Drought by Bert Kaufmann
Be sure your plants have a good layer of organic mulch to retain as much moisture as possible.
If your town does not allow watering your garden during the drought period there is not much you can do. People and animals come first.
If you are allowed to water, remember that the best time to water is in the early morning hours before the sun comes up and temperatures start to rise. Water as close to the ground as possible so that the water gets to the roots of the plants. Water deeply, not superficially. If you cannot water early, next best is to water after the sun goes down in the evening. Again water close to the ground. If water stays on the leaves, fungus can grow – that is why morning watering is best for the water to evaporate off any watered leaves. (see here)
If you are considering an irrigation system, consider a drip or soaker hose system.  This system allows little water lost to evaporation or run-off, so the system delivers more water to the roots of plants where it’s needed. Soaker hoses are good for your garden, the environment and are economical.  If you do have a “traditional” sprinkler irrigation system, consider installing a smart “irrigation” controller that senses the weather in your area and adjusts the water flow accordingly.
Install a gutter water collection system for the days when rain will once again fall. If you are handy you can build your own rainwater collection system.   Or you can add a rain barrel to your existing system. There are many rain barrel choices on the market that are becoming more attractive as more people use them.
If your town allows it, save and use your greywater or graywater. Graywater is household water that was used for washing, bathing or cleaning- NOT water from the toilet. I try not to pour any water down the drain if I can, but save and use it on my flowers- even though where I live water has not yet been restricted. Water is a precious commodity and we should all start conserving it before we are mandated to do so. If you are not sure about the safety of gray water, read this website on how to be sure the water is safe for your plants.
If you have recently planted new trees and shrubs and want an easier way of watering them, consider tree watering bags. One company that makes them is treegator. You put a treegator bag around the trunk of the tree, fill it with water and the water is slowly released into the root system of the tree or shrub.
Remember if you have a limited supply of water to use, save your most expensive trees and shrubs by watering them first. Grass is pretty, but that can be easily replaced. If you are not sure how to water trees or how much water trees need, read this website.
Good luck.