Forty years ago, from June 20-24, 1972, a downpour from Hurricane Agnes created the most costly natural disaster in Pennsylvania history.

Hurricane Agnes drenched the state with from 7-18 inches of rainfall, causing devastating flooding across the state that damaged 68,000 homes. More than 220,000 people were left homeless, with damage estimated at $2.3 billion. That amount would be equivalent to $17 billion today.

Historically, the flood-prone borough of Jim Thorpe would have been badly flooded by the overflow of Mauch Chunk Creek, which is funneled into a culvert that flows under the historic district. Roughly, every 20 years, heavy rains overloaded the culvert, sending several feet of water streaming through the streets.

Forty years ago, it didn't happen.

It didn't happen because another Agnes, the late Agnes T. McCartney, dammed Mauch Chunk Creek to create Mauch Chunk Lake. Inundated by the floodwaters of Hurricane Agnes, the month-old dam held, saving the downstream Jim Thorpe Historic District from flooding.

The borough of Jim Thorpe had never been a stranger to flooding. Situated at the confluence of the Lehigh River and the Mauch Chunk Creek, it has been vulnerable to flooding on either body of water.

Periodic flooding devastated Carbon County since the early days of its industrial heritage when its forests were clear-cut and its timbers were fashioned into dams.

The flood of 1861 destroyed the Upper Division of the Lehigh Navigation System. Floods in 1901 and 1902 destroyed bridges across the Lehigh River. In 1961, the Bear Creek Dam, later renamed the Francis E. Walter Dam, was built by the U.S. Army Corps of Engineers to provide flood control and effectively stop the flooding of the Lehigh River.

But for the town of Jim Thorpe, formerly Mauch Chunk, flooding continued. In August 1969, "Floodwaters reached the second floor of the Carbon County Courthouse," said McCartney, former Carbon County planning commissioner, according to published reports.

In 1953, newspaperman Joe Boyle had written an April Fools story about a dam on Mauch Chunk Creek. After the 1969 flooding of Jim Thorpe, everyone was saying something should be done. The Jim Thorpe Borough Council was agonizing over it.

"People were talking but not acting," McCartney said. "I was born in April, and Aries people are very determined, If we want something, we are going to get it."

She contacted the U.S. Dept. of Agriculture's Soil Conservation Service to get an estimate for the project.

"They said it would cost $3 million. I said we could raise that."

The Carbon County Commissioners approved the project, and I was put in charge of it," she said. "I called every federal agency I could find to raise money. The boroughs of Jim Thorpe and Summit Hill each gave $20,000."

The dam was commissioned in 1972 by McCartney and Rep. Dan Flood. Few would have suspected the irony of those names, for in a month, Hurricane Agnes would flood Pennsylvania.

A rare June tropical storm caused little problem to most of the Atlantic coast of the United States as it approached Pennsylvania, a state that had already received two inches of rain. It stagnated over the state, dropping up to 18 inches of rainfall.

The month-old Mauch Chunk Dam held. McCartney had saved Jim Thorpe from Hurricane Agnes. Sadly, her former hometowns of Harrisburg and Wilkes-Barre had to be evacuated from an overflowing Susquehanna River. Gov. Milton Shapp called out the National Guard to help with the evacuation of Harrisburg. In Wilkes-Barre, 13,000 homes were lost.

In 1974, Mauch Chunk Lake Park, a multipurpose flood control and recreational facility in the boroughs of Summit Hill and Jim Thorpe, was opened. It continues to be Carbon County's mecca for swimming, hiking, bicycling, wildlife and boating.

McCartney served as an executive assistant to David L. Lawrence in Gov. George H. Earle's administration. She married Frank G. McCartney, who became Pennsylvania Police Commissioner. They moved to Carbon County in the 1950s.

She became interested in tourism and economic development and in 1962, became the first executive director of the Carbon County Planning Commission. McCartney continued to work part-time for the Carbon County Tourism Promotion Agency. After serving 30 years as executive director of the agency, she stepped down in 1993. She passed away in 2008 at the age of 93.