I have this situation, and wanted someone's opinion.


  • Concrete foundation basement, slab floor
  • Weeping tiles and a sump pump is present / operational
  • The house is near a pond.
  • Grading is alright, all downspouts are extended a couple of feet away from the house.
  • NO LEAKS in the basement floor is dry.

When it rains - the Sewer Back Flow Preventer valve access hole fills up with water. It seems like water collects below the weeping tile - as the backflow preventer is installed lower in the ground.

I'm guessing the water either is getting under the weeping tile or it's ground-level water.

I was thinking of running pipe under the slab to the Back Flow Preventer access hole connecting it to the sump basin and letting the gravity keep water in check and draining it.

But this is not an option... but I managed to run the pipe under the slab and connect it to a self-priming pump with a float switch.


A) My questions is this a good idea to manage the water under the slab?

B) Should I be concerned about washing out clay while pumping water and undermining the foundation?

C) Should I stick the pipe with a strainer deep in gravel to get as much water as possible, or just, pump water that is above the gravel? ( This would I think remove the least of the clay particles )

Appreciate any feedback, is this a good or bad idea?

Thank you! Water Mgmt


1 Answer 1


It is the most practical one, better than breaking a lot of cement and making a sump pit.

As for trying not to wash the clay off, you submerge your pump in a cavity lined with coarse sand and a layer of gravel on top of the sand.

The smaller the pump the better it is, or if you can put a valve on suction to restrict the flow.


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