Y Bwthyn Palliative Care Unit, Pontyclun Response to Natural Resources Wales

Transcription

1 SUMMARY OF FRA RESPONSES Y Bwthyn Palliative Care Unit, Pontyclun Response to Natural Resources Wales This document summarises the resolution of the comments issued by Natural Resources Wales (NRW) on the Flood Consequence Assessment (FCA) for the development at The Royal Glamoran Hospital in Puntyclun. See Appendix A for the full correspondence. Price & Myers have carried out a flood modelling exercise to determine the results of flooding as per the Government s climate change requirements effective as of st Dec 206. Please see Appendix B for the results. The concerns by NRW are summarised below:. Paragraph 4 highlights that hospitals are classified as Emergency Services,as per Section 5 of TAN5, and should be flood free up to and including the in 00 year flood event. It was recommended that we seek advice from the LPA on how they intend to classify the development. 2. Paragraph 5 raises concerns as to the lack of information regarding flood depths, maximum velocity of floodwaters, speed of inundation and rate of rise. Information regarding maximum velocity is needed as a minimum for further comment. 3. Paragraph 6 raises concern regarding flood impact on 3 rd parties. 4. Paragraph 7 recommends that the development not make use of underfloor voids. Price & Myers response to the raised concerns:. At the recent meeting with the LPA, it was explained by Simon Gail that as the proposed building is a stand-alone unit and non-hospital/emergency unit, it should be classified as Highly Vulnerable and therefore designed to in 00 year plus CC standards. It is suggested that the Finished Floor Levels (FFL) for the proposed building will match the existing hospital building FFL of 60.38m AOD. This will be well above the flood model s design flood levels of m AOD for the in 00 year plus 25% CC flood event. A FFL of 60.38m AOD will also be well above the flood model s design flood levels of m AOD for the in 000 year flood event. 2. Please see Appendix B for the information regarding floodwaters. 3. The results from the flood modelling exercise show that 3 rd party land in the surrounding areas will not be adversely affected by the proposed development. In fact the flooding extent on the 3 rd party land to the south will be reduced as the proposed building acts as a

2 Y BWTHYN CARE PALLIATIVE CARE UNIT barrier to divert the flood water back to the watercourse thereby reducing the volume of water entering the properties to the south. 4. Although underfloor voids were recommended for flood volume compensation, the flood model shows that the proposed building does not increase the extent of flooding on 3 rd party land but in fact improves it to the south. Therefore the need for flood volume compensation is seen as unnecessary. Conclusion:. The proposed building will be classified as Highly Vulnerable. However the design meets the flood design criteria for Emergency Services too. 2. It is suggested that the Finished Floor Levels (FFL) for the proposed building will be well above the flood model s design flood levels for the in 00 year plus 25% CC flood event and the in 000 year flood event rd party land will not be affected by increased flooding extents 4. Therefore the development is considered safe in all flood event scenarios. [Job Number] [Insert Date - month & year] Ver Page 2 of 4

3 Y BWTHYN CARE PALLIATIVE CARE UNIT Appendix A Correspondance [Job Number] [Insert Date - month & year] Ver Page 3 of 4

4 Ein cyf/our ref: CAS ZX9 Eich cyf/your ref: n/a Rivers House St Mellons Business Park Fortran Road Cardiff CF3 0EY Rhondda Cynon Taf CBC Sardis House Sardis Road Pontypridd CF37 DU Ebost/ Ffôn/Phone: FAO: Guiliano Guadagnino November 206 Annwyl Syr/Madam / Dear Sir/Madam Y Bwthyn Palliative Care Unit, Pontyclun- Advice on Flood Consequences Assessment (FCA) Thank you for referring us to the above, which we received on 9 October 206. We understand that you have submitted the Flood Consequences assessment (FCA), produced by Price and Myers, dated September 206, in order for us to provide you with advice on the acceptability of flooding consequences. We understand that this document will be submitted in support of a future planning application. As you are aware, the proposed development is partially within Zone C2, as defined by the Development Advice Map (DAM) referred to in Technical Advice Note 5: Development and Flood Risk (TAN5) (July 2004). Our Flood Map information, which is updated on a quarterly basis, confirms the site to be partially within the 0.% ( in 000 year) annual probability fluvial flood outlines of the Nant Muchudd, a designated main river. The FCA states that the topographical survey drawing shows the ground levels of the site to be below the predicted in 00 year plus climate change flood level, suggesting the site is currently at risk of flooding from the Nant Muchudd. We note that the intention is to raise the ground levels of the site to 60.00m AOD. Based on this level the development is predicted to be flood free during the in 00 year plus climate change flood event. The FCA states that during the predicted in 000 year flood event the site will flood to a depth of approximately 70mm. We refer you to Section 5 of TAN5, which classifies hospitals within the Emergency Services development category. The guidance set out in section A.4 of TAN5 states that Emergency Services should be flood free up to and including the predicted in 000 year flood event. We do acknowledge however the particular nature of this proposal and that it is an extension to an existing hospital. We therefore recommend you seek advice Tŷ Cambria 29 Heol Casnewydd Caerdydd CF24 0TP Cambria House 29 Newport Road Cardiff CF24 0TP Croesewir gohebiaeth yn y Gymraeg a r Saesneg Correspondence welcomed in Welsh and English

