Oregon's rocky intertidal habitats have been subjected to gradually increasing human-use pressures as the coastal and tourist populations have risen over the years. Brosnan and Crumrine (1991,1992) have documented impacts to intertidal communities at Yaquina Head, Sunset Bay, and Haystack Rock that have resulted from people walking on the intertidal...
The Tualatin River Basin in Washington County, Oregon, is a complex area with highly developed agricultural, forestry, industrial, commercial, and residential activities. Population has grown in the past thirty years from fifty to over 270 thousand. Accompanying this population growth have been the associated increases in transportation, construction, and recreational...
Water quality and stream flow data for tliree representative land uses in the Tualatin River Basin were evaluated to determine the comparative levels of various pollutants. In addition, the data were used in an effort to identify the extent to which observed concentrations of total and ortho phosphorus could be...
The goal of this phase of the study was to develop a model of the Tualatin River incorporating Scoggins Creek and Hagg Lake. This tool will be used in conjunction with a hydrologic model, the EPA HSPF model (Johnson, Imhoff, and Kittle, 1984), to analyze management strategies to improve water...
The Tualatin River Basin in Washington County, Oregon has been identified by the Oregon Department of Environmental Quality (DEQ) as "Water Quality Limited." Algal blooms have become commonplace in the lower , reaches of. the river during summer months. Phosphorus has been identified as the nutrient upon which to base...
This report summarizes the conclusions reached in "A Project to Collect Scientific Data and Provide Evaluation and Recommendations for Alternative Pollution Control Strategies for the Tualatin River Basin."
This study was funded by the Oregon Department of Environmental Quality as a grant to the Oregon Water Resources Research Institute on...
The Tualatin River Basin along the east side of the Coastal Mountains in Oregon is subject to a complex mixture of land uses. Approximately half the area is devoted to forestry production. The remainder is divided between agriculture and urban uses. In addition to this diversity in land use, there...
This report presents estimates of land uses, concentrating on agricultural land in the Tualatin drainage basin. Acreage in different crop groups and agricultural water use and distribution in the watershed were estimated. The total amounts of nitrogen and phosphate applied to agricultural land and the average loading of nutrients per...
The Tualatin River is a major water resource for Washington County. In its course, the river drains forest lands, farmlands, and urban areas receiving toxic materials from non-point source runoff: Wastewater treatment plant effluents from municipalities and industries also contribute toxic materials to the river. Many materials discharged into the...
In response to Oregon House Bill 3338, the Oregon Department of Environmental Quality requested proposals in 1991 to assemble available information on Tualatin River Basin conditions to provide a scientific basis for improving river water quality. An interdisciplinary team of researchers from Oregon State University and Portland State University was...
The Tualatin River in northwest Oregon has been designated as water quality limited by the Oregon Department of Environmental Quality. Restoration and enhancement of riparian areas to improve water quality is one task to be pursued by management agencies. This paper examines some of the potential costs and benefits of...
About one-third of the land in the Tualatin Basin is used for agricultural production (Miner, Scott, and Wood, 1994). The variety of crops produced includes grains, specialty seeds, vegetables, fruits, berries, and nursery corps. Cattle and hog enterprises are the most prevalent livestock operations in the area (measured by number...
Dionysius said that history is philosophy learned from examples. As one of the original four counties of the Territory of Oregon, the Tualatin River Basin is rich in history. While still a prime agricultural region, the Tualatin Valley is one of the state's fastest developing areas. The slow accumulation of...
The Tualatin Basin landscape has undergone extensive change since the initiation of Euro-American settlement, with important consequences for basin hydrology and water quality. Changes that include the isolation of the Tualatin River from its floodplain areas, losses of important wetlands and riparian areas, and urbanization associated with population growth in...
As part of the Willamette Basin Geographic Initiative Program, the Environmental Protection Agency (EPA) funded The Nature Conservancy of Oregon to inventory, classify, and map native wetland and riparian plant communities and their threatened biota in the Willamette Valley. Between October 1994 and September 1996, we evaluated 172 wetland and...
The pages which follow contain the authors responses to a series of comments that were received in response to "A Project to Collect Scientific Data and Provide Evaluation and Recommendations for Alternative Pollution Control Strategies for the Tualatin River Basin, 11 submitted to the Oregon Department of Environmental Quality (DEQ)...
The purpose of this study was to develop a mass-balance model for total suspended solids in the Tualatin River in order to better understand the clarity-turbidity problem in the river. Major sources and sinks of suspended solids in the river were identified, and seasonal effects were explored. The study also...
Dairy Creek, located in Washington County, Oregon, has a drainage area of approximately 230 square miles, and includes West Fork, East Fork, and McKay Creek drainages. Dairy Creek is a major tributary of the Tualatin River which experiences algal problems during the late summer when stream flows decrease and water...
Tributaries of the Tualatin River cascade down high gradient slopes for relatively short distances, then flow into the low gradient mainstem which meanders for much of its length. The gentle, east-facing slopes of Oregon's Coast Range provide the geomorphic and climatic template for the watershed's patterns of discharge, water quality,...
Watershed assessment is a process for evaluating how well a watershed is working. The purpose of this assessment was to determine how natural and human-induced changes have impacted the sustainability of salmon populations in the Nehalem River Watershed. Both historical and current information is included regarding the watershed’s ability to...
This project, commissioned in 1998, is part of the MidCoast Watersheds Council's efforts to better understand the status and condition of the area's natural resources and to work with interested landowners to enhance and protect important areas.
Coho salmon have been the most important variety of salmon caught commercially in Oregon. Until recently, coho were also the most common variety in most coastal streams. Based on records from salmon canneries, coho in Oregon north of Cape Blanco (near Port Orford) numbered about 1.25 million adults annually 100...
This analysis was performed for two reasons: 1) the KWG needed a way to focus and synthesize the results of applied research on the condition and trends of natural resources, and the factors affecting those resources; and 2) a detailed watershed analysis was needed to supplement watershed assessments planned for...
Anglers and naturelovers prize steelhead trout for their mystique and power. Oregon has two subspecies of steelhead (so-called because of the metallic appearance of maturing adults) or rainbow trout: a coastal form and an inland form.
The purpose of this document is to
help guide the Council toward its goals of improving, maintaining and
protecting watershed health, and fostering stewardship and
understanding of the watershed.
Chinook salmon are the largest of any of the salmon in Oregon. Mature fish range from less than 2 pounds to more than 70 pounds. In the late 1800s, chinook salmon were almost the only species taken for canning in the Columbia River, with production peaking at 43 million pounds...
The Lower Alsea River Watershed Analysis contains information which characterizes the processes and trends for resources of concern, and provides a context relating the function of this lower portion of the watershed to the Alsea River Basin as a whole. Critical problem areas both inside and outside federal lands are...
Coastal cutthroat trout is one of three cutthroat subspecies found in Oregon. The coastal subspecies, which is closely related to steelhead/rainbow trout and Pacific salmon, displays the most diverse and flexible life history of any of the Oregon salmonids. Coastal cutthroat can be found in streams and rivers from the...