We have run drip irrigation to all of our garden beds and mulched them all to try to get water to the right places and keep it from evaporating too quickly.  However the summers get drier every year and we have to wonder if we should be doing something else to provide water for the garden.  I found 2 books that I am reading to try to see if harvesting rainwater during the wet season is the way to go.  I will update on what method we decide to try.  Check out the link to the books we are reading below in case you are also struggling with the same thing.