For the efficient use of water, all irrigation schedules shall be developed, managed and evaluated to utilize the minimum amount of water required to maintain plant health. Irrigation schedules shall meet the following criteria.
(A) Irrigation scheduling shall use automatic irrigation systems and evapotranspiration data such as those from the Bureau of Reclamation AgriMet tool and local or regional weather-monitoring stations.
(B) The irrigation schedule shall:
(1) Include run time (in minutes per cycle), suggested number of cycles per day, and frequency of irrigation for each station.
(2) Provide the amount of applied water (in hundred cubic feet, gallons or in whatever billing units the local water supplier uses) recommended on a monthly and annual basis.
(3) The total amount of water for the project shall include water designated in the estimated total water use calculation, plus water needed for any water features, which shall be considered as a high-water-using hydrozone.
(4) Recreational areas designated in the landscape design plan shall be highlighted and the irrigation schedule shall indicate if any additional water is needed above the maximum applied water allowance because of high plant factors (but not due to irrigation inefficiency).
(5) Whenever possible, irrigation scheduling shall incorporate the use of evapotranspira-tion data, such as those from local or regional weather-monitoring stations (as close as geograph-ically possible to the city), to apply the appropriate levels of water for irrigation and season.
(C) Overhead irrigation shall be scheduled between 8:00 p.m. and 10:00 a.m. unless weather conditions prevent it. If allowable hours of irrigation differ from the local water purveyor, the stricter of the two shall apply. Operation of the irrigation system outside the normal watering window is allowed for auditing and system maintenance.
(D) For implementation of the irrigation schedule, particular attention must be paid to irrigation run times, emission device, flow rate, and current reference evapotranspiration, so that applied water meets the estimated total water use. Total annual applied water shall be less than or equal to maximum applied water allowance (MAWA). Actual irrigation schedules shall be based on current, time-reference evapotranspiration data or soil-moisture sensor.
(E) Parameters used to set the controller shall be developed and submitted for each of the following:
(1) The plant establishment period;
(2) The established landscape; and
(3) Temporarily irrigated areas.
(F) Each irrigation schedule shall consider for each station all of the following that apply;
(1) Irrigation interval (days between irrigation);
(2) Irrigation run times (hours or minutes per irrigation event to avoid runoff);
(3) Number of cycle starts required for each irrigation event to avoid runoff;
(4) Amount of applied water scheduled to be applied on a monthly basis;
(5) Application-rate setting;
(6) Root-depth setting;
(7) Plant-type setting;
(8) Soil type;
(9) Slope-factor setting;
(10) Shade-factor setting; and
(11) Irrigation-uniformity or efficiency setting,
(Ord. 2021-12-01, passed 1-11-2022)