Move from totals to places
A regional population forecast does not show which main, reservoir or pressure zone will carry the demand. Link planning horizons to development areas and customer categories. Document the spatial allocation method, source date and uncertainty in the timing of connections.
Reconcile the starting point
- Align billing periods, bulk flow data and demand zones.
- Separate existing consumption from committed but unoccupied development.
- Check large customers individually and avoid double counting planned growth.
- Track losses and efficiency changes as explicit assumptions.
Keep GIS and models aligned
A changed supply-zone polygon does not necessarily change the operational boundary or reallocate demand in a hydraulic model. Check the software workflow, customer links, boundary valves and zone totals after an update. Retain an auditable comparison with the previous baseline.
Test alternative trajectories
Compare plausible development sequences and peak-demand conditions. A delayed growth area can change staging without removing a long-term need. Pair GIS quality checks with demand forecasting and investment triggers.
Sources & further reading
- Best Practice Modelling Guidelines ↗eWater · 2011
External source · Checked 24 September 2026 - QGIS: a free and open-source geographic information system ↗QGIS Project · Living documentation
External source · Checked 24 September 2026 - InfoWorks WS Pro overview ↗Autodesk · Living product documentation
External source · Checked 24 September 2026
Source findings are distinguished from editorial interpretation. Apply current local criteria and project evidence when making engineering decisions.