Seven Oaks Irrigation System Analysis Report

SEVEN OAKS COUNTRY CLUB BAKERSFIELD, CALIFORNIA

Introduction The purpose of this report is to present an assessment of the current condition and expected remaining service life of the irrigation system at Seven Oaks Country Club. The information in this report is based on an analysis of record drawings of the irrigation system, discussions with the maintenance staff, visual observations during a site visit and catch can testing performed to evaluate the distribution uniformity of the sprinklers. Background The irrigation system covered in this report was completed in two phases. The original 18 holes were opened in 1990. This course covers approximately 133 acres of irrigated turf. The west 9 was opened around 2000 / 2001 and covers about 100 acres of irrigated turf. Depending on the design, the quality of the materials used, the quality of the installation and how the system has been operated, an irrigation system generally last between 15 and 30 years, with 20 being the average, before major upgrades or complete replacement are required. Because the overall irrigation system is made up of component parts and sub-systems, some parts or sub-systems wear out sooner than others. These components and sub-systems will be discussed in more detail in this report. Water Source and Water Requirement The primary water source for the entire 27 holes is supplied by a well that is located immediately adjacent to the pump stations. The reported capacity of the well is 3000 gpm however when the pump was started during our visit, it only registered 1500 gpm on the flow meter. We presume the well was dug during the original construction in 1990. It was upgraded in 2014 with a new well casing and a deeper set. There is also a backup supply from a city water meter adjacent to the maintenance yard that has a 6” backflow preventer. Although we do not know the exact meter size, based on the backflow size, we estimate that this source should be able to provide up to 1000 gpm. The city water meter has not been used for at least the last 5 years.

We prepared an estimated water requirement by month for each course. This is included at the back of this report as Attachment 1.

PO Box 2949

PO Box 2243

Newport Beach, CA 92659

Leander, TX 78646

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The average peak water requirement for the original 18 holes is approximately 850,000 gallons per day (gpd) and the average peak water requirement for the west 9 is approximately 640,000 gpd for a total of just under 1.5 million gallons on an average peak day. It should be noted that absolute peak requirements may exceed this on extremely hot days. At the observed flow of 1500 gpm from the well, it can deliver a maximum of just over 2 million gallons per day which should be adequate for the anticipated average peak requirement, but on an absolute maximum day this may fall short, and it has been reported that from time to time the well cannot keep up with the irrigation demand resulting in the main irrigation lake level dropping. From past discussions with well pump professionals, we have been told that a well pump should not be run for more than 23 hours in any given 24-hour period, so at 1500 gpm, you should not expect to get much more than 2,070,000 gpd from the well. This is intended to protect the pump motor and allow the well to recover. Pumping Stations There are two pump stations that supply the irrigation systems for Seven Oaks. One station was installed with the original 18 holes, and the second station was installed to supply the west 9 holes. These pump stations are not interconnected to the best of our knowledge. Both pump stations are located in the maintenance yard. They both appear to be Flowtronex/PSI stations and are both pretty much original equipment dating back to the original installations. Both are located out in the open without any protection from the elements. At an estimated 30 years old, the pump station for the original 18 has considerably exceeded its expected life span of 15-20 years (See Attachment 2). The station has an upgraded control panel which was installed in 2017 and it was reported that two of the pump motors have been either repaired or rewound in the past (one was replaced in 2015, the other in 2017). The upgraded control panel included a new Variable Frequency Drive (VFD) that controls the pump speed. Undoubtedly, these repairs and upgrades have allowed the station to survive as long as it has. The pump station configuration for the original 18 has (3) 75 hp motors and (1) 40 hp motor for a total of 265 hp. The discharge pressure is set to 115 psi. Generally, the 75 hp motors are intended to run during the night time irrigation cycle and the 40 hp motor is intended to provide the ability to water during the day without starting a larger horsepower motor. The 40 hp motor may also run during night time irrigation as well. By our calculations, this station should be able to produce approximately 2800 gpm. If the 40 hp motor is excluded from the mix, the total may be somewhere around 2300 gpm.

The capacity of the station for the original 18 is currently set to 2000 gpm in the irrigation control system computer program. Based on the average peak irrigation

