The supplemental use of water for course play and non-play areas is essential to supporting healthy turfgrass and sustaining optimal playability, aesthetics, marketability, and club membership participation. BMPs related to water use conserve and protect water resources. Conservation and efficiency-related efforts consider the strategic use of appropriate course and irrigation design, plant selection, computerized and data-integrated scheduling, and alternative water quality/supply options to maximize plant health and reduce the potential for negative impacts on natural resources (Figure 4). Water quality protection is an integrated approach that includes irrigation practices, pesticide and nutrient management, regulatory compliance measures, and structural measures as they concern environmental stewardship and policy.
Irrigation BMPs may also provide economic, regulatory compliance, and environmental stewardship advantages to those who utilize them within their irrigation management plan. BMPs are not intended to increase labor or place an undue burden on the owner/superintendent. If applied appropriately, BMPs can help stabilize labor costs, extend equipment life, limit repair and overall personal and public liability, and conserve water.
3.1 Regulatory Considerations
Golf course owners are responsible for contacting federal, state, and local water use authorities at the pre- and post-construction phases to determine annual or specific water consumption (water rights), permitting guidelines, and other regulatory requirements. Most uses of water in Delaware require a Water Allocation Permit (WAP) from DNREC. Permitted users with withdrawals (surface water or groundwater) exceeding 50,000 gallons per day are required to report monthly withdrawals to DNREC. Facilities within the Delaware River Basin are required to file annual surface water usage reports with the Delaware River Basin Commission.
An application for a water allocation permit must include a Drought Management Plan. Superintendents should be aware that the water allocation amounts are calculated to:
- Provide adequate water for the turf during a drought emergency based on historical rainfall.
- Protect the aquifer.
Superintendents should be aware that maintaining water levels in ponds for aesthetic purposes is not included in this calculation. If the resource is not adequate to maintain turf grasses during a drought emergency, it must be addressed during the permitting process. This may also be the only viable opportunity to address the reuse of wastewater for turf grass irrigation.
3.2 Water Conservation and Efficient Use Planning
Potable water supplies in many areas of the United States are limited, and demand continues to grow. The challenge is to find solutions to maintain the quality of golf while using less water. Opportunities to conserve water exist when courses are initially designed and during renovation, during irrigation system design and use, and by incorporating the use of management zones (Figure 5).
Some courses are designed using a “target golf” concept that minimizes the acreage of irrigated turf. If properly designed, water hazards and stormwater ponds can capture rain and runoff that may provide supplemental water under normal conditions; backup sources may be needed during severe drought. During times of intense heat stress, syringing, or the practice of applying a small amount of water to help cool the turfgrasses as it evaporates, may be beneficial under certain conditions. These conditions include turf with a very shallow root system, turf compromised by disease, poor soils, or wet-wilt. Because the cooling effect of syringing is very brief, repeated syringing and/or the use of fans will maximize the cooling effect.
In addition to utilizing well-adapted cultivars for in-play areas, existing golf courses can convert out-of-play area turf to naturally adapted native plants, grasses, or ground covers to reduce water use and augment the site’s aesthetic appeal (Figure 6). Native plant species also provide wildlife with habitat and food sources, such as native flower areas that benefit pollinators. After establishment, site-appropriate plants normally require little to no irrigation. See the “Pollinator Protection” and “Landscape” chapters of this document for more information on native and drought tolerant plants.
Drought management plans should identify ways to achieve a 10% reduction in water use. For more guidance on developing a plan, see the USGA publication Developing a Drought Emergency Plan. Communication with water managers, golf club members, and the public should be maintained to explain water conservation efforts as a proactive approach to addressing water-related issues.
3.3 Irrigation Water Suitability
Golf course designers and managers should endeavor to identify and use alternative supply sources to conserve freshwater drinking supplies, promote plant health, and protect the environment. DNREC prepared a seminar detailing Beneficial Uses of Reclaimed Water in Delaware.
Studies of water supplies are recommended for irrigation systems, as are studies of waterbodies or flows on, near, and under the property. Water sources for irrigation must be dependable and offer sufficient resources to accommodate turf grow-in needs and ongoing maintenance. Environmental Best Management Practices for Virginia’s Golf Courses describes the methodology and provides example calculations to determine water requirements using a seasonal and maximum bulk water requirement analysis (pages 37 and 38). In addition to quantity, the water quality must be suitable for plant growth and pose no threat to public health.
