4 - Irrigation
The supplemental use of water for course play and non-play areas is essential to supporting healthy turfgrass and landscape plant health. It is also necessary to sustaining optimal course playability, aesthetics, marketability, and golfer participation.
The purpose of this section is to identify BMPs related to water use that conserve and protect water resources. Additionally, irrigation BMPs may provide an economic, regulatory compliance, and environmental stewardship advantage to those who consider them part of their irrigation management plan. If applied appropriately, they can help stabilize labor cost, extend equipment life, limit repair and minimize risks.
The monetary investment in non-structural BMPs costs little to nothing to implement in a daily course water-use plan. Other advantages include reduced administrative requirements, improved employee communication, and effective training procedures.
There are several water-management approaches which may be utilized:
Conservation and Efficiency
Conservation and efficiency consider the strategic use of appropriate course and irrigation design, plant selection, computerized and data-integrated scheduling, and alternative water quality/supply options that maximize plant health benefits and reduce the potential for negative impacts on natural resources.
Resource Protection
Resource protection is an integrated approach that includes irrigation practices as part of the course design, pesticide and nutrient practices, and regulatory compliance measures and structural measures as they concern environmental stewardship and policy.
Regulatory Considerations
Golf course owners are responsible for contacting federal, state, and local water use authorities at the pre-and post-construction phase to determine annual or specific water consumption (water rights), permitting guidelines, and other requirements allowed by regulators.
See Connecticut’s water diversion program: https://portal.ct.gov/DEEP/Water/Diversions/Water-Diversion-Program
See Connecticut BMPs for Golf Courses for state guidelines: https://portal.ct.gov/DEEP/Water/Diversions/Water-Diversion---Related-Guidance
Superintendents have a responsibility to adhere to water-quality standard rules regarding groundwater and surface water flows resulting from the removal of water for irrigation use.
Connecticut golf courses may be subject to obtaining a water withdrawal permit. More information: https://www.ct.gov/deep/cwp/view.asp?a=2709&q=324178&deepNav_GID=1643
Best Management Practices
Design and/or maintain a system to meet site’s peak water requirements under normal conditions and be flexible enough to adapt to various water demands and local restrictions.
Develop an annual water budget for the golf course and maintain accurate records of actual annual water use as compared to the water budget and actual annual evapotranspiration data.
Look for ways to increase efficiency and reduce energy use associated with irrigation systems and practices.
Demonstrate good stewardship practices by supplementing watering only for the establishment of new planting and new sod, hand watering of critical hot spots, and watering-in of chemicals and fertilizers (if permissible).
Protect aquatic life and impairment of water systems by adhering to state and local water withdrawal allocations (gallons/day).
Design an irrigation system that delivers water with high DU (distribution uniformity) and operate (schedule) the system for maximum application efficiency.
Some golf courses are being designed using a “target golf” concept that minimizes the acreage of irrigated turf. Existing golf courses can try to convert turf in out-of-play areas to naturally adapted native plants, grasses, or ground covers when feasible to reduce water use and enhance aesthetics.
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. The routine use of potable water supply is not a preferred practice; municipal drinking water should be considered only when there is no alternative. Studies of water supplies are recommended for irrigation systems, as are studies of waterbodies or flows on, near, and under the property. These maybe helpful to properly design a course’s stormwater systems, water features, and to protect water resources.
When necessary, treatment options should be included in the budget to address water quality and equipment maintenance. Maintaining good internal soil drainage to manage saline and/or sodic water quality may require additional soil cultivation to relieve compaction and/or chemical amendments to exchange with sodium in severe circumstances.
Additional information on irrigation water suitability:
http://gsr.lib.msu.edu/2000s/2000/000914.pdf
http://plantscience.psu.edu/research/centers/turf/extension/factsheets/water-quality
Best Management Practices
Use alternative water supplies/sources that are appropriate and sufficiently available to supplement water needs.
Use salt-tolerant varieties of turf and plants to mitigate saline conditions resulting from an alternative water supply or source, if necessary.
Amend sodic water systems appropriately (with gypsum or an appropriate ion) to minimize sodium buildup in soil.
Flush with freshwater or use amending materials regularly to move salts out of root zone and/or pump brackish water to keep salts moving out of the root zone.
Monitor sodium and bicarbonate buildup in the soil using salinity sensors.
Routinely monitor shallow groundwater table of freshwater for saltwater intrusion or contamination of heavy metals and nutrients.
Reclaimed, effluent, and other non-potable water supply mains must be protected by an approved backflow protection device as specified by state and/or local regulations.
Potable supply lines to buildings (for domestic uses) at recycled (reclaimed, effluent, non-potable) water use sites typically must be protected with backflow prevention device(s) in place, that are operating correctly and tested regularly.
Irrigation pipeline systems directly connected to municipal water distribution mains must have an approved backflow device at the point of connection.
Backup/emergency supplies of potable water used to replenish recycled water storage reservoirs must be protected by an approved backflow protection device such as a reduced pressure principle device or an air gap structure as specified by state and/or local regulations.
Post signage 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.
Regularly perform soil testing to monitor the accumulation of salts and sodium delivered in the recycled (reclaimed, effluent, or non–potable) water supplies.