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requirement, this should be capable of completing an irrigation cycle in approximately 9.5 hours. At 2300 gpm, the water window could potentially be reduced to around 8.5 hours and at 2800 gpm, the water window should be just over 7 hours. Due to its age, the pump station may not currently be capable of producing the originally designed 2800 gpm capacity at the designed pressure point. The design point for the west 9 pump station is 2400 gpm at 100 psi as is indicated on the Serial Number plate on the front of the station control panel. Currently the pump station is set to operate at 1500 gpm in the control system computer and the discharge pressure has been increased to 110 psi in the pump control software. The 1500 gpm setting should allow an average peak irrigation cycle to be completed in about 10 hours. At the full station capacity of 2400 gpm, the average peak irrigation cycle should be able to be completed in about 7 hours. We presume the increase in the discharge pressure was done in an attempt to resolve some perceived pressure issues at the furthest points end of this course; holes 3 and 4 Islands. It should be noted that an increase in the discharge pressure of a pump will typically result in a decrease in the total gpm the station can produce. However, in this case, with the (3) 75 hp motors, the station may still be able to produce 2400 gpm even with the 10 psi increase in the set point. We will discuss this in more detail later in the report. Each pump station has a single Amiad ABF filter (Automatic Brush Filter). The design of this particular filter model has proven to be problematic due to its inability to self-clean sufficiently. The brush basically imbeds debris deeper into the filter mesh rather than removing it. Over time the filter becomes inefficient and can cause excessive pressure loss across the filter element. Additionally, a single filter is never a good choice since it does not allow for adequate filtration or flow if the filter needs to be taken off line for service. This may have been a budgetary decision rather than the best recommendation of the designer. Hydraulic Design The golf course elevations range from a high of about 360’ at maintenance, to a low of about 345’ at various locations around the course. Static pressures on the original 18 holes should be between 115 and 121 psi. Static pressures on the west holes should be between 110 and 115 psi. This should be more than adequate to allow for normal friction losses through the piping system and valves assuming the main lines have been sized appropriately and the flow rates in the computer hydraulic tables are set correctly for the designed piping sizes. That being said, it is our opinion that many sections of the main line pipe are undersized for the existing pump station capacities. Much of the 8” pipe should actually be 10” or 12” to evenly distribute the water around the course. Although it was common practice to use at least some 4” pipe for main lines when the original 18 holes were installed, it is more common today to use nothing smaller than 6” pipe

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for main lines. This is partially because of the increased flexibility of modern irrigation computer systems over those that were available 30 or even 20 years ago.

The under sizing of the main line pipe is evidenced by the excessive flows we noted in the irrigation computer hydraulic tree as past irrigation managers attempted to provide adequate flow to various areas of the course. Industry design standards are to not exceed a flow velocity of 5 feet per second in the piping system. In several areas, flow rates have been set to exceed this by as much as 40%. There are long ranging implications of doing this that we will discuss in more detail in the following sections. High flow rates are also associated with high friction losses in the pipe. If there is too much friction loss due to high flow rates, pressures will be affected as you get further away from the pump station. In Attachment 3 we present friction loss calculations and the resulting dynamic pressures at two locations on the course, one for each pump station. Because of the high flow rates and long distance from the pump station out to 4 Islands tee, you will note that the resulting dynamic pressure is between 58 and 68 psi. This is below the base operating pressure for the sprinklers. As a result, the performance of the sprinklers in that area will most likely be adversely affected. Note that this is a worst-case example and may not occur daily depending upon how the irrigation computer schedules stations in that area. Losses on the original 18 out to 5-Oaks are acceptable even with the excessive flow rates in at least one section of main line. We could not calculate the friction losses out to 3- Lakes because of problems with the irrigation computer hydraulic database which we will discuss later. When the system was originally designed it was not uncommon to target a water window of 8 hours for an average peak irrigation cycle. For the original 18 holes, that would equate to a pump station capacity of around 2500 gpm. For the west holes, that would equate to a pump station capacity of around 2000 gpm. This is exactly where it appears the design points were. On a budget driven project, we will often find main line pipe sizing that is marginally capable of supporting the designed pump station capacity, much less a main line system designed to improve maintenance and agronomic practices. With today’s more advanced control systems, a target water window closer to 6 hours is much more common. This also allows for improved maintenance practices and less of an impact on early or late rounds of golf during the summer which could be impacted by irrigation occurring while golfers are present. For a 6-hour water window, the original 18 holes would need a pump station capacity of around 3500 gpm and the west course would need a pump station capacity of around 2600 gpm. Pipe sizing would need to increase accordingly.

