Teesdale Flood Risk Identification Study: Joint Validation Modelling Report.pdf

It includes validation modelling to assess the effectiveness of existing flood modelling techniques and data. The study aims to provide an updated understanding of flood risks and inform future management strategies.

## Study Area
The focus is on Native Hut Creek and its catchment, which has experienced significant flooding events in the past (e.g., 1973, 2001, 2011). The study area includes the township of Teesdale and surrounding rural lands.

## Methodology
The report employs a combination of hydrological and hydraulic modelling techniques:
- Hydrology: Utilizes the Runoff, Routing, and Flood Extent (RORB) model to simulate rainfall, runoff, and flood extent.
- Hydraulics: Uses TUFLOW for river flow and flooding simulations, considering topography, roughness, and structures.

## Hydrology
### RORB Model Setup:
- Daily rainfall data from nearby stations is used, with spatial variation considered to reflect microclimates.
- Imperviousness fractions are adopted based on township and RORB extent, influencing runoff generation.
- The model calculates flood depths and extents, with validation against historical events.

## Hydraulics
### TUFLOW Model:
- Covers the entire study area, including Native Hut Creek and surrounding channels.
- Incorporates model parameters like topography, roughness (from field measurements), and structural features (e.g., bridges).

## Validation Runs and Results
The report includes validation runs for three significant flood events:
- February 1973: Modelled streamflow and flood depths at Teesdale Bridge are compared with historical records.
- April 2001: Similar comparisons are made, highlighting changes in infrastructure and land use.
- January 2011: Validates the model's performance during a recent major flood event.

## Summary
The study concludes that the validation modelling provides a robust representation of historical floods, demonstrating the effectiveness of the RORB and TUFLOW models for Teesdale. The report offers valuable insights into flood risks, supporting informed decision-making for flood management and mitigation in the area.