​​​​​​​Current Welsh Government guidance is to undertake a formal S.19 investigation report when there have been 20 or more incidents of internal property flooding.
Canllawiau presennol Llywodraeth Cymru yw ymgymryd ag adroddiad ymchwiliad ffurfiol A19 pan fo 20 neu ragor o achosion o lifogydd mewn eiddo.