A funny time of year to be talking about irrigation but it is a surprisingly popular search term for the site.
So what are the costs of running irrigation on your green?
Well as you would imagine this can easily turn into a “how long is a piece of string?” type of debate. That’s due of course to the plethora of different irrigation systems around the country and of course the weather.
However, what we can do is look at some basic irrigation facts and then, armed with some key information from your irrigation hardware and utility bills; we can make a good estimate of the costs of running the system.
First let’s look at fixed costs:
These are primarily the cost of maintaining the system after its in place. On newer systems this will probably take the form of the cost of a maintenance contract with a qualified irrigation engineer; as the system gets older this will also have to have an element of contingency planning for new parts etc.
Then we look at the variable costs such as electricity and water:
Where most of your irrigation is carried out on automatic (recommended) the variable cost of labour is negligible. So we need to know how much a unit of electricity costs us and we can get that information from the bill, same with the water costs.
Armed with the cost of water per m3 and the cost of electricity per kw/h we can then work out the actual true cost of running irrigation on our greens.
Pump Outputs are typically expressed in litres per minute.
However, for the majority of systems that are configured as 1 sprinkler per side running from a multi-stage pump through standard sprinklers from the main manufacturers such as Toro, Rainbird, Hunter and Watermation we have found that they are all very close in output terms at around 2 minutes of runtime per sprinkler to achieve 1mm of coverage on an average bowling green.
The average green will lose around 25mm of moisture to evaporation and transpiration combined in an average dry week.
This means that to replace all of the moisture lost you would need to run the system for 50 minutes per head in the week. However, it isn’t always necessary or indeed desirable to replace all of the lost water as readers of Performance Bowling Greens, a practical guide will know.
Armed with this it is possible to make a good estimate of cost per millimetre applied as follows:
- Runtime required in dry week (minutes) X pump output (litres per minute) = water used…then:
- Water used (m3) X £/m3= cost of water…then:
- KW/H used by pump X £/KWH = cost to run pump
- Cost of water + cost to run pump / millimetres applied = cost per millimetre applied.
When we have all of this together we can create a very accurate “estimate” of cost per millimetre of irrigation required.
Now as I said earlier this can only ever be an estimate…why?
Because there is one more variable that we can do nothing to influence…the weather…I’m working on it and as soon as I’ve got that fixed you will be able to contact me on my private island in the Caribbean.
Now, I’ve posted this due to the sheer number of similar search terms directing people to the site and the telling thing about that type of query being so popular in October is that it probably highlights a more serious issue:
Bowling clubs are more than ever seeking ways to reduce costs and maximise efficiency due to the extreme financial pressure being felt by many of them.
My new eBook Bowling Club Survival and Turnaround will be launched on this site on 1st November 2010; that’s next Monday.
Thank you to all of you who have waited patiently for the release of the book and who have endured the frustration of the launch being put back on two occasions now.
If you haven’t already signed up to receive my updates by email, please do so now and you will be among the first to be alerted to the new eBook going live on Monday.