Where practical, use reverse-osmosis (RO) filtration systems to reduce chlorides (salts) from saline groundwater; if using RO to improve water quality, be certain the reject concentrate (brine) is disposed of in a legal, proper, and environmentally responsible manner.
Monitor the quantity of water withdrawn to avoid aquatic life impairment.
Identify appropriate water supply sources that meet seasonal and bulk water allocations for grow-in and routine maintenance needs.
Meter the water supply and maintain accurate records to document irrigation water used monthly and annually. Avoid relying on estimated flow data provided by the central irrigation control computers, instead install a totalizing flow meter for accurate record keeping.
Water Conservation and Efficient Use Planning
Document the watering practices at the golf course to show savings in water use over averages and set goals for reductions when practicable. Communication regarding actions taken and purpose for those actions should be maintained with water managers, golf course members, and the public. Potable water supplies in many areas of Connecticut are limited and demand continues to grow. The best and most effective method to reduce water use on any golf course is to reduce the irrigated acreage where possible. The challenge is to find solutions to maintain the quality of golf while using less water. BMP usage and communications are important to educate the community and public around water use.
Best Management Practices
Selecting drought-tolerant varieties of turfgrasses can help maintain an attractive and high-quality playing surface, while minimizing water use.
Non-play areas may be planted with drought-resistant native or other well-adapted, noninvasive plants that provide an attractive and low-maintenance landscape.
Native plant species are important in providing wildlife with habitat and food sources. After establishment, site-appropriate plants normally require little to no irrigation.
The system should be operated to provide only the water that is needed by the plants, or to meet occasional special needs such as salt removal.
If properly designed, rain and runoff captured in water hazards and stormwater ponds may provide supplemental water under normal conditions, though backup sources may be needed during severe drought.
Always closely monitor soil moisture levels, particularly during a drought. Whenever practicable, irrigate at times when the least amount of evaporative loss will occur.
Control invasive plants or plants that use excessive water.
During a drought, closely monitor soil moisture levels. Whenever practicable, irrigate at times when the least amount of evaporative loss will occur.
General information on water conservation on golf courses:
United States Golf Association (USGA) Research on Turfgrass Water Use
http://www.usga.org/course-care/water-resource-center/research-on-turfgrass-water-use.html
“Water Conservation” Golf Course Superintendents Association of America (GCSAA)
http://www.gcsaa.org/course/communication/golfcoursefacts/water-conservation
Irrigation System Design
A well-designed irrigation system should operate at peak efficiency to reduce energy, labor, and natural resources. Irrigation systems should be properly designed and installed to improve water application efficiency through high distribution uniformity. Irrigation managers should be properly trained to understand soil-water relationships, principles of crop coefficients and evapotranspiration for efficient scheduling, to prevent applying excess water that will percolate beyond the root zone (except when purposely leaching salts). An efficient system, combined with a well-educated irrigation manager, maximizes water use, reduces operational cost, conserves supply, and protects water resources. When in the design phase, pipe sizing and pump capacity should be budgeted for to have the shortest and most efficient water-time-window. Sprinkler selection, spacing, configuration (as triangular or rectangular arrangements) and nozzle selections should all be made to maximize distribution uniformity.
Best Management Practices
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 and slopes and surrounds to be watered independently.
Design should offer individual sprinkler control instead of “block systems”, particularly with fine turf areas.
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 location.
The application rate must not exceed the infiltration rate, ability of the soil to absorb and retain the water applied during any one application. Conduct saturated hydraulic conductivity tests periodically. (Note: Since golf rotors and many other sprinkler’s precipitation rates may exceed soil infiltration rates, avoiding surface runoff is often accomplished by operating sprinklers in short durations with a “soak in time” programmed to occur between each application cycle.)
The design operating pressure must not be greater than the available source pressure or a booster pump will become necessary.
The design operating pressure must account for peak-use times, maximum flow rates and supply line size and operating pressures at final buildout for the entire system.
The system should be flexible enough to meet a site’s peak water requirements and allow for operating modifications to meet seasonal irrigation changes or local restrictions. (Typically, a system should be designed with at least 15 percent additional capacity (i.e; flow rate at the specified operating pressure) to accommodate “catching up” over 7 days if an irrigation event is missed due to a power failure, etc.)
Turf and landscape areas should be zoned separately. Specific use areas zoned separately: greens, tees, primary roughs, secondary roughs, fairways, native, trees, shrubs, etc.
Design should account for the need to leach out salt buildup from poor-quality water sources by providing access to freshwater.
Only qualified specialists should install the irrigation system.
Construction must be consistent with the design.
The designer should be a qualified irrigation designer/consultant.
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.
Sprinkler spacing distance should be based on average wind conditions during irrigation.
For variable wind directions, triangular spacing is more uniform than square spacing.
Distribution devices and pipe sizes should be designed for optimal uniform coverage.
The first and last distribution device should have no more than a 10% difference in flow rate. This usually corresponds to about a 20% difference in pressure.
Distribution equipment (such as sprinklers, rotors, and micro-irrigation devices) in each zone must have the same precipitation rate.
Sprinklers in 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 shutoff devices, and backflow prevention.
Water conveyance systems should be designed with thrust blocks (or joint restraints) and air-release valves and/or vacuum release valves as necessary.
