Leaky window needs sealing

[Bodrey]

Two summers ago, I had rain water seeping into my basement through one of my windows. The wood frame was rotted. So, I replaced all of the pieces and reinstalled the window. All has been well ever since until a few days ago. We had a wicked downpour. The next day, I went into the basement to do laundry and once again discovered rain water seeping in through the bottom of the window. So, it seems it was never sealed properly (the flashing) and in the 2 years since we just hadn't had a rainfall big enough to cause water to seep in. It's hard to tell from the pic but if you look closely you can see the gap between the window opening and the bottom piece of flashing. I've already been in touch with a guy who says he can re-flash it for $150. I'm pretty good with my hands and mechanically inclined. So, I'd like to try and fix the issue myself if it's possible. Does anyone have any suggestions on how I can fix this problem? The gap is not huge. I could probably secure the bottom piece of flashing to the window opening using Tapcon screws and then use silicone sealant on the lip of the bottom piece of flashing. Or, perhaps install something that's weather/rot-resistant between the lip of the bottom piece of flashing and the window opening for it to brace up against and then seal it with silicone. TIA for your advice/ideas.

 

[ekrig]

I'm not sure that you need screws at all but it is hard to see from the photo. I can't see silicone on the bottom edge, so maybe that's all that it needs.

The photo seems to suggest that there is a driveway or ramp next to the bottom edge though. If that's the case, I would think of ways to prevent the water in that from ever getting close to the window. Given enough of it and enough time, water tends to find a way in. So, the best is to reduce the amount of water around the window first, get whichever amount that does get there drained further away as quickly as possible, and the sealing to handle the rest.