[1][2][3][4] The lake was formed sometime in the first decade of the twentieth century alongside the construction of the Kirkfield Lift Lock, which was completed and operational by the end of 1907.

However, most of the lake is relatively shallow (Between 3 and 6 feet deep), swampy, and filled with partially or wholly submerged tree stumps remaining from before the flooding.

Each year on thanksgiving weekend the Trent-Severn Waterway is closed, Mitchell lake floodplain drops its water elevation 2ft, and the shoreline recedes up to 20ft.

In late May the Trent-Severn Waterway opens up again and the Mitchell Lake floodplain raises its water elevation 2ft, and the shoreline expands up to 20ft.

It has decimated the oxygen and natural flora of the water, and begun spreading to other lakes on the Trent-Severn Waterway via boat travel.