Installing & Maintaining Irrigation Systems Ms. Gripshover Landscaping Unit 15

Our Objectives  Obtain 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 plants  Evapotranspiration (ET)- the loss of water from plant tissue, soil, and soil surface  Affected by: relative humidity, solar radiation, day length, temperature, and even wind  Irrigation- supplying water to land through artificial means  Usually clean enough to drink however, in some parts of the country waste water is used for irrigation to conserve good water

Using Automated Irrigation  Irrigation allows you to use water in the most economical way  Being aware of weather, soil types, and plant knowledge assures correct usage of water  Using 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 h20  Automated systems save water because it applies only the amount of water needed  If pesticides/ fertilizer that are used are soluble they can be applied through the irrigation system saving time

How is the water capacity and pressure of a project determined?  1 st we must know the GPM or gallons per minute and the PSI or working pressure at the point of connection  Static water pressure- the PSI in a close system with no water moving  Determined using a direct pressure gauge reading or calling the water company  Most sprinkler heads need 3GPM to operate  Working 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 heads  3 calculations should be made to determine PSI and GPM  The pressure loss through a water meter should not exceed 10% of the minimum static pressure  Maximum flow should not exceed 75% of the maximum safe flow of the meter  Water meter flow chart will be needed  Velocity of flow should not exceed feet per second  A loss chart for the type and size of piping will be need for this calculation

How can students select and locate sprinkler heads for maximum benefit and coverage?  Two main categories of irrigation: sprinkler and trickle 1. Sprinkler- when spray heads or rotating sprinklers are used to water plants  Sprinkler heads are determined based on:  Size/ shape of area  Type of plant  Water pressure/ flow  Soil type  You want to use as few sprinkler heads as possible to save money  Two 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 range  Example: greenhouse  Rotating- nozzles that rise and revolve to distribute water  Have a much larger spray range  Higher operating water pressure is needed

Sprinkler Irrigation SprayheadRotating

How can students select and locate sprinkler heads for maximum benefit and coverage? (cont.) Two main categories of irrigation: sprinkler and trickle 2. Trickle irrigation- bubblers, emitters, or drip irrigation devices are used to water Used to conserve water

Placement of Irrigation Systems  Once equipment is chosen, proper spacing needs to be determined  3 major spacing patterns  Triangular patter- used where area has irregular boundaries  Square pattern- used when there are equal sides running between  Rectangular pattern- used to fit areas with defined straight boundaries and corner

Determining the Amount of Water Delivered  Precipitation rate- water delivered to the landscape, usually expressed in inches per hour, used to make sure necessary amount of water is deliver  Formula used is 96.3 X GPM S X L  96.3 IS THE CONSTANT WHICH INCORPORATES THE INCHES PER SQUARE FOOR PER HOUR  GPM is the total gallons per minute applied  S is the spacing in feet between sprinkles  L 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 together  Each circuit is called a valve group  Cannot exceed the system flow limit  Valves should be located near the center of the sprinkler group to balance flow  Mainline- line from water source to the valve  Lateral pipe- line from valve to sprinkler head

Irrigation 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 system  Controls which days it will water, how long it will water, and what time it will water  When multiple controls are use, in is best to group them together for easier control  Station- a single electric switch in an irrigation controller  Runs a solenoid valve on or off

The Final Irrigation Plan  A diagram representing what the irrigation system should look like after installation