Northumbrian Water

1. Northumbrian Water Ouseburn Flooding - Brunton Park Meeting 17th January 2006

2. Introductions Les Hall – Investment Delivery Team Leader

3. Presentation Topics: - • Flooding 2005 – An Overview • Progress to Date • Key Findings • The cause of flooding on 30th June 2005 • Growth • Future Plans • Timescales

4. Sewer flooding – significant events • 2005 – significant sewer flooding events Contact numbers 14/15/16/17 April 376 19 June 70730 June 312 13 August 207 31 August 7649 September 275 12/13 October 220 24 October 232

5. Sewer flooding – monthly contact

6. Sewer flooding – daily call volumes

7. DG7 operational contact breakdown 2004/05 2005/06

8. Acomb Crescent, Fawdon - Progress to date – Operations • CCTV of 3 km • Sewer Cleansing almost complete (3 km) • Flap valve installed on Surface Water Sewer • New Grill and safety railings installed on Overflow • CSO chamber de-silted as part of regular maintenance programme

9. Acomb Crescent, Fawdon - Progress to date – Investigation • Independent consultant appointed - Entec • Entec have visited site and spoken to some residents to understand floodmechanisms and establish all areas affected • Hydraulic model revisited and updated • Details of 30th June fed into the model • Model predicts flooding in the areas where actually experienced

10. Key Findings – Ouseburn • A1 Western Bypass & Retail Park discharge to Ouseburn u/s of Redhouse Farm Estate • Intense rainfall causes Ouseburn to react quickly • Ouseburn re-profiled by EA since 2000 • Ouseburn levels can be higher than weir level in the Combined Sewer Overflow

11. Key Findings – Initial Investigation • Rainfall data not available for 30/6/05 – unable to attribute a return frequency for this ‘extreme’ very localised event • Hydraulic model predicts incapacity at 1 in 10 year event and flooding could occur without the influence of the Ouseburn • River levels are however a significant factor in terms of frequency and severity of flooding • Had river level been that of 2000 flooding in 2005 would have been much worse • Siltation of continuation pipes and mechanical screen have a small effect of spill volume

12. The Cause(s) of Flooding • ‘Extreme’ very localised rainfall event (30/6/05) • Incapacity in part of the Combined Sewer network • Levels of the Ouseburn • Topography and relative position/level of properties to the Ouseburn • Invert of Sewer 49.76m AOD • Low spot (65-77 Acomb) 50.45m AOD • CSO Weir 50.55m AOD • Ouseburn (30/6/05) 50.78m AOD • Ouseburn (20/9/00) 51.09m AOD

13. Proposed development within the Ouseburn catchment • 320 Houses on Cell G of Newcastle Great Park • Additional Cells of Great Park • Hotel Development at Newcastle International Airport • Business Park at south side of airport

14. Proposed peak foul sewage flows from development

15. 2006 onwards • Identification of short term measures to prevent flooding (where possible) • Commence Feasibility Study – Identify potential solutions (advance works already underway ie flow monitors) • Prioritisation of Project in Sewer Flooding Programme • Catchment Study incorporating further developments at Great North Park and Newcastle Airport • Continued liaison with Red House Farm Residents Association/customers • Continued liaison with EA & Newcastle City Council with particular regard to the Atkins Study.

16. Timescales • Cause Report review 15 Dec 05 • Identification of short term measures by end Jan 06 • Feedback to RHF residents (7/12) and Newcastle Great Park Advisory Committee early Dec 05 • Completion of Feasibility Study (relies on weather dependant surveys) • Major catchment study planned completion by March 07 • Following prioritisation the scheme would be programmed accordingly • Construction typically 3 to 12 months depending on size/complexity

17. QUESTIONS ?