Over there, nestled between Winchester, Arlington, and Medford, lie the Mystic Lakes. These closely linked bodies of water whisper tales of ancient settlements and innovative engineering. The Mystic Reservoir and its surroundings are a testament to Boston’s history.
Let’s delve into the story of the Mystic Lakes. Upper Mystic Lake and Lower Mystic Lake form this beautiful area. They sit just one meter above sea level. The Aberjona River feeds Upper Mystic Lake. From there, water flows south over the Mystic Dam. It then enters Lower Mystic Lake. Finally, it empties into the Mystic River and Boston Harbor.
Lower Mystic Lake is special. It is a meromictic lake. This means its deep waters rarely mix with the surface. Because of this, the sediments at the bottom form annual layers called varves. These varves have remained undisturbed for nearly a thousand years. They act like tree rings, preserving a historical record. Mark Besonen and his team used these varves to study past hurricane activity. They found a 1,000-year record of hurricanes near Boston.
People enjoy the Mystic Lakes for swimming, sailing, and fishing. However, Upper Mystic Lake faces challenges. It suffers from arsenic and heavy metal contamination from the Aberjona River. The eastern shore is part of the Mystic River Reservation. The Massachusetts Department of Conservation and Recreation manages it.
Centuries ago, the Squaw Sachem of Mistick lived near these lakes. She deeded much of Greater Boston to settlers. Her Naumkeag band likely fished here. They built weirs at the lake’s outlet and along the Mystic River. They also grew corn on the lake’s eastern shores. In 1862, workers discovered an indigenous burial site east of the lakes. It may hold the remains of Sachems Nanepashemet or Montowompate. Today, this area is Sagamore Park.
From 1803 to 1851, the Middlesex Canal ran along the Mystic Lakes’ eastern shore. This canal connected Lowell to Charlestown. It was a precursor to the Erie Canal. Also the lakes were previously part of the drinking water supply for Charlestown and later Boston.
The Mystic Dam itself has its own story. Built in 1864 and 1865, it controlled water flow between the upper and lower lakes. The Charlestown Water Commission, before Charlestown merged with Boston, built it. The dam is over 1,500 feet long. Most of it consists of earthen embankments. These are lined with riprap and puddle clay. A spillway sits near the center. It has granite columns with grooves for stop logs. A wooden walkway once ran across the dam’s top.
A gatehouse on the Medford side connected the upper lake to an aqueduct. This supplied water to Charlestown. The dam impounded 186 acres of lake area. Both the dam and gatehouse are on the National Register of Historic Places since 1990.
By the early 2000s, the dam needed repairs. A major storm in 2006 showed the dam’s inability to handle high water. This could cause downstream flooding. From 2010 to 2012, major work improved the dam. Workers built a new spillway, repaired the old one and embankments. They added a new fish ladder and bridge. The historic gatehouse was also restored.
Today, the Mystic Reservoir stands as a reminder of our past. From indigenous settlements to vital infrastructure. This area has shaped the region. Its waters continue to flow. They connect us to the stories of those who came before. Take a moment to appreciate the layers of history beneath the surface. The Mystic Reservoir whispers tales of resilience innovation and connection.