Mitchell Creek Restoration
Abstract
JCWC’s instream habitat program is focused on restoring salmon habitat and water quality and restoring fish access to these habitats, with emphasis on cold water tributaries. One such tributary is Mitchell Creek, which flows into Kelley Creek before joining Johnson Creek near the center of the watershed. Mitchell Creek is less than 2 miles in length, however it runs cold throughout the year and its headwaters in largely intact forest that is protected in perpetuity by Metro ownership. Since 2015, JCWC has been working with the Centennial School District to restore a 900’ section of Mitchell Creek by removing 2 fish passage barriers and a 1 acre in-line pond. The pond, which monitoring has shown to increase water temperatures in Mitchell Creek by as much as 14 degrees Celsius, was created over 40 years ago when the property owner constructed an earthen track for racing horses and ATVs. This track also crossed Mitchell Creek in 2 locations, ultimately creating 2 fish passage barriers. The downstream culvert was perched, in that its inlet opening was higher than the creek flowing into it, which helped create the pond and contributed to downstream scour. The latter affected accessibility to fish moving upstream. The upstream culvert was undersized, and overly steep which served to scour the upper portion of the pond. Funding for this project was provided by the East Multnomah Soil and Water Conservation District, Oregon Watershed Enhancement Board, PGE/TNC, USFWS Willamette Valley Refuge Complex, mitigation funding and a new grant from Metro Nature in Neighborhoods to support revegetation efforts!
Subjects
Habitat restoration, Water quality, Wildlife biology, Land/watershed management, Fisheries
Persistent Identifier
https://archives.pdx.edu/ds/psu/33821
Mitchell Creek Restoration
JCWC’s instream habitat program is focused on restoring salmon habitat and water quality and restoring fish access to these habitats, with emphasis on cold water tributaries. One such tributary is Mitchell Creek, which flows into Kelley Creek before joining Johnson Creek near the center of the watershed. Mitchell Creek is less than 2 miles in length, however it runs cold throughout the year and its headwaters in largely intact forest that is protected in perpetuity by Metro ownership. Since 2015, JCWC has been working with the Centennial School District to restore a 900’ section of Mitchell Creek by removing 2 fish passage barriers and a 1 acre in-line pond. The pond, which monitoring has shown to increase water temperatures in Mitchell Creek by as much as 14 degrees Celsius, was created over 40 years ago when the property owner constructed an earthen track for racing horses and ATVs. This track also crossed Mitchell Creek in 2 locations, ultimately creating 2 fish passage barriers. The downstream culvert was perched, in that its inlet opening was higher than the creek flowing into it, which helped create the pond and contributed to downstream scour. The latter affected accessibility to fish moving upstream. The upstream culvert was undersized, and overly steep which served to scour the upper portion of the pond. Funding for this project was provided by the East Multnomah Soil and Water Conservation District, Oregon Watershed Enhancement Board, PGE/TNC, USFWS Willamette Valley Refuge Complex, mitigation funding and a new grant from Metro Nature in Neighborhoods to support revegetation efforts!
