Merrimack water levels to drop again

After weeks of low water levels on the Merrimack River earlier this summer, the water will be getting lower again, as repairs continue on the Pawtucket Dam in Lowell, Mass.

Unless heavy rains arrive and throw off the schedule, which the weatherman says isn’t likely as of this morning, the owners of the dam will allow extra water to flow over it until the river is about 5 feet below its normal level.

If all goes well, the river – “headpond,” in dam parlance – will stay low until a week from Friday, according to the announcement from Enel North America, which owns Boott Hydropower, the company that controls the Lowell dam.

The lowered Merrimack River will allow more maintenance and replacement of flashboards, which make a moveable wall atop the permanent dam used to control water levels as needed for hydropower and flood control.

Flashboards take the brunt of damage on dams, because they are struck by trees and other objects carried downstream.

The river was lowered for similar repairs at the beginning of the summer; those repairs took longer than expected.