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The Balch subwatershed extends from the ridge of the West Hills near NW Skyline Boulevard to the Willamette River and includes the canyon containing NW Cornell Road. The upper portion of the watershed is mostly wooded, including parts of Forest Park, Macleay Park, and the 180-acre Audubon Society Nature Sanctuary. Balch Creek enters a large concrete box culvert at the lower end of Macleay Park and flows underground to the river. The lower portion of the subwatershed includes the site of historic Guilds Lake, filled in the early 1900s to create land for industrial development.
West of Highway 30, the stream gradient of lower and upper portions of Balch Creek main stem ranges from 15 to 30 percent. Stream gradient in the middle portion is interspersed with sections less than 15 percent and sections ranging between 15 and 30 percent. The stream gradient of most Balch Creek tributaries is greater than 30 percent.
Click here for a summary of rainfall data.
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CHANNEL TYPE
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| LENGTH (FEET) |
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| Combined Stormwater/Sewer Pipe |
2417.3 |
| Open Channel |
90520.0 |
| Roadside Ditch |
322.3 |
| Stormwater Pipe or Culvert |
18185.4 |
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111445 |
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Government 