What factors were considered when drawing the boundaries for the councils? Is the population deviance ±1% (like congressional districts in the US), ±10% (like state legislative districts in the US), or something else? (Unless population isn't really taken into account)
The original district council boundaries back in the early 1970s were drawn on the basis of catchment areas around specified towns or cities, although pre-existing county or rural district boundaries often formed part of the boundaries.
For the current round of reorganization, Belfast city was always considered as a unit on its own, but the other districts were to be grouped into 6, 10 or 14 clusters depending on the model being used. While the populations are meant to be
approximately equal, there's no strict limit.
The
districts are the equivalent of counties in the US rather than congressional or legislative districts (referred to in Britain and Ireland as
constituencies). Each district is divided into a set of single-member
wards whose electorates should be roughly equal to the others within the district. The wards are then grouped into
electoral areas of between 5 and 7 seats.