I think the base wall of your house needs protecting with a wall of blue bricks on the lawn side.
Then a trench dug, and filled with gravel to enable the water to drain down, under the house wall.
Best consult your local Council experts, not any Tom Dick or Harry.

Sorry. Forget that. A copy of Building Regulations can be found in your local Reference Library. All Councils employ a Buildings Inspector. His job is to visit all properties under construction to make sure each phase conforms to Building Regulations.
He is the man you need to find.
I am sure he will be pleased to help you find the right solution to the problem of your sloping lawn, and water eventually damaging your property by it.
Its a serious matter.

When we first married we moved into a new build and during one particular downpour, found a river running down the back garden perilously near to the back door. The builders had to come back and put a French drain in at the top of the garden to catch the water before it reached the houses. Its the same trench that Diane is talking about and it worked.