The devastation that accompanied massive flooding in downtown Peterborough in 1936 and again in 1938 are indelibly stamped on the collective historic memory of the region.

The latter disaster, prompted by a hurricane, submerged Union Street under five feet of water and Bridge Street under a full fathom, drove scores of people from their homes along the Contoocook River, and caused fires that destroyed four buildings, including a large grain mill housing the Peterborough Transcript.

According to town histories, the flood of Sept. 28, 1938, caused heavy damage throughout the town and losses were estimated at a quarter of a million dollars (almost $3.8 million in 2010).

The two floods were the region’s most devastating natural disasters in memory at the time, and combined to be the straw that finally broke the proverbial camel’s back.

Before year’s end, engineers were surveying sites along Nubanusit Brook to determine the best place to build the thousand-foot-long dam made possible by the U.S. Flood Control Act of 1936. After a long site-research process, the dam was built between the years of 1948 and 1950 and has been administered by the U.S. Army Corps of Engineers ever since.

Public celebration this weekend

The corps is celebrating Edward MacDowell Dam’s 60 years of service to the community on Saturday and is asking the public to join in the party.

The dam’s gatehouse and the Edward MacDowell Lake Project Office will be open from 10 a.m. to 2 p.m., according to Park Manager Jason Tremblay. Gatehouse tours will start every 20 minutes and offer the public a look at the workings of the structure.

In preparing for the 60th anniversary event, MacDowell Dam staff began researching the dam’s history, and it took a bit of extra digging to determine why it was named after the composer that helped inspire the MacDowell Colony.

All Army Corps of Engineers documentation preceding the 1950 dedication of the dam refers to it as the West Peterborough reservoir dam, Tremblay said.

“They knew the dam was named the Edward MacDowell Dam, but there was nothing to explain how it happened.... It all just became a big mystery. ‘How did this all happen and when?’ “ Tremblay said.

The construction of the “West Peterborough Dam” was made possible by the Flood Control Act of 1936, which was authorized by Congress and signed into law by President Franklin Delano Roosevelt on June 22, 1936. It was a reaction to the many floods and natural disasters that hit New England and the rest of the country and had destroyed residential and industrial properties during the early part of the century, but became a priority as a result of Peterborough’s localized disasters.

Photographs of the Peterborough floods of 1936 and 1938 will be on display at the project office on Saturday.

The dam and the lake impound the waters of Nubanusit Brook, which feeds into the Contoocook River in downtown Peterborough. The dam protects Peterborough and the other communities downstream. It is one of five flood control dams in the Merrimack River Basin. Since 1950, it is estimated to have prevented $9.3 million in flood damages.

Edward MacDowell’s connection

Tremblay said that the dam’s design and construction cost $2.01 million. Those details were easy to find, but Tremblay still couldn’t figure out why the dam was stamped with a composer’s name.

Finally, the newspaper archives at the Peterborough Town Library gave Tremblay the answer to his mystery. It turned out that two politicians had championed the idea.

“To pay tribute to Edward MacDowell, Senator Charles Tobey and Congressman Norris Cotton wanted this facility to be named after Edward MacDowell,” Tremblay said. “Those two gentleman actually put through legislation to get the name changed. ... Those two men were instrumental in getting the dam named after Edward MacDowell.”

Not only is MacDowell a significant American composer, he is the man behind the nation’s oldest artist colony.

MacDowell, and his wife Marian MacDowell, a pianist, bought a farm surrounded by woodlands in Peterborough in 1896, according to the MacDowell Colony. MacDowell said he wrote more and better music during the summers he composed in the tranquil farm surroundings then he ever had anywhere else.

In 1907, after Edward had become gravely ill, Marian MacDowell fulfilled his wish to create that peaceful environment for other artists by establishing the MacDowell Colony on High Street. Shortly after, Edward died in 1908.

“He was such a noted celebrity in his time. And when they started the Colony it kicked off an artist movement in the area,” Tremblay said. “It was a pretty big deal back then because typically federal structures were never named after artists. This was kind of a big thing.”

Just prior to the dam dedication Marion MacDowell was awarded the honorary title “Peterborough’s first citizen,” Tremblay said.

On July 28, 1950, the dam was officially dedicated as the Edward MacDowell Dam. The manmade lake it created was likewise named Edward MacDowell Lake.

Marion, then 92, was honored at the dedication with the duty of being the first person to turn on the power at the dam, Tremblay said, becoming its first official operator.

Tremblay noted that he was still researching the event and would like to speak to anyone who was at that dedication 60 years ago. In a photo of Marion MacDowell pressing the button to power-up the dam there are several Girl Scouts and Boy Scouts. Tremblay said he would love to speak to any of them who might still live in the area.

Saturday’s event is also an opportunity for the Army Corps of Engineers to educate people about the floods prevented by the dam over the past 60 years. It’s a chance to present images of devastation and ask the question, ‘what if the dam didn’t exist?’

The third highest flood storage event since the dam has been in operation took place this year in late March and early April, Tremblay said.

“When we stored our flood water this past March, not only were we protecting Peterborough ... our flood storage operation this year also prevented Henniker from flooding and all the towns in between.”

“The river was right at the edge of the stream bank for days, couldn’t take anymore water basically,” Tremblay said. “The rivers were really pumped with a lot of water.”

According to Tremblay, the greatest amount of water on record held back by the dam occurred in 1987 with the second most significant event taking place in 1984.