Given: Finely-perforated pipes are driven into the ground around the perimeter of an area to be excavated. These pipes are connected to one or more above-ground pipes in order to maintain or reduce a water table level during the site construction. What is this known as?

Given: Finely-perforated pipes are driven into the ground around the perimeter of an area to be excavated. These pipes are connected to one or more above-ground pipes in order to maintain or reduce a water table level during the site construction. What is this known as?