Estimates of Historic Columbia River Basin Flows and Sediment Transport
Period of Record Estimated: 1878 - 2004

Interest in sediment transport in the Columbia River Basin is continually increasing. Management of the Columbia River system requires balancing the interests of many stakeholders with requests for navigation channel improvements, increased water supply for hydropower and irrigation, and improved environmental conditions. One of the most challenging aspects of system management is mitigating negative impacts to protected salmon populations as required by the Endangered Species Act while still accommodating development such as the recently initiated project to deepen the navigation channel to 43 feet. The role of sediment transport is vitally important in management decisions regarding these and other aspects of the Columbia River.

To learn more about how the Columbia River and estuary has changed under the influence of modern development river flow and sediment transport was estimated from the available data within the 1878 - 2004 time period. Three different estimates were completed to account for changes in system conditions that alter the flow regime. Observed flow represents river flow recorded at the stream gauge. Observed flow data includes all available data and estimations based on routed flows. Adjusted flows account for changes in upstream storage and represent that river flow that would be observed in absence of the reservoir system. The virgin flow calculation removes the influence of irrigation on river flow and is considered to be the flow that would occur without anthropogenic influences on the river system. Different levels of sediment transport are calculated based on the associated flow regime.

This data is made available to the public with the disclaimer that many of the values are estimations not measured data.

River Flow Data

Columbia River at:

The Dalles
Observed Flow
Adjusted Flow
Virgin Flow

Vancouver
Observed Flow

Beaver Army Terminal at river mile 54  (readme)
Observed Flow
Adjusted Flow
Virgin Flow

Columbia River Tributaries

Willamette River at Portland
Observed Flow
Adjusted Flow
Virgin Flow

Cowlitz River
Observed Flow
Adjusted Flow
Virgin Flow

Lewis River
Observed Flow
Adjusted Flow
Virgin Flow

East Fork Lewis River
Observed Flow

Kalama River
Observed Flow
Virgin Flow


Sediment Transport Data (readme)

Columbia River at

Vancouver
Total Load
Sands

Beaver Army Terminal at river mile 54 (read me)
Total Load


Columbia River Tributaries
Willamette River at Portland  (read me)
Total Load
Sands
Fines

Cowlitz River at
          Fine sediment transport under observed flow conditions

Lewis River
         Fine sediment transport under observed flow conditions
         Fine sediment transport under adjusted flow conditions
         Fine sediment transport under virgin flow conditions

East Fork Lewis River
         Fine sediment transport under observed flow conditions

Kalama River
         Fine sediment transport under observed flow conditions
         Fine sediment transport under virgin flow conditions