When the Douglas Memorial Bridge was built to span the Klamath River in Klamath, Calif., in 1926, it drew immediate controversy because its piers, anchored in the channel, obstructed the river’s natural course.
During the dry summer of 1930, low-water flow caused a 40-foot-wide swath of sand and gravel to build up for a half-mile parallel to the shoreline. The river’s current diminished to a sluggish seep into the ocean, causing the channel to fill in and close. Water backed up, low ground and several campgrounds flooded, and salmon could not migrate upstream.
After a week with no sign of a new channel breaking through, the townspeople reacted. Six men armed with shovels boarded a boat, rowed downstream, and began digging at a selected location. Soon, 50 more men arrived. By day’s end, they’d made good progress.
The next morning, 200 laborers and spectators arrived. The ditch was completed and opened. A slow flow turned into a 100-foot-wide torrent that caused the river to drop to tide level.
Flooding problems continued to occur until the Great Flood of 1964 demolished the bridge. An improved version was located farther upstream.
Sources: Hughes, Ralph L. Tales of Del Norte County. Crescent City, CA, Del Norte Historical Society, 1997, pp. 57-58.
Bridge Hunter - Historic and Notable Bridge in the USA, https://bridgehunter.com/ca/del-norte/douglas-memorial/. Accessed 7 Jan. 2018.