Operation and Maintenance Manual - Irrigation Systems

Irrigation Systems

Operation and Maintenance Manual

This Operator’s’ Manual has been developed to help you understand the components and workings of a basic irrigation system, and to assist in servicing and troubleshooting any minor issues should they occur. 1. Water Supply a) Scheme water systems - Plumber’s Retic “Cut- In” and Mains Isolation Valve

For scheme/mains fed systems, water will usually be sourced near the water meter at the front of the property. Close to the water meter, a licensed plumber will ‘cut in’ to the main water supply to the house, and will install a dual check / non-return valve and an isolation valve ready for the irrigation system. In some cases, the ‘cut-in’ and isolation cannot be located near the water meter, and may need to be installed at an alternate location at the property (eg. copper feeding hose taps). In either case, the ‘cut-in’ isolation valve is the point where to shut off the mains water feed to the irrigation system in case of emergencies. b) Bore water systems

Most bore pumps are activated by a pump start relay – which is generally located next to the irrigation controller. The controller sends a 24VAC signal to the pump start – which via the relay – sends 240VAC to the pump. Pump start boxes generally have a reset button on the housing– which may need to be used if you are experiencing problems with starting your bore. 2. Master Solenoid Valve

The Master Solenoid Valve (located near the water meter) protects the garden and lawn solenoid valves from being pressurised when the controller is off and avoids wasting water if one of the zone solenoid valves fails to open. 3. Fertigation System (if installed)

The fertigation system injects fertiliser into your drip system directly. If installed, the operation of this will be explained by your commissioning installer. 4. Filtration

Filters removed unwanted solids such as sand from entering the system. The filter elements should be inspected and cleaned every three months. Simply take the element out, separate the discs and/or wash the screen with a coarse bristled brush under the tap. Tech Filters are chemical filters designed to deter roots from entering the drippers. If they have been installed on your system, it is recommended that the filter element be replaced at least every 2 years to maintain its protective properties. 5. Pressure Regulating Valve (PRV)

After the filter is the pressure regulating valve. This small black device ensures no more than 300kPa of pressure is downstream of this device, maintaining a constant pressure and eliminating the chance of drip fitting blow outs due to high pressure. Earth and Water Pty Ltd

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Irrigation Systems


6. Irrigation Controller

The controller automates irrigation events by turning on and off solenoid valves for particular ‘zones’ for a set time and on a set date as per the programme. Further information on controller operation and programming can be found in the enclosed manual. 7. Station (Zone) Solenoid Valves

Station solenoid valves supply water to the various areas of your garden. All of the solenoid valves, including the master valve, are wired up to your controller that, when automatically or manually activated, will turn on one of the lawn or garden Solenoid Valves and the Master Solenoid at the same time. 8. Mainline and Sub-Mains

From the solenoid valve generally low density poly pipe, known as the sub main, runs off the solenoid valve to a garden bed or part of the lawn. 9. Vacuum Breakers / Air Valves

Located in the sub main is an air release valve, it is installed to prevent drippers sucking in dirt when that zone is turned off. When the zone turns off, the water in the drip line seeps out, as this volume of water lost it is replaced by air entering through the air release valve. 10. Dripline Laterals

From the sub main drip line laterals are fed in parallel lines covering either an area under the lawn or under the mulch in the garden beds. 11. Collection / Flushing Manifold

At the end of the drip line laterals is the Collection or Flushing Manifold. The drip lines are connected into this poly pipe for the purpose of flushing. 12. Manual Flushing Valves

A manual valve will be located in a round valve box with a green lid. The valve needs opening while the system is operational once per month for around 1 minute to release any foreign particles that might have entered the system. This flushing process ensures that the filter on the back of the drippers does not get blocked.

Earth and Water Pty Ltd

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Irrigation Systems


Irrigation Scheduling Calculating how long to run your system depends on a number of factors including:     

The application rate of the sprinklers or drippers The flow rate and spacing of the driplines and sprinklers Seasonal and daily weather conditions Landscape water demand (ie. veggies, natives, turf or or exotics) Local watering restrictions

Application Rate The application rate is a measure of the depth of water applied to an area over a given time period. The standard unit of measurement is millimetres per hour (mm/hr). Evapo-transpiration (ET) = Loss of moisture from the soil through the combined effects of evaporation and plant transpiration. Usually measured in millimetres per day (mm/day). In Perth’s summers, we lose an average of 8mm of water per day due to evapotranspiration. Whilst it would be nice to replace all the water lost through this process, we have to help save water and only irrigate a supplementary amount in order to keep our landscapes alive. The amount of water we can responsibly use for residential landscapes is governed by the Water Corporation’s Permanent Water Efficiency Measures – which have been developed in collaboration with the Department of Water and other government agencies.

