Presumpscot River
Presumpscot River at Westbrook in January 2008
Location
Country	United States
State	Maine
Region	Cumberland County
Physical characteristics
Source	Sebago Lake
• coordinates	43°49′49″N70°27′18″W / 43.83028°N 70.45500°W /43.83028; -70.45500[1]
• elevation	270 ft (82 m)
Mouth	Casco Bay
• coordinates	43°41′30″N70°14′43″W / 43.69167°N 70.24528°W /43.69167; -70.24528[1]
• elevation	0 ft (0 m)
Length	25.8 mi (41.5 km)

v t e Presumpscot River
Legend
Sebago Lake Eel Weir Dam SR 35,North Windham North Gorham Dam North Gorham Otter Brook Dundee Dam Babb's Bridge Nason Brook Pleasant River Mountain Division Newhall Gambo Dam Black Brook US 202 Little Falls Dam South Windham Mallison Dam Colley Wright Brook Little River Anderson Brook Mosher Brook Inkhorn Brook Sacarappa Dam Westbrook Mountain Division Cumberland Mills Cumberland Mills Dam Mill Brook US 302 Minnow Brook Meader Brook I-95 Pan Am Railways SR 26 Piscataqua River I-495 Presumpscot Falls Bridge,Falmouth SR 9 St. Lawrence and Atlantic Railroad I-295 US 1 Casco Bay

ThePresumpscot River (/prɪˈzʌmpskət/)^[2] is a 25.8-mile-long (41.5 km)^[3]river located inCumberland County,Maine, United States. It is the main outlet ofSebago Lake. The river provided an early transportation corridor with reliable water power for industrial development of the city ofWestbrook and the village ofSouth Windham.^[4]

The river flows through the communities ofStandish,Windham,Gorham, Westbrook,Portland, andFalmouth before emptying intoCasco Bay at Falmouth. The river is bridged byMaine State Route 35 between Standish and Windham, nearNorth Windham, by the North Gorham to Windham Center road between Gorham and Windham, by theMaine Central RailroadMountain Division between North Windham and South Windham, and byU.S. Route 202 in South Windham. The river is bridged again by the Maine Central Mountain Division in Westbrook and byU.S. Route 302 at Riverton between Westbrook and Portland. In Falmouth the river is bridged by the formerInterstate 495, (now route 295);concurrentMaine State Routes 26 and100,Interstate 95,Maine State Route 9, theMaine Central Railroad,Interstate 295, theGrand Trunk Railway, andU.S. Route 1.^[5]

The Sebago Lakedrainage basin includes theCrooked River draining Songo Pond south ofBethel, and the Bear River fromWaterford throughLong Lake. The basin is between theSaco River drainage basin to the west and theAndroscoggin River drainage basin to the north and east. In addition to Sebago Lake's being its primary source, four significanttributaries of the river are thePleasant River fromGray through Windham, theLittle River fromBuxton through Gorham, Mill Brook in Westbrook (which is an outlet of Highland Lake in Windham), and thePiscataqua River in Falmouth (which is an outlet of Forest Lake inCumberland). An East Branch Piscataqua River flows separately into the Presumpscot main stem.^[6] The Presumpscot River drainage basin south of Sebago Lake is between theRoyal River drainage basin to the east, and the Saco River andStroudwater River drainage basins to the west and south, respectively.^[5]

Little Sebago Lake originally drained westerly into Sebago Lake through Boody Meadow and Outlet Brook. An artificial outlet was constructed through amoraine at the south end of Little Sebago Lake as an early 19th-century water power diversion to the Pleasant River via Ditch Brook. On 4 June 1814, the diversion became enlarged by erosion as the lake level dropped 50 feet (15 m) within a few hours, draining great quantities of water into the Pleasant River. The resulting flood swept away two mills and six bridges along the Pleasant and Presumpscot rivers as far downstream as South Windham.^[7] The erosion scar is bridged today byMaine State Route 115 east of North Windham. The level of Little Sebago Lake was partially restored by construction of a dam which failed with similar downstream damage on 7 May 1861, and has been subsequently rebuilt.^[8]

Sawmills were built on the river during the 1660s. The first Mainepaper mill was built on the river at Falmouth in 1731 by GeneralSamuel Waldo.^[9]

The river was an early transportation corridor betweenCasco Bay andSebago Lake. A series of dams and locks were completed in 1830 to form theCumberland and Oxford Canal.^[10] The canal operated until replaced by thePortland and Ogdensburg Railway in 1870. The canal lock system provided elevation control of the 45-square-mile (117 km²) surface area of Sebago Lake as a reservoir for water-powered mills along the river. TheS. D. Warren Paper Mill in Westbrook vied with theOriental Powder Company in Gorham and Windham to control water flow after the canal ceased operation of the locks. The paper mill exercised control for more than half a century after thegunpowder factory closed in 1905.^[11]

There are sevendams impeding the flow of water as it makes its way from Sebago Lake to the ocean, some of which producehydroelectric power 1) Eel Weir Dam (National Inventory of Dams ID number 00070,^[12] (also called the Headgates Dam) controls outflow from Sebago Lake (not to be confused with the Eel Weir Hydroelectric Project at 138 Middle Jam Rd, approximately 1.5 miles after the Headgates Dam at the source of the river, which empties Eel Weir Hydroelectric Project water into the river, but in no way impedes the river), 2) North Gorham Dam, 3) Dundee Dam, 4) Gambo Dam, 5) Little Falls Dam, 6) Mallison Dam, and 7) Cumberland Mills Dam. The Saccarappa Dam removal commenced in 2019. Since the removal of the Smelt Hill Dam in Falmouth in 2002, the last 7 miles (11 km) of the river after the Cumberland Mills Dam now flow unimpeded to the ocean.

ThePresumpscot River Preserve, a 48-acre nature preserve, is located in North Deering alongside the Presumpscot River. It was purchased and preserved in 2001 by the Land for Maine's Future program as well as the City Land Bank Commission and Portland Trails.^[13]

In August 2014, Portland Trails preserved 20 acres of land in the Presumpscot River estuary in Falmouth around Mile Pond.^[14]

• Barnes, Diane; Barnes, Jack (1996).The Sebago Lake Area. Acadia Publishing.ISBN 978-0-7385-4943-9.
• The Maine Atlas and Gazetteer (Thirteenth ed.).Freeport, Maine:DeLorme Mapping Company. 1988.ISBN 0-89933-035-5.
• Jones, Robert C. (1993).Two Feet to the Lakes, The Bridgton & Saco River Railroad. Pacific Fast Mail.
• Moody, Linwood W. (1959).The Maine Two-Footers. Howell-North.
• Meade, Edgar T. Jr. (1968).Busted and Still Running. The Stephen Greene Press.
• Ward, Ernest E. (1967).My First Sixty Years in Harrison, Maine. Cardinal Printing.

• "Presumpscot River".Geographic Names Information System.United States Geological Survey,United States Department of the Interior. Retrieved2009-04-06.
• The promise of the Presumpscot River KeepMEcurrent.com, March 28, 2013

• Rivers of Cumberland County, Maine
• Geography of Portland, Maine
• Falmouth, Maine
• Gorham, Maine
• Standish, Maine
• Westbrook, Maine
• Windham, Maine
• Rivers of Maine

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