basementdrainagewaterwaterproofing
I have found two small holes in the foundation, near the floor, in the cellar.
Water trickles in through these two holes. I am thinking of plugging them up with spray foam. Are there any possible downsides to this plan?
If plugging up these two holes turns out to trigger some other problem — can the foam be easily removed, so as to restore the flow through those two holes?
If I understand your question and ascii art, what you're looking for is called a bulkhead fitting.
There are a ton of different types: made from different materials, inside thread, outside thread, barbed, one-sided, two-sided, and all different sizes. I'm sure you can find one that is suitable for your application. The big box stores should at least have a few to select from, your local plumbing supplier will have more, and of course you can find anything online.
We had an almost identical situation in a former garage that we refinished to be an office. Our contractor suggested this and we liked the result: he installed a piece of wood about an inch out from the concrete, putting insulation between them and keeping the wood a consistent and level height - a little higher than the concrete. I can't remember if it was pink fluffy insulation or spray stuff. Then a shelf about 6 inches out from the wall - nice and level by being a bit up from the concrete and supported by the vertical wood, and there's insulation under the shelf too. The whole thing is a good looking clear pine and is well varnished.
Looking from the side gives an idea of the distance from the wall:
The shelf runs around the entire room and is remarkably useful for something so low. It hides all the lumpy bumpy aspects of the concrete and while it's not something you see everywhere, no-one has ever mentioned it so it can't be that unusual.
Best Answer
Those two holes are relieving hydraulic pressure and draining the soil outside. If you plug them, the pressure may build up and you could have water coming in somewhere else.
Is the water coming in now going into a sump? Is it wetting the floor and causing high humidity in the "cellar"? It sounds like you might need a French drain outside the foundation to lower the water table around the foundation. But with the current situation maybe you could just fit flexible plastic hoses into the holes and conduct the water to the sump or to a drain.