Sites with significant elevation change may require a design incorporating pressure regulating valve (PRV) station(s) and/or multiple points of connection (POCs), pump stations and/or mainline systems separately pressurized to minimize zones of excess and/or insufficient pressure due to elevation-related pressure loss and/or gain.
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 while making repairs to the system.
Manual quick-coupler valves should be installed near greens, tees, and bunkers so these can be hand-watered during severe droughts.
In areas that are known to be drier than others, consider adding manual quick-coupler valves to these areas, as well.
Update multi-row sprinklers with single head control to conserve water and to enhance efficiency.
Ensure heads are set at level ground and not on slopes.
Irrigation Pumping System
Properly maintained and running pump stations are critical for water and energy conservation. Pump stations should be sized to provide adequate flow and pressure. They should be equipped with control systems that protect distribution piping, provide for emergency shutdown necessitated by line breaks, and allow maximum system scheduling flexibility.
Variable frequency drive (VFD) pumping systems should be considered if dramatically variable flow rates are required, if electrical transients (such spikes and surges) are infrequent, and if the superintendent has access to qualified technical support. VFDs can help reduce energy usage to improve conservation and cost reductions.
Best Management Practices
The design operating pressure must not be greater than the available pump’s capabilities or source pressure.
The design operating pressure must account for peak-use times, peak flow rates, and supply-line diameter and operating pressures at final buildout for the entire system.
Maintain the air-relief and vacuum-breaker valves by using hydraulic-pressure-sustaining values.
Install VFD systems to lengthen the life of older pipes and fittings until the golf course can afford a new irrigation system.
An irrigation system should also have high- and low-pressure sensors that shut down the system in case of breaks and malfunctions.
Pumps should be sized to provide adequate flow and pressure.
Pumps should be equipped with control systems to protect distribution piping.
System checks and routine maintenance on pumps, valves, programs, fittings, and sprinklers should follow the manufacturer’s recommendations.
Monitor pumping station power consumption.
Monthly bills should be monitored over time to detect a possible increase in power usage.
Compare the power used with the amount of water pumped. Requiring more power to pump the same amount of water may indicate a problem with the pump motor(s), control valves, or distribution system.
Quarterly checks of amperage by qualified pump personnel may more accurately indicate increased power usage and thus potential problems.
Pump efficiency tests performed every 3 to 5 years will document wells and/or irrigation pumps are in good working order, operating efficiently, and not wasting energy.
Irrigation System Program and Scheduling
Responsible irrigation management conserves water plus reduces nutrient and pesticide movement. Irrigation scheduling must take plant water requirements and soil intake capacity into account to prevent excess water use that could lead to leaching and runoff. Plant water needs are determined by ET rates, recent rainfall, recent temperature extremes, and soil moisture.
Irrigation should not occur on a calendar-based schedule; it should be based on ET rates and soil moisture replacement. 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.
Time-clock-controlled irrigation systems preceded computer-controlled systems, and many are still in use today. Electric/mechanical time clocks cannot automatically adjust for changing ET rates. Frequent adjustment is necessary to compensate for the needs of individual turfgrass areas.
An onsite weather station will offer the best ET information. When unavailable, follow several local weather stations that can be found on Weather Underground: www.weatherunderground.com or the Northeast Regional Climate Center: http://www.nrcc.cornell.edu/wxstation/pet/pet.html. It is important to note when using a local weather station’s data, that the E.T. may not be calibrated for turf and the weather station location may not be on turf, so the numbers may not be exactly what is desired. It is possible to still draw conclusions over time in relation to what the turf requirements are.
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.
An irrigation system should have rain sensors to shut off the system after 0.25 to 0.5 inch of rain is received. Computerized systems allow a superintendent to access the control system and cancel the program if it is determined that the course has received adequate rainfall.
Install control devices to allow for maximum system scheduling flexibility.
Generally, granular fertilizer applications should receive 0.25 inch of irrigation to move the particles off the leaves while minimizing runoff.
Irrigation quantities should not exceed the available water holding capacity of the soil based on texture and root zone depth.
Irrigation schedule should coincide with other cultural practices (for example, the application of nutrients, herbicides, or other chemicals).
Irrigation should occur in the early morning hours before air temperatures rise and relative humidity drops.
Base plant water needs should be determined by ET rates, recent rainfall, recent temperature extremes, and soil moisture. All of this is driven by site surveying and scouting.
Use mowing, verticutting, aeration, nutrition, and other cultural practices to control water loss, reduce compaction to maintain infiltration rates and minimize runoff, and to encourage conservation and efficiency.
Visually monitor for localized dry conditions or hot spots to identify poor irrigation efficiency or a failed system device.
Use predictive models to estimate soil moisture and the best time to irrigate.
Avoid use of a global setting; adjust watering times per head.
Base water times on actual site conditions for each head and zone.
Adjust irrigation run times based on current local meteorological data.
Use computed daily ET rate to adjust run times to meet the turf’s moisture needs.
ET rates should be adjusted by the appropriate crop coefficient (Kc). Average Kc values are 0.80 for cool season turfgrasses and 0.60.for warm season turfgrasses. Kc values may require minor adjustment through the growing season. Average Kc values can be used when creating annual water budgets and/or as a starting point when scheduling for ET replacement.
