Project Appreciation and Objectives
Approximately 5% of the many thousands of sewer blockages and collapses that occur each year lead to internal and external flooding of properties. With such a small proportion of small diameter pipes at risk, knowing where to concentrate preventative efforts is difficult and potentially very expensive. Consequently, defensive action tends to focus on areas that have experienced blockages and flooding problems in the past. This approach inevitably will not prevent flooding from sewers, which have not previously suffered such problems. Using blockage data, case studies and available low-cost data, this project identified flooding risk factors and gave participants a cost-effective approach to manage and reduce \ the risk of sewer flooding.
Benefits to Client
- Ability to proactively and cost-effectively target work to reduce sewer-flooding incidents due to "other causes".
- Identify high risk flooding locations, which could help prioritise responses to incidents when a call is received.
- Justify capital maintenance or operating expenditure to reduce the incidents of flooding due to "other causes" in accordance with the UKWIR Capital Maintenance Planning Common Framework, by helping to identify the consequences of failure should it occur (Step B2.3(b) of the framework).
- Collect collapse, blockage and flooding incident data for a number of drainage areas and compare incidents that caused flooding with those that did not.
- Build a coarse topographical model using low cost data and integrate with information from sewer records.
- Identify detailed case study areas for more detailed investigation to identify the common flooding mechanisms.
- A prototype methodology for the identification of properties most likely to flood in the event of a failure.
- A feasibility study, including costs and benefits, of the application of the methodology to whole systems or to selected areas.
- End of project dissemination meeting and workshop.
Managing the risks of critical sewers and trunk mains, CP220, 2005.
Numerous sewer blockage/flooding studies, 1995-2006.
Duration: 12 months