Coeur d’Alene Lake Comprehensive Coring Project

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Project Sponsor

Coeur d’Alene Tribe

Purpose

This project is a collaboration between the Coeur d’Alene Tribe, Idaho Department of Environmental Quality, University of Oregon, and Indiana State University. This team is analyzing lakebed sediment core samples from Coeur d’Alene Lake and determining how the history of metals contamination and recovery actions along the Coeur d’Alene River have impacted the lake. The analyses focus on geochemistry and ecological parameters through time and seeks to answer the following questions:

  1. What was the lake’s baseline ecology and environmental condition before mining impacts and other human activities? 
  2. How has the lake’s ecology and environmental condition changed through the mining era and the subsequent remedial, restoration, and lake management work?
  3. If recent history continues, how do we expect the lake’s ecology and environmental conditions to respond, given the paleolimnologic context generated by this study?

Funding

This project received $200,000 from Governor Little’s Leading Idaho initiative, with matching funds provided by Avista Corp ($200,000) and the Coeur d’Alene Basin Restoration Partnership.

Current Status

Core samples were collected in September 2024. The analyses have started and will continue over the next two to three years. The final report is expected in 2027.

Outcome

This project will provide information to guide future restoration efforts. More realistic lake restoration goals can be set when viewed through a richer historical lens than what is provide by the current lake monitoring record.

Third Street Stormwater Volume Reduction Project

Areal image of the 3rd Street outfall location.

Project Sponsor

City of Coeur d’Alene

Purpose

The city of Coeur d’Alene is installing a stormwater storage and filtration system to divert stormwater runoff from an existing outfall.

The Third Street outfall discharges stormwater from 240 acres of city streets and parking areas, including downtown alleys. The outfall currently releases this stormwater, untreated, by the Third Street boat launch next to McEuen Park. While all stormwater carries pollutants as it passes over residential yards, city parks, sidewalks, and streets, this area includes special considerations related to dumpsters, grease, food waste, cigarette butts, and other substances that tend to concentrate in downtown streets and alleys. In addition, large rainfall events have overwhelmed the capacity of this storm system in recent years, causing localized flooding.

Improved stormwater treatments will manage this runoff and reduce pollutant loading to Coeur d’Alene Lake.

Funding

This project received $413,143 from Governor Little’s Leading Idaho initiative.

Current Status

Project design is complete and out for bid.

Outcome

Currently, the funding available is not sufficient to treat stormwater from the entire drainage area, but this project is expected to reduce phosphorus loads to Coeur d’Alene Lake by at least 35 pounds annually. As more funding is secured, the city will expand the treatment capacity.

DEQ prepares IPDES preliminary draft permit for the city of Post Falls

May 24, 2023

The Idaho Department of Environmental Quality (DEQ) released an Idaho Pollutant Discharge Elimination System (IPDES) preliminary draft permit to the city of Post Falls for preliminary review on May 18, 2023.

The facility has ten days to review the preliminary draft permit and fact sheet for any errors and omissions that should be addressed before the public participation period. After the preliminary draft period has concluded, DEQ will revise the preliminary draft permit as needed, at which point it will soon become a draft permit for public review and comment.

DEQ will formally notify all necessary parties that the draft permit, fact sheet, and associated application have been posted on DEQ’s website for public review and comment, per the “Rules Regulating the Idaho Pollutant Discharge Elimination System Program” (IDAPA 58.01.25.109). To be notified of the forthcoming posting, go to the DEQ’s “Newsroom” page and click the “Subscribe” link.

Northside Stormwater Drainage Improvements (Marmot Trail Road) 

Project Sponsor 

East Side Highway District 

Purpose   

The purpose of this project is to improve drainage systems along Marmot Trail Road, which includes approximately 3,600 feet of asphalt along a steep gradient. Managing erosion will reduce discharge into the north end of Coeur d’Alene Lake.  

Funding  

This project was awarded $14,100 from Governor Little’s Leading Idaho initiative.

Status

This project is complete. 

Outcome 

This project is expected to decrease phosphorus loading and sediment discharge from soil erosion that flows from stormwater into Coeur d’Alene Lake near the Silver Beach Marina. 

Mica Creek Watershed Agricultural Sediment Reduction and Improvement Project (Phase 2) 

Project Sponsor

Kootenai Shoshone Soil and Water Conservation District

Purpose

This project stabilized 1,600 feet of streambank on Mica Creek, a tributary to Coeur d’Alene Lake, by removing collapsed vegetation, armoring the banks, and replanting willows to prevent further erosion. These upgrades will reduce sediment and phosphorus loads to Coeur d’Alene Lake.

Funding

This project received $49,000 from Governor Little’s Leading Idaho initiative.

Current Status

The project was completed in summer 2024.

Outcome

This project is estimated to reduce phosphorus loads to Coeur d’Alene Lake by 50 pounds annually.