Surface Water

Surface water weaves across the Oregon landscape, defining distinct ecoregions and watersheds. Surface freshwater includes rivers, lakes, and wetlands. Surface water is an important environmental resource for natural systems and human use.



Created by Gareth Baldrica-Franklin, Institute for Water and Watersheds, Oregon State University














Rivers

Rivers are the primary driver of surface water systems. The largest river in Oregon is the Columbia, which snakes its way across the northern Oregon border. Many of Oregon's larger rivers are tributaries of the Columbia, such as the Willamette, Deschutes and John Day. Other major rivers include the Klamath, Rogue and Umpqua.



Widespread damming has reduced the flow of many Oregon Rivers below their natural levels. The John Day River is the longest river in Oregon that has remained undammed.



Hover over rivers for details.

Watersheds

Rivers define watersheds (or basins). Watersheds represent the total area that drains into a river, or river section. Watersheds can be defined at various scales, representing vast basins of major rivers, or small areas of urban creeks.



Watersheds shown in the map are recorded at the 4th level of delineation, and colored based on the third level of delineation. At lower levels of delineation, watersheds are generalized to major rivers and regions.



Hover over watersheds for details.

Lakes

Oregon is filled with lakes. Some are naturally occurring, some are manmade, and some are ephemeral, only existing in wet months. Many of Oregon's largest naturally occurring lakes exist in the southern part of the state.



Lake Type


Natural


Manmade/Reservoir


Hover over lakes for details.

Watershed Councils

Watershed councils are independent, voluntary organizations designed established to improved watersheds in their localities. Watershed councils are strictly managed locally, although the state provides guidance for their formation. Councils assess local water conditions, provide restorative and conservation services, and create communities revolved around protecting water.



Hover over map for details.

Wetlands

Over 40% of Oregon's wetlands have drained or filled since Euro-American settlement. However, wetlands are among the most important ecosystems for wildlife and water quality. Wetlands store and clean water, prevent erosion and control flooding. They are also important habitats for a variety of plants and animals.



This map shows Oregon's "Greatest Wetlands", which were identified by the Wetlands Conservancy.



Hover over wetlands for details.

Pollution

The Oregon Department of Environmental Quality (DEQ) assesses rivers and lakes for pollutants. Pollutants can include minerals, chemicals, biological agents, sediment or temperature issues. If identified pollutants are above certain concentrations, a waterbody is declared Water Quality Limited for that pollutant.



The map aggregates all identified water quality limited pollutants for 2012 into their respective watersheds.



Number of Pollutants


Greater than 101


51-100


26-50


11-25


Less than 10


Hover over watersheds for details.