operation and maintenance manual - irrigation systems

8/10/2019 Operation and Maintenance Manual - Irrigation Systems

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Irrigation Systems Operation and Maintenance Manual

Earth and Water Pty Ltd Page 1 of 12

This Operators Manual has been developed to help you understand the components andworkings of a basic irrigation system, and to assist in servicing and troubleshooting any minorissues should they occur.

1. Water Supply

a) Scheme water systems - Plumbers Retic Cut- In and Mains Isolation Valve

For scheme/mains fed systems, water will usually be sourced near the water meter at the frontof the property. Close to the water meter, a licensed plumber will cut in to the main watersupply to the house, and will install a dual check / non-return valve and an isolation valve readyfor the irrigation system.

In some cases, the cut-in and isolation cannot be located near the water meter, and may needto 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 theirrigation 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 ifyou are experiencing problems with starting your bore.

2. Master Solenoid Valve

The Master Solenoid Valve (located near the water meter) protects the garden and lawnsolenoid valves from being pressurised when the controller is off and avoids wasting water ifone 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 ofthis will be explained by your commissioning installer.

4. Filtration

Filters removed unwanted solids such as sand from entering the system. The filter elementsshould be inspected and cleaned every three months. Simply take the element out, separatethe 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 havebeen installed on your system, it is recommended that the filter element be replaced at leastevery 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 than300kPa of pressure is downstream of this device, maintaining a constant pressure andeliminating the chance of drip fitting blow outs due to high pressure.


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6. Irrigation ControllerThe controller automates irrigation events by turning on and off solenoid valves for particularzones for a set time and on a set date as per the programme. Further information on controlleroperation and programming can be found in the enclosed manual.

7. Station (Zone) Solenoid ValvesStation solenoid valves supply water to the various areas of your garden. All of the solenoidvalves, including the master valve, are wired up to your controller that, when automatically ormanually activated, will turn on one of the lawn or garden Solenoid Valves and the MasterSolenoid 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 thesolenoid 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 dirtwhen that zone is turned off. When the zone turns off, the water in the drip line seeps out, asthis volume of water lost it is replaced by air entering through the air release valve.

10. Dripline LateralsFrom the sub main drip line laterals are fed in parallel lines covering either an area under thelawn or under the mulch in the garden beds.

11. Collection / Flushing ManifoldAt the end of the drip line laterals is the Collection or Flushing Manifold. The drip lines areconnected into this poly pipe for the purpose of flushing.

12. Manual Flushing ValvesA manual valve will be located in a round valve box with a green lid. The valve needs openingwhile the system is operational once per month for around 1 minute to release any foreignparticles that might have entered the system. This flushing process ensures that the filter onthe back of the drippers does not get blocked.


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The Standard Drink

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

Table 1: Calculations for Standard Drink Runtimes

DriplineType

NominalFlow Rate@100 kPa

(L/hr)

Dripperspacing

(m)

Row Spacing(m)

ApplicationRate (mm/hr)

Min. runtime toapply 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 RotatorSprinklerNozzles

NominalFlow Rate@ 250 kPa

(L/hr)

Spacing (variable)Head to head coverage

Radius of throw(180 degree)

ApplicationRate (mm/hr)

Min. runtime toapply 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 Dripper Flow Rate: 3.5 L/hro Dripper spacing along dripline: 30cm (0.3 metres)o Spacing between runs of dripline: 40cm (0.4 metres)

Application Rate (mm/hour) = Volume (L/hr) = 3.5 L/hr = 29 mm/hr Area (m2) 0.3m x 0.4m

Example 2:

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

Application Rate (mm/hour) = Volume (L/hr) = 4.0 L/hr = 66 mm/hr Area (m2) 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


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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 filterelement.

IMPORTANT: Ensure system is not runningand/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.

Pull apart the discs of the filter.

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.

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

Expose the dripline to find the break in the

line.

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.

Insert a straight barbed joiner into one end

of the dripline.

