Water and wastewater tariff components (adopted from Hoque & Wichelns 2013)
| Tariff component . | Description . |
|---|---|
| Basic service charges | |
| Fixed charge | An annual or monthly fixed amount with no minimum consumption requirements. The charge typically depends on the size of the meter and covers infrastructure and account maintenance costs. Water and wastewater fixed charges can either be combined or separate. |
| Minimum charge | A fixed amount, typically monthly which allows for a free minimum water consumption quantity. |
| Volumetric water charge | |
| IBT | A charge per unit volume increasing stepwise according to the level of consumption. |
| DBT | A charge per unit volume decreasing stepwise according to the level of consumption. |
| Constant unit charges (CUCs) | A charge per unit volume, which remains the same for all levels of consumption. |
| Seasonal charge | A charge per unit volume, which changes according to the time of year accounting for peak (summer) and off-peak (winter) demands. Can be IBT, DBT or CUC. |
| Wastewater or sewerage charge | |
| Volumetric charge | The volumetric charge can be either IBT, DBT or CUC. |
| Flat | A fixed percentage of the water bill usually less than 100%. This could also be considered a volumetric charge but in the case of a flat rate, the per unit volume charge is not specified. |
| Additional components | |
| Conservation or pollution tax | A charge to account for shortage values of water or environmental externalities (i.e. wastewater discharge downstream effects). This is usually a fixed portion (%) of the total water bill. |
| Stormwater or property drainage charge | A monthly or annual fixed charge that varies according to property size, with the aim to account for the fact that rainwater falling on a paved surface ultimately discharges into public sewers, and increases the volume of wastewater treatment required. |
| Water resource development fee or capital contribution | Utilities may impose a temporary fixed charge on consumers to earn revenue for infrastructure development and expansion. |
| Tariff component . | Description . |
|---|---|
| Basic service charges | |
| Fixed charge | An annual or monthly fixed amount with no minimum consumption requirements. The charge typically depends on the size of the meter and covers infrastructure and account maintenance costs. Water and wastewater fixed charges can either be combined or separate. |
| Minimum charge | A fixed amount, typically monthly which allows for a free minimum water consumption quantity. |
| Volumetric water charge | |
| IBT | A charge per unit volume increasing stepwise according to the level of consumption. |
| DBT | A charge per unit volume decreasing stepwise according to the level of consumption. |
| Constant unit charges (CUCs) | A charge per unit volume, which remains the same for all levels of consumption. |
| Seasonal charge | A charge per unit volume, which changes according to the time of year accounting for peak (summer) and off-peak (winter) demands. Can be IBT, DBT or CUC. |
| Wastewater or sewerage charge | |
| Volumetric charge | The volumetric charge can be either IBT, DBT or CUC. |
| Flat | A fixed percentage of the water bill usually less than 100%. This could also be considered a volumetric charge but in the case of a flat rate, the per unit volume charge is not specified. |
| Additional components | |
| Conservation or pollution tax | A charge to account for shortage values of water or environmental externalities (i.e. wastewater discharge downstream effects). This is usually a fixed portion (%) of the total water bill. |
| Stormwater or property drainage charge | A monthly or annual fixed charge that varies according to property size, with the aim to account for the fact that rainwater falling on a paved surface ultimately discharges into public sewers, and increases the volume of wastewater treatment required. |
| Water resource development fee or capital contribution | Utilities may impose a temporary fixed charge on consumers to earn revenue for infrastructure development and expansion. |