There is an Armenian proverb: “On a rainy day many offer to water the chickens.” And in a very dry year there are many who want to follow the call to tear out their lawns. The call is coming from the Department of Water Resources and others for urban homeowners to start tearing out their lawns, with financial incentives for doing so (see “Lawn Water: A Fix for the Drought?” Chris Austin, Capitol Weekly, May 19).
According to David Powell, P.E., former head of the San Diego Office of DWR and former chief planning engineer with Bookman-Edmonston Engineering, the one-size-fits-all policy of tearing out lawns is short sighted. It would deplete local aquifers in communities on sandy soils with subsurface water basins that rely on imported water for a significant amount of their water supplies.
The reason is that in dry years conservation is critical not only in agricultural areas but also in urban areas, particularly with watering home landscaping. But during wet years it is just as critical to water lawns in order to recharge the groundwater basin with imported water. Hydrologists for the Raymond Basin in Pasadena, for example, use a 15% recharge rate per year mainly from imported water during wet years.
The DWR among many other agencies use a figure of 70% of household water goes to landscaping. This is vastly inflated. The best study we have in San Diego is landscaping uses 44% of household water.
This doesn’t apply to communities on clay or sandstone soils, on communities that rely on 100% of their own groundwater and no imported water, or in dry years. Communities with impervious soils can’t recharge non-existent water basins. And communities that are self-reliant on their own groundwater (e.g., Downey) would just be recirculating their own water supplies without much benefit unless they also received imported water.
If we tear out lawns a significant amount of recharge to local water basins will be lost from imported water. Fifteen percent per year recharge rate means a near total loss of recharge from imported water over a 6-year period.
The DWR among many other agencies use a figure of 70% of household water goes to landscaping. This is vastly inflated. The best study we have in San Diego is landscaping uses 44% of household water. According to DWR data, urban uses comprise 13% of all system water in a dry year. If 44% of that goes to landscaping that is only 5.7% of all system water.
Five percent is not a trifling amount when farmers’ water allocations are cut to 5% in dry years such as this year. But that 5% can be achieved from conservation during dry years without tearing out lawns and depleting groundwater basins and ruining residential property values. Most communities have ordinances that require a certain percentage of the lot area of a home or apartment building must be landscaped. DWR’s policy would usurp home rule and would deplete local water basins that need to be recharged in critical wet years when we need to store up water for dry years.
What we’re going to end up with is low income neighborhoods tearing out lawns and residents using the bare dirt for parking cars which is a reality in many overly dense neighborhoods in older cities where there is not enough off-street parking.
HUD’s Community Development Block Grant Program has worked for decades to combat neighborhood blight by offering rehab loans to low-income homeowners and implementing neighborhood revitalization projects. DWR’s shortsighted policy would negate such programs and return to neighborhood blight, which has been connected with higher crime rates. Having a lawn is not a crime and helps recharge groundwater basins in communities with sandy soils in wet years that depend on imported water which is most of Southern California.
In a dry year many want to offer to pull up their lawns and get free drought landscaping paid for by other water ratepayers. Apartment landlords will be the first to offer to do that to reduce their water bills. Be careful of those who want to offer to water the chickens on a rainy day or who want to pull up their lawns in a dry season. The unintended, but foreseeable, consequences would be the depletion of local groundwater basins and the increase of urban blight in the most vulnerable neighborhoods.
Ed’s Note: Wayne Lusvardi lives in Pasadena and writes on water policy for Calwatchdog.com and energy policy for Masterresource.org.