Making space for water
Urban flood risk and integrated drainage
Lincoln (Environment Agency, Anglian Region)
Pilot Summary
Significant parts of Lincoln's urban areas have been identified as being at risk of flooding. Whilst major fluvial flooding has not occurred since 1947, recent summer downpours have been a reminder of the misery of flooding and the fragility of infrastructure to heavy rain, new development, responsibility issues and the advent of climate change. Given the interactions between these factors, urban flooding is a complex subject requiring an integrated approach by a range of responsible organisations. The pilot has combined the expertise of the Environment Agency, local planning authorities, Anglian Water and other stakeholders to identify ways to solve a series of urban drainage/flooding problems in Lincoln. These solutions will then inform future development plans, the Lincoln Water Cycle Study infrastructure planning, asset operation and maintenance.
Approach
The pilot study adopted a partnership approach, involving nine key stakeholder organisations, each stakeholder with some level of responsibility for surface water drainage. The pilot identified five site specific case studies for investigation, and examined and evidenced seven key surface water issues to highlight the problems currently associated with Lincoln’s urban drainage systems.
Key Findings
- Multi Agency Responsibility - the division of responsibility between organisations has lead to increased flood risk over time due to ineffective management. The partnership approach of the pilot has lead to greater understanding of the problem a key first step in identifying solutions.
- Permissive Powers – are not always effective in resolving causes of flooding.
- Private Sewers - effective maintenance of sewer systems would be better served in the hands of a competent agency
- Modelling - availability of water company and Environment Agency hydraulic models enabled an assessment of the interaction between pluvial and fluvial systems, a shared understanding of complex flooding mechanisms, and provided an opportunity for the partners to formulate and implement a solution
- Riparian Ownership - riparian owners are not always aware of their responsibility to maintain watercourses. The planning system has an important role to play. Policies for maintaining development distance from watercourses/culverts can be identified in SWMP’s.
- Data - provision of data should be supported by expert knowledge on the asset information. The partnership proved to be a successful forum to discuss flooding issues, which should continue through the newly formed Lincoln Drainage Group.
- Stakeholder Involvement - stakeholder engagement is essential in the assessment and design of new significant development particularly in respect of surface water flooding and drainage provision when there are many partners involved.
Next Steps
In response to the issues identified, and in light of designated growth point status for Lincoln, the partnership decided to form the ‘Lincoln Drainage Group’ c/w ‘Good Drainage Guide’ for use by developers so that partners can continue to work together and avoid creating future s/w problems associated with new developments. The findings from this project will inform the development of the Lincoln Water Cycle Study.
The formation of the Lincoln Drainage Group is testament to the benefits of partnership working recognised by the stakeholders involved in this study. Data sharing, integration of modelling, common understanding of problems, awareness of options and development of appropriate solutions. Sharing this finding and promoting a pro-active approach to problem identification and allocation of responsibilities is an important next step. The Partners acknowledged that some Barriers could still work against realisation of the benefits of Integrated Urban Drainage Management. These were noted as; conflicting policies, variable standards, lack of resources, fragmented responsibilities and the continued use of permissive powers. The findings of the Lincoln pilot are presented for Defra to consider in their review of surface water policies. Revised legislation, agreed planning horizons and rationalised standards would help to remove some of the remaining barriers.
Outputs
Page last modified: 25 June 2008
Page published: 5 March 2007