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ANNE THOMPSON: Los Angeles, California and its surrounding
county is the second most populous region in the United
States, with nearly ten million people. A population this large
requires a lot of water-- most of it transported from hundreds
of miles away.
STEPHANIE PINCETL: We depend on imported water from the Colorado
River, from the Eastern Sierra and from Northern California
that runs through The Bay Delta.
THOMPSON: L.A.'s water system was established in the early
1900's as a way of bringing water from the snow-covered
Eastern Sierra Nevada and Rocky Mountains to the city. This
system capitalizes on an important part of the Earth's
water cycle-- snowmelt runoff. When snows slowly melt, water
moves down the mountains and eventually reaches rivers, in
this case the Owens River. The Los Angeles Aqueduct then pumps
some of this water, about 200 billion gallons a year, more
than 400 miles to L.A. The management of this water is
fragmented among multiple basins and water rights holders along
the way, making it difficult for L.A. to fully utilize these
water sources. Stephanie Pincetl, a researcher partly
funded by the National Science Foundation, is director of the
California Center for Sustainable Communities at UCLA.
PINCETL: A sustainable city needs to be able to understand
or address water as a complete entity from supply and reuse and
not simply separating them into different divisions or different
labor and science. So the challenge going forward is how
do we reconfigure how cities are run?
THOMPSON: Adding to the problem is a growing population in
Southern California and a reduced snowpack in the
mountains that supplies the water due to warming
temperatures. A slowly melting snowpack releases water
throughout the summer. But warmer winters bring more rain
than snow, causing rivers to run much drier by late summer,
creating the potential for water shortages.
PINCETL: It actually depends on how much rainfall and snowpack
there is. So this year, we will probably be importing more water
from the Colorado River, because the Sierra Nevada snowpack is
going to be very light.
THOMPSON: To become more sustainable, several local and
regional organizations, such as the Los Angeles Department of
Water and Power, are devising methods to use something
known as the urban water cycle, which seeks to capture, store
and reuse the water that already exists in the city.
MARK GOLD: The city of Los Angeles is trying to move
towards a more urban water cycle where they're treating water all
the same as one water, whether it's coming from rainwater,
storm water, or waste water, or flood control,
or recycled water.
THOMPSON: Local groundwater, or water that is below the ground
surface and is recharged by rain and runoff, can provide an
additional source of water.
GOLD: Right now in the city of Los Angeles, it's around ten to
thirteen percent of local water supply.
THOMPSON: New innovative projects are looking at how
runoff can be better controlled and filtered, rather than
running directly into the sea. On Elmer Avenue in Sun Valley,
water in the gutters is filtered through roadside bioswales, or
landscape drainage systems. In the parking lot of the
LA Zoo in Griffith Park, runoff is directed into the ground
through pervious, or porous, pavement, to eventually filter
through soils and into nearby streams.
IFTEKHAR AHMED: What they do is, they capture the storm
water, hold it in the parking lot, it helps to infiltrate into
the ground, recharge the ground water.
THOMPSON: L.A. is also improving how it reuses its
water. At the West Basin Water Recycling Facility, pre-treated
waste water is further purified to produce clean, useable water.
RON WILDERMUTH: It's water that has been cleaned enough to go to
the ocean. And we take it and then we refine it and make it
into ultra-pure water in many cases.
THOMPSON: Sustainability also means conserving water, even
rain and storm water, something that L.A. residents are
already good at.
PINCETL: People are putting in rain barrels, people are putting
in rain gardens and so forth and people are really much, much
more aware of the importance of treating water well as
a precious resource.
THOMPSON: While the issues around the management of water
continue in California, by building an urban water cycle
that uses and reuses water sources more efficiently, Los
Angeles hopes to pave the way to a more sustainable future.
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