Lake Lacha is the source of the Onega, one of the major waterways of the White Sea basin.

The southern part of the Kenozersky National Park also drains into Lake Lacha.

There are occasional recreational boat trips from Kargopol to the lake but no passenger or cargo navigation.

Several villages are located on or close to the banks, including Morshchikhinskaya, Tobolkino, and Filosofskaya.

Another unpaved road runs from Kargopol along the right bank of the Onega to the lake and then to the village of Bolshaya Kondratovskaya, several kilometers from the lakeshore.