Gravity-Fed Drip Irrigation: Will 1-Inch Header Supply Seven 300-ft Runs?

System: 10 psi gravity feed from a tank, ½ gph drip tape at 10 psi per 100 ft. Seven 300-ft runs (2,100 ft total) off a 65-ft, 1-inch header supplied by a 2-inch main.

Pressure Loss Reality

Friction loss in 1-inch pipe at ~10 gpm (7 runs × 300 ft × 0.5 gph/100 ft ≈ 10.5 gpm) exceeds 10 psi over 65 ft. With only 10 psi static head, there’s insufficient pressure to operate the tape uniformly, regardless of header size.

Solution

Add a small booster pump with a pressure tank and switch to maintain 12–15 psi at the header. Gravity alone won’t work for this layout.