The 303(d) list is used as a first step in locating water quality-impaired reaches, as described in the OWEB Watershed Assessment Manual. However, the 303(d) list does not include all streams that are impaired by high temperatures, sedimentation, fecal coliform, or other factors. Most of the 303(d) listed streams are mainstem rivers or large tributaries. This may reflect the methods used to designate 303(d) streams (i.e., larger rivers may receive more scrutiny during the designation process) as well as actual differences in water quality. For 6th fields that show a high length of 1:100k streams that are 303(d) listed, we recommend using finer-scale data to locate and characterize the nature of the water quality impairment. For example, STORET data may provide useful data for some locations in the study area. For areas within the Siuslaw National Forest, the Forest's stream temperature data will provide useful details. Carefully planned monitoring is recommended to increase the understanding of water quality issues in the study area.

Please address questions or comments to:

Dr. Ralph Garono
Principal Investigator
Earth Design Consultants, Inc.
rgarono@earthdesign.com

Laura Brophy
Principal Investigator
Green Point Consulting
brophyl@peak.org | homepage