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Piping System The piping system is PVC (polyvinyl chloride) material for both main lines and lateral pipe. Main lines are designed with Class 200 PVC ranging in size from 4” up to 12” Although it is not noted on the Record Drawings, it is assumed that the larger 14” to 18” pipe is C900/C905 rated pipe of a dimension ratio (DR) adequate for the design pressures. We know the original Irrigation Design company and trust that they selected proper materials for the project. PVC is a normal choice of material for piping in golf course irrigation systems, especially at the time that this system was installed. Today, high density polyethylene or HDPE has become popular as a substitute material for PVC. While PVC is still a viable option for golf course irrigation systems, HDPE has grown in acceptance due to its projected longer service life and flexibility during installation. Although it is not noted on the Record Drawings, the staff irrigation expert indicated that the lateral piping is all Schedule 40 PVC pipe. This is the recommended pipe for golf course projects with normal pressure requirements such as you have at Seven Oaks. It is difficult to predict the actual life of piping or other system components. The major causes for pipe or fitting failures are: 1) high static design pressure, which also results in higher than normal operating pressure, 2) high pressure surges resulting from high flow velocity, and 3) air in the system. Pressure surges are normal in a golf course irrigation system and occur when valve- in-head sprinklers shut off causing a rapid deceleration in water velocity. The valve in a valve-in-head sprinkler closes faster than valves used to serve a block of sprinklers in a landscape situation, but the benefit of individual head control and pressure regulation make them the obvious choice for golf course applications. This makes it necessary to properly control water velocity to limit pressure surges. To control surge pressure, irrigation systems are designed to limit flow velocity to an industry standard maximum of 5 feet per second (fps). When water velocity increases beyond this recommended limit, surge pressures increase at an exponential rate. The primary reason that water velocity increases occur is due to changes in system operation. Modern irrigation systems are run by computers that are programmed to turn on sprinklers via field satellite controllers located throughout the golf course. The program must be set up with flow limits based on designed pipe sizes to limit system velocity throughout the irrigation cycle. If this is not done in the beginning, it can lead to uncontrolled velocity changes during the irrigation cycle and can lead to extreme pressure surges that can reduce system life over time. Even if the system is initially programmed correctly, changes can occur over the life of the system, and if the flow management is not carefully monitored, then system velocities can increase unexpectedly.

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In our review of the computer system hydraulic settings, we noted flow rates for many of the main line segments that exceed the 5 fps design standard. Flow rates in some 6” and 4” pipe exceed 6 fps, and some 8” pipe exceeded 7 fps. Flow rates in some of the 2” laterals approach 8 fps where three sprinklers on the same lateral operate at the same time because they are linked together. The size of the sprinkler groupings in the computer hydraulic database may even allow the flow rate in some laterals to exceed 10 fps. Flow rates on all pipe 10” and larger were within standard design parameters. All golf course irrigation systems should include air/vacuum release valves. As the name implies, these valves allow air into the piping system when it is drained down to prevent a vacuum from occurring, and allow air to be released from the system as it is filled. These valves are very important to an irrigation system and must be checked regularly to ensure that they are open and operating. Water does not compress, but air does. When air is captured in the piping system, it acts as a spring, rapidly collapsing and allowing water to fill the void, resulting in extremely high increases in water velocity which results in extremely high pressure surges. Based on the record drawings, there are only 8 of these valves on the original 18 holes and 4 on the west 9 holes. This may be adequate, but this is a small number of valves for a golf course irrigation system and is probably a result of budgetary constraints. The important question is if they have been maintained and if they are operational. The weakest components in irrigation system of this age are PVC fittings used for changes of direction and connection of sprinklers to the piping system. PVC fittings of this time period were not as robust and did not have the same pressure rating as PVC fittings that are now available. PVC fittings are generally used only for pipe sizes up to and including 3”. These fittings typically begin to fail around the 20 year mark. Failure is typically from cracks forming in the crotch of tees and elbows due to cyclic fatigue. The rate of failure is compounded when high velocities, and therefore high surge pressures are introduced into the mix. That is what is occurring to your system. There are reportedly as many as 3 to 6 lateral fitting failures per week during the summer during maximum irrigation periods, and 2 to 3 per week during the winter when the system is operated fewer days per week. This is considered very high.

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WET SPOT FROM BROKEN FITTING

TYPICAL FITTING FAILURE

DAMAGE FROM LATERAL FITTING FAILURE

Valves There are essentially three important valve types on the golf course; main line gate valves that are typically located between golf holes to isolate various areas of the course, lateral isolation valves that shut off water to the 2” lateral pipes that supply the sprinklers, and air/vacuum relief valves that allow air to be purged from the system and also allow air back in the lines when they are depressurized for repairs. A high enough vacuum in the main line can collapse a section of pipe.

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The main line gate valves available today are essentially unchanged from those that were available when the course was originally built. Although some valves may fail with time, it is not common to have issues with these valves and there do not seem to be any widespread problems with the valves you have. The lateral gate valves on both the original 18 and the west course are standard bronze gate valves. These valves are critical for shutting off limited areas of the course in the event of a sprinkler or line break or for repairing or replacing sprinklers or other valves. The lateral valves used during the construction of your courses typically lasted 7 to 10 years before failures begin to occur due to corrosion on the valve stem and the gate itself. This life can be extended by “exercising” the valve a couple times per year to loosen any corrosion that may be occurring. This basically means the valve is closed then re-opened. Unfortunately, a failed valve is typically found only when it is needed due to a piping or sprinkler failure. In most cases, these valves are just cut out and replaced instead of being repaired. As expected, valve failures are reportedly a common problem on both courses. The currently available ductile iron lateral isolation valves are much more robust and have about double the expected life of the older bronze gate valves. As noted in the Piping System section, air/vacuum relief valves are an important component in the system and need to be routinely serviced. It is not uncommon for us to find that some of the valves have been turned off because they were leaking. These are frequently forgotten and never repaired. If an adequate number of valves are not operational, it can lead to significant pressure problems due to surges caused by air trapped in the lines. Air will eventually be purged through the sprinklers, but high surge pressures will occur while this is happening. There is no magic number for how many air relief valves are needed on a system and a system with very little elevation change such as yours can typically get by with fewer valves. Newer designs incorporate about one air/vacuum relief valve per golf hole. You have about one valve for every 2.3 golf holes. As long as they are functioning, this is probably fine for your site. Sprinklers and System Coverage For the original 18 holes, the primary sprinkler was initially Rain Bird 47 and 51 impact sprinklers. At some point prior to 2002 (the date of the Record Drawings) the tees, greens, and greens surround sprinklers where changed to the Rain Bird 700 series which first became available in 1993. It appears that the original layout was based on 65’ triangular spacing, although the sprinkler grid occasionally changes at the turning points on some golf holes. Even for parallel golf holes, a different grid was used for each hole. This was a fairly common design practice at the time, but has since proven to be less effective than keeping the same pattern for the entire golf hole for most locations. At some point after 2002, the 47/51 series sprinklers were all changed out to the 700 series gear driven rotors, which is the dominant

