I am finally opening my new pool for the summer. What are my responsibilities as a homeowner?

Having a pool creates increased liability risks for homeowners. There is no doubt about that.  Many homeowners do not want pools for that very reason.
The obligations imposed upon homeowners can be found in the Occupiers Liability Act of Ontario.
Simply put, you have a duty to ensure that your premises are safe, properly maintained and free of hazards. This duty also applies to activities carried out on the premises.  If you breach this duty and someone is injured as a result, you may be liable. You are not held to a standard of perfection as a homeowner but one of reasonableness. What is reasonable depends on the specific circumstances of each case.
Examples of hazards which can cause injury and may attract liability include uneven decks, lack of proper signage, broken diving boards, broken ladders, improper or insufficient lighting, slippery surfaces, lack of safety equipment and unsupervised pools.
If someone is injured on your property, your homeowners liability policy should respond and cover you for any claims that may be brought against you.
Drowning is one of the leading causes of death in children. If you own a pool, supervise children at  all times. Keep them safe this summer!