Rio Communities is a young city on an old river, wide streets laid out under a very big sky. In late summer the monsoon comes through in the afternoons and the grass answers within days, which is when a mowing schedule earns its keep. Tierra Grande Improvement Association handles that stretch — regular cuts, close trim work, cleanups that take the storm litter out of the grass before it settles in. Kept up, a lawn here can carry a whole street's worth of green. Left alone for a month in August, it can't.