Manually adjust individual control stations’ automated ET data with a Kc to reflect wet and dry microenvironments on the course.
Use soil moisture sensors, or if unavailable a soil sampling tube, to assist in scheduling or to create on-demand irrigation schedules.
Use multiple soil moisture sensors to reflect soil moisture levels. Evaluate variations in soil types across the property using the USDA Web Soil Survey when selecting locations for multiple sensors placement. https://websoilsurvey.sc.egov.usda.gov/App/HomePage.htm
Install soil moisture sensors in the root zone for each irrigation zone as feasible to enhance scheduled timer-based run times.
Place soil moisture sensors in a representative location within the irrigation zone. Installing a soil moisture sensor in the driest or wettest irrigation zone of the irrigation system may lead to over or under watering on a larger scale.
Wired soil moisture systems should be installed to prevent damage from aerification.
Periodically perform catch-can uniformity tests.
Reducing dry spots and soil compaction improves water infiltration, which in turn reduces water use and runoff in other areas.
Install emergency shutdown devices to address line breaks.
Check to ensure system is operating properly after power outages.
To prevent excess water use, irrigation scheduling should consider plant water requirements, recent rainfall, recent temperature extremes, and soil water holding characteristics.
Sensor Technology
Irrigation management and control devices need to be installed correctly for proper irrigation management. Soil moisture sensors and other irrigation management tools should be installed in representative locations and depths and maintained 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. The use of soil moisture probes, and inspections for visual symptoms such as wilting turf, computer models, and tensiometers may 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 and accuracy of data collected and the number of assumptions made.
Best Management Practices
Irrigation controllers/timers should be reset as often as practically possible to account for plant growth requirements and local climatic conditions.
Properly calibrated flow meters, soil moisture sensors, rain shut-off devices, and/or other automated methods should be used to manage irrigation.
Irrigation rates should not exceed the maximum ability of the soil to absorb and hold the water applied in any one application.
Irrigation should not occur on a calendar-based schedule but should be based on ET rates, root depths, and soil moisture holding vs. replacement requirements.
Computerized control systems should be installed on all new course irrigation systems to help ensure efficient irrigation application. These allow for timing adjustments at every head when systems are designed to provide individual head control.
Rain shut-off devices and rain gauges should be placed in open areas to prevent erroneous readings.
Use multiple soil moisture sensors/meters for accuracy and to reflect soil moisture levels.
Be sure that all on-site weather stations are properly calibrated and maintained.
Turf Drought Response
The presence of visual symptoms of moisture stress is a simple way to determine when irrigation is needed. Use a soil moisture meter to determine moisture needs of greens and tees. Managers of golf greens cannot afford to wait until symptoms occur, because unacceptable turf quality may result. Be prepared for extended drought or restrictions by developing a written drought management plan in consultation with public water suppliers, and applicable local and state agencies.
Best Management Practices
Use soil moisture meters to determine moisture thresholds and plant needs.
Irrigating too shallowly encourages shallow rooting, increases soil compaction, and favors pest outbreaks.
For golf greens and tees, most roots are in the top several inches of soil, use a soil sampling tube or soil profiler to regularly monitor and determine rooting depths.
For fairways and roughs, use infrequent, deep irrigation to supply enough water for plants and to encourage deep rooting.
Proper cultural practices such as aeration, mowing height, irrigation frequency, and irrigation amounts should be employed to promote healthy, deep root development and reduce irrigation requirements.
Create a drought management plan for the facility that identifies steps to be taken to reduce irrigation/water use and protects critical areas, etc.
Use appropriate turfgrass species adapted to the location of the golf course being managed.
Irrigation System Quality
Irrigation system maintenance on a golf course involves four major efforts: calibration or auditing, preventive maintenance (PM), corrective maintenance, and record keeping. Good system management starts with good PM procedures and recordkeeping. Corrective maintenance is simply the act of fixing what is broken. It may be as simple as cleaning a clogged orifice, or as complex as a complete renovation of the irrigation system.
As maintenance costs increase, the question of whether to renovate arises. Renovating a golf course irrigation system can improve system efficiencies, conserve water, improve playability, and lower operating costs.
Best Management Practices
Respond to day-to-day failures in a timely manner, maintain the integrity of the system as designed, and keep good records.
System checks and routine maintenance on pumps, valves, control systems, adjustment of programs, fittings, and sprinklers should follow the manufacturer’s recommendations.
Systems need to be observed in operation at least monthly and more often if the system is problematic. This can be done during maintenance programs such as fertilizer or chemical applications where irrigation is required, or the heads can be brought on-line for a few seconds and observed for proper operation. This process detects controller or communications failures, stuck or misaligned heads, and clogged or broken nozzles.
Part-circle sprinklers should be checked periodically for proper adjustment. This is of particular importance when irrigating with recycled (effluent or reclaimed) water so that it does not spray outside of the designated use area.
Even under routine conditions, keeping filters operating properly prolongs the life of an existing system and reduces pumping costs.
Keep records of filter cleaning and/or other servicing, as this could be an early sign of system corrosion, well problems, or declining irrigation water quality.
