They could perhaps have picked a better day, as it was quite serious – at the stroke of midnight on the 1st of April, 37 district councils and 7 county councils in England ceased to exist, replaced by 9 new unitary authorities. This means people in Durham, Northumberland, Cornwall, Shropshire, Wiltshire, Chesire, and Bedfordshire only have one principal local authority to deal with now. The Wikipedia article on the changes has more information on the background to this change.
Obviously this meant some work for WriteToThem and FixMyStreet, both of which require up-to-date local council information. Our database of voting areas, MaPit, has “generations”, so we can keep old areas around for various historical purposes. So firstly, I created a new generation and updated all the areas that weren’t affected to the new generation. Next, six of the new unitary authorities (all the counties except Cheshire and Bedfordshire, plus Bedford) share their boundaries and wards with the coterminous councils they’re replacing, so for them it was a simple matter of updating those councils to be unitary authorities.
That left Bedfordshire and Cheshire. I created areas for the three new councils (Cheshire West and Chester, Cheshire East, and Central Bedfordshire), and transferred across the relevant wards from the old county councils – basically a manual process of working out the list of correct ward IDs. april2009-update.sql has the gory SQL details if you care.
WriteToThem was now dealt with, but FixMyStreet needed a little more work. The councils that no longer existed had understandably disappeared from the all reports table, so I had to modify the function that fetches the list of councils to optionally return historical areas so they could be included. And lastly, FixMyStreet needs a way of mapping a point on a map to the relevant council. For this, it needs to know the area covered by a council, which was missing for the new authorities I’d manually created. Thankfully, each of the three new authorities are made up of the areas of either 2 or 3 district councils (e.g. Cheshire East is the area covered by Congleton, Macclesfield, and Crewe and Nantwich), so I just had to write a script that stuck those areas together to create the area of the new council. april2009-construct-new.pl. It all seems to work, and I’m sure our users will be in touch if it doesn’t :)
So goodbye to Alnwick, Bedfordshire, Berwick-upon-Tweed, Blyth Valley, Bridgnorth, Caradon, Carrick, Castle Morpeth, Cheshire, Chester, Chester-le-Street, Congleton, Crewe and Nantwich, Derwentside, Durham City, Easington, Ellesmere Port and Neston, Kennet, Kerrier, Macclesfield, Mid Bedfordshire, North Cornwall, North Shropshire, North Wiltshire, Oswestry, Penwith, Restormel, Salisbury (which is getting a new town council), Sedgefield, Shrewsbury and Atcham, South Bedfordshire, South Shropshire, Teesdale, Tynedale, Vale Royal, Wansbeck, Wear Valley, and West Wiltshire. RIP.