When necessary, include sodic water system treatment options in the budget to address water quality and equipment maintenance. Irrigation water that is high in soluble salts or sodium (Na+) may result in a soil that has a high electrical conductivity (EC) leading to direct injury to turfgrass root and shoot tissues or manifest as negative effects on soil physical properties. High soil EC can result in osmotic drought or the inability of roots to absorb soil water. High Na+ can disaggregate soils leading to poor water infiltration, restricted drainage and low soil oxygen. Treatment options include flushing with clean water, along with core aeration and soil-test prescribed additions of gypsum.
3.4 Wellhead Protection
Wellhead protection is the establishment of protection zones and safe land-use practices around water supply wells in order to protect aquifers from accidental contamination. It includes protecting wellheads from physical impacts, keeping them secure, and sampling wells according to the monitoring schedule required by the regulating authority. Before installing new wells, DNREC and the local regulatory authorities should be contacted to determine the permitting and construction requirements and the required isolation distances from potential sources of contamination. Locate new wells up-gradient as far as possible from potential pollutant sources, such as petroleum storage tanks, septic tanks, chemical mixing areas, or fertilizer storage facilities.
3.5 Irrigation System Design
The irrigation system design should meet the site-specific needs identified by water quantity analyses and a thorough site assessment. The system’s capacity to deliver water should not exceed the infiltration of the soils on site to avoid runoff. Though the design of an irrigation system is complex, some of the most important design decisions that influence the efficiency and effectiveness of water usage include those related to sprinkler and piping placement, sprinkler coverage and spacing, and communication options (Figure 7).
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. Detailed BMPs for irrigation system design are published by the Irrigation Association in 2014 in Landscape Irrigation Best Management Practices.
Pump stations should be efficient and sized to provide adequate flow and pressure. Equip pump stations with control systems that protect distribution piping, provide for emergency shutdown necessitated by line breaks, and allow maximum system scheduling flexibility. Consider variable frequency drive (VFD) pumping systems where feasible. These systems only expend enough energy to meet the demands of the irrigation pump(s). VFD systems reduce water hammer to fittings, pipes, and sprinklers when systems are pressurized.
3.6 Irrigation System Maintenance
Irrigation system maintenance on a golf course involves four major efforts: calibration and auditing, preventive maintenance, corrective maintenance, and record keeping. Personnel charged with maintaining a golf course irrigation system face numerous challenges. This is particularly true for courses with older or outdated equipment. Irrigation audits can be conducted to assess the system function, ensuring that the irrigation system works reliably and is cost effective. The Irrigation Association has published irrigation audit guidelines.
Good system management starts with proper utilization of preventive maintenance procedures and record keeping. Corrective maintenance is simply the act of fixing what is broken and may be as simple as cleaning a clogged orifice or as complex as a complete renovation of the irrigation system (Figure 8). As maintenance costs increase, an evaluation of whether a system renovation is needed should be conducted.
3.6.1 Irrigation Leak Detection
Irrigation systems are complex and should be closely monitored to ensure leaks are quickly detected and corrected. An irrigation system should also have high- and low-pressure sensors that shut down the system in case of breaks and malfunctions. Golf courses without hydraulic pressure-sustaining valves are much more prone to irrigation pipe and fitting breaks because of surges in the system, creating more downtime for older systems.
3.6.2 Irrigation System Renovation
Renovating a golf course irrigation system can improve system efficiencies, conserve water, improve playability, and lower operating costs.
3.6.3 Winterization and Spring Startup
Winterization of the irrigation system is important to protect the system and reduce equipment failures resulting from freezing. In the spring, inspecting the system for corrective maintenance issues and conducting a catch-can test to audit the system will ensure that the system is functioning properly.
3.6.4 Record Keeping
Careful record keeping is an important part of managing an irrigation system, as well as part of regulatory requirements for reporting water withdrawal.
3.7 Irrigation System Scheduling
An irrigation system should be operated based only on the moisture needs of the turfgrass — or to water-in a fertilizer or chemical application as directed by the label. It should not run on a calendar-based schedule. Therefore, irrigation scheduling must consider soil infiltration and percolation rates as well as plant water requirements to determine the appropriate amount of irrigation to apply.
The goal of successful irrigation management is to limit excessive soil moisture while preventing wilt. Golf managers strive to precisely apply irrigation, so plant-available water is only slightly greater than predicted evapotranspiration (ET). For many highly maintained turf areas, like greens, small amounts of water should be applied as needed to replace what was lost. Soil moisture probes can help further improve irrigation precision. These technologies can guide irrigation head run times and identify locations that might benefit from additional hand watering (Figure 9).