Application/distribution efficiencies should be checked annually. Implement a PM program to replace worn components before they waste fertilizer, chemicals, and water.
Conduct a periodic professional irrigation audit at least once every five years.
Document pumping equipment run-time hours. Ensure that all lubrication, overhauls, and other preventive maintenance are completed according to the manufacturer’s schedule.
Keep sprinklers edged regularly to ensure proper distribution.
Keep valve boxes edged regularly to be able to quickly locate and shut a section of the system off if there is a leak.
Exercise manual isolation valves annually by closing and reopening to prevent the threads of operating stems from corroding and seizing.
Annually disassemble, clean and service air and vacuum release valves, pressure regulating valves, and any other specialized components included in the design. These devices are commonly used where significant elevation change occurs to avoid water hammer from escaping air during spring recharge, allow complete drainage during fall system evacuation and/or over pressurization of lower elevations where pressure reduction and regulation are needed to avoid pressure surges.
Gather all the documentation collected as part of the PM program, along with corrective maintenance records for analysis.
Correctly identifying problems and their costs helps to determine what renovations are appropriate.
Collecting information on the cost of maintaining the system as part of system overall evaluation, allows for planning necessary upgrades, replacement etc. and to compare after changes are made.
Pond Location and Design
Understanding natural lake processes and accommodating them in the design and management of a pond can create significant aesthetic value and reduce operational costs. Lakes and ponds have several distinct defining characteristics. Their size, shape, and depth may all affect how they respond to various environmental inputs. Most golf courses plan lakes and water hazards to be a part of the stormwater control and treatment system. This usually works well for all concerned; however natural waters may not be considered treatment systems and must be protected.
Lakes and ponds may be used as a source of irrigation water. It is important to consider these functions when designing and constructing ponds. Careful design may significantly reduce future operating expenses for lake and aquatic plant management.
Best Management Practices
Consult with a qualified golf course architect with stormwater experience, working in conjunction with a stormwater engineer, to develop an effective stormwater management system that complies with the requirements of the water management district/department or other permitting agency.
When constructing drainage systems, pay close attention to engineering details such as subsoil preparation, the placement of gravel, slopes, and backfilling.
Where practical, internal golf course drains should discharge through pretreatment zones and/or vegetative buffers to help remove nutrients and sediments. Carbon filters can be added in cases where vegetative buffers are unavailable.
Studies of water supplies are needed for irrigation systems, and studies of waterbodies or flows on, near, and under the property are needed to properly design a course’s stormwater systems and water features, and to protect water resources.
Peninsular projections and long, narrow fingers into ponds may prevent water mixing. Ponds that are too shallow may reach high temperatures, leading to low oxygen levels and promoting algal growth and excess sedimentation.
In shallow or nutrient-impacted ponds, the use of aeration equipment may be required to maintain acceptable dissolved oxygen (DO) levels in the water.
Pond Use and Maintenance
Successful pond management should include a clear statement of goals and priorities to guide the development of the BMP necessary to meet those goals.
Each pond has regions or zones that significantly influence water quality and are crucial in maintaining the ecological balance of the system. It is important to understand their function and how good water quality can be maintained if these zones (riparian zone, littoral zone, limnetic zone, and benthic zone) are properly managed.
Use an expert in aquatic management to help develop and monitor pond management programs. There are various considerations which need to be managed. Surface water sources can present problems with algal and bacteria growth. Algal cells and organic residues of algae can pass through irrigation system filters and form aggregates that may plug emitters. Also, pond leaks should be controlled and managed properly. Use of herbicides including some colorants requires aquatic pesticide permit and may require additional pesticide certification.
Best Management Practices
Use leak controls in the form of dike compaction, natural-soil liners, soil additives, commercial liners, drain tile, or other approved methods.
Maintain a riparian buffer to filter the nutrients and sediment in runoff.
Reduce the frequency of mowing at the lake edge and collect or direct clippings to upland areas.
Prevent overthrowing fertilizer into ponds. Practice good fertilizer management to reduce nutrient runoff into ponds, which causes algae blooms and ultimately reduces dissolved oxygen levels. Use drop spreaders instead of rotary spreaders near these sensitive areas.
Establish a special management zone around pond edges.
Dispose of grass clippings where runoff will not carry them back to the lake.
Encourage clumps of native emergent vegetation at the shoreline.
Maintain water flow through lakes, if they are interconnected.
Establish wetlands where water enters lakes to slow water flow and trap sediments.
Maintain appropriate silt fencing and BMPs on projects upstream to reduce erosion and the resulting sedimentation.
Manipulate water levels to prevent low levels that result in warmer temperatures and lowered dissolved oxygen levels.
Aerate ponds and dredge or remove sediment before it becomes a problem.
Pond Water-Level Monitor
Evaporation losses are higher in some regions than others and vary from year to year and within the year. However, evaporative losses could approach six inches per month during the summer. Aquatic plants are more difficult to control in shallow water.
Best Management Practices
A pond should hold surplus storage of at least 10 percent of full storage; in other words, the difference between primary spillway elevation and auxiliary spillway elevation provides 10 percent of pond volume when water level is equal to elevation of the primary spillway.
Provide an alternative source for ponds that may require supplemental recharge from another water source such as a well during high-demand periods.
