Have done a bit in Aus' (Canberra last season was interesting!)
As others have said ... sometimes the helo is the only (best) way and they are effective. Realy works best when supported with good ground crews though. One thing I noted though was that the "heavy lifters" can & do cause a lot of damage at times with topsoil stripping. On steep terrain, dumping several tonne's of water in a concentrated area has quite an impact on the topsoil. Not an issue when weighed against life & property, but is when "environmental conservation" is the point.