Hi Eric,

I've seen and remarked the same! How 'bout the following -

(1) use an above ground sensor to detect rate and duration of
rainfall,
(2) do not allow sprinklers to begin cycling if rain is falling,
this logic is equivalent to delaying artificial rain based
on the potential for future rain of 'sufficient' quantity
AND duration,
(3) determine what sufficient duration means to get rain through
taller (read denser, hence more water adhering to the plant
leaves and less getting to the ground) plants like trees
and bushes,
(4) determine what sufficient quantity means to get rain through
taller ...,
(5) If the rain quantity and duration is sufficient AFTER the
rain stops don't water.

Determining what sufficient means may be as simple as placing a couple of small cans and an oscillating sprinkler in strategic locations and 'simulating' rain. Place one can in an 'open' area and another under a bush of tree of concern. Vary the rate at which water is delivered from the oscillating sprinkler to simulate the rate of rainfall.

Cheers,

Bruce