Agenda item

The Committee noted the report and agreed that the strategy should be implemented. It was also agreed that the Committee’s comments be referred to Mayor and Cabinet as follows –

·           The Committee recommends that Mayor and Cabinet should consider the options and resource implications of commissioning a comprehensive survey of underground water sources and streams in the borough. The Committee acknowledges the constrained financial situation facing the Council and it encourages Mayor and Cabinet to consider innovative and collaborative approaches to implementing this recommendation.

·           The Committee would welcome additional education and outreach on the issues related to homeowners paving their gardens. This should include updated information on the Council’s website about the potential impacts of replacing gardens and green spaces with impermeable paving.

5.1    Marcus Gayle (Flood Risk Manager) introduced the report – noting Lewisham’s responsibilities as a lead local flood authority and outlining the approach that had been taken to developing and delivering the new strategy.

5.2    Marcus Gayle and Martin O’Brien (Climate Resilience Manager) responded to questions from the Committee – the following key points were noted:

·         An outline business case was being developed for flooding alleviation works on Verdant Lane.

·         All options for integrating green spaces and reducing impermeable surfaces into developments would be welcomed and supported.

·         Officers had contributed to the development of the Council’s Infrastructure Delivery Plan – with recommendations for the retrofit of sustainable drainage measures across the borough.

·         The Council worked with partners to manage flood risk across borough boundaries – particularly through the South East Flood Partnership, the London Drainage Group and the Environment Agency.

·         Some information was available regarding underground water sources. To further understanding of the impact of development on underground springs and water flows would require a full hydrological study.

·         Proposed developments had to demonstrate how they would mitigate the impact of new building on flood risk. There were some good examples of where this had been successfully achieved.

·         Planning policy required that where gardens were paved then the surface should be permeable.

·         The definition of risk management authorities was defined in legislation. It was not something that Lewisham could designate or change by itself.

·         There was an action in the strategy to support the implementation of small scale sustainable drainage measures and de-paving of gardens.

·         The Council had an internal flooding and water management action group of officers (including those from the highways team) – which met quarterly to consider issues related to drainage and flooding.

·         A full survey of all the gullies in the borough had been carried out to determine the risk of flooding and to prioritise areas for cleansing.

·         Information about flooding and options for reporting flooding incidents were available on the Council’s website.

·         The Environment Agency had withdrawn its flooding alleviation plans for Lewisham and Catford because it was unable to develop a viable business case using its model - some of this work had been integrated into the alleviation scheme in Beckenham Place Park.

5.3    In Committee discussions the following key points were also noted:

·         Members were concerned about the potential scale of development in some parts of the borough due to the potential flooding risk. The wet woodlands site adjacent to the Hither Green sidings in the Railway Children Urban National Park was noted as one such location in particular.

·         The Council should consider how best to address the issue of front gardens that had been paved over due to the potential flooding risk this posed.

5.4    Resolved: The Committee noted the report and agreed that the strategy should be implemented. It was also agreed that the Committee’s comments be referred to Mayor and Cabinet as follows –

·         The Committee recommends that Mayor and Cabinet should consider the options and resource implications of commissioning a comprehensive survey of underground water sources and streams in the borough. The Committee acknowledges the constrained financial situation facing the Council and it encourages Mayor and Cabinet to consider innovative and collaborative approaches to implementing this recommendation.

·         The Committee would welcome additional education and outreach on the issues related to homeowners paving their gardens. This should include updated information on the Council’s website about the potential impacts of replacing gardens and green spaces with impermeable paving.