How To Install An Irrigation System

7 May 2021


How To Install An Irrigation System

With summer approaching and many people spending more time at home and in their gardens, it is no wonder people are considering easier ways to water their garden and be more Ecologically friendly.

It is widely known that rainwater is better for garden watering than mains water, and as a nation we are well used to utilising this natural resource by storing water with water butts. But what if you want to go further? In this article we will discuss what options you have for garden watering systems.

Rainwater Harvesting

Whilst rainwater harvesting isn’t a new concept, it is still a concept that the wider population haven’t heard about or considered. The concept is relatively simple, water from the roof gets stored, typically in an underground chamber (a tank), where it can be pumped to a tap for use within the garden. Storage volumes can range from 1500L to 7500L and beyond. Pumps are normally automatic, and therefore when plumbed into a tap, as soon as the tap is open the pump will come on delivering mains like pressure. Great for watering the garden and better for washing the car than mains water.

Automatic Irrigation

More and more people want to enjoy their garden but struggle with the time needed to water a lawn or flower bed. Irrigation systems are a great addition to any garden. Sprinklers can be set to different zones, come on at different designated times and flower beds can have very efficient drip irrigation systems installed. Whilst it may seem simple to implement such a system, sprinklers need specific pressure to work, and the pressure and flow rate you get at a tap will change the further the water travels through a pipe. An irrigation system needs to be designed to ensure it does what it is meant to do well.

How to use a rainwater harvesting system with an irrigation system

This seems like a no brainer. Store rainwater and have an automatic irrigation system to use that stored water to irrigate the garden. We discussed this with wetlands irrigation ltd, who agree it is very viable to do, however there are certain complexities that need to be considered. Whilst we cannot list every different specific detail that needs to be considered, here are some things to give you an idea:

  1. Sprinklers need a specific flow rate and pressure to pop up and throw water. A pump will deliver a certain flow rate but this will change depending on how much pipe, how many bends, and what size of pipe is used between the pump and the sprinkler.
  2. Multiple sprinklers will need more flow, therefore zoning sometimes needs to be employed to ensure that one zone can work, then another (there might not be enough pressure for all sprinklers to work at the same time).
  3. Drip irrigation: each metre of leaky pipe, or small “drippers” will use a small amount of water per minute. A pump likes to pump at full power. If the flow rate on the drippers is too low, a pump might turn on, and switch back off again, only to have to turn on again, this rapid “on and off” can cause a pump to burn out. It is normally necessary to install an expansion vessel (pressure vessel) to help prevent this, and to ensure that at any given time, enough water is being asked of the pump to ensure it remains turned on. An alternative is to use a more advised variable speed pump which will slow down or speed up depending on what is being asked of it.

To summarise:

Owls Hall Environmental are happy to help you with the purchase or questions around rainwater harvesting systems. However, for irrigation enquiries, we will direct to our colleagues at Wetlands Irrigation Ltd who specialise in this area. We do not offer irrigation services to our customers.

If you are considering a project with rainwater harvesting and an irrigation system, then free to give us a call to discuss further.

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