Skip to Main Content View Text-Only

Environmental Services

working for clean rivers

Phone: 503-823-7740

Fax: 503-823-6995

1120 SW 5th Avenue, Room 1000, Portland, OR 97204

More Contact Info

Table of Contents
Streams & Water Bodies

This subwatershed is named for Stephens Creek, but it contains several other small, unnamed tributary streams. The stream gradient of portions of Stephens Creek and its tributaries in the lower and southern portion of the subwatershed generally ranges from 15 to 30 percent. The upper reaches, including a tributary stream in the northwestern portion of the subwatershed, have gradients less than 15 percent. Additionally, numerous small streams occur in the Riverview Cemetery in the southern portion of the subwatershed. The Public Facilities Plan ( BES, 1999) indicates that recent modeling indicates that many sections of the stream channel have excessive velocity, possibly leading to erosion.

A preliminary analysis of the flow data revealed that during the spring (late May-late July), average flow in Stephens Creek was 1.0 cubic feet per second (cfs). The lowest summer flow in Stephens Creek was 0 cubic feet per second (cfs). This occurred during the middle of June 2003, and lasted for approximately 2 days. BES is currently monitoring flow in Stephens Creek. This monitoring began in late August 2002 and continued through December 2002, then resumed in May 2003. Winter flows were not measured due to concern that the flow sensors would be damaged by rocks and large debris that move within the stream during winter months.

Peak flow during the summer was 9.4cfs, and occurred during the middle of May 2003 (Stephens Fig 1). Precipitation data were not yet available for the 2003 summer months.

During the winter, flow in Stephens Creek is heavily influenced by precipitation. Peak flows always occurred after relatively larger precipitation events (greater than 0.15 inches; Figures 2 and 3). The largest flows during fall 2003 (17.4cfs on 11/13/02) occurred after five days of rain. Still, not all rain events produced increased flows in the creek. For example, precipitation data show a rain event on 10/28/02 of 0.14 inches, but flow in Stephens Creek did not increase significantly (Stephens Fig’s 2 and 3). This may have been due to the fact that it had not rained for almost a month before this date. Average winter flow was 1.9cfs, with a minimum flow of 0.4cfs.

Click here for a summary of stream flow monitoring.
Maps & Files

Stephens Fig 1.jpg

Stephens Fig 2.jpg

Stephens Fig 3.jpg

Questions & Comments
If you have any questions or comments on our web site, please contact our webmaster.