Estimated losses from evaporation and seepage should be added to the recommended depth of the pond and if supplied by the irrigation supply, they should be included in irrigation water budgets.
Metering
Rainfall may vary from location to location on a course; the proper use of rain gauges, rain shut-off devices, flow meters, soil moisture sensors, and/or other irrigation management devices should be incorporated 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. Knowing the flow or volume will help determine how well the irrigation system and irrigation schedule are working.
Best Management Practices
Calibrate equipment periodically to compensate for wear in pumps, nozzles, and metering systems.
Properly calibrated flow meters, soil moisture sensors, rain shut-off devices, and/or other automated methods should be used to manage irrigation.
Flow meters should have a run of pipe that is straight enough — both downstream and upstream — to prevent turbulence and bad readings - consult the manufacturers recommendations for the minimum length of straight pipe required in front of the meter.
Flow meters can be used to determine how much water is applied over the irrigated area. That can then be converted to inches applied and compared to ET to confirm the average application of water applied as a percentage of ET.
Irrigation Leak Detection
Irrigation systems are complex systems that should be closely monitored to ensure leaks are quickly detected and corrected. 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. If staff or golfers notice part of the course is moist during dry periods and/or lush vegetation, this could be an indication of a leaking system. In addition to promptly repairing leaks, a good preventive maintenance program is very important.
Best Management Practices
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.
An irrigation system should also have high- and low-pressure sensors that shut down the system in case of breaks and malfunctions.
The system should be monitored daily for malfunctions and breaks. It is also a good practice to log the amount of water pumped each day.
Document and periodically review the condition of infrastructure (such as pipes, wires, and fittings). If the system requires frequent repairs, determine why these failures are occurring. Pipe failures may be caused not only by material failure, but also by problems with the pump station.
Ensure that pump control systems provide for emergency shutdowns caused by line breaks and allow maximum system scheduling flexibility.
Programming of central controllers with flow management software must be performed by qualified individuals who understand the relation between pipe size, flow rates, flow velocities and friction loss (of dynamic pressure) so to not create water hammer or pressure losses by allowing zones to exceed maximum allowable values.
Sprinkler Maintenance
Good system management starts with comprehensive PM procedures and record keeping. This can be done during maintenance programs such as fertilizer or chemical applications where irrigation is required, or the heads can be brought on-line for a few seconds and observed for proper operation.
Maintaining a system is more than just fixing heads. It also includes documenting system- and maintenance-related details so that potential problems can be addressed before expensive repairs are needed. It also provides a basis for evaluating renovation or replacement options. Be proactive; if the system requires frequent repairs, it is necessary to determine why these failures are occurring.
Pipe failures may be caused by material failure or by problems with the pump station and/or control system programming resulting in pressure surges and spikes.
Wiring problems could be caused by corrosion, rodent damage, insulation knicks, or frequent lightning or power surges.
Control tubing problems could result from poor filtration or water supply chemical precipitants such as calcium carbonate.
Best Management Practices
System checks and routine maintenance on pumps, valves, programs, controllers, fittings, and sprinklers should follow the manufacturer’s recommendations.
The system should be inspected routinely for proper operation by checking computer logs and visually inspecting the pump station, remote controllers, and irrigation heads.
A visual inspection should be carried out for leaks, misaligned or inoperable heads, and chronic wet or dry spots, so that adjustments can be made or replaced.
Part-circle sprinklers should be checked periodically for proper adjustment particularly on the perimeters/borders of sites using reclaimed, recycled or effluent irrigation supplies.
Flush drip/micro-irrigation irrigation lines and filters 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.
Clean and maintain filtration equipment.
Systems should be observed in operation at least monthly or more frequently if regularly occurring problems with the system dictate otherwise. This process detects controller or communication failures, stuck or misaligned heads, and clogged or broken nozzles.
Check filter operations frequently. An unusual increase in the amount of debris may indicate problems with the water source.
Even under routine conditions, keeping filters operating properly prolongs the life of an existing system and reduces pumping costs.
Keep records of filter service performed, as this could be an early sign of system corrosion, well problems, or declining irrigation water quality.
Application/distribution uniformity should be checked annually. Conduct a periodic professional irrigation audit at least once every five years. Implement a PM program to replace worn components before they waste fertilizer, chemicals, and water.
Conduct pump efficiency tests every 1 to 5 years to monitor pump wear. Test frequency should depend on the water quality with 1 to 3-year intervals used if the water is contaminated with sand, silt, clay etc., and longer intervals of 3 to 5 years used with clean or potable water.
Document pump motor/equipment run-time hours.
Ensure that all lubrication, overhauls, and other preventive maintenance are completed according to the manufacturer’s schedule.
Monitor pump station power consumption. Monthly bills should be monitored over time to detect a possible increase in power usage. Compare the power used with the amount of water pumped. Requiring more power to pump the same amount of water may indicate a problem with the pump motor(s), control valves, or distribution system. Quarterly checks of amperage by qualified pump personnel may more accurately indicate increased power usage and thus potential problems.
Monitor and record the amount of water being applied, including system usage and rainfall. By tracking this information, you can identify areas where minor adjustments can improve performance. Not only is this information essential in identifying places that would benefit from a renovation, but it is also needed to compute current operating costs and compare possible future costs after a renovation.
