Doncaster Local Authority Area Model Update
Contents Middle Lower Don Model ...... 1 Upper Humber Model 2016 ...... 1 River Torne Hazard Mapping Study 2018 ...... 2 The River Idle and River Ryton ...... 2 Tidal Trent Model 2013 ...... 2 The Isle of Axholme Flood Risk Management Strategy...... 2
Middle Lower Don Model Location: Don_Dearn section covers from Barnsley & Rotherham to the A1 at Doncaster Lower Don section covers from the A1 at Doncaster to the River Went Don_Rother section covers from Doe Lea to Whiston Brook, Rotherham. Detail: This project reviews the EA flood mapping (i.e. flood zones), investigates defended and undefended scenarios, and takes account of the February 2016 climate change predictions. The defended model is currently being recalibrated in 3 reaches (Rother/Don & Dearne at Rotherham/ Ea Beck to take into account the November 2019 flood. The outputs of this are due early 2021. Timescales: The undefended model runs that inform the flood map were completed and approved in March this year. The majority of the model outputs are now available to use but are subject to change once the calibration is complete. Additional breach modelling to that carried out as part of the Upper Humber was scoped as part of this model package but has been de-scoped due to a lack of funding. The model package is ready to progress but requires funding to be sought.
Upper Humber Model 2016
Location: River Don (downstream of the railway line Barnby Dun). Detail: This study follows a review of the Humber Flood risk Management Strategy after tidal surge experienced in December 2013. The study builds upon previous work by improving understanding of tidal and fluvial interaction, floodplain interactions and the risk from defence breaches. Breach scenarios do not include an allowance for climate change.
Timescales: Complete
River Torne Hazard Mapping Study 2018 Location: River Torne, Hatfield Waste Drain, North Soak Drain and South Soak Drain
Detail: Includes hazard mapping and 2016 climate change allowances.
Timescales: This modelling was completed in January 2019 and is now publicly available.
Note: This modelling should be used in conjunction with the SFRA and critical flood levels (CFL) when proposing finished floor levels.
The River Idle and River Ryton Location: From the head of main river to the confluence with the Trent.
Timescales: Modelling of the River Idle is in the final stages and is programmed for delivery before the end of 2020. Modelling of the River Ryton is expected to be completed by mid-2021.
Tidal Trent Model 2013 Location: Tidally influenced River Trent from Cromwell Lock to Trent Falls
Detail:
Fluvial scenarios: 1 in 5, 1 in 10, 1 in 20, 1 in 50, 1 in 75, 1 in 100, 1 in 100CC, 1 in 200 and 1 in 1000 year AEP fluvial flows with a 1 in 5 year tidal downstream boundary.
Tidal scenarios: 1 in 10, 1 in 20, 1 in 50, 1 in 100, 1 in 200, 1 in 200CC and 1 in 1000 AEP tidal water levels with a 1 in 2 year fluvial flow.
Breach scenarios are available for both fluvial and tidal scenarios and include an allowance for climate change.
Timescales: This model was last updated in 2014.
The Isle of Axholme Flood Risk Management Strategy Timescales: The IoA FRMS was signed off by DEFRA in 2014.