Installing & Maintaining Irrigation SystemsMs. 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? 1st 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 5- 7.5 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

Sprayhead Rotating

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