Candidiates for County Councils run in local districts known as Local Election Area (LEA).
The boundaries of these areas are set from time to time by the Local Area Boundary Committee (Click Here for the website of the Boundary Committee.) The last revision was in 2018.
They are set nationwide following a review of the data from each census to ensure that the number of electors to each Councillor is kept within certain limits across the country. They also accept submission before they make recommendations to the relevant Minister.
In total there are 30 councillors elected to Mayo County Council
The Boundary Commission publish a report outling the changes in advance of each election. These reports are available on their website.
Following the most recent revision of the boundaries in Mayo in 2018 the following are the LEA’s and the number of councillors elected from each LEA :
Ballina – 6 seats
Belmullet – 3 seats
Castlebar – 7 seats
Claremorris – 6 seats
Swinford – 4 seats
Westport – 4 seats