Basement gets flooded when it rains
I have lived in this house for three years and the first year we had no problem with the basement flooded after it rains whether it was an hour or a week. The person who lived in this house before us always put his grease in the sink and the second year we had about 6 inches in the basement after it rained the drains would not work. We had a plumber come in and use a professional snake and it took out the grease build up in the pipes but ever since then our basement gets flooded. We just finished with three days of constant rain and got about 6 inches of water in our basement. We have put a sump pump in one drain that does drain very slowly but the other two drains don't work at all. This house was built in the 1950's I believe. Can you help me in finding a reason why the two drains don't work and the one drains slowling even after using a professional snake? Thank you.