The mechanism is erosion, not the water itself. Over months and years, a steady leak in granular soil removes support from under a footing.
Where subsidence is suspected, insurers routinely require a CCTV drainage survey as part of the investigation, because ruling drainage in or out changes the whole remediation approach.
If you have both cracking and a known drainage defect, deal with the drainage promptly — the structural repair will not hold while the cause is still active.