There are many points of entry for water intrusion. Some things can be done by the homeowner to prevent such occurrence. Let’s start at the bottom.
Water should exit the property completely. Many homes only have the yard sloped so that water runs away from the home and into the street. This is actually the best way but causes some problems with regards to certain types of landscape. If water creates a puddle in the yard this is not good. Find some way to get it to exit the yard. Filling some areas will sometimes help get the water to drain away.
Area drains are usually added when the homeowner adds a pool or major landscaping make sure that these drains are check each year before the rains come. Sometimes it is as simple as clearing away debris around the drains. Other times it is necessary to have a professional run a rooter through the pipes to get any debris that was trapped in the pipes. Also, tree roots like water and they tend to find their way into these pipes and sometimes it is necessary to actually remove the pipes to get the roots out.
Planters next to the house collect dirt and debris and also homeowners add extra mulch which brings up the elevation of the soil to a point above the house plate line. Homes are not made to be boats. Water will enter if the level of the water rises above the plate line or the threshold at door entries. Lower the dirt level in planters.
Leaking sprinklers underground can be a big problem as one can not see the water and the water will sometimes penetrate the house slab. Check the street water meter to see if it is running when all fixtures in the house are shut off. Get your landscaper to make repairs as needed.
The exterior of the house comes in many different skins. Many homes have stucco which is usually the least of the products to leak. Some homes have wood or concrete siding. The wood siding is the most prone to leaking as it gets damaged from the sun’s rays and constant watering from sprinklers. Make repairs and keep a good coat of paint on these surfaces.
Windows and doors and dissimilar adjacent materials need to be sealed periodically. Buy a good 40-year caulking sealant and seal all of these areas. If the windows or doors themselves are leaking, then call a professional out to repair or replace them.
Gutters need to be cleaned out periodically so they don’t trap water and also so they don’t deteriorate. Clean time annually.
Roofs have projections for the various pipes to allow gases to escape as well as chimneys. These usually need to be sealed at least every three years. I know most of you have never done it and have been in your home for many years. The water may be running down between your walls and you don’t even know it.
Have an experience roofing contractor serving the roof periodically. Once every three years at a minimum. Be careful if you decide to take on this project yourself. Most accidents in the construction industry or falls are from ladders.
Constant water on wood and other materials causes mold and dry rote to wood. This becomes expensive to remedy.
Good luck and stay dry.