If you are planning to install a pool in your backyard, there are a few things you should consider, first. As you probably realize, having a pool is a hazard, especially for children
Many cities require fences of a certain type or height. These may need to surround your entire property, or be built as pool enclosures. There may also be restrictions on the type of gate you are allowed to install in this fence. For example, it may need to be kept locked all of the time. If you do have a gate, consider a gate alarm that will sound if the gate is opened, to let you know that someone may be entering the pool area. Research the local regulations before installing a pool; in most cases, such fencing must be installed prior to the pool itself. Don't commit to the expense of a pool only to later realize that you needed fences or other features to keep your pool from becoming a hazard.
Once your pool has been installed and the fencing is up, you still need to protect the pool from anyone who might inadvertently wander in. This is especially important if you have children yourself, as they will quickly learn how to gain access to the pool. Covering the pool with a hard cover during the offseason is one way to keep young children from falling into the pool. This also protects the surface from falling leaves, bugs, and other debris.
Another way to protect your pool is through the use of a pool alarm. Such devices attach to the side of a pool, and will sound an alarm if anyone should enter the pool before disabling such an alarm. This can instantly alert you to any children or others who have found their way into the pool, and give you enough time to get them out without serious harm. These pool alarms are helpful for families with young children or those in neighborhoods with young children who may not know better than to jump into a neighbor's unattended pool.
For your family and invited guests, be sure to keep flotation devices on hand. These can come in quite handy if you have weak swimmers who want to use your pool. This way, they can stay safe and still have fun. If the depths and size of your pool warrant it, you may also want to keep additional lifeguarding floats on hand in case of an emergency. Even strong swimmers can form cramps after spending some time in a pool.
If you do have children, or a neighbor has small children, be sure to instruct them on proper use of the pool as it is being installed. For example, require them to ask permission before just jumping into the water.
When you are installing a pool, whether above ground or in-ground, you'll want to make sure to consider the safety aspects. Make your pool less accessible for those from your neighborhood, especially children, and have measures in place to make sure that people can not use your pool without your knowledge.