Peoria Irrigation System & Turf Reduction Study
Peoria, AZ – Merit Award, Planning & Analysis
Douglas Macdonald, Aqua Engineering, Inc.
- In order to meet the scope requirements of the RFQ from the City of Peoria, a team of subconsultants including a landscape architect and a landscape contractor to conduct a comprehensive irrigation system efficiency and turfgrass reduction study at (18) neighborhood parks within the City was assembled.
- Aqua Engineering performed an extensive site analysis for (18) neighborhood parks managed by City of Peoria, AZ Parks & Recreation staff.
- Site-specific reports were developed based on site visit observations, equipment audits, historical water use data, theoretical hydraulic models and GPS irrigation system mapping.
- Site-specific improvement recommendations were combined and prioritized to develop a system-wide renovation and improvement plan.
ROLE OF THE IRRIGATION CONSULTANT
- Performed an irrigation site and inventory analysis to identify quantity, types, general condition, and anticipated remaining functional life of the existing irrigation equipment and pumping systems at each of the (18) neighborhood parks.
- Observed existing irrigation equipment in operation at each park site to determine probable remaining service life and to identify equipment or system layout that is not performing
- Using a digital pressure recorder attached to the irrigation water source, the consultant collected dynamic water pressure data in one-minute intervals over the course of one week at each site.
- Helped to develop potential turfgrass reduction strategies to identify turfgrass areas within each park that might be replaced with a lower water-using landscape to improve water use efficiency, without affecting the usefulness or aesthetics of the park for the neighborhood user groups.
- Despite observed inefficiencies in irrigation system design, incompatibility and aging of equipment at the (18) parks in this study, none exhibited significant over-watering relative to the theoretical irrigation water requirement calculations.
- City staff expressed a desire to reduce the peak season watering window of all the participating parks to a 30-hour weekly irrigation schedule (6-hours per night, 5-nights per week).
- Theoretical hydraulic models and system pressure loss calculations were used to evaluate if existing water sources, pumping systems, mainline piping and control systems are capable of effectively irrigating each park within the City of Peoria’s preferred 6-hour nightly peak season water window criteria.
- The study determined that only one of the (18) parks in the study had a water source of sufficient size to meet the requested window
- The consultant concluded that it may be more realistic and cost-effective for the City to establish a standard for a 40-hour (8-hours per night, 5-nights per week) or a 48-hour (8-hours per night, 6-nights per week schedule.
The consultant began by performing a thorough irrigation system operational review and efficiency evaluation.
Equipment inventory and evaluation, GPS mapping and historical water use analysis was conducted for each park.
A pressure-recorder was connected to the backflow preventer at each park to identify available water pressure and pressure fluctuations in the system over a week’s timeframe.
Observations for passive and active use and practicality of maintenance for turfgrass areas were detailed, as well as a summary of turfgrass condition.
The consultant recommended the immediate implementation of comprehensive irrigation design and operational standards.