Suffice it to say that stormwater management can be a Big Deal in Arizona as well. Even the DOT sometimes gets it wrong: when the news shows floating cars in Phoenix, it's quite often the I-17 where it crosses Greenway[1].
Fortunately for Culdesac, the area they're in is mostly flat and won't accumulate runoff from mountains, and is near canals and Tempe Town Lake (the Salt River), so they're probably pretty safe. Also developers were allowed to build Anthem about 45 minutes north in a wash. A coworker who just moved there mentioned today that he saw his neighbors' cars float by last week when it rained. So sadly your latter sentiment does seem to be in full force out here. But probably not in that area of Tempe.
Fortunately for Culdesac, the area they're in is mostly flat and won't accumulate runoff from mountains, and is near canals and Tempe Town Lake (the Salt River), so they're probably pretty safe. Also developers were allowed to build Anthem about 45 minutes north in a wash. A coworker who just moved there mentioned today that he saw his neighbors' cars float by last week when it rained. So sadly your latter sentiment does seem to be in full force out here. But probably not in that area of Tempe.
[1] https://www.google.com/search?tbm=isch&q=greenway%20underpas...