Henry Hagg Lake

Henry Hagg Lake
Hagg Lake as seen from near Scoggins Dam
Location	Oregon Coast Range foothills, Washington County, Oregon, United States
Coordinates	45°28′24″N 123°12′12″W / 45.47345°N 123.20344°W / 45.47345; -123.20344Coordinates: 45°28′24″N 123°12′12″W / 45.47345°N 123.20344°W / 45.47345; -123.20344
Primary inflows	Scoggins Creek
Primary outflows	Tualatin River
Basin countries	United States
Surface area	1,153 acres (4.67 km2)
Average depth	51 ft (16 m)
Max. depth	110 ft (34 m)
Water volume	59,910 acre·ft (73,900,000 m3)
Surface elevation	303.5 ft (92.5 m)

Henry Hagg Lake (also Hagg Lake) is an artificial lake in northwest Oregon, in the United States. The reservoir is an impoundment of Scoggins Creek, which drains a small portion of the eastern side of the Northern Oregon Coast Range. The lake and creek are part of the Tualatin River’s watershed in the Tualatin Valley. It is located about 5 miles (8.0 km) southwest of Forest Grove.

Scoggins Dam was built in 1975 by the United States Bureau of Reclamation, which still owns and operates the facility. Hagg Lake contains 53,640 acre feet (66,160,000 m³) of water that can be used. Some water from the lake is used by Clean Water Services to augment the flow of the Tualatin River during the summer months to reduce the temperature and improve water quality. Other users include four cities and the Tualatin Valley Water District.