Press Release – Mother Of All Clean Ups Mother Of All Clean Ups Returns To Christchurch Waterways This Winter With Renewed Energy And A Focus On City-wide Inclusion. The Event Is Held Annually On The First Saturday Of May And Attracts Hundreds Of Volunteers From More Than 40 Local Organisations … Mother Of All Clean Ups Returns To Christchurch Waterways This Winter With Renewed Energy And A Focus On City-wide Inclusion. The Event Is Held Annually On The First Saturday Of May And Attracts Hundreds Of Volunteers From More Than 40 Local Organisations Who Come Together To Remove Tonnes Of Rubbish From Christchurch’s Urban Waterways.