To keep your basement walls from getting any moisture, it’s important to waterproof them. To do that though, you must first figure out exactly where they need to be waterproofed from both the outside and inside. So look around the entire perimeter of your home to double-check that the earth slopes away from your foundation, not towards it. Otherwise, you will need to add dirt to create that effect. Also check to make sure your gutters have nothing blocking them, and your downspouts are at least five feet away when discharging moisture.
In new house construction, be sure there are drains installed at footing level, sloped between one and two inches per 10 feet, to direct water away from the house. As you backfill the trench, apply waterproof membranes to the foundation wall. That will help to prevent against moisture buildup, which can damage the basement. In an existing house, you can still dig drainage ditches and install waterproofing membranes or chemicals as above.
To waterproof from the inside, apply a coating of concrete waterproofing material, which will usually penetrate up to 12 inches of previously untreated concrete. If other waterproofing chemicals have been previously applied, it will be less effective. Once the material penetrates, it expands and seals the concrete pores. It was designed originally to work from the inside out on foundation walls, but works equally well from the exterior.
While chemicals will help block water movement through concrete, they do not stop the hydrostatic pressure of groundwater, which is constantly pushing against the foundation wall. Installing perimeter drain lines relieves that pressure. You can install French drains or anything other kind of deep drain that will receive the water during the storm and lead it to the street and away from the foundation of your home.