Many of the changes have resulted in less water percolating into the soil and more water running off the surface. Higher flows during major precipitation and run-off events tend to scour stream bottoms and banks. Streambed scour results in lower stream channels and the associated water table. Diking, drainage, channelization and other alterations to streams and wetlands in Oregon's watersheds have isolated streams from their floodplain. Watershed restoration is any activity which helps the watershed function better, i.e., to store water by capturing it and holding it longer and releasing higher quality and quantities of water longer through the summer season.
Watershed restoration starts with protection of existing systems.
Changes in land management practices, i.e., timber management, agricultural practices and road building for example, directly affect areas lower down in the watershed. Often, work in the stream corridor can raise the streambed and the water table, provide fish habitat or other stream benefits. Care must be taken to ensure such efforts have long-term benefits. Other restoration efforts can focus on restoring riparian vegetation which may be beneficial to both land managers as well as to fish and wildlife. Healthy riparian zones are highly productive wildlife areas providing both food and habitat.