How can I save my pond and prevent it from drying up?

There is a large (about 120 feet around), man-made pond on my property. I live in El Cajon, San Diego County, California where it barely ever rains. I could tell it was at it’s maximum depth two years ago because the water level even with the pipe drain. We have a rainy season here that lasts for three months then it doesn’t rain until the following rainy season. We had a pretty dry rainy season and a hot dry season last year. My pond is down about five feet. The current rainy season seems to be another dry one. I feel like the pond will dry up over the summer. There are a lot of fish, birds and other animals that depend on the pond for living.

Is there any creative ideas to fill the pond or maybe get more out of the little rain we get?