For older systems utilizing electric/mechanical clocks that cannot automatically adjust for changing ET rates, frequent adjustment is necessary to compensate for the irrigation needs of individual turfgrass areas. In low-maintenance areas, such as golf course roughs, waiting until visual symptoms appear before irrigating is an acceptable method for determining irrigation needs. The amount to irrigate is important as well. Irrigating too shallowly encourages shallow rooting, increases soil compaction, and favors pest outbreaks while over-irrigating can lead to leaching and runoff. For golf greens and tees, the majority of the roots are in the top several inches of soil. Overall, use infrequent, deep irrigation to supply sufficient water for plants and to encourage deep rooting.
3.7.1 Sensor Technology
Install soil moisture sensors and other irrigation management tools in representative locations and maintain them to provide the information necessary for making good irrigation-management decisions. Rain gauges are necessary measurement tools to track how much rain has fallen at a specific site on the golf course. On some courses, more than one station may be necessary to get a complete measure of rainfall or evaporation loss. Use soil moisture probes, computer models, and tensiometers, as well as visual inspections for symptoms such as wilting turf, to supplement these measurements. Computerized displays are available to help visualize the system.
Predictive models based on weather station data and soil types are also available. These are relatively accurate and applicable, especially as long-term predictors of annual turf water requirements. Weather data such as rainfall, air and soil temperature, relative humidity, and wind speed are incorporated into certain model formulas, and soil moisture content is estimated. Models, however, are only as effective as the amount of data collected and the number of assumptions made. It is best to have an on-site weather station for daily weather information and ET rates to determine site-specific water needs.
Rainfall may vary from location to location on a course; incorporate the proper use of rain gauges, rain shut-off devices, flow meters, soil moisture sensors, and/or other irrigation management devices into the site’s irrigation schedule. It is also important to measure the amount of water that is delivered through the irrigation system, via a water meter or a calibrated flow-measurement device (Figure 10). Knowing the flow or volume will help determine how well the irrigation system and irrigation schedule are working.
3.8 Irrigation Best Management Practices
Water Conservation Best Management Practices
- Select drought-tolerant varieties of turfgrass to minimize water use.
- Utilize hand watering or targeted irrigation only as needed, such as dry spots, to conserve water.
- During hot and dry weather, consider sequential applications of wetting agents to enhance water infiltration and achieve more uniform soil moisture availability.
- Control invasive plants or plants that require excessive water.
- Reduce the amount of irrigated area on the golf course, if possible, such as non-play areas.
- Identify opportunities to achieve water use reductions before mandatory water restrictions are enacted in times of drought.
- In times of drought, reduce mowing frequency to conserve water.
- During a drought, monitor the state’s drought status to ensure compliance with restrictions.
Irrigation Water Suitability Best Management Practices
- Identify appropriate water supply sources that meet seasonal and bulk water allocations for grow-in and routine maintenance needs.
- Use alternative water supplies/sources that are appropriate and sufficiently available to supplement water needs and follow guidelines for use.
- Ensure that reclaimed, effluent, and other non-potable water supply mains have a thorough cross-connection and backflow prevention devices are in place and are operating correctly.
- Post signs in accordance with local utility and state requirements when reclaimed water is in use.
- Account for the nutrients in effluent (reuse/reclaimed) water when making fertilizer calculations.
- Monitor reclaimed water tests regularly for dissolved salt content.
- Routinely monitor shallow groundwater for saltwater intrusion or contamination by heavy metals and nutrients.
- Flush with fresh water or use amending materials regularly to move salts out of the root zone and/or pump brackish water to keep salts moving out of the root zone.
- Amend sodic water systems appropriately (with gypsum or an appropriate ion) to minimize sodium buildup in soil.
- Monitor sodium and bicarbonate buildup in the soil using salinity sensors.
- Monitor the quantity of water withdrawn to avoid impacting aquatic species.
Wellhead Protection Best Management Practices
- Surround new wells with bollards or a physical barrier to prevent impacts to the wellhead.
- Maintain records of new well construction and modifications to existing wells.
- Obtain a copy of the well log for each well to determine the local geology and well depth. These factors will have a bearing on how vulnerable the well is to contamination. Sample wells for contaminants according to the schedule and protocol required by DNREC.
- Inspect wellheads and the well casing at least annually for leaks or cracks. Have a Delaware-licensed well contractor make repairs as needed.
- Use backflow-prevention devices at the wellhead, on hoses, and at the pesticide mix/load station to prevent contamination of the water source.
- Properly plug abandoned or flowing wells.
