J Jay is right. However, you always don't have to wait for rain.
Depending on where you live, the solution will vary. In the hills of PA, we use french drains and let gravity do its thing.
Since you know where the water is coming in, you can experiment with a garden hose. This will take two people. One outside with the hose, and one inside ready to yell "that's it!"
Begin with the gutter and downspouts. Run water into the gutter for 1/2 hour and see where it goes. Then move onto the next suspect area. For example, you may have a patio that funnels the water towards the house instead of away and when the storm comes from a specific direction then it happens (a flooded basement).
Water often comes into a basement above the block at ground level becuase of something simple being overlooked. Mat need calking under a sliding glass door. May need calking between cement porch and brick at house. Once you troubleshoot the leak, its usually easy to fix.
Before doing major excavation, do some troubleshooting first. It could save you $8,000