Watershed/Basin Studies

Fish, wildlife, and human populations along the lower Columbia River are exposed to an ever-growing variety of contaminants as a result of increasing urbanization, industrialization, and agricultural development.

Warming air temperature may change water temperature and water column mixing in Oregon’s Crater Lake over the next several decades, potentially impacting the clarity and health of the iconic lake.

The USGS documents historical and current channel and floodplain processes and conditions to assist management and regulatory agencies in evaluating restoration proposals and designing effective restoration and monitoring strategies for the Sprague River and its principle tributaries. The study involves multiple analyses, including assessments of historical channel change, riparian and floodplain...

The streamflow and water-quality conditions monitored by the USGS in the North Santiam River basin provide valuable information to water resource managers

The USGS has characterized nutrient concentrations in the Klamath River and Lost River drainages over multiple years, identified spatial and temporal patterns in nutrient and organic carbon concentrations, and quantified surface water nutrient loads entering and exiting the Klamath Project.

The Wild and Scenic North Umpqua River is one of the highest-quality waters in the State of Oregon, supporting runs of wild salmon, steelhead, and trout. The USGS has been studying water-quality in the Umpqua River Basin since 1998.

Each autumn Fall Creek Lake is drawn down to allow endangered juvenile salmonids to pass freely through the dam. The drawdowns involve lowering the lake water level to the lake bed, creating a fluvial environment characterized by large amounts of sediment being transported through the dam and into Fall Creek and the Middle Fork Willamette River.

The Columbia River Basalt Group (CRBG) consists of a thick sequence of Miocene flood basalt that covered northern Oregon, eastern Washington, and western Idaho between 17 and 6 million years ago. It is an important regional aquifer system, and, in its folded and faulted flows, it records the late Cenozoic structural evolution of much of the Pacific Northwest.

Starting in 1997, the USGS began routinely studying water resources in the Clackamas River Basin. Whether it be assessing harmful algal blooms, runoff issues, streamflow, or watershed health, the USGS has worked with its partners to maintain one of Oregon's most beloved rivers.

Cottage Grove Reservoir is an impoundment of the Coast Fork of the Willamette River and is managed by the U.S. Army Corps of Engineers (USACE) as part of the Willamette Valley Flood Control Plan. The reservoir is currently under a fish consumption advisory because of elevated levels of mercury in fish tissue observed in an Oregon Department of Environmental Quality sampling survey in 2003 (Oregon...

Drinking water for the city of Eugene, Oregon, is drawn from the McKenzie River, a high-quality source that is nonetheless threatened by urban, agricultural, and forestry land uses upstream as well as by changes in water management in the watershed. In 2002, the USGS began monitoring dissolved pesticides in the McKenzie River and its tributaries.

Environmental flows are defined as "streamflow needed to sustain ecosystems while continuing to meet human needs."