Design landscape and irrigation systems to maximize native and adapted species, use efficient irrigation technology, and reuse water where possible. Evaluate the different irrigation technologies for their efficiency and suitability to the project. These include subsurface, bubbler, drip, and rotor sprinkler. Installing weather controls or soil moisture sensors can greatly reduce unnecessary irrigation. Consider directing rainwater to planting beds to reduce the need for potable irrigation water.

Evaluate a number of scenarios to achieve the credit. Look for options that work best for the design, and see if there are any trade-offs or overlaps with other LEED credits.

Look for local incentives for sub-grade irrigation, efficient irrigation, irrigation controls, and/or irrigation sub-metering. For example, one city provides up to $7,000 per acre-foot of water saved, and another program provided rebates up to $1,000 per acre for weather-based irrigation controls. Some municipalities even support “cash for grass” programs that provide rebates for the replacement of turf and with native plantings. For example, one pilot program provides $1.00 per square foot of replaced turf grass.

You can avoid submitting calculations for credit compliance by not using permanent irrigation. In this case, no permanent irrigation system can be installed, even with the intent to turn it off. Irrigation for plant establishment, allowable for one year, must be manual, or through temporary, above-grade systems. Using hose bibs to water when plants are being established and during drought conditions is allowed as “temporary irrigation.”

For Option 2: No Potable Water Use or No Irrigation, projects have to achieve a 50% reduction in total water applied in addition to eliminating irrigating with potable water. That is, even if a project uses non-potable water for irrigation, it must also reduce the total water use for irrigation by 50%. To use non-potable water to pursue Option 2, projects must provide a detailed narrative on the actual source and available quantity of the non-potable water as well as the anticipated schedule for implementation of the non-potable system.

Starting the LEED calculations early, along with early completion of a compliant landscape design can avoid costly redesign due to non-compliance.

The following water sources count as reused for credit purposes: graywater (lavatory, sink and shower water), harvested rainwater (cistern, underground, or pond), nuisance water (water that must be pumped away from the building), treated wastewater, air-conditioner condensate, reverse-osmosis reject, and sump-pump water. All well water is counted as potable for credit purposes.

Work with the whole project team to evaluate synergies and tradeoffs with other LEED credits or green building strategies. These may include using rain gardens for stormwater infiltration, trees for shading the building and hardscapes for cooling-load reduction, porous surfaces, soil selection encouraging infiltration, windbreaks, water reuse, rainwater capture and acoustical barriers.

Evaluate the potential for nonpotable water sources, including rainwater reuse and graywater reuse. If non-potable water use seems feasible for your project evaluate the water demand for your landscape and the quantity of water reuse available to your project. Calculations, usually done by the landscape architect, have to account for annual rainfall on a monthly basis for the project location. Rainwater, which may need basic filtration but not usually additional treatment, can be piped directly to plantings to reduce the need for potable irrigation water.

Research native or drought-tolerant plants and efficient irrigation systems and controls. Check for local incentives for efficient systems and controls.