We're considering buying a house with a driveway that slopes toward the garage. It's a double car garage built in the 60's with a narrow drain the width of half of it that isn't draining, and with the crazy rain Seattle's been getting, the water has gotten all the way into the basement. So far we've been told two different things: install a sump pump (not sure where) or put a trash pump in a bigger drain in the driveway which would drain into the storm drain. I clearly have no idea what is the best option, but do not want to buy a house whose water issue cannot be fixed. Any suggestions?
1. Get some pictures so you can negotiate a price reduction with the seller.
2. Figure out how you could drain the water away to a sump/catch basin outside the garage before it gets there. Then, put a pump in the catch basin. You will want to divert as much as you can before it gets there, perhaps with a small hump that will keep it away from the garage door.
3. Calculate how much water you will have to pump to keep it from getting to your garage/basement. 1" of runoff per hour from 1000 square feet is about 11 gallons per minute. Calculate your runoff area and put in a pump that will handle at least 1" of runoff per hour.
4. Remember that power outages often accompany heavy rain. If you need to pump to stay dry, you may want a generator to run the pump if power fails.
B4 you can get a price reduction on the home you need to get 3 estimates on the cost of correcting the problem. It could be far more than you think.