Morris Dam
Encyclopedia
Morris Dam is a concrete gravity dam across the San Gabriel River
in the U.S.
state of California
. The dam was built in the 1930s as a water supply facility for the city of Pasadena
, but is now mostly utilized for flood control and flow regulation for groundwater recharge. Situated in northern Los Angeles County
, the dam impounds the 417 acre (168.8 ha) Morris Reservoir
in the Angeles National Forest
, a few miles northeast of Azusa
. From the 1940s to the 1990s, the reservoir was also used for underwater missile testing by the United States military.
and 6 miles (9.7 km) downstream of the river's beginning at the confluence of its East and West Forks. The reservoir is about 3 miles (4.8 km) long and 1152 feet (351.1 m) above sea level at maximum pool, covering 417 acres (168.8 ha). The dam's crest itself is at an elevation of 1161 feet (353.9 m).
Serving mainly flood control, flow regulation and groundwater recharge purposes, the slightly arched Art Deco
-style gravity dam is 245 feet (74.7 m) high and 750 feet (228.6 m) long. Its spillway
, located slightly north of the main structure, is a concrete-lined chute controlled by three steel drum gates. The dam was capable of storing 39300 acre.ft of water when first put to use, but sedimentation
has since reduced its capacity by about 29%, giving it a present full volume of about 27800 acre.ft.
, groundbreaking was in April 1932 and construction was completed in May 1934, four months behind schedule. Upon completion the dam was dedicated by former United States President Herbert Hoover
. In 1935, contrary to its original purpose, Morris Dam was sold to the Metropolitan Water District of Southern California
(MWD), which owned it through most of the 20th century.
The dam was completed in time for the catastrophic Los Angeles Flood of 1938
, the most severe flood recorded in Southern California since the Great Flood of 1862
. Along with San Gabriel Dam
(then still under construction) and Cogswell Dam
upstream, Morris greatly reduced the flood peak on the San Gabriel River, saving downstream cities millions of dollars' worth of damages. If it were not for the three dams, the flow past Azusa may have exceeded 150000 cuft/s, but was limited to just 65700 cuft/s, with Morris Dam alone reducing the flood peak by some 30000 cuft/s.
Beginning in World War II
, Morris Reservoir was used as a naval weapons test facility for the U.S. Navy in conjunction with the California Institute of Technology
. A wide variety of weapons, including torpedo
es and ballistic missile
s, had their trial runs here. Testing continued until the 1990s, when most of the structures at the associated military compound were demolished. However, the concrete foundations remain and are easily seen from State Route 39
, which runs past the dam and reservoir. In 1995, MWD sold the dam to the Los Angeles County Department of Public Works
, which continues to operate it today.
San Gabriel River (California)
The San Gabriel River flows through southern Los Angeles County, California in the United States. Its main stem is about long, while its farthest tributaries extend almost altogether...
in the U.S.
United States
The United States of America is a federal constitutional republic comprising fifty states and a federal district...
state of California
California
California is a state located on the West Coast of the United States. It is by far the most populous U.S. state, and the third-largest by land area...
. The dam was built in the 1930s as a water supply facility for the city of Pasadena
Pasadena, California
Pasadena is a city in Los Angeles County, California, United States. Although famous for hosting the annual Rose Bowl football game and Tournament of Roses Parade, Pasadena is the home to many scientific and cultural institutions, including the California Institute of Technology , the Jet...
, but is now mostly utilized for flood control and flow regulation for groundwater recharge. Situated in northern Los Angeles County
Los Angeles County, California
Los Angeles County is a county in the U.S. state of California. As of 2010 U.S. Census, the county had a population of 9,818,605, making it the most populous county in the United States. Los Angeles County alone is more populous than 42 individual U.S. states...
, the dam impounds the 417 acre (168.8 ha) Morris Reservoir
Morris reservoir
Morris Reservoir is located in the San Gabriel Mountains about 5 miles north of the city of Azusa along California State Route 39. Morris Reservoir is below San Gabriel Dam. The mean elevation is about 1100 ft...
in the Angeles National Forest
Angeles National Forest
The Angeles National Forest of the U.S. National Forest Service is located in the San Gabriel Mountains of Los Angeles County, southern California. It was established on July 1, 1908, incorporating the first San Bernardino National Forest and parts of the former Santa Barbara and San Gabriel...
, a few miles northeast of Azusa
Azusa, California
Azusa is a city in Los Angeles County, California, United States. The population was 46,361 at the 2010 census, up from 44,712 at the 2000 census. Though sometimes assumed to be a compaction of the phrase "everything from A to Z in the USA" from an old Jack Benny joke, the place name "Azusa"...
. From the 1940s to the 1990s, the reservoir was also used for underwater missile testing by the United States military.
Design and location
This dam sits south of Silver Mountain and north of Glendora Ridge, which flank the spectacular 1500 feet (457.2 m) deep San Gabriel Canyon. It is roughly 37 miles (59.5 km) upstream of the San Gabriel's mouth on the Pacific OceanPacific Ocean
The Pacific Ocean is the largest of the Earth's oceanic divisions. It extends from the Arctic in the north to the Southern Ocean in the south, bounded by Asia and Australia in the west, and the Americas in the east.At 165.2 million square kilometres in area, this largest division of the World...
and 6 miles (9.7 km) downstream of the river's beginning at the confluence of its East and West Forks. The reservoir is about 3 miles (4.8 km) long and 1152 feet (351.1 m) above sea level at maximum pool, covering 417 acres (168.8 ha). The dam's crest itself is at an elevation of 1161 feet (353.9 m).