Rostered Watering Days (Perth & Mandurah) Last Digit of House Number 1 2 3 4 5 6 7 8 9 0

Source: Water Corporation Website

Scheme and Bore Water Users Wednesday and Saturday Thursday and Sunday Friday and Monday Saturday and Tuesday Sunday and Wednesday Monday and Thursday Tuesday and Friday Wednesday and Saturday Thursday and Sunday Friday and Monday

Bore Owners Additional Day Monday Tuesday Wednesday Thursday Friday Saturday Sunday Monday Tuesday Wednesday

Where a house number is not available, it defaults to your lot number. You may only water once either before 9am or after 6pm.


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The Standard Drink The ‘Standard Drink’ is currently set at 10mm or 10 Litres/m2 (ie. 1mm = 1L / 1m2) Scheme water users can apply 20mm / week to their gardens (ie. 2 Std. drinks) o o Bore water users can apply 30mm / week (3 Std. drinks) Table 1: Calculations for ‘Standard Drink’ Runtimes Dripline Type

Nominal Flow Rate @100 kPa (L/hr)

Dripper spacing (m)

Row Spacing (m)

Application Rate (mm/hr)

Min. runtime to apply standard 10mm drink

Toro DDC

6.0

0.2

0.3

66

9 minutes

Techline AS

3.0

0.3

0.3

33

18 minutes

Tiran

8.0

0.3

0.3

88

7 minutes

Uniram

3.5

0.3

0.3

38

16 minutes

MP Rotator Sprinkler Nozzles

Nominal Flow Rate @ 250 kPa (L/hr)

Spacing (variable) Head to head coverage Radius of throw (180 degree)

Application Rate (mm/hr)

Min. runtime to apply standard 10mm drink

MP1000

81

4.0m

10

1 hour

MP2000

160

5.5m

11

55 minutes

MP3000

393

8.5m

11

55 minutes

Example 1: o o o

Dripper Flow Rate: 3.5 L/hr Dripper spacing along dripline: 30cm (0.3 metres) Spacing between runs of dripline: 40cm (0.4 metres)

Application Rate (mm/hour) = Volume (L/hr) = 3.5 L/hr = 29 mm/hr 2 Area (m ) 0.3m x 0.4m Example 2: o o o

Dripper Flow Rate: 4.0 L/hr Dripper spacing along dripline: 20cm (0.2 metres) Spacing between runs of dripline: 30cm (0.3 metres)

Application Rate (mm/hour) = Volume (L/hr) = 4.0 L/hr = 66 mm/hr 2 Area (m ) 0.2m x 0.3m Irrigation Runtime (minutes) = Required depth (mm) x 60 Application Rate (mm/hr) To apply a standard 10mm drink using Example 2: 10mm x 60 (mins) = 9 minutes 66mm/hr Earth and Water Pty Ltd

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Irrigation Systems


System Maintenance Filter Cleaning The filter is located in a valve box in the ground. Un-screw the top of this and pull out the filter element. IMPORTANT: Ensure system is not running and/or pressurised before removing filter cap. This shows the different parts of the filter. Although this is a Tech filter it has the same parts as a standard disc filter. The filter on the left needs cleaning and the one on the right is a clean element. Remember that a tech filter element needs to be replaced every year to prevent root intrusion.

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Pull apart the discs of the filter.

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Rinse under a tap to remove all the loose particles until the filter is clean.

For systems with a bore running a large area there will be a screen filter fitted to your system.

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Open the red tap on the end of the filter with the system running for 20 seconds every month or when a loss of pressure is noticed to flush out any dirt that might be inside the filter.


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Repairing Damaged Dripline Pooling of water while the system is running can indicate that a dripline has been cut or damaged and needs repair

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Expose the dripline to find the break in the line.

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Cut the dripline on the break. A pair of scissors or sharp secateurs will cut this. If the break is on a dripper then cut the dripper out.

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Insert a straight barbed joiner into one end of the dripline.