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sprinkler for the original 18 holes today. During the recent greens renovation work, the greens sprinklers were replaced with the Toro Infinity sprinkler with the adjustable trajectory option; a feature not available from Rain Bird at this point in time.

For the west 9 holes, the primary sprinkler is the Rain Bird 700 series geared rotor.

Our observation is that when the change over from the impact to the geared rotors occurred, the primary nozzle set for the 700 series sprinklers was the -36 nozzle set with a performance of 65’ radius and 27.5 gpm at the 70 psi regulator setting. At present, sprinklers in the fairways have had their nozzle sets changed to the -44 nozzle set that has a catalog performance of 69’ and 33 gpm at the 70 psi regulator setting. We will discuss this nozzle selection later in the report. The original sprinkler design at the greens for both the original 18 and the west 9 utilized a full circle sprinkler as the primary greens sprinkler and supplemental part circle for irrigating surrounds when needed. For most superintendents, this is not the preferred method of irrigating greens that are sand based construction (USGA or California Greens). During the greens renovation on the original 18 holes, these full/part sprinklers have been replaced by part/part sprinklers so that greens can be irrigated independently of the surrounds. This change is also planned for the west 9 holes when those greens get renovated. Sprinklers generally last between 15 to 20 years in your area before they become inefficient and begin to have component failures. Based on the age of the sprinklers in this system, they are most likely due for replacement within the next few years. Even though your water quality is good, the original nozzles are probably worn and not within the original design specifications. We assume this is part of the reason the fairway nozzle sets have been changed out. Old nozzles can result in more water being distributed by the sprinkler than is recorded in the control system database. When this occurs throughout the golf course, more water is running than the control system is aware of, and this will result in higher flow rates and more friction loss than the system is programmed for. This can cause lower available pressure in the system. The wear can also result in inconsistent distribution of water. This is a reported issue that the club has been dealing with. Water application close in to the sprinklers does not appear to be good and in some cases is resulting in significant declining turf quality next to the sprinkler. This does not occur everywhere, but in enough locations for it to be a concern.

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TURF ISSUES NEAR SPRINKLERS

The pressure setting of the existing sprinklers is 70 psi. These are valve-in-head (VIH) sprinklers and include a control valve and pressure regulating module in each sprinkler. The pressure regulator ensures that the same amount of water is distributed by each sprinkler regardless of higher base pressure at the bottom of the sprinkler. In a new design, options could be considered for closer spacing that may provide improved Distribution Uniformity (DU). This will be discussed in more detail in the report section covering the on-site testing we performed. In reviewing the Record Drawings of the system, the sprinkler spacing is primarily 65 foot triangular spacing but it is inconsistent, particularly where the grid pattern of the sprinkler layout changes at turning points and between golf holes. In these locations, the spacing varies from about 45’ to over 75’. To operate best and most efficiently, sprinklers should be in a consistent and uniform pattern. Whether the pattern is triangular, rectangular, or square, it should be consistent with uniform spacing between sprinklers. In this climate uneven coverage from inconsistent spacing will result in irregular application of water, and this will ultimately lead to less than healthy and acceptable turf conditions. In a new design, an emphasis should be placed on uniform sprinkler spacing. During the performance testing, we noted a few anomalies with the sprinkler performance and upon further investigation, some of the reasons may have been uncovered. The rotation speed for a full circle sprinkler is specified by the manufacturer to be approximately 3 minutes for a full revolution. Your sprinklers are completing a full revolution in about half of this time. We generally expect that a sprinkler will rotate slower as it ages rather than faster, and eventually it will stop rotating at all. One of the results of this increased speed is that the sprinklers do not throw as far as they should. The original -36 nozzle should be capable of throwing head to head, and the updated -44 nozzles in the fairway sprinklers should all be throwing about 4

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feet further than head to head. We observed most sprinklers not quite reaching head to head as they should on every pass.

