Sometimes that low damp spot in the backyard is your septic system. Nothing will ruin one like a weeping willow. But this guy has a big job with the Gubmint and is smarter than me.
You couldn't put a septic field there because it wouldn't pass the perc test. Water goes nowhere. Which is why I planted the 3 weeping willows . . . if you have a horse trough and the horses splash their water and trample up the mud, a few willows right behind the fence will work wonders (and eventually give Dobbin some shade.)
Thank heavens the county put the sewer out here!
We had a septic tank in our old house (IN the City of Atlanta - now we're in the county - go figure!) but I mapped the drainfield when they installed it and marked the edges. (I hate living in a house we didn't build, because I don't know exactly where all the wiring, plumbing, etc. is.)