§ 50-373. Requirements for efficient irrigation.

(a)

System design. Irrigation systems shall be designed, constructed, and permitted to include:

(1)

Automatic irrigation controllers, when utilized, shall contain a functional rain sensor device, capable of being set to one minute run times, and battery backup capability to retain programming in the event of a power failure;

(2)

A rain sensor placed on a stationary structure, free and clear of any overhead obstructions and above the height of the sprinkler coverage;

(3)

Equipment with check valves used in low-lying areas to prevent low head drainage;

(4)

Backflow prevention methods and other provisions prescribed in section 74-42;

(5)

Irrigation design with the appropriate uniformity for the type of plant being grown and for the type of soil;

(6)

Irrigation system equipment installed as designed;

(7)

Irrigation zones divided according to: available flow rate, vegetated groupings (i.e., turf, shrubs, native plants, etc.), sprinkler types (i.e., sprinklers with matching precipitation rates), and soil characteristics;

(8)

Spray heads and rotors not mixed in same zone;

(9)

Distribution equipment in a given zone having matched precipitation rates;

(10)

Application rates that avoid runoff and permit uniform water infiltration into the soil, considering land slope, soil hydraulic properties, vegetative ground cover, and prevailing winds;

(11)

A minimum separation of four inches between distribution equipment and pavement;

(12)

A minimum separation of 12 inches between distribution equipment and buildings and other vertical structures;

(13)

No direct spray onto walkways, buildings, roadways, and drives;

(14)

Lawn spray patterns providing head to head coverage;

(15)

Water conveyance systems with a flow velocity of five feet per second or less;

(16)

Pipelines designed to provide the system with the appropriate pressure required for maximum irrigation uniformity;

(17)

Pressure regulating heads; and

(18)

A maintenance checklist provided to the property owner by the irrigation contractor accompanied by a recommended maintenance schedule, proper irrigation system settings according to season, recommendations for checking rain sensor device, filter cleaning recommendations and information on the current water restrictions.

(b)

System layout and native vegetation retention. Irrigation systems shall comply with the following requirements:

(1)

A high volume irrigation area shall not exceed 50 percent of the landscaped area. Low or medium volume irrigation areas may be utilized in lieu of any high volume irrigation area.

(2)

A medium volume irrigation area shall not exceed 25 percent of the landscaped area. However, the landscaped area may contain up to 75 percent medium volume irrigation area, if no high volume irrigation area is utilized on site.

(3)

A low volume irrigation area may be utilized for an entire landscaped area with the exception of native vegetation areas regulated by subsection 50-373(b)(4).

(4)

In the alternative to subsections 50-373(b)(1)), (2), and (3) above, if 25 percent of the pre-existing native vegetation is retained on site, the remaining 75 percent of the landscaped area may be a high volume irrigation area. For all pre-existing native vegetation retained on a parcel:

a.

No supplemental water shall be applied to the native vegetation area;

b.

Only hand pruning of native vegetation is allowed;

c.

Mechanical mowing or clearing is prohibited.

(c)

System operation flows. Systems shall dispense no more water than provided in section 50-314.

(d)

Irrigation system operation and maintenance.

(1)

Irrigation systems shall be operated properly and in compliance with section 50-314 and this section.

(2)

All automatic controllers shall be programmed to the appropriate level of water conservation set forth in section 50-314.

(3)

Irrigation systems shall be maintained to meet the requirements of this section.

(Ord. No. 2004-05, § II, 5-20-04; Ord. No. 2009-16, § II, 5-21-09)