A Review of Water Characteristics of Grays Harbor 1938-1979 and an Evaluation of Possible Effects of the Widening and Deepening Project upon Present Water Characteristics
Abstract
The Seattle District U.S. Army Corps of Engineers proposing to widen and deepen the navigation channel in Grays Harbor, Washington. The objectives of this report are 1) to evaluate the existing water characteristics of Grays Harbor, 2} to summarize these data, 3} to evaluate the possible impacts the proposed dredging project may have upon the water characteristics and 4) to evaluate mathematical models for use as predictive tools in describing the distribution of dissolved oxygen (DO). Water characteristics data were obtained from many sources and covered the years from 1938 through 1979. Over 36,000 records were analyzed and are published as a separate appendix to this report. Grays Harbor is a dynamic body with the water moving in response to the tides. Frequently during periods of low river flow a "DO sag" occurs from Hoquiam to Cosmopolis. The amount of DO in Grays Harbor has increased from 1975 to date because of improved methods of waste treatment practices by industry and municipalities. Three mathematical models- designed to predict the distribution of DO in Grays Harbor were examined. After careful review, the EPA model developed by Region X, Seattle office, was implemented. Output from the model did not reproduce the migratory nature of the "DO sag" nor the tidal periodicity observed in DO at a given location. Hence the results from this model are not suitable for use in applied problems. t is the conclusion of the authors that the proposed widening and deepening of the navigation channel in Grays Harbor will have no significant impact upon the water characteristics of Grays Harbor.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 01, 1981
- Accession Number
- AD1220883
Entities
People
- Eugene E. Collias
- Lincoln C. Loehr
Organizations
- University of Washington