How performing a bucket flow test can help you design your irrigation system

Why would you perform a bucket flow test?

A bucket flow test is an essential step in sprinkler system design, especially a pop-up sprinkler system. This test is performed to determine the flow rate of the water supply to ensure that the sprinkler system will work correctly and efficiently. The test involves filling a bucket with water and timing how long it takes to fill the bucket to a specific level. This data is used to calculate the flow rate of the water supply, which is necessary for determining the proper size of the water pipes, the number of sprinkler heads required, and the spacing of the sprinkler heads. It’s important to perform a bucket flow test before designing and installing a sprinkler system to ensure it meets the necessary performance standards.

Is a bucket flow test accurate enough to determine the flow rate for residential irrigation system designs?

The accuracy of a bucket flow test in determining the flow rate of residential irrigation systems depends on the size and complexity of the system. For small, simple systems such as garden watering systems, residential drip irrigation settings and residential pop-up irrigation systems, a bucket flow test can be accurate enough to determine the flow rate. However, for larger, more complex irrigation system designs, such as pop-up irrigation systems on sporting grounds, traditional commercial sprinkler systems, and agricultural drip irrigation systems, a bucket flow test may not be sufficient.

In these cases, a more comprehensive water pressure and flow test may be necessary to accurately determine the flow rate and pressure requirements of the system. A professional irrigation designer or installer can perform these tests and create an irrigation system design accordingly.

It’s important to note that even for smaller systems, a professional irrigation designer or installer can provide valuable expertise in designing and installing the system to maximise efficiency and effectiveness. They can also advise on the appropriate type of irrigation system, the best placement of sprinkler heads, and the necessary pipe diameter and spacing.

How much water pressure do I need to efficiently run a residential irrigation system?

Different irrigation systems require different amounts of water. It is important to understand your available flow rate at your desired operating pressure when designing your irrigation system.

  • Pop up sprinklers require a pressure of at least 300kpa
  • Garden sprinklers and travelling sprinkler bases need at least 200kpa
  • Drip irrigation systems need a minimum of 100kpa

What equipment do I need to conduct a bucket flow test and how do I do it?

The good news is you don’t have to go out and buy irrigation system supplies to conduct a bucket flow test. All you need is

  • A bucket ( you will need to know its capacity. A standard bucket is usually 9 litres)
  • The garden tap you will be using as your water source
  • A timer such as the stopwatch on your smartphone

Then all you need to do is remove the fittings from the tap, turn it on full and time how long it takes to fill up the bucket.

How do I calculate the flow rate?

This part of designing an irrigation system is a little trickier.

Use the following equation to calculate the flow rate:

(60 ÷ Time (in seconds) x bucket size in litres = litres per minute

Substitute your results into the equation and calculate to determine how many litres per minute your flow rate is.

For example:

Let’s say you filled your 9-litre bucket in 15 seconds.

Time (sec) = 15

Litres = 9

So, according to our equation, we have (60 ÷ 15) x 9 = 36 Litres per minute.

Then, to find out your flow rate in Litres per hour, multiply this by 60 (i.e. 36 x 60 = 2,160 L/hr)

Still not sure? Watch this video on how to calculate the flow rate.

If you need further help with these calculations, our team at Think Water are more than happy to help you. 

How do I use the flow rate to help design my irrigation system?

The flow rate of water is an essential factor in designing an effective and efficient irrigation system. Using the flow rate obtained from a bucket flow test, you can determine the number of sprinklers or drip emitters that can be installed in each zone, based on the available water flow. You can also calculate the pipe size required to deliver the necessary water flow to each zone without compromising the system’s pressure. Additionally, if the water flow is low, you may need to consider installing a water pump to increase the pressure and flow rate. Properly designing your irrigation system using the flow rate can help you save water, reduce costs, and ensure optimal plant growth.

To ensure your irrigation system design meets your needs and you buy the correct irrigation equipment supplies, speak to a professional irrigation designer and installer at your Nearest Think Water Store

They will also be able to supply you with all the irrigation equipment you need to install and maintain your irrigation system.