Factor in rainfall and compare the total amount of water applied per irrigated acre to ET as a measure of application efficiency.
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. For diagnosis of PVC failure causes visit: https://edis.ifas.ufl.edu/ch171Maintain written and photo records of pipe or other component failures & repairs. This can become valuable documentation when proposing system renovations and replacements.
System Maintenance
Routine maintenance helps ensure water quality is maintained and water is used responsibly. System checks and routine maintenance include pumps, valves, programs, fittings, and sprinklers. An irrigation system should be calibrated regularly by conducting periodic irrigation audits to check actual water delivery and nozzle efficiency.
Best Management Practices
Irrigation audits should be performed by trained technicians.
A visual inspection should first be conducted to identify necessary repairs or corrective actions. It is essential to make repairs before carrying out other levels of evaluation.
Pressure, flow, and precipitation rate should be evaluated to determine that the correct nozzles are being used and that the heads are performing according to the manufacturer’s specifications.
Pressure and flow rates should be checked at each head to determine the average application rate in an area.
Catch-can tests and basic schedule calculations should be executed to determine uniformity of coverage, precipitation rate, and to accurately determine irrigation run times.
Catch-can testing should be conducted on representative areas of the golf course to ensure that the system is operating at its highest efficiency.
Conduct an internal irrigation audit annually to facilitate a high-quality maintenance and scheduling program for the irrigation system.
Inspect for interference with water distribution due to sprinklers below grade, or blockage by tree limbs and/or shrubs.
Inspect for broken and misaligned heads.
Check that the rain sensor is present and functioning.
Inspect the backflow device to determine that it is in place and in good repair.
Examine turf quality and plant health for indications of irrigation malfunction or needs for scheduling adjustments.
Be aware that early symptoms of root feeding insects may initially be misdiagnosed as droughty areas.
Schedule documentation: make adjustments and repairs on items diagnosed during the visual inspection before conducting pressure and flow procedures
Preventive Maintenance
In older systems, inspect irrigation pipe and look for fitting breaks caused by surges in the system. For diagnosis of PVC fitting and pipe failure visit: https://edis.ifas.ufl.edu/ch171
Install thrust blocks to support conveyances.
The system should be inspected daily for proper operation by checking computer logs and visually inspecting the pump station, remote controllers, and irrigation heads. A visual inspection should be carried out for leaks, misaligned or inoperable heads, and chronic wet or dry spots so that adjustments can be made.
Maintain air-relief and vacuum-breaker valves.
Annually service pressure regulation, pressure relief and/or pressure sustaining valves to assure proper operation.
Check filter operations frequently; keeping filters operating properly prolongs the life of an existing system and reduces pumping costs.
Application/distribution efficiencies should be checked annually.
Conduct a periodic professional irrigation audit at least once every five years.
Document equipment run-time hours. Ensure that all lubrication, overhauls, and other preventive maintenance are completed according to the manufacturer’s schedule.
Monitor the power consumption of pump stations for problems with the pump motors, control valves, or distribution system.
Qualified pump personnel should perform quarterly checks of amperage to accurately identify increased power usage that indicates potential problems.
Increase frequency of routine inspection/calibration of soil moisture sensors that may be operating in high-salinity soils.
Winterize irrigation system to prevent damage.
Corrective Maintenance
Replace or repair all broken or worn components before the next scheduled irrigation.
Replacement parts should have the same characteristics as the original components.
Record keeping is an essential practice; document all corrective actions.
System Renovation
Appropriate golf course renovations can improve system efficiencies, conserve water, improve playability, and lower operating costs.
Correctly identify problems and their cost to determine which renovations are appropriate.
Determine the age of the system to establish a starting point for renovation.
Identify ways to improve system performance by maximizing the efficient use of the current system.
Routinely document system performance to maximize the effectiveness of the renovation.
Evaluate cost of renovation and its return on investment and other benefits including financial, course playability, and turf management (fewer weeds, disease, wet and/or dry spots, etc.)
Winterization and Spring Startup
Winterization of the irrigation system is important to protect the system and reduce equipment failures resulting from freezing.
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.
Conduct a catch-can test to audit the system.
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 with compressed air or open drain plugs at the lowest point on the system.
Clean filters, screens, and housing; remove drain plug 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 plug 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 in the spring with water and inspect for corrective maintenance issues.
Ensure proper irrigation system drainage design.
Maintained Turf Areas
Courses should use well-designed irrigation systems with precision scheduling based on soil infiltration rates, soil water-holding capacity, plant water-use requirements, the depth of the root zone, and the desired level of turfgrass appearance and performance in order to maximize efficient watering.
Best Management Practices
The irrigation system should be designed and installed so that the putting surface, slopes, and surrounding areas can be watered independently.
Account for nutrients in effluent supply when making fertilizer calculations.
Install part-circle heads that conserve water and reduce unnecessary stress to greens and surrounds.
Avoid use of a global setting; adjust watering times per head.
Base water times on actual site conditions for each head and zone.
Adjust irrigation run times based on current local meteorological data.
Use computed daily ET rate to adjust run times to meet the turf’s moisture needs. If ET data has not been adjusted for turfgrass apply the appropriate crop coefficient (Kc) for warm season turf (Kc = 0.6) or cool season turf (Kc = 0.8).
