Complete Guide to Drip line

Dripline irrigation is one of the most efficient ways to water your garden, helping to conserve water while promoting healthier, stronger plant growth. By delivering water directly to the root zone, dripline systems reduce waste, improve uniformity, and ensure every drop counts.

Why Choose Dripline Irrigation?

• Precise Water Application: Dripline systems match the water output to the soil’s infiltration rate, reducing runoff and waste.
• Targeted Watering: Water is applied directly to the root zone, minimising evaporation and overspray.
• Highly Efficient: A properly designed and installed system can achieve over 90% water efficiency.

Ideal for Challenging Landscapes

Dripline irrigation is especially effective for areas that are difficult to irrigate using traditional sprinklers, including:

• Curved or narrow garden spaces
• Sloped or steep areas
• Heavily planted beds and borders

Additional Benefits of On-Surface Drip Irrigation

• Eliminates runoff on paths and paved areas
• Prevents overspray onto windows, fences, and walls
• Improves watering uniformity
• Encourages deep, healthy root growth

What Are the Downsides of Dripline Irrigation?

While dripline systems are highly efficient, they do have a few limitations. Because drippers are fixed-output, they may not perfectly suit areas that require different water levels. This can be managed by adding extra drippers where needed, similar to traditional LDPE systems. Visually, dripline can also be more noticeable if installed on the surface across large areas.

Types of Dripline

There are three main types of dripline available, each suited to different irrigation applications:

1. Standard Dripline

The most common type of dripline, designed for surface use. It delivers a consistent water flow without built-in pressure compensation, suitable for smaller, level areas.

2. Pressure Compensating Dripline

These driplines maintain an even water output across varying water pressures and elevation changes, ensuring uniform watering throughout the system.

3. Sub-Surface Dripline

Designed for underground use, sub-surface driplines feature copper shield technology that prevents root intrusion into the drippers. This makes them ideal for permanent or professional installations.

Planning a Dripline System

When designing a dripline irrigation system, consider the following four key factors to achieve consistent and efficient watering:

• Soil Type: Clay, loam, or sand all absorb water differently.
• Emitter Flow Rate (L/h): The amount of water each dripper releases per hour.
• Emitter Spacing: The distance between each dripper on the line.
• Lateral Spacing: The spacing between each line of drip pipe within the bed.

Selecting the Correct Dripline Product

The most important factor when selecting your dripline is the soil type. The table below provides general recommendations for emitter flow rate, emitter spacing, and lateral spacing based on soil type.

For most home DIY systems, a dripline suited to sandy soil is a safe all-round choice when paired with appropriate irrigation timing.

Common Dripline Layouts

Loop or Snake Layout

This layout is common for smaller areas or hedgerows. The pipe is woven back and forth across the area without a dedicated header or footer. You can terminate the line once coverage is complete or incorporate a flush valve for easier winter maintenance. It is recommended to only use up to 100m of drip line in this configuration. 

Tip: Always install an air relief valve when using subsurface driplines to improve system performance.

Grid Layout

Ideal for large or densely planted areas, grid layouts feature header and footer pipes that connect the laterals. A drain or flush valve is typically installed at the footer to simplify winter drainage. This design ensures even pressure and uniform watering across all rows.

Designing Dripline for Slopes

Dripline systems on slopes require special consideration to avoid low head drainage — where water drains out at the lowest point after the system shuts off, leading to overwatering.

• Slopes under 3% need no special adjustments.
• For slopes over 3%, increase lateral spacing by 25% in the final third of the slope.
• Whenever possible, install driplines perpendicular to the slope.
• Consider creating a separate irrigation zone for the lower third of the slope.
• Driplines with built-in check valves can help prevent low head drainage but will require a drain valve for proper water release.

Calculating Equal Lateral Row Spacing

To calculate correct spacing between dripline rows:

1. Measure the total width of the bed in centimetres.
2. Subtract 5cm from any hardscape boundary (10cm if adjacent to another watering zone).
3. Use the emitter spacing from the table above to determine the number of rows.
4. Round up to the nearest whole number and apply the formula:

Row Spacing = Bed Width (cm) ÷ Number of Rows

Example: For a loam soil bed 240cm wide with a 10cm boundary gap:
(240 - 10) ÷ 5 = 45cm spacing between rows.

Calculating Water Requirements for a Dripline Zone

Before installation, always perform a simple flow test to ensure your water supply can support the planned dripline length.

Formula:
Length of dripline (m) × Emitters per metre × Emitter flow rate (L/h) = Total litres per hour

Then divide by 60 to convert to litres per minute.

If your available flow exceeds the dripline requirement, and the installation uses a single coil, you should have no issues with performance.

Other Considerations

• Check your pipe diameter — some driplines are 13mm internally, while others are 14mm. Use the correct fittings and adaptors for your system.
• Use hold-down stakes every 1–2 metres to keep the pipe securely in place.
• Always flush and winterise your system to prolong its life and maintain performance.