Conversion of quarterly to monthly figures

The billing data from WAJ are available as quarterly statistics for calendar years. The time-relation between quarters (of the billing table) and months (for the balancing model) is shown in the table below:

Period year quarter month
1st October to 31st December n-1 1 1, 2, 3
1st January to 31st March n 2 4, 5, 6
1st April to 30th June n 3 7, 8, 9
1st July to 30th September n 4 10, 11, 12

The module is splitting these figures into monthly values.

By default, an equal distribution is assumed (each month has a rate of 33.33%). However, the user has also the option to adjust the figures for the first 2 months in a quarter. The third month is than given the remainder:

DR(3) = 100-(DR(1)+DR(2))

For each month, the billed volume is then calculated as follows:

MWUbm(i) = DR(i) * MWUbq / (100)


MWUbm(i) = Municipal Water Use - billed monthly
MWUbq(i) =

Municipal Water Use - billed quartely

DR(i) = Distribution Rate month i for domestic, commercial enterprise and industrial consumers