Serving mainly flood control, flow regulation and groundwater recharge purposes, the slightly arched Art Deco
Art Deco
Art deco , or deco, is an eclectic artistic and design style that began in Paris in the 1920s and flourished internationally throughout the 1930s, into the World War II era. The style influenced all areas of design, including architecture and interior design, industrial design, fashion and...
-style gravity dam is 245 feet (74.7 m) high and 750 feet (228.6 m) long. Its spillway
Spillway
A spillway is a structure used to provide the controlled release of flows from a dam or levee into a downstream area, typically being the river that was dammed. In the UK they may be known as overflow channels. Spillways release floods so that the water does not overtop and damage or even destroy...
, located slightly north of the main structure, is a concrete-lined chute controlled by three steel drum gates. The dam was capable of storing 39300 acre.ft of water when first put to use, but sedimentation
Sedimentation
Sedimentation is the tendency for particles in suspension to settle out of the fluid in which they are entrained, and come to rest against a barrier. This is due to their motion through the fluid in response to the forces acting on them: these forces can be due to gravity, centrifugal acceleration...
has since reduced its capacity by about 29%, giving it a present full volume of about 27800 acre.ft.
History
Morris Dam was originally slated to be called Pine Canyon Dam, but was renamed for the chief engineer of construction, Samuel Brooks Morris of the Pasadena Water Department. With the dam envisioned as a private structure for PasadenaPasadena, California
Pasadena is a city in Los Angeles County, California, United States. Although famous for hosting the annual Rose Bowl football game and Tournament of Roses Parade, Pasadena is the home to many scientific and cultural institutions, including the California Institute of Technology , the Jet...
, groundbreaking was in April 1932 and construction was completed in May 1934, four months behind schedule. Upon completion the dam was dedicated by former United States President Herbert Hoover
Herbert Hoover
Herbert Clark Hoover was the 31st President of the United States . Hoover was originally a professional mining engineer and author. As the United States Secretary of Commerce in the 1920s under Presidents Warren Harding and Calvin Coolidge, he promoted partnerships between government and business...
. In 1935, contrary to its original purpose, Morris Dam was sold to the Metropolitan Water District of Southern California
Metropolitan Water District of Southern California
The Metropolitan Water District of Southern California is the largest supplier of treated water in the US. The name is usually shortened to the "Metropolitan Water District" or simply "MWD". It is a cooperative of 14 cities and 12 municipal water districts that indirectly provides water to 18...
(MWD), which owned it through most of the 20th century.
Los Angeles Flood of 1938
The Los Angeles Flood of 1938 or 1938 Los Angeles flood was a major flooding event that was responsible for inundating much of Los Angeles, Orange, and Riverside counties, California, during early 1938...
, the most severe flood recorded in Southern California since the Great Flood of 1862
Great Flood of 1862
The Great Flood of 1862 or Noachian Deluge was the largest flood in the recorded history of Oregon, Nevada and California, occurring from December 1861 to January 1862. It was preceded by weeks of continuous rains that began in Oregon in November 1861 and continued into January 1862...
. Along with San Gabriel Dam
San Gabriel Dam
San Gabriel Dam is a rockfill dam on the San Gabriel River in the San Gabriel Mountains, in Los Angeles County, California, within the Angeles National Forest...
(then still under construction) and Cogswell Dam
Cogswell Dam
Cogswell Dam is a rockfill dam on the West Fork of the San Gabriel River in Los Angeles County, California. It forms Cogswell Reservoir, which has a capacity of with an average storage of , and serves mainly for flood control in conjunction with San Gabriel and Morris Dams downstream....
upstream, Morris greatly reduced the flood peak on the San Gabriel River, saving downstream cities millions of dollars' worth of damages. If it were not for the three dams, the flow past Azusa may have exceeded 150000 cuft/s, but was limited to just 65700 cuft/s, with Morris Dam alone reducing the flood peak by some 30000 cuft/s.
Beginning in World War II
World War II
World War II, or the Second World War , was a global conflict lasting from 1939 to 1945, involving most of the world's nations—including all of the great powers—eventually forming two opposing military alliances: the Allies and the Axis...
, Morris Reservoir was used as a naval weapons test facility for the U.S. Navy in conjunction with the California Institute of Technology
California Institute of Technology
The California Institute of Technology is a private research university located in Pasadena, California, United States. Caltech has six academic divisions with strong emphases on science and engineering...
. A wide variety of weapons, including torpedo
Torpedo
The modern torpedo is a self-propelled missile weapon with an explosive warhead, launched above or below the water surface, propelled underwater towards a target, and designed to detonate either on contact with it or in proximity to it.The term torpedo was originally employed for...
es and ballistic missile
Ballistic missile
A ballistic missile is a missile that follows a sub-orbital ballistic flightpath with the objective of delivering one or more warheads to a predetermined target. The missile is only guided during the relatively brief initial powered phase of flight and its course is subsequently governed by the...
s, had their trial runs here. Testing continued until the 1990s, when most of the structures at the associated military compound were demolished. However, the concrete foundations remain and are easily seen from State Route 39
California State Route 39
State Route 39 is a state highway in the U.S. state of California that travels through Orange and Los Angeles counties. Its southern terminus is at Pacific Coast Highway , in Huntington Beach, and its northern terminus is at Islip Saddle on Angeles Crest Highway in the Angeles National...
, which runs past the dam and reservoir. In 1995, MWD sold the dam to the Los Angeles County Department of Public Works
Los Angeles County Department of Public Works
The Los Angeles County Department of Public Works is responsible for the construction and operation of Los Angeles County's roads, building safety, sewerage, and flood control...
, which continues to operate it today.