For the sprinklers with the updated -44 nozzle set, we believe what is happening is that the flow through the head has been affected by the nozzle swap. There is a component in the base of the sprinkler, called the stator, that also needs to be changed when this nozzle is used and that component remains as it was for the original -36 nozzle set. The stator will affect the gallonage through the sprinkler as well as the radius of throw. We also noted that the nozzles that throw out the back side of the sprinklers are not the standard factory nozzle set. The factory has done extensive testing on their nozzles and recommends that in most cases these nozzles remain as originally supplied. We believe the changes to the back nozzles were made in an attempt to resolve the dry areas near the sprinklers, but there is no data that suggests this change has made any difference. Span of Control The span of control refers to the level of control you have over the operation of individual sprinklers. The history of golf course irrigation began with a series of quick coupling valves being installed at relatively large spacing down the middle of each golf hole. A night waterman would move a single sprinkler from valve to valve during the night on a set schedule until the entire golf course was irrigated. The single row of quick couplers frequently became multiple rows and the night waterman’s task grew accordingly. As sprinklers evolved, one of the next steps in the progression was the development of an in-ground sprinkler that could be operated by a manual valve. To be expedient, typically multiple sprinklers would be installed on a single valve which became known as a Block System, where blocks of sprinklers operate at the same time, thus reducing the time required to irrigate the golf course. In general, two to six sprinklers would be operated from a single valve, however most systems operated three to five on a block. The primary drawback for block systems was the lack of fine control over where water was applied. The more sprinklers on the valve, the more likely you would be to have wet and dry spots due to variations in soil, slope, shade patterns and even turf types. You generally had an option to either irrigate to the wet spot or to the dry spot. If you irrigate to eliminate the wet spot, you end up with more dry spots. If you irrigate to eliminate the dry spot, you end up with more wet spots. To combat this issue as block systems became automated, design styles started reducing the number of sprinklers on a block in an attempt to reduce the number of problem areas. As sprinkler design evolved even further, an automatic valve was added to each sprinkler. The ultimate goal was to be able to operate each sprinkler independently. This is the whole premise behind the valve-in-head sprinkler. Each sprinkler is intended to be operated on its own station so that you can control the

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amount of water applied to each finite area on the course. Initially this was met with resistance due to the cost of adding automatic control to all the sprinklers on the course. To reduce costs, many systems in the early days of valve-in-head sprinklers were designed with 2, 3 and even 4 sprinklers on a control station. This was strictly a budgetary decision and not an agronomic one. Unfortunately, the system at Seven Oaks was caught in the period where 3 to 4 sprinklers were combined on a single control station for budget reasons. As a result, you currently have sprinklers on a single station that may be a combination of fairway heads and rough heads or worse yet, fairway and approach heads; each of which may have a different water requirement at various times of the year. This can be particularly problematic for courses that employ over-seeding.

STATION 8-8 HAS TWO SPRINKLERS IN THE FAIRWAY AND ONE IN THE APPROACH

For many systems that tied multiple valve in head sprinklers to a single station, a separate wire was often installed from each sprinkler back to the field controller so that sprinklers could be separated should a significant issue arise for a particular area. Unfortunately, at Seven Oaks, these multiple sprinklers were wired together in the field, and a single wire runs back to the field controller to operate that station. This does not allow the sprinklers to be separated without significant cost for installing new control wire and upgrading the field controllers to add additional capacity. There are any number of examples around the golf course where fairway and rough sprinklers are operating on the same station, where 3 sprinklers on the

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same lateral are operating together, and where 4 and 5 sprinklers are on the same station in the rough and on the range. Here again, this appears to have been a cost savings measure during construction. All greens and most greens surround sprinklers are single station operation for improved control for all 27 holes. Tee sprinklers on the west course are also primarily single station control. The tees on the original 18 holes are primarily 2 and 3 sprinklers per station. Performance Testing To evaluate the sprinkler performance, we performed six catch can tests at various locations around the course. Tests were done mostly in areas of concern, but we also did a few tests in areas that were considered to be performing well. The Irrigation Association has laid out guidelines for this type of testing which we follow. Results of the test are presented as the Distribution Uniformity or DU. Catch devices are evenly spaced throughout the test area and volumes are collected and recorded. The average volume in the lowest quarter of the catch devices is compared to the average for all devices and is expressed as a percentage. DU’s of 80% are considered Excellent, 70% is considered Good, 60% is considered Fair and anything 50% or less is considered Poor. We also map out this data for additional analysis that can sometimes suggest where problems may be occurring. Guidelines recommend that testing be done with wind speeds less than 5 miles per hour. Anything over that can substantially affect how water falls out in the pattern. During our testing, wind speeds were negligible, rarely exceeding 1 or 2 mph.