5 from the LPA on how they intend to classify the development and whether they will expect it to be flood free in events up to and including the in 000 year flood event, as per the guidance in A.4. In any case, it should be noted that a flood depth of 70mm is in excess of the indicative thresholds for both residential development and Emergency Services, as described in A.5 of TAN5. Furthermore, no information has been provided on the other elements within A.5 i.e. maximum velocity of floodwaters, speed of inundation and rate of rise. As a minimum, information is needed regarding maximum velocity before we can provide further comment. It is of concern that there is no discussion of impact to third parties within the FCA. If the site is being raised to mitigate the flood risk to the site, the potential risk of displaced water to third parties should be quantified. It is not known if compensation has been investigated for this loss of flood plain and what this flood compensation will be. We note that the FCA suggests an alternative mitigation measure with the use of voids as form of mitigation. We do not recommend the use of voids as they can become blocked and there is no guarantee that they will remain as an open area indefinitely. The use of stilts reduces the impact on the development but does not guarantee that the flood plain will be retained in the same way as a compensation scheme (which is a form of risk substitution). We therefore suggest that you address the above points in an amended FCA and then submit it to us for further comment. Please note, on 23rd August 206 the Welsh Government published a Policy Clarification Letter regarding climate change allowances for planning purposes, supplemented by a guidance note and map. The letter and supporting documents supplement the policy advice provided in TAN5. Local planning authorities, applicants and their consultants are expected to use these climate projections from st December 206. Therefore, if your amended FCA is submitted after this date, it must use the revised climate change allowances. We recommend that you also seek advice from the Council s Land Drainage Department in relation to the disposal of surface water. If you have any further queries, please don t hesitate to contact us. Yn gywir / Yours faithfully Helen Griffiths Ymgynghorydd Cynllunio Datblygu / Development Planning Advisor Cyfoeth Naturiol Cymru / Natural Resources Wales Ffon / Tel: Gwefan / Website: / Page 2 of 3

6 Ein diben yw sicrhau bod adnoddau naturiol Cymru yn cael eu cynnal, eu gwella a u defnyddio yn gynaliadwy, yn awr ac yn y dyfodol. Our purpose is to ensure that the natural resources of Wales are sustainably maintained, enhanced and used, now and in the future. Page 3 of 3

7 Y BWTHYN CARE PALLIATIVE CARE UNIT Appendix B Flood Model Results [Job Number] [Insert Date - month & year] Ver Page 4 of 4

8 ± Notes:. Add notes 303,649, 84,0 Key Plan N/A N/A Contains OS data Crown Copyright and database right Issued for Information Rev. Date Drn Eng Amendment Y Bwthyn Palliative Care Unit, Royal Glamorgan CF72 8XR River Model :00yr + 25% Climate Change Existing Status FOR INFORMATION NOT FOR CONSTRUCTION Drawn: Eng: DLin Scale (A) :,000 Drawing No Revision

9 ± Notes:. Add notes 303,649, 84,0 Key Plan N/A Contains OS data Crown Copyright and database right Issued for Information Rev. Date Drn Eng Amendment Y Bwthyn Palliative Care Unit, Royal Glamorgan CF72 8XR River Model :00yr + 25% Climate Change Proposed Status FOR INFORMATION NOT FOR CONSTRUCTION Drawn: Eng: DLin Scale (A) :,000 Drawing No Revision

10 ± Notes:. Add notes 303,649, 84,0 Key Plan N/A N/A Contains OS data Crown Copyright and database right Issued for Information Rev. Date Drn Eng Amendment Y Bwthyn Palliative Care Unit, Royal Glamorgan CF72 8XR River Model :00yr + 70% Climate Change Existing Status FOR INFORMATION NOT FOR CONSTRUCTION Drawn: Eng: DLin Scale (A) :,000 Drawing No Revision

11 ± Notes:. Add notes 303,649, 84,0 Key Plan Contains OS data Crown Copyright and database right Issued for Information Rev. Date Drn Eng Amendment Y Bwthyn Palliative Care Unit, Royal Glamorgan CF72 8XR River Model :00yr + 70% Climate Change Proposed Status FOR INFORMATION NOT FOR CONSTRUCTION Drawn: Eng: DLin Scale (A) :,000 Drawing No Revision

12 ± Notes:. Add notes 303,649, 84,0 Key Plan Contains OS data Crown Copyright and database right Issued for Information Rev. Date Drn Eng Amendment Y Bwthyn Palliative Care Unit, Royal Glamorgan CF72 8XR River Model :000yr Existing Status FOR INFORMATION NOT FOR CONSTRUCTION Drawn: Eng: DLin Scale (A) :,000 Drawing No Revision

13 ± Notes:. Add notes 303,649, 84,0 Key Plan Contains OS data Crown Copyright and database right Issued for Information Rev. Date Drn Eng Amendment Y Bwthyn Palliative Care Unit, Royal Glamorgan CF72 8XR River Model :000yr Proposed Status FOR INFORMATION NOT FOR CONSTRUCTION Drawn: Eng: DLin Scale (A) :,000 Drawing No Revision