Drip Zone Pressure Drop on One Branch: Finding Hidden Restriction

One branch of a drip zone loses pressure while the other stays strong—no visible leaks. A kinked or root-crushed lateral line is the usual culprit.

Isolation Method

1. At a working emitter, note flow.
2. Move to next emitter on weak branch—compare.
3. Work backward toward main poly line until flow drops sharply.
4. Expose poly at that point. Look for kink, rock pinch, or root compression.

Fix

Cut out damaged section. Insert new poly with two barbed couplings and clamps. Use pressure-compensating emitters throughout for uniformity.

Prevention

• Bury poly 6–8" deep (below most roots).
• Use landscape fabric under poly.
• Avoid routing under large trees.

Root damage is the #1 cause of mysterious drip pressure loss. Systematic isolation finds it fast.