Does the eco sac need to sit on level ground?
Yes. The ground under an eco sac® cannot be sloping. It needs to sit on level ground in order to ensure that maximum storage is achieved (water won’t run uphill!) However you do not need to prepare the ground with concrete. The bare earth is sufficient just as long as a paver or brick is put under each leg but so that the top of the paver/brick is flush with the ground.
