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IRRIGATION EXPRESS: SIMPLE GUIDE TO LANDSCAPE IRRIGATION

March 25th, 2019

STEP 1: PLAN YOUR AREA

Draw a plan of the area that you want to irrigate, to scale. This should include the house, boundaries, gardens, anything that may affect the irrigation process.

Detail the taps, water supply and where you would like the controller to be. You could use a title plan, google earth, google maps, or a landscaping plan as a basis for your plan. If you haven't got any of these available, drawing on graph paper is a great way to do it.

House-pic

STEP 2: HOW MUCH WATER DO YOU HAVE

Firstly choose the tap you would like to use, fill a bucket with the tap on full and time how long it takes to fill, turn this into litres per minute. A rule of thumb is to use a design flow that is half of what you have measured.

The above rule of thumb is not accurate and it is possible your water supply may not be able to supply 50% of your flow test at operating pressure. If you decide to use this rule of thumb it is advisable to test your biggest zone flow with the actual sprinklers to ensure it works before you install, so adjustments to your design can be made.

It is also likely you may be able to have bigger zones, so doing a proper pressure/flow test could easily pay for itself.

tap-bucket-flow-test

(60 / Time in seconds) x bucket size in litres

Lets say you filled your 10 litre bucket in 15 seconds.

Time = 15
Litres = 10
So through the equation we have 60 Divided by 15 = 4

4 x 10 = 40 litres per minute

Max L/pm for our irrigation is 50% of this therefore 20 L/pm

STEP 3: CHOOSE HOW TO IRRIGATE

LAWN POP UPS

LOW MAINTENANCE GARDEN

POTTED PLANTS

FLOWER BEDS

VEGGIE GARDENS

LAWN POP UPS

For the standard New Zealand lawn we recommend two pop up sprinklers.

Hunter MP Rotators

The majority of lawns will use a Hunter MP Rotators sprinkler nozzle on a 100mm Hunter Pro-spray Pop up, these are spaced from 1.5m to up to 10 meters. If you have a big lawn that has a width and length of more than 12m you could consider the Hunter PGP sprinklers. To make the design simple, the majority of you should go with the hunter MP Rotators. Check out the link to the MP Rotator Design Guide and the Sprinkler layout design guide.

Hunter Sprays

With those who are looking for cheaper options be careful. You can install spray pop up sprinklers, the spray nozzles are about a third of a cost of the MP Rotators sprinkler nozzles but they can use three times as much water and end up costing you more as you need more pipe work, more zones and valves and bigger controllers.
The cheaper sprinklers are rarely a better priced option in the full scheme of things

sprays

LOW MAINTENANCE GARDEN

Dripperline & Driptape

Use either T-tape or Techline can be snaked throughout the garden, T-tape is a short term option lasting between 1 and 5 years. Techline will last a lot longer but you will need to be careful when weeding not to damage the drip lines. Drip irrigation keeps the water off the plants which can reduce the amount of disease problems and water can be focused on the root system reducing weed growth.

POTTED PLANTS

They are often irrigated with drippers on spikes or shrubblers.

Shrubblers & Drippers

They are often irrigated with drippers on spikes or shrubblers. Getting water to your pot plants is hard work, normally done with 4mm tube up the side of the pot or up inside the pot. shrubblers can use lots of water but are easily adjustable so are a good option for most potted systems. Drippers are lower flow rate and can work well in small pots or if you have a lot of pots. Always irrigate your pots on a separate zone from other parts of your garden. You may want to install a soil moisture sensor in the pots to help with figuring out when you need to irrigate.

FLOWER BEDS

Micro Sprinklers

Are commonly used in garden boxes or smaller garden beds. There is a huge range of these sprays. You will need to select the spray that has the spray distance and coverage for your garden. Make sure that your selection of sprays on any zone have the same application rate. Be careful that you don’t use too many sprays as some have high flow rates and it is easy to have more in a garden bed than your water supply can handle. For even coverage it is wise to have these sprinklers set up in a head to head fashion.

