He previously bought up tracts of land around the river, and with the help of Canadian financier George Glines, began construction of the Elwha Dam in 1910.

Aldwell and his contractors cut corners on constructing the dam, including illegally not building fish passages and not securing it to the bedrock.

[4] Initially, along with the Glines Canyon Dam, which was completed in 1926, it helped to fuel economic growth and development for the Olympic Peninsula and the community of Port Angeles, Washington.

However, by the early 21st century, the combined power output of both dams only provided the equivalent of 38% of the electricity needed to operate one sawmill, the Daishowa America mill.

[citation needed] After the construction of the dams, the lower reach of the river saw a drastic decrease in sediment delivery.

This led to a net erosion of the riverbed, including the gravels needed to create suitable habitats for spawning.

[7] The delta at the mouth of the river, where it enters the Strait of Juan de Fuca, also saw a net erosion effect, confirmed by local tribal leaders.

[9] At its peak, the Elwha supported spawning runs of Chinook, coho, chum, pink, and sockeye salmon as well as steelhead, cutthroat, and bull trout.

The most valuable spawning habitats are located far upstream from the Glines Canyon Dam, so it still acted as a major barrier to the recovery of the runs.

A drawdown experiment was conducted on the Glines Canyon Dam to assess the erosion of the sediments from Lake Mills.

This test showed that the river would rapidly cut into the existing delta as soon as the lake level dropped, creating a deep, narrow channel.

The model showed that after the two year dam removal period, the river would begin to restore itself to natural conditions.