Fanno Creek Mainstem
Fanno Creek Mainstem originates in the Tualatin Mountains of southwest Portland and drains 1,831 acres within the city boundary. The mainstem begins at the intersection of SW 25th Avenue and SW Beaverton-Hillsdale Highway and flows west through West Portland along and north of Beaverton-Hillsdale Highway.
The mainstem of Pendleton Creek originates near SW Fairvale Court and SW Kanan Street and drains 230 acres in the City of Portland. The creek flows west for eight tenths of a mile and leaves the Urban Services Boundary (USB) south of Beaverton-Hillsdale Highway around SW 65th Avenue. It then continues west until it joins the Fanno Creek Mainstem near the intersection of Beaverton-Hillsdale Highway and Oleson Road.
Vermont Creek originates east of Gabriel Park and drains 758 acres within the City of Portland. A southern tributary, it originates just north of SW Multnomah Boulevard and flows north paralleling SW 45th Avenue, and joins the mainstem near SW 45th Avenue and SW Caldew Street. The creek flows west from this confluence for 1.4 miles, exits Portland’s USB west of SW Shattuck Road north of SW Vermont Street, and continues west until it joins the Fanno Creek Mainstem west of Oleson Road.
Woods Creek originates near SW Taylors Ferry Road and Capitol Highway and drains 576 acres with the Portland's jurisdiction (784 acres total). The creek flows northwest for 1.8 miles, crossing Multnomah Boulevard near SW 51st Avenue. The creek then flows west, leaving the Portland city limits 350 feet north of SW Canby Street near SW 64th Place. Woods Creek continues west until it joins the Fanno Creek Mainstem west of Oleson Road near Oregon Episcopal School.
North Ash Creek
North Ash Creek originates near SW Bruegger Streetand SW 50th Avenue and drains 282 acres within the Portland's jurisdiction. The creek flows west for eight tenths of a mile until exiting the USB at SW Dolph Road.
South Ash Creek
South Ash Creek originates just west of I-5 near SW 52nd Avenue and drains 360 acres within Portland’s jurisdiction. Stormwater from sections of I-5 drains into South Ash Creek. The creek flows west and exits the USB north of SW Dickson Place prior to joining Fanno Creek.
Red Rock Creek
Red Rock Creek originates just south of I-5 near Capitol Highway and drains 413 acres within Portland’s jurisdiction. Stormwater from sections of I-5 drains into Red Rock Creek. The creek flows west and exits the USB near SW 64th Avenue before joining Fanno Creek.
Only a small portion of the overall Sylvan Creek drainage area is within the City of Portland. Sylvan Creek is generally addressed with Fanno Creek Mainstem.