Irrigate with rainwater, graywater

Santa Fe is enjoying one of the wettest springtimes on record. And although that is reason enough to rejoice, conserving water is always in season. We are lucky to live in a city that is one of the most water-efficient (per capita) in the country. We have progressive city and county ordinances that promote water conservation in various forms.

For newhomes being built, city and county land-use codes require roof rainwater catchment (depending on the size of your home). Also, new homes, remodels, and additions in the city (if adding more plumbing fixtures) are required to meet the requirements of the toilet retrofit program, as well as the water-efficiency requirements under the city’s Green Building Code. These programs assure that all new plumbing fixtures in the city are water-efficient, and that when adding new fixtures we simultaneously replace old inefficient plumbing elsewhere in the city. The city’s Land UseDepartment is working currently to update its codes sur- rounding rainwater and graywater re-use to streamline the uptake of thesemethods in the city.

The water-conserving techniques we have found to be the most effective have been those that are low-tech and easy to maintain. Roof rainwater catchment can be as simple as downspouts that empty into drain pipes that convey rainwater into cisterns for storage or below-ground infiltrators to passively water the landscape. Gravity can be the most effective distribution method, if the site allows. If it requires a more aggressive distribution system, rainwater can be pumped to supply a water-efficient drip irrigation system. Try grouping plants of similar watering needs into irrigation zones so as to optimize water conservation. Use drip emitters sized appropriately to plants’ needs, and add a rain-moisture detector to stall the pre-scheduled watering routine when it has just rained.

Rain is not the only source of water available for re-use. Graywater may be re-used, and that can be done very cost-effectively. Waste water from showers, tubs, vanity sinks, and laundry can be piped into the landscape to supplement irrigation. Untreated waste water from toilets and the kitchen sink cannot be used for irrigation. Graywater should not be stored, to avoid the risk of bacterial growth, so graywater cisterns are not used. Allowgravity to bring the appropriate waste water out of the home and into the landscape. Graywater must be distributed below the surface of the ground, never sprayed or dripped onto the surface— again, avoiding potential exposure to bacteria. Simple infiltrator beds can be used where graywater can drain into mulch, gravel, or pumice beds that are covered by soil and cover crops, fruit trees, or ornamental plants.

By re-using water from our roofs and our drains, we can continue to enjoy a green landscape without adding any further burden on our public water supply.

Mark Giorgetti and Leslie Giorgetti are both principals at Palo Santo Designs, a Santa Fe design-build contractor specializing in high-performance homes. Mark serves as president of the Santa Fe Area Home Builders’ Association, and Leslie is an associate broker with Santa Fe Properties. Contact Mark at 505-670-4236, mark@palosantodesigns.com and Leslie at 505-670-7578, leslie.giorgetti@sfprops.com, and visit www.palosantodesigns.com.