Quantifying, managing and communicating the differences in storm overflow spill data between EDM outputs and hydraulic model predictions

Published On 14/11/2023

The project aims to analyse and address the discrepancies in storm overflow spill data between event duration monitor (EDM) outputs and hydraulic model predictions.

Such hydraulic modelling is used for strategic planning through Drainage & Wastewater  Management Plans (DWMPs) and the Water Industry Natural Environment Programme (WINEP), and initial data analysis has found significant differences between modelled and measured spill counts.

The primary focus of the report is quantifying, managing, and effectively communicating these differences for better understanding and decision-making.

Recommendations include:

• A standard approach to comparing EDM and model predicted spills should be adopted which standardises EDM data processing, model procedures, rainfall data, and spill
  counting methods
• EDMs must be proactively maintained
• Water companies should not apply a volume threshold when counting the number of spills predicted by a model
• Sufficient time in the early stages of Storm Overflow

Assessment Framework (SOAF) investigations – or other overflow investigations – must be granted to gather and analyse data effectively.

The report concludes that if these recommendations are implemented it will lead to greater alignment between measured and modelled spill data. 

This project is part of Big Question 6: How do we achieve zero uncontrolled discharges from sewers by 2050?. Atkins was the main contractor and the Project Steering Group was formed of representatives from across the water industry. Project Lead was Paul Tipper, and UKWIR’s project manager was Linda Hustler.

For more information on the full report - Quantifying, managing and communicating the differences in storm overflow spill data between EDM outputs and hydraulic model predictions 23/SW/01/25 visit this link