Public Service pensions such as the Local Government Pension Scheme are increased to take account of increases in the Consumer Price Index.
The movement in the Consumer Price Index during the 12 months to the previous September determines the Pension Increase that is applied in April to the pensions in payment and deferred pension benefits, keeping them in line with the cost of living.
The Consumer Price Index to September 2017 was 3%; this means that for your April pension, you will have 8 days at your old rate and 22 days at the new rate. The new monthly amount will commence from May 2018. Please note, if your pension commenced payment after 24 April 2017 you will usually only receive a partial increase.