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Join the dripline together. If you have had to take a dripper out then cut a new bit of dripline in with a dripper using two joiners.

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Make sure the joiner is fully pushed into either end of the dripline.

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Flush out any sand through the flush valve.


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Manual Flushing Points In each area you will have a ball valve (tap) in a round green box as a flushing point.

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Remove the box lid and with the system running open the tap.

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Let the water flush through for a minute until the water runs clear before shutting the tap then replace the valve box lid.

Recommended Maintenance Schedule Monthly

Bi-Monthly

1. Manually Flush all 1. Fertilise – collection manifolds depending on landscape 2. Check and clean requirements filters as required (bore systems) 2. Visually inspect vacuum breakers / air valves are shutting / opening


Quarterly

Annually

1. Adjust irrigation 1. Change batteries in program to suit controller seasonal watering requirements 2. Replace Tech Filter (if installed) 2. Check and clean filters as required 3. Acid rinse bore (scheme systems) systems with iron/calcium problems

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Irrigation Systems


Fertigation System / Venturi Operation 

Mix up you soluble fertiliser in a 9 L bucket. Put the end of the tube into the soluble fertiliser mixture.

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Open Valves A & B that branch off the mainline to allow water to pass through the venturi.

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While a station is running, begin closing the main tap until you can feel that suction has been achieved through the end of the hose. The more the main valve is throttled, the greater the suction. Throttle to a point where it takes approx. 10-15 minutes for the fertiliser solution to be injected. This will ensure that fertiliser reaches all parts of the zone.

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Run water through the station for another 5-10 minutes after fertilising to remove any traces of fertiliser from the driplines.

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Repeat this process for all stations being fertilised.

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IMPORTANT NOTE: When finished, ensure that both ‘branch’ valves are returned to the closed position, and that the main valve is returned to the fully open position.

REMEMBER TO ALWAYS USE SOLUBLE FERTILISER. Earth and Water Pty Ltd

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Fertiliser Recommendations for Residential Gardens To best advise a home gardener on which fertiliser and how much is an easy question, but provides for a wide ranging set of answers and suggestions. The most accurate way is to have a chemical soil analysis done on a say two samples of soil, one for the turf, the other for the garden. This information will provide accurate information as to the balance and availability of nutrients in the soil at that time without any guessing. The average cost per sample is $90.00. If someone can recommend what you require without such an analysis it will only be a “best guess” and possibly only experience been the only supporting suggestion. The following is a general suggestion for some of the organic fertilisers and soil conditioners we promote and sell. Always make sure you cross check any suggestions you are given and ensure the mixtures will not clog the irrigation system, ensure the irrigation filter is in place, make sure the dissolved or liquid fertiliser is free of solids or precipitate. 1. Use Soil Wetting Agents Apply every two months for the first 4 months and then every 4 months thereafter. After two years the non wetting sands will improve as the waxy layer surrounding the sand particles are broken down by the soil wetter. ** Important Note: Use only liquid wetting agents for drip irrigated gardens and turf areas. For best results, apply using a hand held spray dispenser rather than injecting through a fertigation system (if installed). Liquid or granular agents can be used on turf areas irrigated with sprinklers. Application rate: As per manufacturer’s directions. 2. Improve Sandy Soils Regularly add organic matter such as manures, composts, humates and worm castings into the soil. Incorporating inorganic materials such as bentonite clay will also improve the soil’s ability to retain moisture. 3. Soil Organisms - Feed them up The soil micro-flora is the most beneficial aspect of a healthy soil. These organisms work on the minerals and nutrients feeding them to the plants roots. The soil organisms also protect the plants roots from infection and pathogenic attack. In our depleted soils these organisms are in low concentrations. We suggest building up their numbers to create a living soil. 4. Use a mix of Microbes – Garden Microbes Powder 10gms of powder per 10m2 of garden Or


