A summer water line saves you dragging hoses across the plot: you take water from a tap by the vegetable beds, the gazebo or the outdoor shower. It can be built in a weekend from polyethylene pipe and compression fittings — no welding and no special tools. The key is to plan from the start how you will drain it in autumn.

What the diagram shows

1 — the HDPE main laid with a fall, 2 — a standpipe with a tap on a compression tee, 3 — a drain valve at the lowest point, 4 — the pump or tank by the house.

What you need

  • HDPE pipe, 25 or 32 mm for the main and 20 mm for the branches. Black water pipe is UV-resistant and can lie directly on the ground.
  • Compression fittings: tees, elbows, threaded adapters and end caps. They assemble by hand, come apart and can be reused.
  • Taps for the standpipes, plus one drain valve.
  • A water source: a booster set, a submersible pump in a well, or a raised tank.

Step-by-step installation

  1. Sketch the plot: where the source is, where you need taps and how the main will run. Try to give the pipe a slight fall in one direction, towards the drain valve.
  2. Lay the main on the ground or in a shallow trench. Where people walk or drive over it, bury it deeper or protect it with a board.
  3. Fit compression tees where the standpipes go. Run the branch upwards, fix it to a stake or post and put a tap on top.
  4. At the lowest point, fit a tee with a drain valve, or simply a valve on the end of the main.
  5. Connect the main to the pump through a valve and, if the water is sandy, through a mesh filter. Turn on the water and check every joint.
Tighten a compression fitting nut by hand, then add no more than half a turn with a spanner. An overtightened nut cracks; an undertightened one leaks and can let the pipe pull out under pressure.

In autumn: drain the water

Water left in the pipe will freeze in winter and split the fittings and taps. Shut off the supply, open every standpipe tap and the drain valve — thanks to the fall, the water runs out by itself. You can even take the compression fittings apart for the winter. More on preparing plumbing for the cold in “How to winterise cottage plumbing”.

For watering beds, try drip irrigation. HDPE pipe, compression fittings and taps are in pipes and fittings.