Hello Deb! There may be so many different reasons why you have a leak at the foundation of a house. It could be the way the landscape is graded around the home, no rain gutters, a crack in the foundation, heavy rain, etc. Give us a bit more information or a picture to get some good suggestions!
If it is leaking into the basement you may need french drains...digging and directing the water away from the house.
Where is the leak coming from, Deb? If it's a pipe, it needs to be repaired. If it's coming from outside, you may need to change the grading of the ground around the foundation. Also gutters and downspouts will keep water from accumulating near the foundation.
This is one of those times I recommend you call in a plumber immediately for a professional opinion. The foundation supports your entire house and you don't want it to weaken from water. And you don't want to spend money on quick fixes that may not be effective. Your issue may also be covered by HO insurance if it was the result of a one time damage, not lack of routine maintenance