Why should compound wall foundations be deeper on filled or low-lying Bangalore plots?

Filled or low-lying ground, common near old tank beds or drainage channels in certain Bangalore localities, generally has lower bearing capacity than firm, undisturbed soil, which can cause a shallow compound wall foundation to settle unevenly or crack over time. A soil assessment, even a modest one for boundary wall purposes, is worth doing on plots where ground conditions are uncertain rather than assuming a standard foundation depth is sufficient everywhere.