NEW YORK – Baltimore’s reservoirs are so low the city plans to tap the Susquehanna River for drinking water despite complaints about its iron taste. Rivers in Maine have been reduced to a trickle. And in New Hampshire, many of the frozen waterfalls that draw ice-climbing tourists haven’t formed this year.

From Maryland to Maine, the East Coast is seeing some of the driest conditions in decades.

More than 100 counties are under drought warnings, watches or advisories.

Public officials are urging people to take shorter showers, fix plumbing leaks and wash cars with buckets instead of hoses.

“The whole system is being taxed right now,” said George McKillop, a National Weather Service hydrologist in Upton, N.Y.

Precipitation is 6 to 10 inches below average in New England and the mid-Atlantic states over the last six months, off a third or more from the norm.

In New York City, which issued a drought warning Monday, precipitation has been a mere quarter of its normal level since September.

Maryland has put the Monocacy River off-limits to protect it in the drought, cutting off a third of the potential water supply for Frederick, the state’s second-largest city.

Frederick has slowed new development and is considering shutting it down entirely, Mayor Jennifer Dougherty said.

Baltimore’s reservoirs are at their lowest point on record for January. The city plans to tap the Susquehanna River, whose high iron content has irritated customers in the past.

“We’re hoping that it will be a minimal change in taste,” said Kurt Kocher, a spokesman for the city Department of Public Works.

Maine is struggling through its worst drought in 107 years of record keeping. Dam operators are shutting gates to keep reservoirs from plunging, turning rivers and streams into relative trickles.

White-water rafting and salmon, trout and bass fishing could be devastated.

The precipitation level could recover by the spring, but “we could have a situation where there’s no water to go rafting. The worst case is there’s just not enough water to sustain fish spawning,” said Dana Murch, dams supervisor for the Maine Department of Environmental Protection.

Maine’s hydroelectric power generation has dropped, driving up costs for paper mills. As many as 2,000 people have seen their wells dry up.

While New England and the mid-Atlantic states are hardest hit, drought conditions of varying severity exist as far south as Florida.

Rainfall began to decline at the end of the summer as the East Coast saw sharp drop-offs in the two main ingredients of storms – cold air surging down from the north and moisture coming in from the south.

“In essence, we’re just not seeing these storms coming through,” McKillop said. “We know that part of this is a global pattern.”

The warm winter has made matters worse. Normally, snow melt and rainfall run over frozen ground to replenish reservoirs and streams.

But in many spots this year, snow and rain are soaking into the still-soft earth.

In New Hampshire’s White Mountains, many of the frozen waterfalls that draw ice climbers to the town of North Conway have failed to form.

“We’ve got 30 local guides here that make their living teaching ice climbing,” said Dave Kelly, a guide and assistant manager at the EMS Climbing School.

“With conditions as lean as they are, you’ve got guides hanging around twiddling their thumbs waiting for business.”