Cynhaliwyd 'lansiad anffurfiol’ o fersiwn newydd o Nodyn Cyngor Technegol (TAN) 15, ynghyd â’r Map Llifogydd ar gyfer Cynllunio ar 28 Medi, cyn eu cyhoeddiad ffurfiol arfaethedig ar ddydd Mercher 1 Rhagfyr 2021. Ers y lansiad anffurfiol mae rhai Awdurdodau Lleol wedi codi pryderon ynghylch y canllawiau a'r map newydd arfaethedig.
A ‘soft launch’ of a new version of Technical Advice Note (TAN) 15, accompanied by a new Flood Map for Planning, took place on 28 September, ahead of their planned formal publication and coming into full effect on Wednesday 1 December 2021. Since the soft launch some Local Authorities have raised concerns about the proposed new policy advice and map.