Okay, we have stopped procrastinating, and hired a contractor to work on the flooding problem. They are excavating along the front length of the house, and will seal the whole foundation with a series of super-duper high-tech materials to prevent future flooding.
But you have to also address the fundamental problem, and it's fascinating to see what previous attempts are revealed as the excavation goes deeper into the ground. (See how I'm making this sound like a positive experience?) There was some kind of tar applied to the house, but either it wasn't very well done, or it just disintegrated over the years. There is also a long French Drain, which is a good idea, but was incorrectly done. (See my earlier comment on incompetence.) There are holes in the foundation itself, apparently from bolts which rusted over the years.
You have to respect the flow. The water is not going away. The rains will not stop. And the house will (we hope) continue to sit on the side of a hill. So you have to plan for those things, and accomodate as well as you can. We will replace the French Drain with a properly built one, possibly expanded to cover more area. That seems to be the best way to spread the water around over a larger, deeper area. And the series of insulations they're applying should protect the foundation from the inevitable moisture. And the trees which had to be removed will be replaced with more appropriate bushes, placed a little further away from the house.
The cost of respect? Pretty much the same as the cost of disrespect: astronomical. And rising each day. Sigh....
(Painting: "The Sound of Many Waters" by J.E. Millais)
10 hours ago