- Never apply a fertilizer or pesticide next to a wellhead; consult product labels for additional requirements regarding application distance from wellhead.
- Never mix and load pesticides next to a wellhead if not on a pesticide mix/load pad; consult product labels for additional requirements regarding mixing and loading distance from wellhead.
- Have a Delaware-licensed well contractor properly seal abandoned or flowing wells.
Irrigation System Design Best Management Practices
- Create new and upgraded irrigation system designs to deliver water with maximum efficiency, focusing on precision water placement and distribution.
- Conduct a thorough site assessment prior to designing the irrigation system.
- Seek assistance from irrigation professionals, such as Certified Golf Course Irrigation System designers and WaterSense-certified irrigation consultants and follow established BMPs related to system design.
- Sprinkler placement should avoid interfering with the playability of the hole.
- Irrigation pipes should be installed away from the greens’ surface to avoid substantial increases in repairs and damage should pipe failures occur.
- Update multi-head control systems with single-head control systems to conserve water and enhance efficiency.
- Manual quick-coupler valves should be installed for site-specific irrigation so such sites can be hand-watered during severe droughts.
- Install part-circle heads along lakes, ponds, wetlands margins, native areas, and tree trunks to avoid overspray of impervious areas such as roadways, sidewalks, and parking areas.
- Incorporate multiple nozzle configurations to add flexibility and enhance efficiency/distribution.
- Install VFD systems to lengthen the life of older pipes and fittings until the golf course can afford a new irrigation system.
- Use smaller horse power jockey or pm pumps to maintain pressure during periods of low flow to save electricity, reduce water hammer, and prolong the life of higher horsepower pumps.
- Include high- and low-pressure sensors that shut down the system in case of breaks and malfunctions in the irrigation system.
- Size the pumps to provide adequate flow and pressure.
- Equip pumps with control systems to protect distribution piping.
- Only qualified specialists should install the irrigation system.
- Construction and materials must meet existing standards and criteria.
- Construction must be consistent with the design.
- Installers must provide an accurate and comprehensive As-Built map.
Irrigation System Maintenance Best Management Practices
- Examine turf quality and plant health for indications of irrigation malfunction or the need for scheduling adjustments.
- Evaluate pressure and flow to determine that the correct nozzles are being used and that the heads are performing according to manufacturer specifications.
- Visually inspect the entire system to identify necessary repairs or corrective actions and make repairs before carrying out other levels of evaluation.
- Conduct an annual irrigation audit to facilitate a high-quality maintenance and scheduling program for the irrigation system.
- Inspect the system daily for proper operation by checking computer logs and visually inspecting the pump station, remote controllers, and irrigation heads. Carry out a visual inspection for leaks, misaligned or inoperable heads, and chronic wet or dry spots so that adjustments can be made.
- Observe the system in operation regularly to detect controller or communication failures, stuck or misaligned heads, and clogged or broken nozzles.
- Check filter operations frequently. Keeping filters operating properly prolongs the life of an existing system and reduces pumping costs.
- Monitor the power consumption of pump stations for problems with the pump motors, control valves, or distribution system.
- Increase frequency of routine inspection/calibration of soil moisture sensors that may be operating in high-salinity soils.
- Inspect irrigation pipes and look for fitting breaks caused by surges in the system.
- Install thrust blocks to support conveyances.
- Maintain air-relief and vacuum-breaker valves.
- Have qualified pump personnel perform regular checks of amperage to accurately identify increased power usage that indicates potential problems.
- Check application/distribution efficiencies annually.
- Document equipment run-time hours.
- Document and periodically review the condition of infrastructure, such as pipes, wires, and fittings.
- Follow manufacturer recommendations for system checks and routine maintenance.
- Routinely inspect the system for proper operation by checking computer logs and visually inspect the pump station, remote controllers, and irrigation heads.
- Flush irrigation lines regularly to minimize emitter clogging. To reduce sediment buildup, make flushing part of a regular maintenance schedule. If fertigating, prevent microbial growth by flushing all fertilizer from the lateral lines before shutting down the irrigation system.
- Check filter operations frequently. An unusual increase in the amount of debris may indicate problems with the water source.
- Clean and maintain filtration equipment.
- Keep records of filter changes, as this could be an early sign of system corrosion, well problems, or declining irrigation water quality.
Irrigation Leak Detection Best Management
- Monitor water meters or other measuring devices for unusually high or low readings to detect possible leaks or other problems in the system. Make any needed repairs.
- Monitor the system daily for malfunctions and breaks. Log water usage daily.
