Did you know Issaquah Highlands has seven retention ponds for stormwater runoff located throughout the community? Each retention pond serves a function, all part of an elaborate system that pushes water in and through wetlands, streams, lakes, and eventually out to the Puget Sound.
Stormwater runoff is also an important part of the Issaquah Highlands Community Association’s (IHCA) irrigation systems. In partnership with the city of Issaquah, the IHCA has rights to pump water out of some of the ponds for irrigation, transfer water through complex pump houses and filtration devices, and deliver to IHCA common area landscaping. In addition, the city uses the filtered stormwater to irrigate Black Nugget and Central parks.
As a reminder, retention ponds are not for recreation; these ponds are very deep and specially constructed. We recently discovered a school of goldfish (most likely from an aquarium dump) in one of our ponds. In the past, the city has had to drain the entire system due to an exploding Koi population. Unmonitored fish populations can destroy our systems.
Domestic goldfish spawn every two to three weeks and lay 1,000 eggs at a time, living up to five to 10 years. Koi fish typically spawn once a year (May – June), lay up to 400,000 eggs, and can live up to 25-35 years. If you do the math, you can see how quickly this can become a problem and a very expensive one. Donate unwanted fish to fish shops, friends, and in some cases, schools.
Please report illegal dumping into retention ponds through the city of Issaquah website. If you see anyone in the ponds besides authorized city or IHCA employees, please contact the Issaquah Police Department non–emergency line: 425-837-3000. In cases of emergencies, call 911.
Sarah Hoey is the IHCA executive director.