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.

Make sure the joiner is fully pushed into

either end of the dripline.

Flush out any sand through the flush valve.


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Recommended Maintenance Schedule

Monthly Bi-Monthly Quarterly Annually

1. Manually Flush allcollection manifolds

2. Check and cleanfilters as required(bore systems)

1. Fertilise depending onlandscaperequirements

2. Visually inspectvacuum breakers / airvalves are shutting /opening

1. Adjust irrigationprogram to suitseasonal wateringrequirements

2. Check and cleanfilters as required(scheme systems)

1. Change batteries incontroller

2. Replace Tech Filter(if installed)

3. Acid rinse boresystems withiron/calcium problems

Manual Flushing Points

In each area you will have a ball valve (tap) in a

round green box as a flushing point.

Remove the box lid and with the system

running open the tap.

Let the water flush through for a minute

until the water runs clear before shutting

the tap then replace the valve box lid.


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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.

Open Valves A & B that branch off the

mainline to allow water to pass through the

venturi.

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.

Run water through the station for another

5-10 minutes after fertilising to remove any

traces of fertiliser from the driplines.

Repeat this process for all stations being

fertilised.

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.


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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, butprovides 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 tothe balance and availability of nutrients in the soil at that time without any guessing. Theaverage cost per sample is $90.00. If someone can recommend what you require without suchan analysis it will only be a best guess and possibly only experience been the only supportingsuggestion.

The following is a general suggestion for some of the organic fertilisers and soil conditioners wepromote and sell. Always make sure you cross check any suggestions you are given andensure 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 twoyears the non wetting sands will improve as the waxy layer surrounding the sand particlesare 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 afertigation system (if installed). Liquid or granular agents can be used on turf areas irrigatedwith sprinklers.

Application rate: As per manufacturers directions.

2. Improve Sandy Soils

Regularly add organic matter such as manures, composts, humates and worm castingsinto the soil. Incorporating inorganic materials such as bentonite clay will also improve thesoils 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 onthe minerals and nutrients feeding them to the plants roots. The soil organisms also protect theplants roots from infection and pathogenic attack.

In our depleted soils these organisms are in low concentrations. We suggest building up theirnumbers 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 atroom temperature, leave the brew overnight and filter through some stockings/ tights to removethe 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 justspread onto the garden.

Apply 20mls per 10m2 of garden through the dispenser or drip system. Beware it is sticky andsmelly. So do not inject too much at a time through the dripper system, slowly inject it. This isalso 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 theliquid, 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 soilanalysis to indicate the deficiencies and excesses, this information then needs to comparedto the plant types nutrient requirements in your garden.

8. Trace Elements This minor group also play a vital role in plant nutrition, but can onlybe recommended once a soil analysis is carried out.

o Remember pre-mix the fertiliser mix with water to make sure it does notmake solids that might clog your drip or sprinkler system prior to use.

o 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 youhow much you need per square metre. Some instructions are misleading and advise you toapply one watering can per 10m of garden.

The Procedure

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. Theirrigation system should have a back flow prevention device, check valve or dual actingcheck 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 manufacturers label.

For example a great soil wetter called Eco Wet (Organic). The label suggests thefollowing information:

--------------------------------------------------------------------------------------------------

Eco Wet - Application Rate

Soil Wetter Area

150ml 50sqm300ml 100sqm450ml 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:

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 sqmLooking 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:

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 theinline 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.

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 tooshort a time period and it would not allow the 150mL of fertiliser to be spread evenlythroughout the irrigation system for the turf on station 1.

Also, if the fertiliser concentration was too strong it might burn the plant roots.

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

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

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 thedrippers or sprinklers and distribute uniformly throughout.

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 venturior irrigation system.

Rinse - It is a good idea to run a bit of fresh water through the system after thefertigation to rinse out the system to avoid any blockages or fertiliser just sitting in thepipes.

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

operation and maintenance manual - irrigation systems

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