Lower Columbia River Sand Supply and Removal: Estimates of Two Sand Budget Components

Abstract

Long-term changes in the sand balance of a river-estuary system can strongly affect navigation and ecosystems. Here, we examine two sand budget components in the lower Columbia tidal river, fluvial supply and human removal. Rating curves were used to estimate daily sand input between 1900 and 2010. Publications, interviews, and data analyses were used to evaluate sand removal by dredging and mining. Comparison between sand input and removal indicates that a sand deficit has existed for