Mormon Flat Dam


Mormon Flat Dam, a 224-foot high concrete thin-arch structure, is on the Salt River 51 miles northeast of Phoenix. Constructed by the Salt River Valley Water Users' Association from 1923-1926, it creates a 57,852 acre-foot reservoir.

In 1938, Reclamation completed construction of a new gate structure and a concrete-lined spillway discharge channel, and installed two 50-foot-square stoney regulating gates, hoists, motors, two 25-kilovolt-ampere gasoline-engine driven generators, and a new road to the powerhouse.

RegionFacilities in Lower Colorado | Lower Colorado Home Page
ProjectSalt River
Dam TypeConcrete thin arch
ReservoirCanyon Lake
WatercourseSalt River
LocationOn the Salt River, about 51 miles northeast of Phoenix, Arizona
Original Construction1923-1926
Modified Construction1937-1938, 1969-1972
National ID NumberAZ10313
Hydrologic Unit Code

Structural Height224 ft
Hydraulic Height (Normal Operating Depth at Dam)142 ft
Top Parapet (Elevation)
Spillway Crest Elevation1610 ft
Crest Elevation1666 ft
Crest Length380 ft
Crest Width8 ft
Base Width20 ft
Volume of Dam Construction Materials59,900 cu-yds
Streambed at Dam Axis
Top of Exclusive Flood Control Pool (Elevation)
Top of Joint Use Pool (Elevation)
Top of Active Conservation Pool (Elevation)
Top of Inactive Conservation Pool (Elevation)
Top of Dead Storage Pool (Elevation)

Hydraulics & Hydrology
Total Water Storage at Elevation57,852 acre-ft at 1660.5
Maximum Water Surface Elevation1679.04 ft
Normal Water Surface Elevation
Spillway Type Concrete lined channel
Spillway Capacity at Elevation150000.0 cfs at 1671.0
Auxiliary Spillway
Auxiliary Spillway Capacity at Elevation
Uncontrolled Spillway Capacity at Elevation
Outlet Works Capacity at Elevation
Diversion Capacity at Elevation
Drainage Area6101 sq mi
Hydrometeorological Report (HMR)
Probable Maximum Flood (PMF) Report1986 Winter Type

Contact Information
TitleArea Office Manager
OrganizationPhoenix Area Office
Address6150 West Thunderbird Road
CityGlendale, AZ 85306-6200
Phone (Fax)623 773-6480
Phone (Office)623 773-6200
OrganizationArea Office Manager
AddressPhoenix Area Office
CityPhoenix, AZ 85306-6200
Phone (Office)623 773-6200

Last updated: Nov 18, 2009