How well do you know your watershed?
This is my watershed hierarchy as indicated by The Oregon Explorer Map Watershed Levels feature:
Level 1- Pacific Northwest
Level 2- ?
Level 3- Willamette
Level 4- Tualatin
Level 5- Dairy Creek
Level 6- Lower McKay Creek
Glencoe Swale was included in an Environmental Assessment Report prepared for the Port of Portland by CH2MHill as part of Hillsboro Airport’s application process for permission to build a parallel runway. Glencoe Swale was also included in another study done by Tualatin Basin Partners for Natural Places to form guidelines for the use, conservation, protection, and restoration of natural resources in the Tualatin Basin. Facts from these documents allowed me to construct a better understanding for the waters that flow through my front yard.
Glencoe Swale is an intermittent tributary of McKay Creek. From its confluence with McKay Creek, it extends north-northeasterly to it headwaters near NW 253rd Avenue. The streamshed encompasses about 2, 172 acres, most of which are located within the City of Hillsboro. Glencoe Swale is typically drier in the summer and flows during the wet season (November to June). However, some pockets of standing water are possible along the stream year-round. A pond near Glencoe High School holds water year-round.
Water quality data was not known for Glencoe Swale (DEQ, 2008); however, some information can be deduced from known McKay Creek data. Based on upstream conditions, it is expected that ammonia, chlorophyll A, Escherichia coli, phosphorus, and sedimentation concentrations are potential concerns. Dissolved oxygen is likely to low and water temperature too high to sustain fish stocks. The largely urban setting for this streamshed creates a high percentage of effective impervious area throughout the area. To help with infiltration, many neighborhoods have retention basins to prevent surges of water into the swale, and to decrease untreated run-off.
The National Wetland Inventory lists Glencoe Swale as palustrine, emergent, seasonally flooded, and excavated (USFWS, 1992). It consists of three reaches and one tributary, each with differing environmental characteristics. “The lowest reach- located east of the confluence of Glencoe Swale with McKay Creek contains high quality wetlands…(the next reach) located north of NE Harewood Street extending…to NE 15th Avenue, contains moderate quality wetlands. The upper reach…has been channelized, was found to be locally non-significant. The riparian upland wildlife habitat for (the tributary) is high quality” (Tualatin Basin ESEE, page 4-3220.) Our property lies within the quality streamshed area, which is very good news for the Nature Habitat area we are developing.
Our watershed is represented by the Tualatin River Watershed Council. The Council is not a regulatory or enforcement agency; it is interested promoting collaborative, informed problem-solving and decision-making when it comes to managing the Tualatin River Watershed. Community involvement is promoted, riparian restoration, education and outreach information is available on the TRWC website. Council meetings are held the first Wednesday of each month. I am interested in learning more about this agency:)
Oregon Explorer Map Viewer
Tualatin River Watershed Council