Pawtucket Falls is the name of a waterfall on the Merrimack River

Merrimack River

The Merrimack River is a river in the northeastern United States. It rises at the confluence of the Pemigewasset and Winnipesaukee rivers in Franklin, New Hampshire, flows southward into Massachusetts, and then flows northeast until it empties into the Atlantic Ocean at Newburyport...

 at Lowell, Massachusetts

Lowell, Massachusetts

Lowell is a city in Middlesex County, Massachusetts, USA. According to the 2010 census, the city's population was 106,519. It is the fourth largest city in the state. Lowell and Cambridge are the county seats of Middlesex County...

. The waterfall and rapids below it drop a total of 32 feet in a little under a mile., and was an important fishing ground for the Pennacook

Pennacook

The Pennacook, also known by the names Merrimack and Pawtucket, were a North American people that primarily inhabited the Merrimack River valley of present-day New Hampshire and Massachusetts, as well as portions of southern Maine...

 Indians in pre-colonial times.

This location was used as a benchmark for delineating the Northern boundary of Massachusetts

Northern boundary of Massachusetts

The northern boundary of the U.S. state of Massachusetts adjoins two other states - Vermont and New Hampshire. The majority of the line is roughly a straight line from the northwest corner of the state east to a point north of Lowell...

, which was frequently disputed between the Province of Massachusetts Bay

Province of Massachusetts Bay

The Province of Massachusetts Bay was a crown colony in North America. It was chartered on October 7, 1691 by William and Mary, the joint monarchs of the kingdoms of England and Scotland...

 and the Province of New Hampshire

Province of New Hampshire

The Province of New Hampshire is a name first given in 1629 to the territory between the Merrimack and Piscataqua rivers on the eastern coast of North America. It was formally organized as an English royal colony on October 7, 1691, during the period of English colonization...

. The issue was finally resolved in 1740, when it was decreed that the boundary run along a curved line three miles from the river between the ocean and a point three miles north of Pawtucket Falls, where the river begins to turn north. From there a line was to be drawn due west.

The existence of these falls as a barrier to travel along the river necessitated the construction of the Pawtucket Canal

Pawtucket Canal

Completed in 1796, the Pawtucket Canal was originally built as a transportation canal to circumvent the Pawtucket Falls of the Merrimack River in East Chelmsford, Massachusetts. In the early 1820s it became a major component of the Lowell power canal system...

 in the last decade of the 18th century. In the 1820s, the falls, the canal, and the hydropower

Hydropower

Hydropower, hydraulic power, hydrokinetic power or water power is power that is derived from the force or energy of falling water, which may be harnessed for useful purposes. Since ancient times, hydropower has been used for irrigation and the operation of various mechanical devices, such as...

 they provided lead to the choosing of this site as America's first planned factory town, Lowell. Over the next 30 years, hydropower from the falls exclusively ran Lowell's numerous textile factories via the city's canal system

Lowell Power Canal System and Pawtucket Gatehouse

Main Article History of Lowell, MassachusettsThe Lowell Power Canal System is the largest power canal system in the United States, at 5.6 miles in length. The system's estimated output is 10,000 horsepower, operating six major canals on two levels, controlled by numerous gates...

.

To maximize the head

Hydraulic head

Hydraulic head or piezometric head is a specific measurement of water pressure above a geodetic datum. It is usually measured as a water surface elevation, expressed in units of length, at the entrance of a piezometer...

 the canals provided, increase volume, and regulate flow, a dam was begun at the top of the falls in the 1820s and was enlarged into the 1840s. The final structure, which exists in the same form today, is a stone dam topped with wooden flashings, capable during much of the year of channeling the entire Merrimack into the canal system. The effect being the Pawtucket Falls are dry. When heavy flow tops the dam, the waterfall created, which is a fraction of the total loss in elevation of 32 feet, is referred to as the Pawtucket Falls.

Etymology

Pawtucket is an Algonkian

Algonquian languages

The Algonquian languages also Algonkian) are a subfamily of Native American languages which includes most of the languages in the Algic language family. The name of the Algonquian language family is distinguished from the orthographically similar Algonquin dialect of the Ojibwe language, which is a...

word meaning "at the falls in the river (tidal stream)".