Mill Creek is a U.S. Geological Survey. National Hydrography Dataset high-resolution flowline data
The National Map
, accessed March 16, 2011

stream A stream is a continuous body of surface water flowing within the bed and banks of a channel. Depending on its location or certain characteristics, a stream may be referred to by a variety of local or regional names. Long large streams ...

, originating in the

San Bernardino Mountains The San Bernardino Mountains are a high and rugged mountain range in Southern California in the United States. Situated north and northeast of San Bernardino and spanning two California counties, the range tops out at at San Gorgonio Mountain ...

, in

San Bernardino County, California San Bernardino County (), officially the County of San Bernardino, is a county located in the southern portion of the U.S. state of California, and is located within the Inland Empire area. As of the 2020 U.S. Census, the population was 2,181, ...

. It is a major tributary of the

Santa Ana River The Santa Ana River is the largest river entirely within Southern California in the United States. It rises in the San Bernardino Mountains and flows for most of its length through San Bernardino and Riverside Counties, before cutting throug ...

. Their confluence occurs just downstream of the upper Santa Ana Canyon mouth. Part of the upper creek flows through

San Bernardino National Forest The San Bernardino National Forest is a United States National Forest in Southern California encompassing of which are federal. The forest is made up of two main divisions, the eastern portion of the San Gabriel Mountains and the San Bernard ...

, with the headwaters (High Creek and Mill Creek Jumpoff), being in the

San Gorgonio Wilderness The San Gorgonio Wilderness is located in the eastern San Bernardino Mountains, in San Bernardino County and into northern Riverside County, Southern California. It begins north of San Gorgonio Pass, approximately west of Morongo Valley and n ...

. Mill Creek is in much better condition than the lower portions of the Santa Ana

watershed Watershed is a hydrological term, which has been adopted in other fields in a more or less figurative sense. It may refer to: Hydrology * Drainage divide, the line that separates neighbouring drainage basins * Drainage basin, called a "watershe ...

, as its drainage area is less urbanized. However, the creek has three hydroelectric plants owned by

Southern California Edison Southern California Edison (or SCE Corp), the largest subsidiary of Edison International, is the primary electricity supply company for much of Southern California. It provides 15 million people with electricity across a service territory of ap ...

. The first commercial power plant in the United States using

three-phase Three-phase electric power (abbreviated 3φ) is a common type of alternating current used in electricity generation, transmission, and distribution. It is a type of polyphase system employing three wires (or four including an optional neutral ...

alternating current Alternating current (AC) is an electric current which periodically reverses direction and changes its magnitude continuously with time in contrast to direct current (DC) which flows only in one direction. Alternating current is the form in whic ...

was the 250 kilowatt Mill Creek No. 1 Hydroelectric Plant, near

Redlands, California Redlands ( ) is a city in San Bernardino County, California, United States. As of the 2020 census, the city had a population of 73,168, up from 68,747 at the 2010 census. The city is located approximately west of Palm Springs and east of ...

, in 1893 designed by

Almarian Decker Almarian William Decker (born 1852, Ohio; d. Aug. 1893, Sierra Madre, California; interred Sierra Madre Pioneer Cemetery) was an American pioneer of electrical engineering involved in the early development of three-phase electrical power. In 1892 ...

. The streambed is completely dewatered in some places. Also, a

levee A levee (), dike (American English), dyke (Commonwealth English), embankment, floodbank, or stop bank is a structure that is usually earthen and that often runs parallel to the course of a river in its floodplain or along low-lying coastli ...

system was built by the

United States Army Corps of Engineers , colors = , anniversaries = 16 June (Organization Day) , battles = , battles_label = Wars , website = , commander1 = ...

after a severe

flood A flood is an overflow of water ( or rarely other fluids) that submerges land that is usually dry. In the sense of "flowing water", the word may also be applied to the inflow of the tide. Floods are an area of study of the discipline hydrol ...

, which degraded the

riparian 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 terrestrial biomes of the Earth. Plant habitats and communities along the river margins and banks a ...

habitat. In addition, the poor conditions downstream interfere with

fish migration Fish migration is mass relocation by fish from one area or body of water to another. 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 thousa ...

to the creek.

References

University of Southern California: Mill Creek history
* Rivers of San Bernardino County, California San Bernardino Mountains Tributaries of the Santa Ana River Rivers of Southern California {{California-river-stub

See also

References