Hello, we have recently bought a house on a slope. It has a room at the ground level opening to the backyard built on a concrete slab. The front is higher and opend onto the front yard. The front is partly built on concrete stumps. With a lot of rain lately a lot of water has been seeping through under the house in the crawl space where the stumps are but this water then drains under the slab foundation as that's where the slope is. What's the best way to solve this problem? We had a plumber come have a look. He suggested installing a sump pump in the space before the water reaches the slab. Quoted $5000 for it. Is this the right solution. Will all this water affect the foundation and eventually move it and cause cracks in the house? Please advise. Jo

He suggested installing a sump pump in the space before the water reaches the slab
And that's the only option you were giver? Shame on the plumber.
You should have been told about french drains or a Do it yourself dry well, (see image) A french drain directs the water away while allowing the water to percolate back into the soil. These are passive installations that require no power or maintenance Regards, Tom

Speedball has a good answer but here's another possible sollution. Go uphill about 10-15 ft. from the house and build a gentle berm(hill) that arcs around the house. The water should divert around the house. At the base of the house, do the French drain and that will catch the water that falls inside the berm. Put some trees on the berm to anchor it.