Tests were performed on 4-L, 8-L, 5-O, 9-O, 4-I and 9-I. Maps of the test areas including spacing between sprinklers, catch device locations and catch volumes are included at the back of this report in Attachment 4.

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The results were mixed. DU’s on 9-I and 9-O were in the mid to low 80’s which is considered Excellent. Results for 5-O provided a DU of roughly 73% which is considered Good. This area was visually the worst of all areas we tested because of significant ponding which we didn’t see to this degree in any of the other test areas. Regardless of the distribution uniformity, there are local issues here with either soils, drainage, or both that need to be addressed.

PONDING ON 5-OAKS DURING PERFORMANCE TESTING

The test on 4-L resulted in a DU of 73% which is considered Good. Results for the tests on hole 4-I and 8-L were 66%. This is considered Fair.

Specific observations and comments for each test area:

Hole 4-Islands: Pressure during the test was 115 psi. Wind was negligible. The test area was full rough, bordering the fairway. Nozzles for the heads by the cartpath have green main nozzles (44), with black and orange rear nozzles. The rest of the nozzles, including those bordering the fairway all have yellow main nozzles (36) two with black and orange rear nozzles and two with black and green rear nozzles. Average catch volume was 70 ml, lower quarter was 46 ml for a DU of 65.5%-Fair. Sprinkler spacing ranged from 62.1’ to 65.9’.

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Hole 8-Lakes: Pressure during the test was 115 psi. Testing was full rough. All main nozzles are yellow and all rear nozzles are orange and black (note that the order of the rear nozzles has no impact on results). Average catch volume was 71 ml, lower quarter was 47 ml for a DU of 66%-Fair. Sprinkler spacing ranged from 53.9’ to 66.6’. Hole 9-Islands: Pressure was 110-115 psi. Wind was negligible. The test area was approximately 50% rough and 50% fairway. All fairway sprinklers have green main nozzles with orange and black rear nozzles. The rough sprinklers have yellow main nozzles. Average catch volume was 76 ml, lower quarter was 64 ml for a DU of 84% - Excellent. Sprinkler spacing ranged from 60.7’ to 69.7’. Hole 5-Oaks: Pressure was 110 psi. Wind was negligible. The test area was approximately at the beginning of the fairway. It appears that the sprinkler pattern changes direction at this location due to the poor spacing. All fairway sprinklers have green main nozzles with orange and black rear nozzles. The rough sprinklers have yellow main nozzles. Average catch volume was 93 ml, lower quarter was 68 ml for a DU of 73% - Fair. Sprinkler spacing ranged from 40.9’ to to 71.2’. Our assessment is that the closer spacing which results in more sprinklers in the area is the main driver to the increased catch volumes in this location as well as the reason for the ponding we observed. Hole 4-Lakes: Pressure during the test started at 110 psi but dropped to 78-80 psi during the test. We attributed this reduction in pressure to the lake fill valves that were running at the time of the test. This had no impact on test results since pressures did not drop below those needed for proper sprinkler operation. Testing was mostly rough with two heads in the fairway. Part circle sprinklers along the property line contributed to the catchment area and these sprinklers were less than a full 65’ spacing away from the next row of sprinklers. The catch volumes reflect this with most of the high catch volumes along that edge of the test area. All main nozzles are yellow and all rear nozzles are orange and black for the full circle sprinklers. Part circle sprinklers had a single black nozzle. Fairway sprinklers have green main nozzles with black and orange rear nozzles. Average catch volume was 77 ml, lower quarter was 56 ml for a DU of 73%-Good. Sprinkler spacing ranged from 43’ to 67.2’. Hole 9-Oaks: Testing was primarily in the rough, right at the beginning of the fairway. All main nozzles for the rough sprinklers are yellow and all rear nozzles are orange and black. The station that stretched into the fairway was green main nozzles, one with orange and black rear nozzles and one with black and green rear nozzles. Average catch volume was 70 ml, lower quarter was 87 ml for a DU of 81%- Excellent. Sprinkler spacing ranged from 63.4 to 66.8’.

