Salem Ditch is an artificial canal in Marion County, Oregon, United States.

Unbeknownst to Stayton at the time, an easement existed on Lynch's property, allowing a group from Salem to create a canal to divert water from the North Santiam River to Mill Creek, which was traditionally a seasonal watershed.

This allowed settlers of Salem to have access to more water power and permitted year-round operation of the first gristmill and sawmill.

[4][5] The digging of the ditch began in 1855 when settlers cut through a gravel bar along the North Santiam, east of present-day Stayton.

[6] In 2011, as part of the Upper Willamette River Conservation and Recovery Plan for Chinook Salmon and Steelhead, the Oregon Department of Fish and Wildlife recommended that the land use management practices surrounding the Salem Ditch be evaluated to determine upstream passage and habitat access effectiveness for salmonids.