Irrigation System for Home Landscape Developed by: Dr. Teri Hamlin Georgia Department of Education

Planning Before installing a permanent irrigation system, you'll need to: – See if your locality requires a building permit. – Check for underground utilities before digging. – The North America One Call Referral Service at connects you to a national directory of utility companies. – Research your local municipal watering ordinances.

Planning In order to purchase the right components, you'll also have to determine your own specific: Water pressure in pounds per square inch (psi). Water meter size (for a municipal system) or well pump size (for a well). Water service line size. Water flow rate in gallons per minute (GPM). Type of backflow prevention required by local code.

Determining Water Pressure Working Water Pressure PSI (pounds per square inch) Local Municipality source

Determining Water Meter Size Imprinted on Meter Meter Size: 5/8”, ¾” or 1” Well water source obtain pump size

Determining Service Line Size To match the size of irrigation pipe to your existing water service, you'll need to know the size of your incoming supply line. To do so: – Get a piece of string. – Wrap it once around the water pipe. – Measure the length and compare to the given chart.

Conversion Pipe Chart String Length2 3/4"3 1/4"3 1/2"4"4 1/8"5" Type of Pipe Copper ¾”1”1 ¼” Galvanized ¾”1”1 ¼” PVC (sch. 40) ¾”1”1 ¼” Service line size is in Italics

Determining Flow Rate This is measured in gallons per minute: – Get a container that has a measurable or known capacity. – Turn on the water. – Record the time it takes to fill to a measurable level. – Divide the filled container size (in gallons) by time (in seconds) it takes to fill it. – Multiply it by 60 seconds. The number you get is the flow rate in gallons per minute (GPM). (Multiply that number by 60 if you need to determine gallons per hour).

Determining Flow Rates Examples: – A 3-gallon bucket takes 15 seconds to fill. – 3 ÷ 15 = 0.2 – 0.2 x 60 = 12 GPM or 720 GPH. – A 4-gallon bucket takes 30 seconds to fill. – 4 ÷ 30 = 0.13 – 0.13 x 60 = 7.8 GPM or 468 GPH.

Determining Backflow Requirements Refer to local ordinances for backflow prevention requirements Prevent contaminated water getting back into main water supply Most require a double check value at point of connection

Mapping Out the Irrigation System Things to Consider: – Flower beds or mulched areas – Trees – Sidewalks – Fences and other man-made features – Slopes – Areas of sun and shade These factors and the GPM will determine the number of zones needed – A zone (or circuit) is an independently contained set of pipe and sprinkler heads.

Mapping Out Irrigation System Measure and plot property to scale on graph paper. The map should include the house and all permanent landscape features. Mark on the map where the water meter is located.

Mapping Out the Irrigation System Mark on Map: – Landscape features – Prevailing winds – Slopes – Manifold location – Electric, Gas & Water Lines

Mapping Out the Irrigation System

Coverage Goal: 100 % coverage Overlap Spray Pattern Head to Head Coverage

Head Selection Amount Coverage Needed Type of Plants Height of Plants Type of Heads – Pop Up Style Heads – Shrub Sprinklers Mixing head types in one zone decreases efficiency. – Always use the same type of head for each zone. – GPM will determine number of heads per zone

GPM will determine number heads per zone

Primary Parts of Irrigation System Valves open and close pipes to allow watering of each zone. Head styles vary based on the water requirements of the plantings and your water supply. Sprinkler heads are rated according to the GPM they can supply water at your particular psi. Risers connect pipe to sprinkler heads. Fittings or couplings, such as tees and elbows, connect and redirect pipe.

Primary Parts of Irrigation System A manual control should be able to maintain several areas with differing needs. A backflow preventer is an anti-siphon device that's required in most areas. Timers allow presetting of the on/off function of the system. The valve manifold is the master control of the system. Pipe choice depends on the region you live in. You'll use either PVC or polyethylene pipe.

Which Pipe Do I Use? Polyvinyl chloride (or PVC) pipe Most commonly used in Georgia Polyethylene More flexible and used in colder climates Installation: Pipe puller or trench area

Digging Hand Trencher 8-12” deep Heads retract underground Before you dig: – Stake out line location – Flag head location

Assembly Connecting PVC Pipe – Cut the pipe to length. Make your cut straight so the pipe is fully seated in the fitting. – Insert the pipe into the fitting and adjust to the correct position. Mark the pipe and fitting with a reference line to make it easy to find the position again after you have added the cement. – Remove the pipe, clean the surfaces, brush both the outside of the pipe and the inside of the fitting with hot glue/cement. – Push the pipe into the fitting with the marks 1/4 turn apart. Twist the pipe to align the marks. This spreads the cement and makes a bead along the edge of the fitting. The bead should extend all the way around the pipe.

Connecting Heads Most heads thread onto riser Important to flush debris from line before connecting heads Install swing joint riser to give your head some flexibility upon impact

Selecting Nozzles For slopes and compacted soils, select a nozzle with a lower precipitation rate. For windy areas, select a nozzle with a low nozzle outlet trajectory. To achieve even water distribution without having to separate part-circle from full-circle sprinklers, select a nozzle set that features a matched precipitation rate. For flexibility with spray heads, select a nozzle with an adjustable or variable arc.

Connecting the System to the Service Line 2 ways – Connect valve to existing outdoor faucet – Connect directly to service line – Steps: Shut off water supply B/W Main shut off and house cut 1” section out of service line Install compression tee fitting and additional valve to allow the system’s water supply to be controlled independently

Install Backflow Value Prevents – Water being siphoned back into supply – Reverse pressure – Chemical from lawn to enter water supply

Control System One control value per zone A manifold groups the values Timer controls zone Know number of zones needed before selecting a timer Programmed frequency and duration of watering

Sprinkler Maintenance – Plants need minimum of 1” water per week during growing season: how long do you run your sprinkler to get 1” water? Place rain gauge under each zone and time – Routine check for clogged heads – Winterize: blow out residual water