With much of Maryland experiencing severe drought, Baltimore Public Works officials are urging residents in the city and surrounding region to limit their water use heading into the summer.

The Department of Public Works issued a voluntary water restriction Thursday asking all Baltimore residents, along with residents using public drinking water services across southern Baltimore County and parts of Carroll, Harford and Howard counties to reduce consumption until further notice, as Liberty Reservoir, one of the region’s key water resources, has dropped to its lowest point in nearly two decades.

Baltimore DPW manages the drinking water supply for much of the surrounding region, encompassing around 1.8 million homes and businesses.

After a dry fall, Maryland has continued to see drought conditions this year. Much of Central Maryland is experiencing “severe” drought, according to the U.S. Drought Monitor, while 4.5 million residents across the state are in areas of drought.

This January through March was the 16th driest for those months on record, dating back to 1895, with rainfall 2.66 inches below normal. According to the Maryland Department of the Environment, Baltimore County, which largely feeds the reservoirs, saw 11.7 inches less rain in the 12 months ending April 30 than normal.

If conditions get worse approaching the high-demand summer months, DPW may have to resort to drawing water from the Susquehanna River, officials said Thursday. While water from the Chesapeake Bay tributary is safe to drink, officials said residents could notice “a slight change in taste.”

“By taking collective action now, we are trying to mitigate the need for more stringent measures in the future,” Baltimore Mayor Brandon Scott said in a statement.

Residents can check whether their address falls under the voluntary consumption advisory using DPW’s searchable map.

Officials said low rainfall has taken a significant toll on Liberty Reservoir on the border between Baltimore and Carroll counties, while two other reservoirs, Loch Raven and Prettyboy in Baltimore County, are also at lower than normal levels.

In response, DPW has made operational changes at two city filtration plants, reducing intake from Liberty Reservoir and drawing more from Loch Raven.

The voluntary advisory doesn’t apply to essential uses like drinking, cooking or hygiene, but officials encouraged residents to reduce any non-essential use.

Among them, DPW said residents can cut back by postponing lawn and garden watering, avoiding car or equipment washing, refraining from washing outdoor surfaces like driveways and sidewalks, only running full loads in the dishwasher or washing machine, and turning off the tap while brushing teeth or shaving.

Pipe leaks are a major driver of water waste, and DPW also asked residents to report signs of leaks or water main breaks to their local officials.

“DPW is closely monitoring the situation and will continue to assess rainfall and reservoir levels over the coming weeks and months,” DPW Director Khalil Zaied said. “We are urging everyone to voluntarily conserve water now to help ensure the long-term sustainability of our regional supply.”