Three quarters of delegates backed a Central Council motion at Congress to introduce the change for the next three seasons.
Teams in Division Three and Four of the League will play in the new 16 team second tier, unless they reach their provincial final.
A Tipperary motion was carried to determine that Tier Two standings will be determined at the end of the League rather than at the start.
New Plan Approved For Greystones Delgany Kilcoole.
Rás Tailteann Returns to Wicklow with Baltinglass Stage Finish
Going For Gold! Wicklow Digital Agency Secures Nominations at the Spider Awards
Relief for 2,500 Wicklow Residents as Rathdrum Boil Water Notice Lifted
Wicklow Hurlers Maintain Positive Form With Impressive Away League Win