Second Los Angeles Aqueduct Los Angeles Aqueduct

los angeles aqueduct system

faced possible loss of future water supply, los angeles began five-year construction of aqueduct in 1965 @ cost us$89 million. once city received diversion permits, water exports jumped in 1970, adding 110,000 af year aqueduct system. 1974, exports climbed 450,000 afy.

the 137-mile-long (220 km) aqueduct designed flow 290 cu ft/s (8,200 l/s) , begins @ merritt diversion structure @ junction of north , south haiwee reservoirs, south of owens lake, , runs parallel first aqueduct. water flows entirely gravity elevation of 3,760 feet (1,150 m) @ haiwee reservoir through 2 power drops elevation of 1,200 ft (370 m) @ upper van norman reservoir.

the second aqueduct not built single contiguous conduit. design , construction purposes aqueduct divided northern , southern sections , 2 connected san francisquito tunnels, part of first aqueduct.

the northern section carries water starting @ north haiwee reservoir through haiwee bypass passing around south haiwee reservoir. flow continues 115 miles (185 km) south through series of pressure pipelines , concrete conduits connects first aqueduct @ north portal of elizabeth tunnel near fairmont reservoir.

the san francisquito tunnels (which includes elizabeth tunnel) has flow capacity of 1,000 cu ft/s (28,000 l/s) , large enough handle flow of both aqueducts. once combined flow reaches penstocks above power plant #2, water diverted southern section of second aqueduct away through drinkwater tunnel drinkwater reservoir.

an updated version of concrete box construction used on second aqueduct.

the last segment of pipe, known saugus pipeline, carries water south past bouquet canyon, soledad canyon , placerita canyon. there parallels sierra highway before enters magazine canyon towards terminal structure , cascades. water terminal structure can flow either cascade or penstock foothill power plant , upper van norman reservoir.

in addition construction in northern , southern sections, improvements made lined canal between alabama gates , north haiwee reservoir in northern section consisted of adding 24 in (610 mm) sidewalls both sides of canal , raising of overcrosses. work increased capacity of lined canal 710 cu ft/s (20,000 l/s) 900 cu ft/s (25,000 l/s) cfs.

the second aqueduct s impact on water system

the increased flows provided second aqueduct short lived, however, lasting 1971 through 1988. in 1974 environmental consequences of higher exports first being recognized in mono basin , owens valley. followed series of court ordered restrictions imposed on water exports, resulted in los angeles losing water. in 2005, los angeles urban water management report reported forty fifty percent of aqueduct s historical supply devoted ecological resources in mono , inyo counties.