Installing & Maintaining Irrigation Systems

Installing & Maintaining Irrigation SystemsMs. GripshoverLandscapingUnit 15Our ObjectivesObtain site information and determine irrigation requirements.Determine water capacity and pressure.Select sprinklers and establish spacing ranges.Establish sprinkler circuits and install valves.Locate controllers and size wiring.Prepare the final irrigation plan.How can students read the site plan and interpret it to determine the irrigation requirements of the landscape?Climate is the major influence of the water needs of plantsEvapotranspiration (ET)- the loss of water from plant tissue, soil, and soil surfaceAffected by: relative humidity, solar radiation, day length, temperature, and even windIrrigation- supplying water to land through artificial meansUsually clean enough to drink however, in some parts of the country waste water is used for irrigation to conserve good waterUsing Automated IrrigationIrrigation allows you to use water in the most economical wayBeing aware of weather, soil types, and plant knowledge assures correct usage of waterUsing a site plan allows the landscaper to recognize the types of plants Allows for proper placement of sprinkler heads as well as flow rate of h20Automated systems save water because it applies only the amount of water neededIf pesticides/ fertilizer that are used are soluble they can be applied through the irrigation system saving timeHow is the water capacity and pressure of a project determined?1st we must know the GPM or gallons per minute and the PSI or working pressure at the point of connectionStatic water pressure- the PSI in a close system with no water movingDetermined using a direct pressure gauge reading or calling the water companyMost sprinkler heads need 3GPM to operateWorking water pressure- a.k.a. dynamic water pressure, PSI at any give point in a system as a given amount of water moves past Can be affected by gravity, friction of the inside of the pipes, length of pip, grade changes, number of sprinkler heads3 calculations should be made to determine PSI and GPMThe pressure loss through a water meter should not exceed 10% of the minimum static pressureMaximum flow should not exceed 75% of the maximum safe flow of the meter Water meter flow chart will be neededVelocity of flow should not exceed 5- 7.5 feet per secondA loss chart for the type and size of piping will be need for this calculationHow can students select and locate sprinkler heads for maximum benefit and coverage?Two main categories of irrigation: sprinkler and trickle1. Sprinkler- when spray heads or rotating sprinklers are used to water plantsSprinkler heads are determined based on:Size/ shape of areaType of plantWater pressure/ flowSoil typeYou want to use as few sprinkler heads as possible to save moneyTwo types of sprinkler; spray-head and rotating Sprayhead- emits a single or double fan type pattern of water Used for small areas or targeted plantings and have a relatively short spray rangeExample: greenhouse Rotating- nozzles that rise and revolve to distribute waterHave a much larger spray rangeHigher operating water pressure is needed

Sprinkler IrrigationSprayhead

Rotating

How can students select and locate sprinkler heads for maximum benefit and coverage? (cont.)

Two main categories of irrigation: sprinkler and trickle2. Trickle irrigation- bubblers, emitters, or drip irrigation devices are used to waterUsed to conserve water

Placement of Irrigation SystemsOnce equipment is chosen, proper spacing needs to be determined3 major spacing patterns Triangular patter- used where area has irregular boundaries Square pattern- used when there are equal sides running betweenRectangular pattern- used to fit areas with defined straight boundaries and cornerDetermining the Amount of Water DeliveredPrecipitation rate- water delivered to the landscape, usually expressed in inches per hour, used to make sure necessary amount of water is deliverFormula used is 96.3 X GPM S X L96.3 IS THE CONSTANT WHICH INCORPORATES THE INCHES PER SQUARE FOOR PER HOURGPM is the total gallons per minute appliedS is the spacing in feet between sprinklesL is the spacing in feet between rows

How are sprinkler circuits set up and the required valves placed for an installation project?Sprinkler circuits- add the GPM of each head togetherEach circuit is called a valve groupCannot exceed the system flow limitValves should be located near the center of the sprinkler group to balance flowMainline- line from water source to the valveLateral pipe- line from valve to sprinkler headIrrigation System Set- Up

How are sprinkler circuits set up and the required valves placed for an installation project? (cont.)Backflow prevention device- prevents contamination of drinking water by not allowing the irrigation water to flow backward into the water supply

How are controllers effectively placed and suitable wiring sizes chosen?Irrigation controllers- the electrical devices used to regulate and control the sprinkler systemControls which days it will water, how long it will water, and what time it will waterWhen multiple controls are use, in is best to group them together for easier controlStation- a single electric switch in an irrigation controllerRuns a solenoid valve on or offThe Final Irrigation PlanA diagram representing what the irrigation system should look like after installation