Drip irrigation is a water conservation method designed to deliver moisture directly to the root zone of plants in a controlled, low-volume manner. The system releases water slowly, often measured in drops, unlike the wide-area spray of traditional sprinklers. By targeting the application point, drip systems significantly reduce water loss caused by surface runoff and evaporation. This localized delivery ensures plants receive a consistent and measured supply of water beneath the soil surface.
Essential System Components
A functional drip system requires a specific series of components working together, beginning at the water source. The first component is the backflow preventer, which ensures water cannot reverse direction and contaminate the household water supply. Following this is the filter, which removes fine sediment and debris from the water stream. Filtration is necessary because the final exit points are tiny, preventing persistent clogging that would render the system inoperable.
The next component is the pressure regulator, which is necessary because municipal water pressure (40 to 90 PSI) is too high for drip components. This regulator reduces the incoming pressure to a safe operational range, typically between 15 and 35 PSI. The regulated water then enters the main distribution line, usually a larger diameter polyethylene tubing. Smaller distribution tubing, often one-quarter inch in diameter, branches off the mainline to reach individual plants.
The final component is the emitter, or dripper, which restricts water flow to a slow, measured output. Emitters are rated by the volume of water they discharge, measured in Gallons Per Hour (GPH), with common rates ranging from 0.5 to 2 GPH. These devices are inserted directly into the tubing near the plants. The system is completed with various fittings, such as tees and elbows, used to connect the tubing and customize the layout.
The Mechanism of Water Delivery
The system’s operation relies on the precise control of water pressure and flow rate. The pressure regulator uses an internal diaphragm and spring to absorb high pressure from the source. The diaphragm compresses the spring in response to high inlet pressure, restricting flow and maintaining a constant, low output pressure, often preset to 25 PSI. This consistent low pressure is distributed throughout the tubing network.
Water moves through the tubing at a slow, steady flow, unlike the turbulent, high-velocity flow found in conventional pipes. This low-pressure environment allows the emitters to function correctly. Inside the emitter, water is forced through a long, narrow, winding channel (a labyrinth path) or across a flexible diaphragm. This physical restriction creates resistance that slows the water’s speed.
Pressure-compensating emitters use an internal diaphragm that flexes to maintain the specified GPH output despite minor pressure fluctuations. This ensures plants at the beginning and end of a line receive the same volume of water. The water exits the emitter as slow, consistent drops, saturating the soil directly around the root zone. This slow application rate allows the soil to absorb moisture fully, preventing surface runoff and deep percolation losses.
Planning and Installation Steps
Implementation begins with a detailed design phase to ensure efficient coverage. Users first map the area, noting the water source and grouping plants with similar water requirements into specific zones. This planning determines the total flow rate needed for each zone by multiplying the number of required emitters by their GPH rating. The total GPH must not exceed the capacity of the water source to prevent system pressure failure.
The physical assembly follows a sequential order, starting at the water spigot. The backflow preventer, timer, filter, and pressure regulator are connected in series before the mainline tubing begins. This tubing is rolled out according to the mapped design, using tee and elbow fittings to route the line around corners and obstructions. The tubing is secured to the ground using stakes to hold the network in place.
Once the mainline is laid out, the final step involves placing the emitters near the plants. A specialized tool is used to punch holes into the polyethylene tubing at the desired locations. Barbed emitters are pushed directly into these holes, or a smaller distribution tube can be connected and run to the plant base. Before activating the system, the end caps are temporarily removed to flush out any debris or dirt that entered during installation. After flushing, the end caps are secured, and the system is pressurized and checked for proper emitter function and leaks.