Sump installation and tweaking

I've been in my home near (but not too near) Lake Champlain for 28 years and this is the second time I've had a water problem in the basement. The first time was in 1993 at the previous recent record lake level of 101.86 ft. This time we peaked at about 103.3 ft and are still above 102 ft. Flood stage is normally 100 ft. We've been above 102 ft for about a month now. Heavy and frequent rains have compounded the problems. The soil is just plan saturated.

Two weeks ago a contractor friend dropped by, cut a hole in the basement floor, dug out some coarse sand, and put in the proverbial 5 gallon Ace bucket, because that's what we had on hand. I'd been using a small utility pump up until then, so first we put it in the bucket on some bricks to get some relief, then later that day I installed a regular sump pump, plumbed it in, etc.



I know it's a Mickey-Mouse installation, but as I said, this is the second time in 28 years and I haven't considered basement water a normal fact of life. My plan has been to get through the immediate problem and see what happens next spring, in case heavy flooding has become the new normal.

This hasn't cured my water problems, though it has helped control them. Prior to installing the pump we topped out at just under an inch in spots. After installing the pump we've been topping out at about 1/2 inch in those same spots. I suspect if basement water is the new normal, I'm in for cutting and trenching around the inside perimeter and all that stuff. But assuming that this is just a record high, I'd rather not get into all of that.

But I'd still like to make it a little better than it is, if possible getting that extra half-inch or so of water relief that would give me a dry basement. The soil is all basically a fairly coarse sand, and it kind of flows with the water. Getting the original hole done was quite a mess, with the water coming up into the basement while they dug. Since the sand does flow, I was hoping to put off further digging for a better installation until the lake level fell and it would be more stable. However since that last half inch has been so stubborn, I think I need to do something sooner rather than later.

In coarse sand, is it possible to say how much further down I'd have to dig in order to drop the water table that critical half inch about 15 feet away? (Is it even possible?) The pump starts running when the water is 8 inches below the basement floor and drains it to 12 inches below. It's rather fast cycling by any definition of the word, and I recognize that as a problem if this is to be a long-term situation. About a week ago I shut the sump pump off for 15-30 minutes in order to move the outlet, and the water seemed to stabilize at about 2 inches below the floor. (below the top of the concrete, above the bottom)

I do have a larger bucket I can install, recognizing that the increased diameter will at least help the cycling frequency some, in addition to reaching for a little more depth. Is there advice for digging in flowing sand? I'd been thinking in terms of trying to shove a piece of plywood down as I dig under the leading edge, so it would hold things back somewhat.

Thank you for any advice or suggestions.

We had to lower a 60" diameter by 5' high cast iron basin into flowing sand years ago. We had to put 4x4 posts at the corners with 2x8 planks on the outside. As we dug down we drove the posts deeper and slid the boards down. We could only get it within 3" of the finished floor, so we filled it with water to keep it from floating. We also placed heavy metal "clips" over the edges and into the concrete, when the floor was poured so it could not float when the pumps emptied it.