Operating Cost

The operating cost application, whose authors are practitioners working in three companies, Veolia, DSConsulting and RetencjaPL, with comprehensive knowledge, experience and data in the field of shaping, using and financing stormwater infrastructure, allows for a quick and, at the same time, possibly precise calculation of the costs of maintaining drainage and water retention systems rainwater along with the calculation of the rate of potential charges for rainwater.

This is the first application addressed to managers of rainwater drainage systems: waterworks, municipal companies, city authorities interested in making the conditions for maintaining rainwater systems more realistic or introducing charges for rainwater and assessing the conditions in which this process should be carried out.

The application available in Poland.

Operating cost calculation

Data needed for calculations:

  • property tax [PLN net/year] – the value of the property tax paid related to the drainage and retention system (typically 2% of the value),
  • water service fee [PLN net/year] – primarily the fixed fee and the variable fee transferred annually to PGW Wody Polskie,
  • energy costs on facilities [PLN net/year] – annual energy costs on the drainage and retention system facilities,
  • asset depreciation [PLN net/year] – total value of annual asset depreciation and costs of leasing the drainage and retention system infrastructure,
  • average annual rainfall [mm] – average value of the annual rainfall total,
  • area falling on the sewage system [ha] – the area from which water flows into the drainage system,
  • annual increase in area hardened [%] – the value determines the annual increase in the hardened surface over a 10-year forecast period,
  • calculation method [PLN net)] – one of the two methods of calculating fees from system users should be indicated: from the value of the outflow in m³ or from the value of the sealed surface in m²,
  • collectibility of fees [%] – collection of fees is typically assumed at 80%.

Existing infrastructure – characteristics and failures

In the next step, you should provide all cost-generating elements and determine their number, length or size.

This refers to all closed systems (e.g. wells, separators), open systems (retention tanks, culverts, embankments), pumping stations, but also their failure rate, current condition and maintenance costs. To obtain good results, you should provide all elements and information meticulously.

Żarówka Make a projection of the operating costs of the storm sewer network and calculate the operating fee.

Calculation results

Based on the information provided, a calculation is performed and the results are presented in the form of a PDF report.

The report includes:

  • a summary of the entered data about the system,
  • the area weighing on the sewage system,
  • the assumed collection of fees,
  • the costs of maintaining the system,
  • fees for water services,
  • asset depreciation.

The calculator results can be used for:

  • comparing the costs of maintaining the system with market standards,
  • analyses related to planning new infrastructure,
  • calculating the value of the order in system maintenance procedures,
  • as support for organizational changes consisting in changing the entity carrying out tasks in the field of rainwater and meltwater management, including in-house mode,
  • preliminary estimation of the introduction of fees for rainwater.
Operating Cost