The Otay River is a river

River

A river is a natural watercourse, usually freshwater, flowing towards an ocean, a lake, a sea, or another river. In a few cases, a river simply flows into the ground or dries up completely before reaching another body of water. Small rivers may also be called by several other names, including...

 in southern San Diego County, California

San Diego County, California

San Diego County is a large county located in the southwestern corner of the US state of California. Hence, San Diego County is also located in the southwestern corner of the 48 contiguous United States. Its county seat and largest city is San Diego. Its population was about 2,813,835 in the 2000...

. The 25 mi (40.2 km) river begins at San Miguel Mountain, flows through the Upper- and Lower- Otay Reservoirs, and continues on between the southern part of the Chula Vista

Chula Vista, California

Chula Vista is the second largest city in the San Diego metropolitan area, the seventh largest city in Southern California, the fourteenth largest city in the State of California, and the seventy seventh largest city in the U.S....

 and the Otay Mesa West district of San Diego, and empties into San Diego Bay

San Diego Bay

San Diego Bay is a natural harbor and deepwater port adjacent to San Diego, California. It is 12 mi/19 km long, 1 mi/1.6 km–3 mi/4.8 km wide...

. Savage Dam

Savage Dam

Savage Dam is a dam across the Otay River in southern San Diego County, California. It is a concrete arch gravity structure high, and serves to store water from the San Diego Aqueduct's 3rd Pipeline for backup municipal uses in the San Diego metropolitan area. It lies just over east-southeast of...

, completed in 1919, forms the 49510 acre.ft Lower Otay Reservoir

Lower Otay Reservoir

Lower Otay Reservoir is an artificial lake in San Diego County, California, flanked by Otay County Open Space Preserve and Chula Vista. The reservoir is formed by impounding the waters of the Otay River, behind Savage Dam, completed in 1918, and is the terminus for the Second San Diego Aqueduct...

, which is used to supply drinking water to parts of southern San Diego County. The reservoir is also the terminus for Pipeline 3 of the Second San Diego Aqueduct

San Diego Aqueduct

The San Diego Project, more popularly referenced as the San Diego Aqueduct, is a system of four aqueducts in the U.S. state of California, supplying about 90 percent of the water supply for the city of San Diego. The system comprises the First and Second San Diego Aqueducts, carrying water from the...

, which delivers water from the Colorado River

Colorado River

The Colorado River , is a river in the Southwestern United States and northwestern Mexico, approximately long, draining a part of the arid regions on the western slope of the Rocky Mountains. The watershed of the Colorado River covers in parts of seven U.S. states and two Mexican states...

 via the Colorado River Aqueduct

Colorado River Aqueduct

The Colorado River Aqueduct, or CRA, is a water conveyance in Southern California in the United States, operated by the Metropolitan Water District of Southern California . The aqueduct impounds water from the Colorado River at Lake Havasu on the California-Arizona border west across the Mojave...

.

The Upper Otay Reservoir is formed by Upper Otay Dam, built in 1901. The reservoir was established as a hatchery

Hatchery

A hatchery is a facility where eggs are hatched under artificial conditions, especially those of fish or poultry. It may be used for ex-situ conservation purposes, i.e. to breed rare or endangered species under controlled conditions; alternatively, it may be for economic reasons A hatchery is a...

 for the introduction of Florida-strain largemouth bass

Largemouth bass

The largemouth bass is a species of black bass in the sunfish family native to North America . It is also known as widemouth bass, bigmouth, black bass, bucketmouth, Potter's fish, Florida bass, Florida largemouth, green bass, green trout, linesides, Oswego bass, southern largemouth...

 in 1959. The reservoir was chemically treated first, which killed all of the native fish

Fish

Fish are a paraphyletic group of organisms that consist of all gill-bearing aquatic vertebrate animals that lack limbs with digits. Included in this definition are the living hagfish, lampreys, and cartilaginous and bony fish, as well as various extinct related groups...

. In 1996, the reservoir was opened to fishing

Fishing

Fishing is the activity of trying to catch wild fish. Fish are normally caught in the wild. Techniques for catching fish include hand gathering, spearing, netting, angling and trapping....

, but all fish caught must be released. Since the river is used as a municipal water supply, there is no human contact allowed at either reservoir. Early testing of manned gliders by noted aviator John J. Montgomery

John J. Montgomery

John Joseph Montgomery was an aviation pioneer, inventor, professor at Santa Clara College.On August 28, 1883 he made the first manned, controlled, heavier-than-air flights of the United States, in the Otay Mesa area of San Diego, California...

occurred in the region in the late 19th century.