UPDATED: Priority Stream Proposed For Toxin Testing

City staff Roger Dane & Steve Fix bookend Tosh Creek, 8/30/2016 
credit: Bob Yoder

This project is under consideration.

"Restoring Tosh Creek" Bob Yoder (great background on the creek.)

$6.5 Million Restoration, Redmond Reporter

Tosh Creek is a Type 2 Priority watershed destined for complete restoration.  It's headwaters are Overlake neighborhood residential adjacent West Lake Sammamish Parkway.  The creek runs through acres of undeveloped land (prime recharge area); it's mouth is the Lake Sammamish River.  At the mouth the creek provides spawning and backwater for Coho Salmon rearing and cool water for Chinook.

The City's environmental biologist, Jessica Atlakson, presented to Council a Tosh Creek street- sweeping project that could remove copper toxins from vehicular tires.  The specific toxin is "6ppdq."  A $55,500 King County Waterworks grant would determine the effectiveness of street-sweeping on toxin removal.  3.54 miles of West Lake Sammamish will be swept beginning 10/22 until 9/24. 

OLD NEWS:  

 Increased street sweeping within the Monticello Creek Watershed in 2017-2019 was shown to improve water quality of Monticello Creek by reducing the total copper and suspended solid concentrations within the creek. Staff will leverage water quality sampling from the Redmond Paired Watershed Study (RPWS) to determine if increased street sweeping within the Tosh Creek Watershed will also improve water quality. 

The RPWS is designed to measure the effectiveness of actions taken by Redmond’s Stormwater Utility and King County to restore urban streams on a watershed scale. This is done by analysis of monitoring data collected in six watersheds within Redmond, including the Tosh Creek Watershed. Council was provided with an update on RPWS findings during the June 1, 2021 staff report. RPWS data collected from Tosh Creek will be used to determine the effectiveness of street sweeping to improve water quality.

-- Bob Yoder, 7/5/2022

Source:  Council Committee of the Whole, Public Works,  CM Malissa Steward, Presiding Officer.