Agenda item

To inform Members on the conclusions and recommendations of the Flood Investigation report on the significant flood event that affected Knaresborough on 6 May 2024.

Heather Lagan (Senior Flood Risk Engineer) and David Piercy (Senior Flood Risk Engineer) presented the Section 19 Flood Investigation Report, prepared in response to the severe flooding in Knaresborough on 6 May 2024, which affected over 50 homes and businesses.  The event saw 54mm of rainfall in just 35 minutes, exceeding the monthly average and representing a 1-in-516 year storm.  The investigation confirmed that the intensity far surpassed design standards for drainage infrastructure and highlighted key areas of flood risk.  While some blockages were identified in smaller drains, the overall drainage systems were overwhelmed.  The community’s response was commended, and officers sought comment on the report ahead of its formal approval.

Members welcomed the Section 19 Flood Investigation Report but raised concerns regarding its scope, timing, and engagement.  It was noted that flooding in areas such as Plompton Drive and Hookstone was shown on the map but not referenced elsewhere in the report, prompting calls for broader geographic recognition.  Questions were raised about the adequacy of public engagement, particularly with displaced residents, and the need for clearer communication and equitable access to support such as council tax relief.  Members emphasised the importance of acknowledging the human and community impact of flooding, including the strain on local infrastructure and wellbeing, and requested that this be reflected in future reporting.

The potential for water attenuation measures, such as water butts, was discussed, with members urging Yorkshire Water to consider wider implementation as a quick and cost-effective intervention.  Concerns were expressed about the report’s treatment of blocked gullies and historical flooding patterns, with repeated incidents cited in 1999, 2006, 2021, and July 2024.  The classification of Park Avenue as low risk was challenged, and calls were made for a review of flood mapping and maintenance regimes.  Members highlighted the need for clearer communication around private responsibilities, particularly regarding soakaways, and welcomed proposals for public information campaigns.  Officers acknowledged the feedback, clarified technical aspects of gully design, and confirmed that the report remains in draft form, with opportunities to incorporate recommendations and improve dialogue with elected members.

Resolved:  That the Area Committee note the report, and make the following recommendations to the Executive Member ahead of the decision:

1. Commission a Strategic Infrastructure Plan for Knaresborough as a full review of surface water and sewer flood risk mapping for the town, ensuring it reflects observed impacts and provides a reliable basis for future planning. This should inform a dedicated planning document, drawing on Section 106 funding where appropriate (similar to the West of Harrogate Plan) to ensure the drainage network meets current needs and that future development does not worsen flood risk.

2. NYC produce a Prioritised Gully Inspection & Maintenance Plan for Knaresborough, with particular attention to Halfpenny Lane and other high-risk locations where gullies were non-operational during recent flooding. Findings and improvements should be reported back to Area Committee as part of the six-month progress review.

3. Support Knaresborough Town Council in developing a communications plan for residents, providing guidance on flood prevention and resilience measures, clarifying maintenance responsibilities, and signposting local reporting routes and support services.
4. Review the Section 19 Report through the Transport, Environment, Economy, and Enterprise Overview & Scrutiny Committee, recognising the need for a holistic approach by NYC in its roles as Lead Local Flood Authority, Planning Authority, and Highways Authority. This should serve as a case study to strengthen processes and policies for managing future flood events across North Yorkshire.

5. Come back to the Area Committee and Knaresborough Town Council with a six-month progress review.

6. Include an assessment on the impact of the flooding event on the local community.

The Harrogate & Knaresborough Area Committee further proposes that the Executive write to Yorkshire Water and the Environment Agency, to request that they:

1. Undertake an urgent audit of all sewer assets in Knaresborough, ensuring asset transfer and mapping records are complete and up to date, and share this data with NYC’s Lead Local Flood Authority.

2. Review maintenance and inspection regimes for key sewers, particularly those on Queen’s Road and St Margaret’s Gardens, to prevent recurrence of known blockages.

3. Work jointly with North Yorkshire Council to develop the Strategic Infrastructure Plan for Knaresborough (as mentioned above), with clear timelines and defined responsibilities.

4. The immediate installation of water butts where possible be considered to improve water attenuation.