- Ensure that control systems provide for emergency shutdowns caused by line breaks and allow maximum system scheduling flexibility.
Irrigation System Renovation Best Management Practices
- Determine the age of the system to establish a starting point for renovation.
- Identify problems and their costs to determine which renovations are appropriate.
- Identify system performance improvements that maximize the efficient use of the current system.
- Evaluate the cost of renovation and its financial and management benefits.
Winterization and Spring Start Up Best Management Practices
- Conduct a visual inspection of the irrigation system: inspect for mainline breaks, low pressure at the pump, and head-to-head spacing.
- Flush and drain above-ground irrigation system components that could hold water.
- Remove water from all conveyances and supply and distribution devices that may freeze by using compressed air or opening drain valves at the lowest point on the system.
- Clean filters, screens, and housings. Remove drain plugs and empty water out of the system.
- Secure systems and close and lock covers/compartment doors to protect the system from potential acts of vandalism and from animals seeking refuge.
- Remove drain plugs and drain above-ground pump casings.
- Record metering data before closing the system.
- Secure or lock irrigation components and electrical boxes.
- Perform pump and engine servicing/repair before winterizing.
- Recharge irrigation system in the spring with water and inspect for corrective maintenance issues.
- In the spring, conduct a catch-can test to audit the system.
Record Keeping Best Management Practices
- Keep records of filter changes, as this could be an early sign of system corrosion, well problems, or declining irrigation water quality.
- Document equipment run-time hours. Ensure that all lubrication, overhauls, and other preventive maintenance are completed according to manufacturer schedule.
- Monitor and record the amount of water being applied, including system usage and rainfall and identify areas where minor adjustments can improve performance.
- Document and periodically review the condition of infrastructure, such as pipes, wires, and fittings. If the system requires frequent repairs, it is necessary to determine why these failures are occurring.
- Document all corrective actions.
- Adhere to all regulatory reporting requirements for water withdrawal.
Irrigation System Scheduling Best Management Practices
- Reset irrigation controllers/timers as often as practically possible to account for plant growth requirements and local climatic conditions.
- Use properly calibrated flow meters, soil moisture sensors, rain shut-off devices, and/or other automated methods to manage irrigation.
- Do not allow irrigation rates to exceed the maximum ability of the soil to absorb and hold the water applied at any one time.
- Base irrigation on ET rates and soil moisture replacement, not on a calendar-based schedule.
- Install computerized control systems on all new course irrigation systems to help ensure efficient irrigation application. These allow for timing adjustments at every head.
- Place rain shut-off devices and rain gauges in open areas to prevent erroneous readings.
- Use multiple soil moisture sensors/meters for accuracy and to reflect soil moisture levels.
- Calibrate soil moisture sensors regularly.
Sensor Technology Best Management Practices
- The reliability of older clock-control station timing depends on the calibration of the timing devices; this should be done periodically, but at least seasonally.
- Shut off an irrigation system after 0.25 to 0.5 inches of rain falls.
- Avoid use of a global setting; adjust watering times per head.
- Place permanent irrigation sprinklers and other distribution devices according to manufacturer recommendations.
- Base spacing on average wind conditions during irrigation.
- Install wireless soil moisture systems to prevent damage from aeration.
- Use soil moisture sensors to bypass preset schedules or for on-demand irrigation.
- Use multiple soil moisture sensors to reflect soil moisture levels.
- Place soil moisture sensors in the root zones of representative locations within each irrigation zone and in the driest irrigation zone of the irrigation system.
- Base irrigation run times on actual site conditions for each head and zone and adjust as needed based on current local meteorological data.
- Use the computed daily ET rate to adjust run times to meet the turf’s moisture needs.
- Manually adjust automated ET data to reflect wet and dry areas on the course.
- Do not let irrigation quantities exceed the available moisture storage in the root zone.
- Time the irrigation schedule to coincide with other management practices, such as the application of nutrients, herbicides, or other chemicals.
- Irrigate in the early morning hours before air temperatures rise and relative humidity drops.
- Visually monitor for localized dry conditions or hot spots to identify poor irrigation efficiency or a failed system device.
Metering Best Management Practices
- Calibrate equipment periodically to compensate for wear in pumps, nozzles, and metering systems.
- Use properly calibrated flow meters, soil moisture sensors, rain shut-off devices, and/or other automated methods to manage irrigation.
- Use flow meters with a run of pipe that is straight enough — both downstream and upstream — to prevent turbulence and bad readings.
- Use flow meters to determine how much water is applied.