Mill Creek (Southern California)
Encyclopedia
Mill Creek is a 17.8 miles (28.6 km) stream
, originating in the San Bernardino Mountains
, in San Bernardino County, California
. It is a major tributary of the Santa Ana River
. Their confluence occurs just downstream of the upper Santa Ana Canyon
mouth. Part of the upper creek flows through San Bernardino National Forest
.
Mill Creek is in much better condition than the lower portions of the Santa Ana watershed
, as its drainage area is less urbanized. However, the creek has three hydroelectric plants owned by Southern California Edison
. The first commercial power plant in the United States using three-phase
alternating current
was the Mill Creek No. 1 Hydroelectric Plant, near Redlands, California
, in 1893 designed by Almirian Decker.
The streambed is completely dewatered in some places. Also, a levee
system was built by the United States Army Corps of Engineers
after a severe flood
, which degraded the riparian
habitat. In addition, the poor conditions downstream interfere with fish migration
to the creek.
Stream
A stream is a body of water with a current, confined within a bed and stream banks. Depending on its locale or certain characteristics, a stream may be referred to as a branch, brook, beck, burn, creek, "crick", gill , kill, lick, rill, river, syke, bayou, rivulet, streamage, wash, run or...
, originating in the San Bernardino Mountains
San Bernardino Mountains
The San Bernardino Mountains are a short transverse mountain range north and east of San Bernardino in Southern California in the United States. The mountains run for approximately 60 miles east-west on the southern edge of the Mojave Desert in southwestern San Bernardino County, north of the...
, in San Bernardino County, California
San Bernardino County, California
San Bernardino County is a county in the U.S. state of California. As of the 2010 census, the population was 2,035,210, up from 1,709,434 as of the 2000 census...
. It is a major tributary of the Santa Ana River
Santa Ana River
The Santa Ana River is the largest river of Southern California in the United States. Its drainage basin spans four counties. It rises in the San Bernardino Mountains and flows past the cities of San Bernardino and Riverside, before cutting through the northern tip of the Santa Ana Mountains and...
. Their confluence occurs just downstream of the upper Santa Ana Canyon
Santa Ana Canyon
Santa Ana Canyon is where the Santa Ana River passes between the Santa Ana Mountains and the Chino Hills, near the intersection of Orange, Riverside, and San Bernardino Counties. It receives particularly strong Santa Ana winds in comparison to surrounding areas, hence the name.-History:Originally,...
mouth. Part of the upper creek flows through San Bernardino National Forest
San Bernardino National Forest
San Bernardino National Forest is a federally-managed forest covering more than 800,000 acres . There are two main divisions which are the San Bernardino Mountains on the easternmost of the Transverse Range, and the San Jacinto and Santa Rosa Mountains on the northernmost of the Peninsular...
.
Mill Creek is in much better condition than the lower portions of the Santa Ana watershed
Drainage basin
A drainage basin is an extent or an area of land where surface water from rain and melting snow or ice converges to a single point, usually the exit of the basin, where the waters join another waterbody, such as a river, lake, reservoir, estuary, wetland, sea, or ocean...
, as its drainage area is less urbanized. However, the creek has three hydroelectric plants owned by Southern California Edison
Southern California Edison
Southern California Edison , the largest subsidiary of Edison International , is the primary electricity supply company for much of Southern California, USA. It provides 14 million people with electricity...
. The first commercial power plant in the United States using three-phase
Three-phase
In electrical engineering, three-phase electric power systems have at least three conductors carrying voltage waveforms that are radians offset in time...
alternating current
Alternating current
In alternating current the movement of electric charge periodically reverses direction. In direct current , the flow of electric charge is only in one direction....
was the Mill Creek No. 1 Hydroelectric Plant, near Redlands, California
Redlands, California
Redlands is a city in San Bernardino County, California, United States. As of the 2010 census, the city had a population of 68,747, up from 63,591 at the 2000 census. The city is located east of downtown San Bernardino.- History :...
, in 1893 designed by Almirian Decker.
The streambed is completely dewatered in some places. Also, a levee
Levee
A levee, levée, dike , embankment, floodbank or stopbank is an elongated naturally occurring ridge or artificially constructed fill or wall, which regulates water levels...
system was built by the United States Army Corps of Engineers
United States Army Corps of Engineers
The United States Army Corps of Engineers is a federal agency and a major Army command made up of some 38,000 civilian and military personnel, making it the world's largest public engineering, design and construction management agency...
after a severe flood
Flood
A flood is an overflow of an expanse of water that submerges land. The EU Floods directive defines a flood as a temporary covering by water of land not normally covered by water...
, which degraded the riparian
Riparian zone
A riparian zone or riparian area is the interface between land and a river or stream. Riparian is also the proper nomenclature for one of the fifteen terrestrial biomes of the earth. Plant habitats and communities along the river margins and banks are called riparian vegetation, characterized by...
habitat. In addition, the poor conditions downstream interfere with fish migration
Fish migration
Many types of fish migrate on a regular basis, on time scales ranging from daily to annually or longer, and over distances ranging from a few metres to thousands of kilometres...
to the creek.