Drip irrigation is a method used to deliver water to vegetation in a regulated and controlled way. Drip irrigation systems help eliminate over- or under-watering plant life. Efficient water management is also achieved using drip irrigation. Systems can be customized for individual areas with proper planning and design. The main consideration for planning and design is the water usage by drip irrigation systems.
Calculate the water pressure per hour needed for the plants; the water pressure per hour is expressed as gallons of water per hour (gph). Calculating gph is carried out by measuring the amount of water used to fill a bucket within 30 seconds from the water supply. The level of water is then converted to decimals and divided by 60 minutes. The total of this calculation is then multiplied by the amount of water collected and that total is multiplied by 60 minutes. The sum of these calculations gives the total gph used by the specific drip irrigation system.
Look for emitters that can regulate the water distribution for the gph of the system. Select the number of emitters depending on the types of plants and proximity to the system. High water use plants such as ferns and fruit require more emitters. Roses and evergreens use low water flow requiring fewer emitters once established. Select the emitter type by their gph rating. Emitters range from 0.5 gph up to 5.0 gph. Select lower gph emitters for perennials and clay soil. Set up emitters with 1 gph rating for shrubs and smaller trees. Reserve the higher gph emitters for larger trees or water-hungry vegetation.
Plan the water use by the system for each area or zone of vegetation. Create a list of plants, their locations and water requirements before the physical layout takes place. Water requirements vary depending on the plant and its age. Keep plants with similar water needs grouped together, creating a zone; this allows adequate water use for the plants in that zone as well as adjustments in water use as the plants in the zone age.
Create a diagram of the garden to to assist with planning water use. Write out a complete inventory of plants within the proposed irrigation area. A map of individual zones or groupings on graph paper is used to place the plant inventory. Place the layout of the irrigation lines on the paper using the shortest route to each area; the ideal design creates a minimal footprint to avoid obstruction while maintaining water usage. Design the secondary lines to reach each individual section, maintaining close proximity to the plant roots. Use curved pieces, "Y" and "T" connectors to route secondary lines that must split into two areas.
High and low pressure emitters cannot be combined within a zone. Emitters with the same gph can be added or subtracted from the zone as water requirements change. Space the emitters and lines to ensure that each plants root system is receiving an adequate water supply.