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Control System The control system is a Rain Bird CIRRUS central and satellite system. This is the top of the line offering from Rain Bird with the most flexibility and functionality. Many of the original field satellites have been replaced over the years to PAR and PAR+ units, with only a few of the more current PAR+ES models. The central control software has just been updated to the most current version this month. The club is on Rain Bird’s Global Service Plan which provides software upgrades and telephone support on a subscription basis. The current control system can be reused for any potential upgrades to the irrigation system, assuming the system remains Rain Bird. Rain Bird also offers a non- satellite option that communicates directly from the central computer to each sprinkler over a wire path without the need for a field satellite. The primary benefit of this type of system is to reduce the presence of the satellites around the golf course. The disadvantage is the lack of redundancy that the satellites offer in the event of a loss signal from the central. As with any software, the quality of the output depends significantly of the inputs. There are basically three areas of concern for the software; 1) the sprinkler database, 2) the hydraulic control database and 3) the operational programs. We reviewed the database extensively and found many areas that need improvement. The sprinkler data itself needs to be audited and updated to reflect the current sprinkler model and nozzle set in use for each station. This is time consuming, but is critical to the overall performance of the system. The fact that your system has multiple sprinklers on a single station makes this more difficult since in some cases there are different models of sprinkler on the same station. In these cases, it is next to impossible to control the amount of water applied since each sprinkler may require a different run time to apply the desired amount of water. Also as previously noted, due to the age of some of the sprinkler nozzles, the actual gallonage being delivered by any given sprinkler may be greater than that of a new sprinkler. The recent nozzle swap may have also had an impact on the gallonage for the sprinklers that is not being taken into account at this point. The Hydraulic Database contains multiple errors; both in how it was built and how the flow rates have been assigned to the various segments of main line pipe. The hydraulic database has several flow assignments that exceed the industry standard flow rate of 5 fps. This creates excessive surge pressures and may be contributing to the high number of lateral pipe fitting failures you are experiencing. We found at least one section of main line pipe that has been assigned to the wrong source. It is impossible to predict the exact affect this is having on system operation, but as best as we can tell, it is probably allowing excess flow to portions of the course

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Bryant Taylor Gordon Golf

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Conclusions It is difficult to predict the age at which an irrigation system must be replaced. Irrigation systems are designed and operated differently and as a result, some systems will begin to require extensive maintenance and repair, while others may not become a problem for many years after the “average” expected life span. The general factors that affect the system life are how the system was designed and programmed, and how it was maintained and operated. The most relevant observation for Seven Oaks is the extremely high lateral fitting failure rate. This is not predicted to slow, rather it is an anticipated failure mode that has been worsened by the excessive flow rates and resulting high surge pressures. We expect this failure rate to be fairly constant, if not increasing for the foreseeable future. At this point, the damage has been done. Regardless of the status of the remaining components of the system, the lateral piping is what connects it all together and that component has now passed its useful life span. Water Source The well pump produced approximately 1500 gpm when we ran it during our site visit. As we noted earlier, this is just a little bit short of being able to keep up with peak summer demands. The presumption of golf course staff was that the well pump may be capable of producing closer to 3000 gpm. We recommend that this be investigated further to see if more capacity is available from the existing well and well pump. This would allow the existing source to keep up with peak summer demands. Although the cost may be prohibitive, the alternative is to utilize the city water meter to make up any difference between irrigation demand and what the well pump can currently produce. A second, more expensive option would be to drill a second well as a supplemental or backup source of water. Water quality does not seem to be a problem and we would not expect this to change. At present, the club pays a recharge rate of approximately $18,000 semi-annually for the water that is withdrawn from the aquafer. Compared to a course that uses a domestic water source, this is a very low cost for water. There is a potential opportunity to reduce the irrigated acreage and lower this fee as well as reduce the maintenance costs of mowing 233 acres of manicured turf. Beginning in 2020, the Sustainable Groundwater Management Act of 2014 starts to require management of local water agencies. San Luis Obispo County has already placed a moratorium on drilling new wells. Although it is not clear what this management will look like, we expect that in the coming years as water becomes a scarcer commodity, the recharge rates are likely to increase to fund these programs. Looking at options to minimize your exposure to these impacts may be a practical exercise. Pump Stations Both pump stations have outlasted their expected life span. That being said, they both look to be in reasonable condition for their age, having been repainted within the last few years. To help protect the stations from the elements, we recommend

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Bryant Taylor Gordon Golf

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that pump stations be enclosed, or at a minimum, covered. For most golf courses, this is typically a simple building with ventilation, or at least a shed roof with chain link fence surrounds to protect it from unauthorized access or vandalism. It should be noted that these stations operate on 460 V, 3-phase power. This is extremely dangerous and potentially deadly if an unexperienced person were to gain access to the control panels. Significant work is anticipated for both stations in the not too distant future. Potential work may include re-winding of the motors, replacement of the pump wet ends due to wear, and for the west course station, a new control panel. New filters should be considered for both stations since the existing filters are generally not considered adequate. Newer style suction scanner filters are much more effective and require significantly less service. The cost of estimated repairs over the next 5 to 10 years should be evaluated by a qualified pump repair company. It is possible that full replacement with a new station may be more cost effective than repairs. The installation of a new pump station is typically undertaken at the same time as a full irrigation renovation. We recommend that your pump station service provider perform testing to establish the current capabilities of both stations to see if they are still able to provide the original discharge pressures and gallonage. This is a standard test and will provide information that is important for setting the hydraulic capacities in the irrigation computer. The 10 psi increased pressure set of the west course station may be acceptable, but it may also have a detrimental effect on the total gallonage the station can deliver. This needs to be evaluated by your pump station service provider. Hydraulic Design We noted above that main line pipe sizes to some areas of the course could be improved. In the short term, improvements could be made by installing supplemental main lines on some holes to reduce velocities and move additional water to various areas of the course. We noted two locations that could benefit from this. For the original 18 holes, we would recommend installing a second 8” pipe between 1-Oaks and the 6” pipe that goes towards the range. On the west course, we would recommend installing a second 8” pipe from hole 7-Lakes tee all the way to 9-Lakes fairway. Both of these sections of main line are currently 8” which has a maximum capacity of about 750 gpm. Both locations need to be able to move closer to 1000 gpm or more to balance flows and reduce the excessive velocity in those sections of main line. We heard a comment about how long it takes to irrigate the range. This could be reduced, at least a little bit, by looping the 4” pipe on the range to the 6” pipe near 2-Lakes green. This would improve flows to the range and allow irrigation to finish sooner in that area.

