Winter average

Some agencies use winter averages to calculate sewer charges.

Sewer usage is typically calculated based on a customer's water usage, because some percentage of the water used is drained into the sewer system. Winter averaging is based on the assumption that sewer usage correlates to water usage most directly during the winter. Increased water usage during the rest of the year typically results from activities that don't affect the sewer system, such as watering gardens and filling swimming pools.

In a winter average scheme, an account's average water usage is calculated for the winter months. This average is then used to calculate sewer charges for the entire year.

Because winter averages might be calculated differently for different accounts, you can define multiple winter average details. Each detail defines a particular method of calculating winter averages based on a selected account property. For example, you might select the Account Class property to create separate calculations for commercial and residential accounts. Details can be nested so that more than one property can be used to select the correct calculation.

To create a winter average detail, specify the months to use for the calculation and the way the winter average for new accounts is determined. Select one or more of these options for new accounts:

  1. Copy the winter average from the previous account at the address.
  2. Specify an interim average, which is a default value that is used for all new accounts.
  3. Use the calculated winter average for all accounts of the same class.

The options are listed in order of priority. If more than one option is selected, the priority indicates the order in which they are applied. For example, if the first and third options are selected, then an attempt is made to first use the winter average from the previous account at the address. If no previous account exists, the class average is used.

To set up winter averaging for a sewer service, specify a winter average scheme when defining the service. The winter average calculations are done by a Winter Average task in the Batch Manager.

See Creating a sewer service.