Interesting - I have never heard of dew ponds before.
Like you said, you have dry air there. It might work in your cooler seasons - not sure about summer.
Also - other than as an interesting feature (which it certainly would be) - what is the goal of the pond? How does it stack functions with other parts of your plan? What functions would this element support and who are it's cohorts in supporting these functions?
One thing I've found it's easy to lose sight of, particularly on larger pieces of
land, is the interrelatedness of
permaculture design.
Something you might try to do to figure this out is to do an element analysis - like the now infamous "permaculture chicken" drawing.
--find out what a dew ponds needs are (certain humidity level, temp level, area/volume, way to keep the dew in one location, etc). Is there a naturally wetter area on the property that might slow down evaporation in your dry air? Like say where a downspout vents, or AC condensate drips?
--determine if you have a place where this would fit - like perhaps under some
trees that would drip dew into the pond from their leaves AND protect the water from quickly evaporating later in the day...
--determine the
energy needs in terms of the time, effort and materials to create it and the yield/payoff in the system.
Now granted I live in a harsher dryland than you do. And I've found that certain things are a waste of my time in Phoenix (raised beds, for example, except for wicking beds) but I have certainly tried my share of experiments and learned a startling amount from them. The ongoing result is that I have a much, much deeper appreciation for how a dryland functions and have been stacking elements and functions more in line with my climates needs and have stopped trying to create something that resembles gardens I've had in much wetter climates like Wisconsin or France. I would have never gained these insights if I didn't experiment. And I
think understanding drylands is going to be one of the critical skills of the next 50 years as more and more land is desertified.
So I say try it if it piques your interest and keep good records on why you did what you did and what worked and what didn't and SHARE it so we can all learn from your
experience. Please! =)