Manually adjust automated ET data to reflect wet and dry areas on the course on a global basis and adjust individual control station run times to account for shade, microclimate, etc.
Install rain switches to shut down the irrigation system if enough rain falls in a zone.
Use soil moisture sensors to bypass preset or to create on-demand irrigation schedules.
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.
Triangular spacing is more uniform than square spacing.
Periodically perform catch-can uniformity tests.
Reducing dry spots and soil compaction improves water infiltration, which in turn reduces water use and runoff in other areas.
Irrigation should occur in the early morning hours before air temperatures rise and relative humidity drops.
Base plant water needs on root depth, soil water holding capacity, ET rates, recent rainfall, recent temperature extremes and soil moisture.
Use mowing, verticutting, aeriation, wetting agents, nutrition, and other cultural practices to promote deep root development, enhance water infiltration, and soil moisture retention to encourage conservation and efficiency.
Depending on physical soil characteristics and turf type, using solid-tine aeration equipment in place of verticutting is an option.
Slicing and spiking help relieve surface compaction and promote better water penetration and aeration.
Visually monitor for localized dry conditions or hot spots to identify poor irrigation distribution uniformity or a failed system device.
Use predictive models to estimate soil moisture and the best time to irrigate.
Install in-ground (wireless) soil moisture sensors or use hand-held moisture meters in the root zone for each irrigation zone to enhance scheduled timer-based run times.
An irrigation system should also have high- and low-pressure sensors that shut down the system in case of breaks and malfunctions.
Place soil moisture sensors in a representative location of the irrigation zone.
Install soil moisture sensors in the driest irrigation zone of the irrigation system.
Wireless soil moisture systems should be installed to prevent damage from aeration
Native vegetation that does not require supplemental irrigation should be retained and enhanced for non-play areas to conserve water where possible.
Non-Play and Landscape Areas
Map any environmentally sensitive areas such as sinkholes, wetlands, or flood-prone areas, and identify species classified as endangered or threatened by federal and state governments, and state species of special concern. Identify and eliminate invasive species. The most efficient and effective watering method for non-turf landscape is drip or micro-irrigation.
Older golf courses may have more irrigated and maintained acres than are necessary. With the help of a golf course architect, golf professional, golf course superintendent, and other key personnel, the amount of functional turfgrass can be evaluated and transitioned into non-play areas requiring minimal, if any, irrigation.
Best Management Practices
Designate 50% to 70% of the non-play area to remain in natural cover according to “right-plant, right-place,” a principle of plant selection that favors limited supplemental irrigation and on-site cultural practices.
Incorporate natural vegetation in non-play areas.
Use micro-irrigation and low-pressure emitters in non-play areas to supplement irrigation.
Routinely inspect non-play irrigation systems for problems related to emitter clogging, filter defects, and overall system functionality.
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 also includes protecting wellheads from physical impacts, keeping them secure, and sampling wells according to the monitoring schedule required by the regulating authority, which is often a local health department and/or the Connecticut Department of Public Health, Drinking Water Section. Licensed water-well contractors may be needed to drill new wells to meet state requirements, local well-construction permit requirements.
When installing new wells, contact the local city regulating authority to determine permitting and construction requirements and the required isolation distances from potential sources of contamination. Locate new wells up-gradient as far as possible from likely pollutant sources, such as petroleum storage tanks, septic tanks, chemical mixing areas, or fertilizer storage facilities.
Additional information on private wells in Connecticut:
https://portal.ct.gov/DPH/Environmental-Health/Private-Well-Water-Program/Private-Wells
References for licensed well contractors in Connecticut:
https://portal.ct.gov/-/media/Departments-and-Agencies/DPH/dph/environmental_health/private_wells/pdf/091416eLicenseRosterspdf.pdf
Best Management Practices
Use backflow-prevention devices at the wellhead, on hoses, and at the pesticide mix/load station to prevent contamination of the water source.
Properly close/plug abandoned or flowing wells.
For wellheads located where runoff may move toward and contact and/or collection around any part of the wellhead from runoff may occur, the area should be graded to include berms to divert surface flow away from the wellhead.
Site new wells so that surface water runoff does not contact or collect around any part of the wellhead, including the concrete pad or foundation; or construct a berm near the wellhead that is sufficient to prevent surface water runoff from contacting or collecting around the wellhead.
Surround new wells with bollards or a physical barrier to prevent impacts to the wellhead.
Inspect wellheads and the well casing at least annually for leaks or cracks; make repairs as needed.
Conduct a well pump efficiency test every 1 to 5 years to monitor pump and electric motor wear. The frequency of testing should depend on the water quality with 1 or 3-year intervals for water contaminated with sand, silt, clay etc., and every 3 to 5 years for clean water.
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 how deep the well is; 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 the regulating authority.
Never apply a fertilizer or pesticide next to a wellhead.
Never mix and load pesticides next to a wellhead if not on a pesticide mix/load pad.
A good source of tips to protect groundwater is the Groundwater Foundation: www.groundwater.org and https://www.cdpr.ca.gov/docs/emon/grndwtr/wellhead_protection.pdf.
