Agenda item

To receive an update on flood risk management

The Committee considered a report, set out in agenda pages 27 to 32, which gave an update on flood risk management within the Borough.

The report outlined a number of areas of focus, including CCTV drainage surveys and repair works, delivery of capital drainage schemes, ongoing drainage revenue works, commenting on planning applications in relation to flooding and drainage works, smart drainage trials, and Thames Water partnership work to reduce surface water flood risk.

Boniface Ngu (Principal Flood Risk & Drainage Engineer) and Francesca Hobson (Service Manager  – Green & Blue Infrastructure) attended the meeting to answer Member queries.

During the ensuing discussion, Members raised the following points and queries:

·         Was there any more that could be done to require residents to retain at least a small portion of green space in their front gardens, rather than paving over the whole area? Officer response – All planning applications were considered, not just major applications. Officers pushed for permeable surfaces to be installed which acted in a similar manner to grass. Officers required drawings to be presented, and if permeable surfaces were not indicated then a recommendation would be made to install permeable surfaces as opposed to concrete. Installation of non-permeable surfaces created a cumulative issue, and a number of social media pieces and newsletters had gone out and were being worked on to inform residents. Officers were working alongside the National Flood Forum to install rain gardens and water butts, whilst there were possibilities to review the SuDs strategy.

·         Officers were thanked for the improving situation with relation to flooding in Norreys.

·         Were officers confident that developers of large sites were implementing optimal drainage solutions? Officer response – Officers encouraged above ground attenuation features such as SuDs basins, attenuation basins, ponds and swales whereby issues could easily be noticed via public notification and inspection by officers. Officers looked at the increase to the one in one-hundred-year flood event in addition to a forty-percent climate change allowance for any large-scale development. There was a riparian responsibility for landowners to maintain ditches next to a development where there was water discharge. There were plenty of cases where riparian owners were not carrying out the required maintenance, and officers were writing to those landowners to remind them of their responsibilities. Wokingham Borough Council (WBC) had powers under the land drainage act to carry out land drainage enforcement where landowners had been notified but had so far failed to take action. In addition, there were additional powers under the recently adopted Wokingham specific land drainage bylaws.

·         Were there any updates in relation to the proposed flood alleviation scheme on the river Loddon? Officer response – Officers were quite surprised that funding had not been received through the DEFRA innovation flood resilience fund given the level of feasibility work which had been carried out. The Environment Agency had now opened up a scheme over the wider Thames catchment area to look to catch and store water, including the river Loddon. Investigative works were now underway for this scheme including partnership working with a wide range of stakeholders. With a scheme of this size, implementation could take several years as reservoirs might have to be created whilst looking at ecological improvements and the potential for hydroelectric power generation. The first round of the consultation had been completed and was currently being reviewed, which would feed into the second stage of the scheme and the emerging business case. The section of land proposed was on the western side of the river, and was currently allocated under the master planning proposals as an eco-valley.

·         Were there any solutions in the works to alleviate flooding at the Waitrose car park in Woodley? Officer response – The car park should have a drainage gulley which may be blocked, and could require a jet to clear any blockage.

·         It was noted that Thames Water were responsible for a significant drainage system and they often had capacity issues. Thames Water were working with WBC to seek potential areas such as on roundabouts to hold back water during times of high demand on the drainage network.

·         At this stage of the meeting, Guy Grandison proposed to extend the end time of the meeting by 30 minutes to a maximum finishing time of 11pm. This was seconded by Clive Jones, and upon being put to the vote the motion was carried.

·         What funding was in place to deliver the 10-year programme of large-scale pipe replacement? Officer response – Officers were looking at over 300km of pipes across the Borough, some of which were over 100 years old and were in need of replacement. A business case would be required to deliver this project, and there were opportunities for grant funding. The £200k per annum figure listed within the MTFP was used to deliver capital drainage schemes.

·         If trials were successful in relation to gulley sensors, what was the approximate cost of delivery and what return on investment might be realised? Officer response – Sensors costed around £450 per sensor, and each sensor could be redeployed to different locations and streets to locate exactly where each blockage was. These sensors would form part of an invest to save business case.

·         It was noted that smart drainage solutions were very much welcomed within the Borough, and the Committee hoped that this could be rolled out across the Borough.

RESOLVED That:

1)      Boniface Ngu and Francesca Hobson be thanked for attending the meeting;

2)      A further update on flood risk management be considered during the next municipal year.