A well-designed irrigation system should operate at peak efficiency and be designed and installed to improve water use efficiency by focusing on water placement and distribution. The design should maximize water use, reduce operational cost, conserve supply, and protect water resources.
Best Management Practices
- New and upgraded irrigation system designs should deliver water with maximum efficiency, focusing on precision water placement and distribution.
- Design and/or maintain a system to meet a site’s peak water requirements under normal conditions with the flexibility to adapt to various water demands and local restrictions.
- Design should account for optimal distribution efficiency and effective root-zone moisture coverage. Target 80% or better Distribution Uniformity (DU).
- Design should allow the putting surface, slopes, and surrounds to be watered independently.
- The design package should include a general irrigation schedule with recommendations and instructions on modifying the schedule for local climatic, soil, and growing conditions. It should include the base evapotranspiration (ET) rate for the particular location.
- The application rate must not exceed the infiltration rate, which is the ability of the soil to absorb and retain the water applied during any one application. Conduct saturated hydraulic conductivity tests periodically.
- The design operating pressure must not be greater than the available source pressure.
- The design operating pressure must account for peak-use times and supply-line pressures at final buildout for the entire system.
- Turf and landscape areas should be zoned separately. Specific-use areas that should be zoned include greens, tees, primary roughs, secondary roughs, fairways, native areas, trees, and shrubs.
- Design should account for the need to leach out salt buildup from poor-quality water sources by providing access to fresh water.
- Only qualified specialists should install the irrigation system.
- Construction must be consistent with the design.
- The designer must approve any design changes before construction.
- Construction and materials must meet existing standards and criteria.
- Prior to construction, all underground cables, pipes, and other obstacles must be identified and their locations flagged.
- Permanent irrigation sprinklers and other distribution devices should be spaced according to the manufacturer’s recommendations.
- Spacing should be based on average wind conditions during irrigation.
- Distribution devices and pipe sizes should be designed for optimal uniform coverage and flow rate.
- Distribution equipment, such as sprinklers, rotors, and micro-irrigation devices, in a given zone must have the same precipitation rate.
- Heads for turf areas should be spaced for head-to-head coverage.
- Water supply systems (for example, wells and pipelines) should be designed for varying control devices, rain shut-off devices, and backflow prevention.
- Water conveyance systems should be designed with thrust blocks and air-release valves.
- Flow velocity must be 5 feet per second or less.
- Pipelines should be designed to provide the system with the appropriate pressure required for maximum irrigation uniformity.
- Pressure-regulating or compensating equipment must be used where the system pressure exceeds the manufacturer’s recommendations.
- Equipment with check valves must be used in low areas to prevent low head drainage.
- Isolation valves should be installed in a manner that allows critical areas to remain functional.
- Manual quick-coupler valves should be installed near greens, tees, and bunkers and in fairways if possible, so that these areas can be hand-watered during severe droughts.
- Use part-circle or adjustable heads to avoid overspray of impervious areas, such as roadways and sidewalks, and surface waters such as lakes, ponds, and wetland margins.
- Update multi-row sprinklers with single head control to conserve water and to enhance efficiency.
- Incorporate multiple nozzle configurations to add flexibility and enhance efficiency and distribution.
- Ensure heads are set level to the ground.
