Long term leakage such as this is possible because underground leakage will follow the path of least resistance. This means that a sewer line, an abandoned main, rock fill, or a drainage tile leading to a pond will accept the water preventing it from surfacing in the street where it would be noticed and then repaired.
40 Years of Leakage
No evidence of a leak
This drainage ditch collected pond overflow.
Pond Overflow
It tested negative for chlorine.
The abandoned service line was discovered.
Abandoned service line leaking for 40 years
Pond fed by city water
Daily fish food - loaf of bread and can of pellets
Next day the pond is receding
Today the former pond has been filled.
The ten gallon per minute leak accounted for 5.25 million gallons of water per year. This adds up to 210,000,000 gallons over 40 years. Watch the feeding the fish movie.
