Kevin Mawson
Introduction
With a changing climate, we are told we will be having warmer wetter winters and hotter and dryer summers. The dryer summers are bad news for the outdoor greens and it is likely that they will need more irrigation each year. The mains water supply used to irrigate the greens will see the cost of water, like other utilities, continue to rise along with the likelihood of watering bans creating a double problem.
Current Situation
Currently, the greens are irrigated using water from a 5,000-litre storage tank that is “slow” fed from the mains water supply. The irrigation sprinkler system, used during dry periods, consumes a great deal of water. Although 1mm of water per two minutes of run time doesn’t sound like much, spread over the area of the greens it amounts to between 2,500 and 3,000 litres each time.
The Project
To safeguard the greens from drought and reduce the cost of irrigation the plan is to buy 12 reconditioned Intermediate Bulk Containers (IBC) each of 1,000 litres. With 12,000 litres of rainwater storage, the greens could be irrigated four times before any “paid for” mains water has to be used. These are high-density plastic bottles inside a steel cage and on a steel pallet. This will enable the IBC units to be double-stacked behind the existing storage tank and linked to the existing storage tank outlet by a 50mm or 75mm pipe and so connect to the current irrigation sprinklers.
Rainwater Harvesting Operation
Collected/Filtered rainwater fed from the building roof Downpipe A to the top IBC container that will have a high-level float switch to enable excess water to be diverted back to Downpipe A. As the roof gutter is continuous Downpipe B and Downpipe C can also be used to harvest additional rainwater if the single feed does not fill the IBC tanks quickly enough. Only if the water level in the main storage tank and the IBC tanks is insufficient to meet demand will a valve activate to switch on the mains water for infill into the main storage tank only.
The combined IBC and existing storage tank will give us a total capacity of 17,000 litres – enough for 5 to 6 irrigation uses.
More to come as the project moves along.
Kevin.
