six steps to solve the problem without the use of toxic chemicals.
They plan to safely remove indigenous wildlife from the pond, dredge the pond to remove sediment, deepen the pond, install treatment wetland to filter out phosphorus and nitrogen, reintroduce water and wildlife to the pond and implement a yearly pond management plan.
The project is expected to start in late fall and be completed by the spring of 2020.