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Grow your own brew, and mix in say 50gms of microbe powder into a 5 litre bucket of water at room temperature, leave the brew overnight and filter through some stockings/ tights to remove the solids. Then irrigate this brew through the dispenser or fertiliser bottle system. Apply 200mls liquid per 10m2 three times a year - Autumn, Spring and Summer. 5. Feed the Microbes – Use Fish and Kelp Mixture – Eco Vital The fish and kelp will feed the soil organisms as well the above the microbes you have just spread onto the garden. Apply 20mls per 10m2 of garden through the dispenser or drip system. Beware it is sticky and smelly. So do not inject too much at a time through the dripper system, slowly inject it. This is also the best way to feed the plants, little and often. Apply with the microbes at the same time, and even mixed together. 6. Feed the plants and Soil Organisms – Liquid Worm Castings A great feeder and stimulant for soil and plants. You might have your own worm farm, use the liquid, filter the bits out first, then use it through the drip system or dispenser. Apply as often and together with the Eco Vital and Microbes. 7. Major Nutrients – NPK (Nitrogen, Phosphorous and Potassium) These are essential nutrients for all plants, in varying concentrations. It requires a soil analysis to indicate the deficiencies and excesses, this information then needs to compared to the plant types nutrient requirements in your garden. 8. Trace Elements – This minor group also play a vital role in plant nutrition, but can only be recommended once a soil analysis is carried out. o

o

Remember pre-mix the fertiliser mix with water to make sure it does not make solids that might clog your drip or sprinkler system prior to use. You should use RPZ valves on scheme water systems

o

Fertilising your Garden – How much fertiliser should I use? How should I mix it?

This is a good question, and one which is misleading because the fertiliser label only tells you how much you need per square metre. Some instructions are misleading and advise you to apply one watering can per 10m of garden. The Procedure 

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Establish what nutrients your garden needs. Then you can decide on the type of fertiliser your garden needs. Ensure the fertiliser is liquid soluble if you are injecting it through the irrigation system


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Ensure the fertiliser is low risk category if injecting through the fertigation system. The irrigation system should have a back flow prevention device, check valve or dual acting check valve to avoid possible contamination of the scheme water supply. In most cases use only organic certified fertilisers / chemicals from your local Nursery. Check the fertiliser is liquid soluble to avoid clogging drippers or sprinkler nozzles.

Calculations How much fertiliser? The amount is according to the manufacturer’s label. For example a great soil wetter called Eco Wet (Organic). The label suggests the following information: -------------------------------------------------------------------------------------------------Eco Wet - Application Rate Soil Wetter

Area

150ml 300ml 450ml

50sqm 100sqm 150sqm

The label then suggests you hose it on using a dilution rate of 1: 50 ---------------------------------------------------------------------------------------------------If you are going to use your fertiliser injector then the calculations as follows: 

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Work out the area to be fertilised off that station, or all of the stations. For example – Station 1 Turfed area = 6 metres x 8.5 metres = 51 sqm Looking at the label you require 150mls of Eco Wet. Check how much fertiliser your injector will suck on station 1 ( the turfed area ) What is the venturi fertiliser suction rate?

To check the suction rate: 

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Fill a graduated container with water, or simply use an old 500mLwater bottle. Fill the graduated container to a known level, say I litre (1,000mL) Start the fertiliser injector sucking by opening the two fertiliser valves and throttling the inline valve to make a change in pressure. Measure the amount of water sucked out of the graduated container over 1 minute.

Note: Most small venturi injectors will suck from 20 litres / hour to a maximum 100 litres /hour. 

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After measuring you might find the venturi sucks 500mL over 1 minute. You have already calculated you need 150mL of Eco Wet for the turf on station 1.


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If you suck straight Eco Wet then you would only suck for about 20 seconds. This is too short a time period and it would not allow the 150mL of fertiliser to be spread evenly throughout the irrigation system for the turf on station 1. Also, if the fertiliser concentration was too strong it might burn the plant roots.

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The fertiliser should be injected over a minimum of 10 minutes.

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Therefore 10 minutes x 500mL injection rate per minute = 5 litres

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Dilute the 150mL of fertiliser into a 5 litre bucket of water. This will ensure the fertiliser is not too concentrated and that it has time to reach all the drippers or sprinklers and distribute uniformly throughout.

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Inject the Fertiliser - Run Station 1 again sucking the fertiliser solution out of the bucket. If the bucket empties and you are not present, no problem, this will not affect the venturi or irrigation system. Rinse - It is a good idea to run a bit of fresh water through the system after the fertigation to rinse out the system to avoid any blockages or fertiliser just sitting in the pipes.

Always make sure you use safe fertilisers, read the manufacturers instructions, use liquid soluble fertilisers and be safe. Use non return valves on scheme water systems.


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Operation and Maintenance Manual - Irrigation Systems

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