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Project Sponsor
City of Coeur d’Alene
Purpose
This project installed stormwater storage and filter systems at outfalls located at Independence Point, Sanders Beach, and along Mullan Avenue in Coeur d’Alene, Idaho. These management strategies divert stormwater runoff from existing discharge points, also known as outfalls, in the urban drainage areas and provide water quality information to the community.
Stormwater runoff pollutants from yards, sidewalks, and streets eventually flow into storm drains that discharge directly to Coeur d’Alene Lake in these neighborhoods. Two Sanders Beach outfalls collect runoff from 76 acres, and the East Mullan outfall drains 13 acres of area. The Independence Point outfall conveys runoff from 131 acres to the lake. Before these stormwater management installations, pet and wildlife waste, vehicle fluid, any fertilizer not taken up by lawns and gardens, and anything spilled onto sidewalks, gutters, alleys, and streets in these areas flowed untreated into Coeur d’Alene Lake. This project redirects runoff through a variety of filtration systems and, barring high precipitation or snowmelt events, prevents this surface runoff from reaching the lake.
Even with these management measures in place, residents and visitors must be mindful about daily habits such as fertilizer use and waste disposal. Less pollution to capture and filter means less maintenance time and cost. Filtration systems can be overwhelmed, increasing the possibility that phosphorus and other pollutants in stormwater can reach Coeur d’Alene Lake.
Funding
This project received $1.4 million from Governor Little’s Leading Idaho initiative.
Current Status
The work for all of these outfalls is complete.
Outcome
This project is expected to reduce phosphorus loads to Coeur d’Alene Lake by approximately 280 pounds annually. The estimated phosphorus load reductions for each drainage area are as follows:
- Sanders Beach: 140 pounds of phosphorus/year
- Mullan Avenue: 20 pounds of phosphorus/year
- Independence Point: 120 pounds of phosphorus/year