Locating the Leak

We have a saying that irrigation leaks will always show themselves in due time.  Therefore it was quite a mystery when the pump station by #5 green began cycling frequently to maintain pressure, yet no leak could be found. 

Based on the amount of water we were losing, we knew that there was exactly one gallon per minute flowing...someplace.  With 25 miles of pipe in the ground, that may not sound like a whole lot of water loss, but it equals over 1,400 gallons per day--something we'd expect to find pretty quickly. 

After isolating various sections of the system we were able to narrow the source of the leak to the irrigation loop around #5 green.  Now we only had a few hundred feet of pipe to check, but once again, still couldn't see any water bubbling to the surface, or turf that felt like quicksand.

A green surrounded by water made locating the leak difficult.

At this point, we speculated that water could be making its way back into the lake, however with the green surrounded on three sides by water, the question of how to determine the exact location still had us scratching our heads.  The thought of using an indicator dye occurred to us, but we needed to get the dye just into the greens loop, and not the miles of pipe which the pump station supplies. 

The solution was to use the quick coupling valves we typically hook into when handwatering the greens.  We shut the isolation valve to #5 green, relieved the water pressure, hooked a portable air tank to a quick coupler to remove water, poured some dye into a second quick coupler, then opened the isolation valve and re-pressurized the green's irrigation loop.

The tools used to get dye into the irrigation loop at #5 green.

Within an hour, we had our answer, and the mystery of where the water was going had been solved.  Sure enough, the point of least resistance for the leaking water was not coming to the surface of the ground as we typically see.  Instead it was making its way into a drain line near the front of the green, which exits into the lake.

The dye seeps into the lake from the drain line.

The 2" PVC irrigation pipe and corrugated 4" drain line run perpendicular to each other, so the place to start digging was where the two pipes cross each other.

The completed repair.

When the pipe crossing area was exposed, it was easy to see why the water never made it to the surface, as the perforated drain line and surrounding pea gravel took this water straight to the lake.  

The actual source of the leak was a glue fitting which had gone bad after 25+ years.  All in all, a relatively simple fix--once we knew where to dig.