Outdoor landscape irrigation systems shall be designed and installed to reduce potable water use by 50 percent from a calculated mid-summer baseline in accordance with Section 404.1.2 or, where permitted by State regulation or local ordinances, the system shall be supplied by municipal reclaimed water or with alternate onsite nonpotable water complying with Chapter 7.
Exceptions: Potable water is permitted to be used as follows:
Where in-ground irrigation systems are provided, the systems shall comply with all of the following:
1. The design and installation of outdoor irrigation systems shall be under the supervision of an irrigation professional accredited or certified by an appropriate local or national body.
2. Landscape irrigation systems shall not direct water onto building exterior surfaces, foundations or exterior paved surfaces. Systems shall not generate runoff.
3. Where an irrigation control system is used, the system shall be one that regulates irrigation based on weather, climatological or soil moisture status data. The controller shall have integrated or separate sensors to suspend irrigation events during rainfall.
4. Irrigation zones shall be based on plant water needs with plants of similar need grouped together. Turfgrass shall not be grouped with other plantings on the same zone.
5. Microirrigation zones shall be equipped with pressure regulators that ensure zone pressure is not greater than 40 psi (275.8 kPa), filters, and flush end assemblies.
6. Sprinklers shall:
6.1. Have nozzles with matched precipitation rates.
6.2. Be prohibited on landscape areas less than 4 feet (1230 mm) in any dimension.
6.3. Be prohibited on slopes greater than 1 unit vertical to 4 units horizontal (25-percent slope).
Exception: Where the application rate of the sprinklers is less than or equal to 0.5 inches (12.7 mm) per hour.
6.4. Be permitted for use on turfgrass and crop areas only excepting microsprays of a flow less than 45 gallons (170 liters) per hour.
6.5. If of the pop-up configuration, pop-up to a height of not less than 4 inches (101 mm).
6.6. Only be installed in zones composed exclusively of sprinklers and shall be designed to achieve a lower quarter distribution uniformity of not less than 0.65.
Where available and approved for use by the authority having jurisdiction, alternate nonpotable onsite water sources complying with Chapter 7 shall be used for outdoor ornamental fountains and other water features constructed or installed on a building site. Where the fountain or water feature is the primary user of the building site's nonpotable water source, a potable makeup water connection is prohibited.
Exception: Outdoor ornamental fountains and water features are allowed to use potable water provided water is recirculated and there is not an automatic refill valve connection to a source of potable water, and provided that either:
- The catch basin or reservoir is no greater than 100 gallons (379 L); or
- Less than 20 square feet (1.86 m2) of water surface area is exposed.
The treatment required to maintain appropriate water quality shall comply with the authority having jurisdiction.