There is a storage area in the basement under the porch shown here. I noticed water coming in during heavy rains and checked the outside wall to see where the water might be getting in. I noticed that the foundation blocks were covered in a layer of cement that seems to have pulled back from the cement block and allowed water to get in behind it (at least I hope this is where the water is coming from ). I started to remove the loose cement and noticed that there's quite a big gap behind it. My question is, what's the best way to patch this up?