Situation: residential property rises up from the street about 10 feet in 60 feet to the manifold. When the zone valve is de-energized by the clock, the heads at the bottom of the hill were "running" or "leaking" for about 15 minutes without popping up. When I raised the Hunter rotaries manually they sprayed steady about 3 or 4 feet out, continuously. No master valve, BTW. I figured that zone valve must be leaking a bit and letting enough water thru until it was "ready" to fully stop. Customer didn't like all that water running down the street for 15 minutes so I dug out the dirt filled valve box and changed the guts of the zone valve. That seemed to stop the 3 or 4 foot stream from the low-lying rotary heads after the clock de-energized that zone. But the heads did "run" or trickle for about 4 or 5 minutes. Not any stream but it did trickle-flow water for 4 or 5 minutes. I explained to the customer that this much smaller amount of water is from gravity causing the zone pipes to empty, and it is not a bad zone valve again. Customer called the office complaining about the water trickle. Also they asked if we could "make the water trickle flow up onto the lawn and not down to the curb". (anyone have a physics-of-gravity-changing tool?) The only thing I can think of is that the old zone valve "housing" is a little off with the new guts (it is a gray Irritrol round screw top zone valve). Any way to prove that before I have to digout around the zone box to completely change that zone valve? Maybe just (temporarily) turn off the water feed too when that zone valve is de-energized? If I change the zone valve completely, and those heads STILL trickle/leak/drain for 5 minutes.... any official resources that explains that gravity is draining the zone pipes for a bit? The customer SWEARS that those heads didnt trickle flow last year after the clock shut down the zone.