Actually, February is the best time to schedule irrigation work for the upcoming dry season.  Most people wait until it is an emergency, a July emergency!  Here is a compromise:  take care of your irrigation in May before it becomes urgent.

If you have a functional irrigation system, now is a good time to fix leaks and conduct minor retrofitting to make your water use more efficient.  Try updating with a pressure compensating drip system with check valves.  This reduces wet spots close to the valves and at low elevations.  Water saving spray nozzles such as the MP rotators are great for reducing run-off with their low precipitation rate.  These are modifications that can save on your water bill and improve the health of the plants in your garden in a quantifiable way.

Check out Netafim and MP rotators for more information.