Subject: FW: Cheltenham Plan - Today's hearing From: ADRIAN MEARS Sent: 01 March 2019 11:38 To: Trevor Gander Cc: John Rowley; Arlene Deane; Tracey Smith; Hannah Millman Subject: Re: Cheltenham Plan - Today's hearing Hi Trevor Thanks for your email and suggestions. I sent some draft wording to John Rowley on 27 February. My email to him is attached below. I would be grateful for any comments you have on the wording or scope. Note that I have not used the wording pluvial or fluvial or flash fluvial in the policy. I used the wording 'flash fluvial' in the wording that I gave to the inspector to indicate that it was more than just surface water flow but was concentrated into a stream. But I could not find this wording on the web. Fluvial is about rivers overflowing. Pluvial is about ponding. Flash pluvial might be correct because it could refer to temporary ponds of water building up behind houses as in the Boo Homes case. But I decided to stick with 'strong flows'. John and I briefly discussed this on 28 February. He agrees that it will be useful to include this and he is going to think about how best to do it and whether this should be a new policy or whether it would be better for CBC to issue a supplementary planning guidance, or whether we need both. The purpose of the policy wording is to ensure that the risk is properly assessed both by the applicant and by planning officers and that the issues are also properly exposed at the application stage. One of the issues in the Boo Homes case was that the drainage system diverted the flow and discharged some of it onto the field above Collum End Rise west of the development. This washed out the footpath and caused flooding in Collum End Rise. The discharge pipe was shown on the drawings but looked like an input rather than an output. So its significance was missed by us and by CBC when the application was assessed. We need to put enough onus on applicants to do a proper analysis and to clearly expose what they are doing and explicitly how the risk is being mitigated. The application also needs to expose any temporary vulnerabilities that might occur during the construction phase. Best wishes Adrian ----- Forwarded Message ----- From: ADRIAN MEARS To: "john.rowley@cheltenham.gov.uk" Cc: Arlene Deane Sent: Wednesday, 27 February 2019, 20:33 Subject: Draft policy Hi John This is my attempt at a draft policy as requested by the Inspector: 'Flood risk management is covered in section INF2 of the JCS and in JCS Policy INF2. The flood risk to Cheltenham is identified there as arising particularly from the River Chelt and from surface water flooding and overloading of the old drainage system, particularly during intense rainfall events. In areas close to the Cotswold Scarp there is a particularly strong risk of flash flooding from the very intense rainfall on the scarp, which can be of the order of 40mm in an hour. The scarp has catchments of various areas from a hectare up to tens of hectares. Depending on the catchment's area, landform, steepness and vegetation, the resulting run-off can become concentrated into strong flows even though the catchment may normally be dry. Major past storms have often been part of a double storm or sequence of storms such that the ground is almost fully saturated at the start of the storm. Policy: For any development located on or close to the Cotswold Scarp such that there is significant risk of flash flooding, the development application must include a careful and detailed assessment of any relevant catchment and of the likely run-off for a worst case storm and must clearly demonstrate that all units in the development together with the drainage system and any SUDs are suitably designed to cope with the impact. Also, the effect of the development on the course of the flow must be carefully examined and clearly documented in the application to show that the flow is not diverted in any way that could significantly increase the flood risk elsewhere. The conditions in JCS Policy INF2 also fully apply.' Best wishes Adrian From: "Tracey.Smith@cheltenham.gov.uk" To: John.Rowley@cheltenham.gov.uk; Hannah.Millman@cheltenham.gov.uk; ADRIAN MEARS Sent: Thursday, 28 February 2019, 9:18 Subject: FW: Cheltenham Plan - Today's hearing Dear Council and Mr Mears, See email below from Mr Gander of Chelt. Flood & Drainage Panel following yesterday’s hearing on Matter 5 which the Inspector asked me to forward to you. Kind regards, Tracey Smith Programme Officer Cheltenham Borough Council Local Plan - Examination T: 01242 264175 E: tracey.smith@cheltenham.gov.uk W: www.cheltenham.gov.uk/LPexamination From: Trevor G Sent: 27 February 2019 21:37 To: Tracey Smith Cc: Trevor G Subject: Cheltenham Plan - Today's hearing Dear Tracey, Thank you for helping us to have an opportunity to discuss the plan with the Inspector today. We are also grateful to the inspector for listening to our issues and for her courtesy. During the meeting we highlighted the fact that the SFRAs presented were silent on the impact of surface water flows onto and off the proposed development sites and were also silent on ensuring the safe management of those flows from the proposed sites. We believe these matters fail the NPPF requirement of paragraph 156 which states:- 156. Strategic policies should be informed by a strategic flood risk assessment, and should manage flood risk from all sources. The Inspector asked Mr Mears of the Leckhampton Hills Parish Council for a proposed wording and we thought the passage below might be helpful for the Inspector which we believe addresses the matter which still needs to be addressed in the plan. Where a Surface Water Management Plan shows the presence of pluvial flooding (surface water flooding from rainfall storm events) , the development will need to compensate for the pluvial flood volume lost (water generated on and flowing off the site) providing additional flow and storage capacity within the developments surface water drainage system and attenuation storage. We believe that this attention to safely managing overland and surface water flows onto and off the proposed development sites would merit being emphasised in the Inspector’s comments as this is a pertinent point both to the plan as well as to all sites mentioned in the plan. In addition, the Inspector acknowledged that National Policy requires that developments should reduce the causes and impacts of flood risk overall the JCS also calls for this but this is not yet delivered or quantified in the plan and FRAs to hand INF 2 of the JCS Para 2 states • Minimising the risk of flooding and providing resilience to flooding, taking into account climate change, will be achieved by: • Requiring new development to, where possible, contribute to a reduction in existing flood risk We highlighted that the plan does not yet address the matter of reduction at all and also that none of the FRAs identify or quantify reductions in existing flood risk which we believe should be a requirement imposed on all of the sites mentioned in the plan. Para 5.3.8 of the JCS also states :- 5.3.8 As an overarching principle, all new development should seek to provide an overall reduction in flood risk? We think the Inspector should question why this has not been addressed in this plan yet or at least for the new developments proposed. One last point, some of the FRA’s discussed had EA statements concerning the achievement of betterment, the lack of any definition in the plan of what is meant by “betterment” or how much “betterment” is desirable is an unacceptable gap in the plan and so it would be helpful if the inspector were to seek clarification here of what is meant by betterment and why this is not called for for all the development sites. We hope these comments are considered to be constructive and do cover matters that fall within the inspector’s scope of work relating to this plan. Please do not hesitate to contact us if you need any more information or clarification. Kind regards Trevor Gander Cheltenham Flood and Drainage Panel This email (and any attachments) is an official Cheltenham Borough Council document. The information in this email and attachments is provided for the intended recipient. If you receive this email in error, please advise the sender by return email and delete the original message from your server. This e-mail is believed to be free of viruses but it is your responsibility to carry out all necessary checks and the council does not accept any liability in connection with it. The security of any information sent by email to the council cannot be guaranteed. Any information sent to the council may be made available to the public, copied to other council officials or outside agencies in line with legislation and data sharing agreements. Any personal data sent to the council may be used in accordance with the council's Privacy Notices https://www.cheltenham.gov.uk/info/81/how_we_use_your_data