State law requires the Surface Water Utility to protect and improve the water quality of the City's streams and lakes. However, the Utility goes beyond the minimum requirements by monitoring the water quality and promoting actions that prevent pollution of these water bodies. 

Water Quality SamplingWater Quality Sampling 2

Collecting water quality samples at Hidden Lake

Lake Monitoring 

Utility staff monitor the water quality of Echo and Hidden Lakes. Staff monitor for potential health risks such as high fecal coliform bacteria levels and toxic algae as well as other water quality indicators such as temperature, dissolved oxygen and turbidity. 

Echo Lake

  • Swimming beach tested for bacteria levels every week in summer, May - October.
  • Profile sample collected every two weeks in summer. 
  • Any signs of toxic algae are sampled and tested when found.
  • Potential health risks are identified, residents are notified and warning signs posted as appropriate. 
  • One water quality warning was issued for the 2017 sampling season. An algal bloom was also monitored and was not found to be harmful.

Hidden Lake

  • Swimming beach tested for bacteria levels every week in summer, May - October.
  • Any signs of toxic algae are sampled and test when found.
  • Potential health risks are identified, residents notified and warning signs posted as appropriate.

The 2018 Lake Sampling season is currently underway. To date, there have not been any exceedances of the water quality standards during the current sampling season.

Stream Monitoring

The Utility collects and analyzes water quality data for six of the city's major streams. Samples are collected year-round on a monthly basis. Streams sampled include:

  • Boeing Creek (east and west forks)
  • Cedar Brook Creek
  • Littles Creek
  • McAleer Creek
  • Storm Creek
  • Thornton Creek

Annual reports are available on the King County Water Quality Index for Streams and Rivers webpage.

Boeing Creek

 

Reports

*NEW* 2017 Monitoring Stormwater Retrofits in the Echo Lake Drainage Basin Report

This report presents an evaluation of the effectiveness of a stormwater retrofit along the Aurora Corridor in the Echo Lake drainage basin. The study was designed to address data gaps by the Washington State Stormwater Work Group (SWG) in the effectiveness of stormwater treatment technologies used in the Puget Sound Region. For more information about this project, visit King County's project page: link.

2016 Freshwater Assessment Report

2016 Freshwater  Report CoverThis report summarizes water quality data collected over an 8 year period between 2009 through 2016. This data builds on the previous 2009 report in order to track long-term water quality in Shoreline and determine if current programs are effective.

2016 Echo Lake Aquatic Vegetation Report

2016 Aquatic Vegetation ThumbnailThe Washington State Department of Ecology, in coordination with the City of Shoreline, conducted an aquatic vegetation survey at Echo Lake in June 2016. The survey revealed that Echo Lake contains nine native vegetation species and three non-native species.

 

2009 Fresh Water Assessment Report

2009 WQ Rept Thumbnail

 This report summarizes water quality data collected over an 8 year period between 2002 through 2009. Comparison of future data to the baseline data will help track long-term water quality trends and determine if current programs designed to improve water quality are effective.

 

2009 Bioassessment Report

Bioassessment

A biological assessment of City streams was conducted in 2003 and 2007, using macroinvertebrates (stream bugs) as indicators of health in Thorton, McAleer, Boeing, and Storm creeks.The report found that all streams are severely or extremely impacted by urbanization.