Larger Sprays

You can use larger sprays, these sprays commonly placed on 15mm poly risers and have throws of up to 5.5 metres delivering a fine spray, a head to head spacing is wise. If you have larger flower beds that are densely planted this option is great.

sprays

Impact Sprays

If you have a large garden a part circle impact sprinkler is common. The bigger the sprinkler the more potential of damage to the plants or flowers by big droplets

VEGGIE GARDEN

Micro Sprinklers

Are commonly used in garden boxes or smaller garden beds. There is a huge range of these sprays. You will need to select the spray that has the spray distance and coverage for your garden. Make sure that your selection of sprays on any zone have the same application rate. Be careful that you don’t use too many sprays as some have high flow rates and it is easy to have more in a garden bed than your water supply can handle. For even coverage it is wise to have these sprinklers set up in a head to head fashion.

Larger Sprays

You can use larger sprays, these sprays commonly placed on 15mm poly risers and have throws of up to 5.5 metres delivering a fine spray, a head to head spacing is wise. If you have larger flower beds that are densely planted this option is great.

sprays

Impact Sprays

If you have a large garden a part circle impact sprinkler is common. The bigger the sprinkler the more potential of damage to the plants or flowers by big droplets

Shrubblers & Drippers

They are often irrigated with drippers on spikes or shrubblers. Getting water to your pot plants is hard work, normally done with 4mm tube up the side of the pot or up inside the pot. shrubblers can use lots of water but are easily adjustable so are a good option for most potted systems. Drippers are lower flow rate and can work well in small pots or if you have a lot of pots. Always irrigate your pots on a separate zone from other parts of your garden. You may want to install a soil moisture sensor in the pots to help with figuring out when you need to irrigate.

STEP 4: DRAW IT UP

Draw on your plan the positions of the sprinklers, drippers, dripperline. You will need to understand what spacing to have these items at and you can read our sprinkler spacing details, or contact us and we can design it all for you.

House-pic-sprinklers-2

STEP 5: BREAK THE PLAN INTO ZONES

Write on your plan the flows of the outlets. You will now need to split your plan into irrigation zones. Your zones need to be split into the different types of irrigation types, sprinklers can not run in the same zone as drippers or dripperline, products with different water application rates should be on separate zones. Have a look at our zone split diagram.

Once you have zoned the area you will need to check that flow rates don't exceed your design flow. If it does you need to split your zones further so the total zone flow rate matches what the water supply is capable of, as per step 2.

House-pic-zones

STEP 6: DRAW IN THE PIPELINE

Pipe sizes, for town mains supply system is 19mm for sprinklers, and 13mm for drippers and drip line. 100 meters of drip line maximum (500 litres per hour). A pumped system you need to talk with one of our experts.

Draw in Pipelines to connect up your sprinklers in the zones that suit the flow you have available. The zone pipelines link back to the control valves (solenoid valves), these are located normally close to the water supply but can be spread out around your garden and feed by a mainline pipe.
See our pipeline layout.

House-pic-pipe

STEP 7: VALVE AND CONTROL SYSTEMS

Add your valves into your system, consider what is the best location for ease of access. Most systems you should group all the valves together closes to the tap connection, however if there is good savings in pipe to spread them out through the system and take wiring from the controller, this works well to.

Valve-box-11-graphic

STEP 8: LANDSCAPE CONTROLLER OPTIONS

Choosing a controller is not easy because there is so many to choose from.

First thing you need to do is design your system and have an idea of what extensions might happen in the future.

Then decide if there will be power at the site, it is always cheaper to have a powered controller as the solenoid valves are a lot cheaper, half the cost in the 25mm size.

Then with the knowledge of how many valves you want to operate, battery or mains powered, indoor or outdoor, wifi cloud based and what sensors and features you might need. The below are the main options we see in domestic irrigation systems.

orbit-tap-timer

Orbit Tap Timer
You can go for an Orbit tap timer but these are restricted to flow of 1000 litres per hour, but are the cheapest option in many situations.

Hunter-XC-Controller

Hunter XC Controllers
The Hunter XC indoor and XC outdoor controllers are our biggest sellers, the price and quality is hard to pass by. The features they have take care of nearly every landscape system we come across, except they are not wifi capable.

hunter-node

Hunter XCH & Nodes
The Hunter XCH and node controllers are the go to for battery operated controllers, the node is great if you do not have a wall or fence to attach a controller to.

Hunter pro-c

Pro C Controllers
For the next level up the Pro C controllers if you have more than 8 valves and require some extra features.

wifi-controllers

Wifi Controllers
Then there are wifi controllers, Hydrawise and Skydrop, these are varying features that you will need to understand what suits you the most.