u/Linkums

Haruko's Vespa from FLCL

And also an original "mystical" Swerve Star inspired by Noita's unsolved eye puzzle.

Here's a video as well to demonstrate how fast the water was flowing in: https://www.youtube.com/watch?v=5DJRTo0wWOA

Facts

• House is an old rowhome.
• Basement flooded for the first time in 3 1/2 years, after several days of on and off rain.
• After cleanup and drywall removal, we found that the water had come in from the front basement wall and wrapped around the edge of the room on the raised concrete behind the drywall before entering through the drywall in the corner of the room and adjacent room.
• There was mud and dirt, 2" deep at its deepest, totaling ~115lbs., between the front-facing brick wall and drywall / wood studs, and in a gradient down to the water's final entry point through the drywall in the adjacent bathroom.
• Our road has had multiple sinkholes patched over the years. Our neighbor reported that she believed one to be forming in front of our home back in February. There is also evidence that our sidewalk has dropped 3/4" over some amount of time (due to the gap from where it was previously sealed beneath the basement window).
• About 4 weeks ago, our neighbor noticed a small hole open up in the road along the curb. (Now patched with quikrete.)
• When water flowed into the hole in the road, it also flowed into our basement (see video). The waterproofing panels and mud was still there at this point, so we could not see the precise entry point.
• We haven't noticed any water entry after patching the hole in the street, even after heavy rain.

Here's what I want to know:

• How'd all that mud (and water) get in? One guy says its from the drainage system under the house being clogged, and the water and mud pushing up from below, between the brick wall and concrete floor. He suggested digging up the perimeter of the basement and installing their better drainage system. Or, maybe he's wrong and it somehow came through the brick wall somewhere?
• Would it be worth somehow poking through the patched hole in the road to pour water in again and try to deduce if it's coming through the wall or up from below? How might I do penetrate the quikrete patch?
• What should we do about it? Is it necessary to replace the drainage system as "the guy" recommends? Or are we good as long as the road is patched to not funnel half the block's water right at our basement wall?