Ecological Design Consultants - Water Balance Modelling

water balance modelling

Water Balance Modelling

We conduct water balance modelling to inform decisions about sizing components and about which systems to install. For instance, installing a greywater system can greatly reduce the yield from an existing rainwater harvest system. We can link the results to costing estimates and pricing forecasts to assess the economic merit of different combinations of systems.

Rainwater Harvesting System

We have developed a detailed daily water balance model to inform the decisions about tank sizing, roof collection area, and usage volumes. This analysis ensures you end up with the best combination of tank size and roof collection area. For a sample summary of the output from our rainwater harvesting model click here. (pdf reader required)

The basic rainwater modelling incorporates:

- daily rainfall modelled over 30 years

- irrigation demand varying by month

- irrigation conditional on recent rainfall events. (modelled on a rain sensor response)

- detailed first flush diverter modelling

Complete Water Balance Modelling

Where a combination of rainwater and greywater or blackwater systems are planned, the relative benefit of each system can be assessed by using a water balance model.

Our complete water balance model includes our rainwater harvesting model together with modelling of wastewater reuse, stormwater harvesting, and borewater. The model accommodates occupancy which varies throughout the year as well as separate pool, lawn and garden usage modelling. The modelling can be used to explore what-if scenarios such as different storage size, usage options and back-up options. Treatment systems including reed beds and wetlands can be analysed to investigate potential overflows. The chart below shows a summary of simulated average monthly supply volumes to indoor uses for a development.