At the Club’s AGM in October, members will be asked to approve expenditure on the full replacement of our on course irrigation and pumping systems. I thought I would take the opportunity to offer some background to the existing system and some details of the proposed system.
The club is supplied with recycled wastewater from the Banora Point Wastewater Plant, which commenced in the 1980’s. A six inch PVC pipeline was installed to connect the plant with the irrigation dam located adjacent to 17R tee. The club owns two pumps at the plant that are capable of delivering 1.2 megalitres in each twenty four hour period. These pumps and the water supply are not part of the Irrigation System Replacement Proposal (ISRP).
Once the water enters the dam it is then pumped on to the courses by a Grundfos pump station consisting of six pumps, 2 x 32kw and 4 x 64kw, which can produce ninety litres per second. This system was installed in 2000 and has been updated regularly to keep it as functional as possible. It is variable frequency drive controlled which ensures smooth pumping operation to prevent spikes in flow that could cause water hammer and pressure surges, resulting in even more damage to the on course pipework. It has had very few issues since being commissioned which can’t be said of the pipe network it pumps into. There is also an automatic filter fitted to the pump station and all this, including the pump controller interface are to be replaced. The new system proposes a very similarly configured pump set. The actual shed will also be replaced as more room is needed for the new pump set and the old pump set will still need to operate during installation and will be removed after completion. For the duration of the installation we will be operating the two systems side by side.
Much of the existing system, particularly on the clubhouse side of the dam, was installed in the late 1970’s and there is still some pipework in this area that dates from 1965, when the initial irrigation system was installed. Most of the pipework on the western side of the course was installed from the 1970’s on, as the new nines were developed and is generally PVC pipe. The existing pipe outlet from the pump shed is 200mm and immediately downsizes to 150mm as it diverts to either side of the course and then branches off to smaller diameter pipe throughout the courses. The new ISRP has 250mm pipe leaving the shed and for the first several hundred metres then downsizing from there allowing for better water circulation. The ISRP stipulates that PE or poly pipe is used for all pipework.
The existing irrigation system is controlled by a central computer located in the maintenance compound which communicates with the twenty four satellite locations around the courses via radio. Each satellite controls between ten and fifty sprinklers depending on their location. Those satellites are no longer commercially supported and there are many components that are no longer available as spare parts. We are doing a band-aid fix on these satellites almost on a weekly basis. The proposed system will still be controlled by a central computer at the compound but with much greater versatility than the incumbent including control via mobile devices. There should only be two satellites located on course in view and each one can control up to one thousand sprinklers. The specification calls for a system so that each sprinkler is controlled individually from the central computer and communication can be retrieved from each sprinkler at any time, so any malfunctions are reported immediately.
The existing sprinklers themselves range in size from those that deliver 60 litres per minute up to the fairway sprinklers that deliver 280 and we have approximately 900 sprinklers on course at present. The ISRP allows for a significant increase in the number of sprinklers but with low flow rates which will allow for an extremely efficient use of our precious water. On our fairways at the moment the single line of sprinklers pump out 280 litres per minute each which is a huge volume and although the sprinklers operate very well, they waste water. For example, the northern side of our east-west fairways such as 2, 4, 5, 11, 12 and 18R require much less water that the southern side due to the shade effect. The new system will allow this precise application of water to occur. Each sprinkler will be individually controlled throughout the courses and the greens will have what is known as back to back sprinklers which will allow us to water the greens alone and not the surrounds which have a much less need for irrigation than the greens, once again conserving water.
Very few other golf clubs have our existing sprinkler configuration with most having a double row of sprinklers and some even triple row depending on fairway size, which helps enormously with irrigation performance and uniformity. The ISRP allows for such a configuration.
As mentioned earlier we pump around 1.2 megalitres down from the wastewater plant in a twenty four hour period. In times of maximum irrigation, as we are nearly in at the moment, the pumps at the plant don’t get turned off and on an average 1.2ML night, the following amounts are applied to.
- River greens – 100,000 l.
- West greens – 110,000 l.
- Tees – 155,000 l.
- Fairways – 810,000 l.
As you can see from the fairway figure, a more
efficient system will make that figure go a lot further or possibly even
reduce, and result in a significant improvement to the playing surfaces.
We currently attend to an irrigation issue every day
and at least two major repairs requiring excavation per week as evidenced by
the repair areas on fairways and around greens.
The cost of the necessary parts and labour is sky high and a drain on
the budget. Not to mention the wear and
tear on our irrigation techs bodies who we fondly call Gophers, as they’re
always down a hole. Burleigh GC commissioned their new irrigation system in
2019, which was nearly an identical specification to our proposal and have not
had one repair since!!
Many of our sprinklers date from the early 1980’s and are
requiring replacing at an ever increasing rate and at an ever increasing
cost. Unfortunately, very little of the
more recent hardware installation on course will be able to be used as they are
suited to our existing ‘’hydraulic system’’ which is very rarely used these
days. All existing pipework will be left
in the ground and all existing satellites and sprinklers removed.
The vast majority of the new system pipework will be ‘’ploughed’’ in which means very little disturbance to the playing surface with only the mainlines requiring trenches to be dug. The mainlines vary in size between 75 and 160mm and the pipe feeding the sprinklers (laterals) is generally 63mm.
Well that’s a snapshot of the proposal and I trust will answer some questions for members.
