Can someone help me decide if this will work for building a 27' round pool.

The site is a shallow valley.

I was thinking of raising the elevation of the pool by excavating only the high sides and filling in the low by laying construction blocks with a tile (to catch the water in the lowest area) covered with gravel and topped with sand. Will this work and has anyone done this before? I do not care about the overall height of the pool since the deck will make up the height.

If this would work - what diameter would be needed for construction?

thanks in advance for all answers

Be sure of yourself before doing this. A 27' above ground pool weight about 144,000 lbs. Any building up you do will have to be able to support it. That's the reasong it's always recommended to dig the high side out and not backfill the low side. It can be done but has to done correctly. If the "valley" collects or diverts any water, that will undermine any backfill you put there.

Yes, dig the high side down. Building up the low side is not a good idea.