No Such Thing as a Green Lawn

©iStockphoto.com/dbuffoon

by Sarah (Steve) Mosko, PhD.

Appeared in:

• El Cuervo de Orange, Feb 14, 2012
• Vall-E-Vents, May 2010.
• E-Magazine’s ‘Our Planet Weekly,’  April 8, 2010.
• Fullerton Observer, early March, 2010, p. 17.
• Orange Coast Voice, Dec. 7, 2009.

Which consumes more fossil fuels, lawn maintenance with gas-powered tools or lawn watering? For residents of Southern California, the correct answer is watering because of the energy it takes to transport water to the region.

Southern California (SoCal) is a semi-arid desert. Rainfall averages only 15 inches per year, for example, in the Los Angeles area.  Local water sources have fallen far short of meeting the region’s water needs for more than a century.

With 2/3 of the state’s rainfall in Northern California and 2/3 of the water demand in SoCal, the State deals with this imbalance by pumping in half of SoCal’s water supply from sources hundreds of miles away, the Colorado River and the Sacramento-San Joaquin Delta.

The Water-Electricity Relationship

Piping water long distances is costly in terms of electricity, especially water imported from the Delta which has to be pumped uphill 2,000 ft to get over the Tehachapi Mountains.

In a first ever analysis of the energy embedded in bringing potable water to residential faucets and hoses in SoCal, a 2005 Calif Energy Commission analysis calculated 11,111 kWh/MG  (kilowatt hours per million gallons), three times costlier than in Northern California. Most of the electricity is for water transportation, much less for water treatment and maintaining water pressure. Every 100 gallons of imported water eats up enough electricity to keep a 100 W bulb lit for 11 hours.