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Bryant Taylor Gordon Golf

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Sprinklers and System Coverage The issue observed with the high rotational speed of the sprinklers needs to be addressed. This is potentially the cause of the short throw being observed (ie no longer head to head). For the sprinklers that have recently been updated to the green 44 nozzles this may be a resolved simply by removing the poppet from the stator to put the sprinkler back to factory specifications. Once this is done, observe the sprinkler rotation to see if it has returned to the expected 3-minute range. If not, there is something else going on that needs to be looked in to. You may find that the radius also increases to something closer to the catalog data of 69’. When you are ready to consider a full irrigation renovation, we recommend that you explore closer spacing of 60’ triangular. Most manufacturers have developed a nozzle set that performs extremely well at this spacing. We also recommend that spacing be consistent on a golf hole by staying with a single grid for the entire hole. In most cases, this also applies to keeping the same grid for parallel holes with a common rough so that spacing between them is also consistent. Span of Control The span of control is currently not on par with industry standards. A new system should be designed around single head control in order to reduce the wet and dry spots you are currently contending with. We fully expect you will see significant improvements in turf conditions once this is done. Control System Although the control system hardware and software are current state-of-the-art, the database requires some significant improvements. The sprinkler database needs to be completely audited for accuracy. At this point, the new greens sprinklers installed on the original 18 have yet to be added to the database. We noted several sprinklers that were either assigned to the incorrect branch of the hydraulic tree or did not have sufficient data entered in the database to operate in the automatic mode. As noted earlier, there are many sections in the hydraulic database that exceed industry standards of 5fps. These should be corrected as soon as practical. We also noted that some branches on the hydraulic database are not linked to the proper source. The impact of this is not easy to predict, but we suspect it is causing an untold number of issues that are masked by other problems – flow to the range and holes 1-4 Lakes may be higher or lower than anticipated and this affects the overall efficiency of the system. The breakout of sprinklers into their assigned flow zones is somewhat arbitrary, not because the person who programmed the database didn’t know what they were doing, but because of the way the sprinkler stations are linked across multiple laterals; there is no clean break of stations from one lateral to the next. We believe the best fix for this is to just start over and create a new hydraulic

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Bryant Taylor Gordon Golf

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database that has proper flow rates, corrected branch assignments and re-worked flow zones.

The assignment of controller addresses is also very confusing and near impossible to follow. The communications model for Rain Bird is based on separate communications cables between the irrigation computer and the field controllers that can have a maximum of 28 “channels” per cable. Each channel can operate a maximum of 24 control stations. The confusion arises when a field controller has more than 24 stations. What are physical stations 25 to 48 on the field controller are logical stations 1-24 on a different channel in the database. The database can be organized so that the channel numbers are all but invisible to the operator so that all they need to know is the physical address in the field controller, however this was not done during the original programming of the system. In concept this is easy to fix, but it is fairly time consuming to accomplish. Controller types are mostly entered as “generic” in the database instead of the specific models that are actually installed. We even noted some controller types entered as electromechanical controllers that have not been made for decades. This should also be re-worked so that the maintenance staff has a more functional tool to use in the field when trying to operate sprinklers from the field satellites First, the issue with the sprinkler rotational speed should be looked into. Once this is resolved, additional changes to nozzle selection need to be addressed. Although the Distribution Uniformity testing does not point to any system wide issue, there are clearly nozzle options that should be looked at. We recommend that the local Rain Bird Distributor be involved with this analysis, along with Rain Bird Factory support in the proper nozzle selection for this spacing. The issues with the control system should be addressed as well, and these changes are as important, if not more so, than the sprinkler issues. The sprinkler database needs to be audited to make sure it reflects what is actually installed in the field. This can be done over several months, a few controllers at a time. Each station needs to be operated and the sprinkler and nozzle type recorded or verified. This information then needs to be transferred to the control system database to ensure accuracy. The hydraulic database needs to be addressed to eliminate the high flow rates that are likely contributors to the pressure and component failures being observed on the courses. Not much can be done about the individual flow zones and sprinkler assignments to these because of the number of sprinklers on each control station, but this is something that clearly needs to be fixed in the next irrigation system design. Recommendations In the short term, there are several items to address.

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