What does it mean to dig a canal to draw water into the lake?

We dug a canal to introduce the river into the lake, which means: we dug an artificial river to introduce the river into the lake. According to relevant data, digging canals to divert water generally means building dams in the upper reaches of rivers to raise the water level, and then digging canals to divert water to high places to solve drinking water for people and livestock and farmland, and diverting water from Shanxi to Linxian County, Henan Province to solve the problem of nine droughts in ten years.