Baltimore City’s Department of Public Works is testing an emergency system that carries water from the Susquehanna River to the region, in case drought conditions worsen.

Baltimore has not needed to use Susquehanna River water in more than 20 years, but low reservoir levels have prompted the precautionary test. The test involves pumping water from the river to the Montebello Treatment Plant 35 miles away.

Officials emphasize the water being used for the test will not be treated for drinking and will not enter Baltimore’s water system.