The Bitterroot National Forest began environmental analysis of the project this week, and work is expected to focus on the 61cm long outlet pipe, which is rusting and leaking. Due to the leaky pipe, the dam has been temporarily labelled as hazardous.
Mill Lake dam is about 100 years old and is used to hold back 962,083m3 of water.
Repairing the pipe would be only the first step in renovating the dam; an extensive upgrade is planned for the next couple of years in order to keep the structure up to date with current federal safety regulations.