River to be lowered

The Merrimack River north of the Pawtucket Dam in Lowell, Mass., will be lowered several feet beginning Monday, so that flashboards on the dam can be replaced. The area, known as an impoundment, is expected to be refilled to normal by May 15, weather and water conditions permitting. Flashboards are removable boards on top of the permanent concrete dam and can be opened or closed to control flooding and hydropower.

The dam is owned by Boott Hydropower, a subsidiary of Massachusetts-based Enel North America Inc., which owns dams and other power sources in the U.S. and Canada.