Great Stone Dam facts for kids
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Great Stone Dam
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U.S. Historic district
Contributing property |
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Great Stone Dam
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 Location in Massachusetts
Location in the United States
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| Location | Lawrence, Massachusetts |
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| Built | 1848 |
| Architect | Charles Storer Storrow, Charles Bigelow |
| Part of | North Canal Historic District (ID84000417) |
| NRHP reference No. | 77000184 |
Quick facts for kids Significant dates |
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| Added to NRHP | April 13, 1977 |
| Designated CP | November 13, 1984 |
The Great Stone Dam is also known as the Lawrence Dam. It was built between 1845 and 1848. You can find it on the Merrimack River in Lawrence, Massachusetts. This amazing dam is about 900 feet long and 35 feet tall.
Lawrence is in Essex County, Massachusetts. It's about 25 miles north of Boston. The dam is 11 miles downstream from Lowell. You can see it from Route 28 in Lawrence.
The dam helps feed two canals: the North Canal and the South Canal. These canals used to provide a lot of power for mills. The North Canal could give up to 13,000 horsepower. The South Canal added another 2,000 horsepower. Companies like the Essex Company sold "mill rights" for this water power. This allowed factories to use the energy. The North Canal was rebuilt in 1848 to work with the dam. It was about a mile long and had special locks to control water. These locks were stopped being used in the 1960s.
Today, the dam is home to a hydroelectric plant. This plant was finished in 1981. It creates electricity from the river's water. Enel, a big energy company, now owns the dam through its parent company, the Essex Company.
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Why Was the Dam Built?
A group of business leaders wanted to create a "New City on the Merrimack." They saw how successful Lowell was using the river's power. This new city became Lawrence.
They bought land along the Merrimack River. The natural river drop was only about 5 feet. But to power factories, they needed a much bigger drop, at least 30 feet. This meant building a very large dam.
In 1843, a group called "The Merrimack Water Power Association" found the perfect spot. It was at Bodwell's Falls. The area had strong blue stone foundations. This made it ideal for a dam and canals.
In 1845, the Essex Company was formed. Its goal was to develop water power for new textile mills. They planned to build the dam at the chosen site. Charles Storer Storrow was the main engineer for the Essex Company. He designed and engineered the dam.
The Essex Company's plans for the dam were very popular. They raised one million dollars in less than a month!
How Was the Dam Built?
Gilmore & Carpenter won the job to build the dam. Construction started on September 19, 1845. It finished exactly three years later, on September 19, 1848. Charles H. Bigelow, an engineer, oversaw the building process.
The dam was built with huge granite blocks. These blocks were set into the riverbed with special cement. The base of the dam is 35 feet thick. It narrows to about 13 feet near the top. The highest part of the stone work is 22 feet. The water usually drops 25 to 26 feet over the dam.
The dam, including its side walls, is 1,629 feet long. The part where water flows over is 900 feet wide. A solid earth filling behind the stone protects the structure. Building the dam cost about $250,000 at the time. This was a lot of money back then!
The way they built the dam was very new for the time. They injected a special concrete into the spaces between the granite stones. This made the dam incredibly strong and long-lasting. Even after many big floods, the stone part of the dam has never needed repairs. Some wooden parts were fixed in 1894, and the water control system was updated in 2007.
When it was built, the Great Stone Dam was the largest dam in the world. It is still a very important landmark for Lawrence. It helped create the city. The Lawrence History Center has exhibits about the dam.
Building the dam and canals was hard work. Many Irish immigrants worked on it. They often worked in tough conditions.
The Dam Today: Power and Nature
After World War II, things changed. Many textile mills closed down. The dam's power was no longer needed in the same way. But there was a growing need for hydroelectric power. This is electricity made from moving water. The Great Stone Dam was perfect for this new use.
In the 1970s, the Lawrence Hydroelectric Associates started building a new power plant. It cost $28 million. This plant was built at the south end of the dam. It was finished in 1981. Now, it can create 16.8 megawatts of energy. This is much more than the dam provided in its early days.
The new plant also included a special fish ladder. This ladder helps fish, like salmon, swim past the dam. More fish are in the river now than before. While fish ladders are helpful, dams can still affect natural resources. Hydroelectric power is a green energy source. But we need to keep finding better ways to help nature and fish.
In 2007, the dam got $3.5 million in upgrades. They replaced old wooden parts with new metal and rubber ones. This helps control water levels better and improves fish migration. These improvements help the dam last a long time.
The Essex Company still owns the dam. It is now part of Enel Green Energy. The Great Stone Dam was added to the National Register of Historic Places in 1977. It's considered one of the greatest engineering projects of the 1800s. It shows how much people could innovate back then. It also represents the birth of Lawrence during the American Industrial Revolution. It was also included in the North Canal Historic District in 1984.
Fun on the River
The Great Stone Dam has changed the river's depth and flow. This has created great spots for fun activities.
Upstream from the dam, there's a large area for sailing, kayaking, and boating. The Greater Lawrence Community Boating Program has a big boat house there.
Even with some concerns about fish numbers, the area right below the dam is popular for fishing. You can catch fish like white perch, American shad, river herring, and striped bass. There are lots of fish here because of the dam. It's also easy to get to the shoreline for both boaters and people fishing from land.
