I've seen rain water-collecting devices that don't rely on gutters or downspouts if that's a direction you'd like to go. I try to limit supplemental watering as well but I will make exception for the few veggies I grow. Or - if we've gone through a hot, rainless period that we've just come through (so early in the season). My rain barrels were empty and I had to rely on city water which I prefer not to do but when plants are drooping, water is water.
