Maybe you've heard that today is the one hundredth anniversary of the Los Angeles Aqueduct, the engineering marvel that brought enough water to the city to seed its growth (and much more on that later). But all it could do was seed. Los Angeles is not a desert, but it has a semi-arid climate with lots of dry periods, and it has enough land to house millions, all of whom need to drink and bathe and water their plants. At the Daily News, Dana Bartholomew explains where SoCal's water comes from and just how endangered it is (pretty endangered); it also provides a brief, incredible history of water in the region, which helps explain how we got in so much water trouble in the first place:
-- "The West has been dry for millions of years, with hugely varying annual rainfall, climatologists say. The Southland gets an average of 15 inches a year — enough water to supply 5 million people."
-- "The 11th century saw an 80-year drought, long enough to wipe out a tribe of pre-Columbian Pueblo peoples."
-- "With the influx a century ago of Eastern and Midwestern settlers to Los Angeles and Southern California, young cities began to look far afield for a reliable source of water — namely the snowmelt from the High Sierra and eastern Rockies."
-- To supplement the Los Angeles Aqueduct (which is actually two pipelines; the second opened in 1970), the Colorado River Aqueduct "opened in 1939 to create the mighty Hoover and Parker dams and generate enough hydroelectric power to pump water from a river now shared by seven states and six Indian nations."
-- The incredible State Water Project opened in 1964; it collects water in Northern California and transports it south to the Bay Area, Central Valley, and SoCal.
-- The thing is that the Twentieth Century happened to be "among the wettest centuries in 2,000 years."
-- And for a decade now, SoCal has been drier than normal; meanwhile climate change has "shorten[ed] the mountain snow season, which acts as a frozen reservoir for the region's water."
-- Recently the Colorado River supplies have been troubled by drought and quagga mussels, which clog waterways and filtration systems.
-- The SWP's "levees are vulnerable to rising sea levels, extreme flood and a major earthquake. And dozens of species of fish and wildlife have been adversely threatened," so a federal court ruled six years ago that water shipments had to be cut by as much as a third. The governor is now pushing a massive new canal plan to make up for it.
-- A JPL climatologist lays it out: "The problem is, now that we're 70 percent dependent on imported water, the snow in the Sierras has been dry for a decade; the Colorado River has been dry for eight years."
-- "On an average year, the city's 4 million residents now get more than a third of their water from the L.A. Aqueduct, half their water from imports by the Metropolitan Water District, 11 percent from groundwater and 1 percent from reclaimed sewer water." (Much more on SoCal's imported water situation.)
-- But we've gotten good at conservation: The Metropolitan Water District, which covers 26 cities and water agencies running from San Diego to Ventura and out to San Bernardino, is "managing on the same amount of imported water since 1990 — we had 14 million (people) then, we're now at 19 million," according to its general manager.
-- The MWD says it now has enough reserves to get through the next year, but there could still be shortages in some areas.
-- But LA expects to cut SWP and Colorado imports in half by 2025, "while boosting groundwater use to 16 percent, recycled sewer water to 8 percent, water conservation to 9 percent and stormwater capture to 3 percent."
· Los Angeles' water future remains challenged by drought, short supplies [LADN]
· Water Wars [Curbed LA]