South Norfolk Village Clusters Housing Allocations Plan (Reg. 19 Pre-submission Draft)

None specified.

Thank you for the opportunity to comment on the Regulation 19 VCHAP. We have engaged with the Planning Policy Team at the Council due to difficulties in managing this consultation and conducting a full review. We are therefore making representation, at a high level which gives an indication for possible comments which we would wish to engage on in more detail and see clarified or addressed ahead of the Council's submission for Examination.

In order to capture these comments given the circumstances and that we have been unable to review the Plan along with its evidence base and supporting documents in detail at this stage, we consider that we are able to recommend that the VCHAP can be considered Sound, providing a number of concerns can be satisfactorily addressed/clarified. We are making this representation, with our position stated, along with the caveat that we may need to amend our comments and provide further comment in more detail at a further date. We would also note that these comments are unlikely to be a complete version of our comments and we may need to pick up on additional sections, particularly with reference to the Evidence Base SFRA, during further engagement. We have identified a number of concerns that will need to be understood. We note the SFRA appears to use new modelling which may need to be submitted through our Evidence and Risk Team for approval once clarifications noted have been understood. If required, we would then need to request that the full model files be submitted alongside the SFRA.

We have engaged with the Council's Planning Policy Team, and an initial acknowledgement that a future Statement of Common Ground may be sought between parties to address additional comments was noted and agreed as a sensible way forward.

Waveney Modelling

The SFRA states that the Environment Agency’s Waveney modelling was updated in 2022 to include the 3.3% flood event for new Flood Zone 3b. However, this is incorrect, the 2022 Waveney modelling was a full 1D/2D remodel of the river, which also included a 3.3% flood event, along with all other return periods. This modelling therefore already includes updated hydrology and topographic survey, and 2D level, depth, velocity and hazard maps. We note that instead the SFRA has undertaken 2D modelling of the old 1D 2013 Waveney model, and that the resulting outlines differ slightly from ours. We question why our 2022 Waveney modelling was not used as the basis of the flood risk information for the sites along the Waveney.

Flood Zone 3b

We question why the SFRA refers to Flood Zone 3b as the 5% outline throughout, such as in section 4.6, when Flood Zone 3b was updated in the NPPF last year to the 3.3% event. While it may be acceptable to clarify that in the absence of 3.3% modelling, the 5% event could be used, it should be clarified in every paragraph that Flood Zone 3b is the 3.3% event and that this should be being worked to where possible.

Site Allocation Interactive GeoPDF Maps

We have some concerns regarding the site allocation maps. Firstly, Flood Zone 2 is listed above Flood Zone 3, so Flood Zone 2 covers Flood Zone 3 and the layers are not able to be viewed at the same time. Flood Zone 3 should be placed above Flood Zone 2.

While 3.2.1 in the SFRA states that Flood Zone 3b has been identified as land which would flood with an annual probability of 1 in 20 years, and paragraph 5.4.1 states the Interactove GeoPDF mapping will include Flood Zone 3b, there is no Flood Zone 3b layer shown on the maps, as required. This should be based on the 3.3% (1 in 30) AEP event where available, which it is for the entire fluvial Waveney, or based on the 5% where there are no 3.3% layers available. While there are depth, velocity and hazard maps for the 5% TUFLOW Lower Waveney runs, there should be a separate Flood Zone 3b outline located with the flood zones. In 3.2.1 the SFRA acknowledges that the updated Waveney modelling has a 3.3% layer and states that the modelling has been used to inform sites upstream of Gillingham, however the maps do not have a Flood Zone 3b layer, or a 3.3% layer, so it is not clear where this layer has been used.

There are also no future flood zones shown on the maps. Again while the 2D TUFLOW layers show climate change depth, hazard and velocity maps, there should be separate future flood zone outlines on the maps.

Flood Risk Assessment

Section 6.2.1 specifies when an FRA is required, however the requirement for an FRA for sites in Flood Zone 1 with “land identified in a strategic flood risk assessment as being at increased flood risk in future” as specified in footnote 55 of the NPPF is missing, so this should be included.

Gillingham

We note that a new 2D flood model has been created to model the fluvial and tidal flood risk at Gillingham, as the site is not covered by detailed modelling, and that this has resulted in site SN0274REVA, which was almost entirely covered by Flood Zone 3, now located entirely in Flood Zone 1. As no channel survey was available, the modelling assumed a 3.5m width of channel. This modelling will need a detailed review to determine if it is acceptable.

Also, the site is at risk of fluvial flooding from the Broads to the south, although the SFRA model report stated that it was beyond the scope of the work to assess the risk from that source. However, we have fluvial flood levels for the River Waveney at Gillingham (from the Broads 2008 model) which could be used to map and assess the risk to the site. We also have tidal flood levels for the River Waveney which could also be used to assess the tidal flood risk from the Broads.

Brockdish

We note that new modelling was undertaken for the Brockdish area including the ordinary watercourse draining south to the Waveney, which is not included in our model. However, it seems strange that the resulting Brockdish site allocation GeoPDF map does not show any flood outlines covering this ordinary watercourse for the Lower Waveney TUFLOW modelling results. Did the modelling show that the flood water remains in channel? If not, then the flood outlines should be shown on the map. The modelling was 2D and included no assessment of the actual dimensions of the watercourse. This modelling is likely to need a detailed review.

Thank you for the opportunity to comment on the Regulation 19 VCHAP. We have engaged with the Planning Policy Team at the Council due to difficulties in managing this consultation and conducting a full review. We are therefore making representation, at a high level which gives an indication for possible comments which we would wish to engage on in more detail and see clarified or addressed ahead of the Council's submission for Examination.

In order to capture these comments given the circumstances and that we have been unable to review the Plan along with its evidence base and supporting documents in detail at this stage, we consider that we are able to recommend that the VCHAP can be considered Sound. We are making this representation, with our position stated, along with the caveat that we may need to amend our comments and provide further comment in more detail at a further date. We would also note that these comments are unlikely to be a complete version of our comments and we may need to pick up on additional sections, particularly with reference to the Evidence Base WCS, during further engagement. We have engaged with the Council's Planning Policy Team, and an initial acknowledgment that a future Statement of Common Ground may be sought between parties to address additional comments was noted and agreed as a sensible way forward.

Evidence base guidance for Local Planning Authorities

Water Cycle Studies – This 2021 guidance is for local planning authorities (and their consultants) and developers who are preparing water cycle studies. It sets out what the Environment Agency expects to see in a water cycle study - Water cycle studies - GOV.UK (www.gov.uk)

Integrated Water Management Strategies – CIRIA hosts the 2019 publication ‘Delivering better water management through the planning system’ (C787F). This sets out the benefits of integrated water management for town planning with case studies and examples of good policy. This is available at https://www.ciria.org/ItemDetail?iProductCode=C787F&Category=FREEPUBS with an account on CIRIA website.

Policy Recommendations – New Residential Developments

We strongly recommend that South Norfolk Council require new residential developments are constructed to meet the optional higher water efficiency standard of 110 litres/person/day, as per Requirement G2 in Part G of the Building Regulations 2010. We would suggest developers submit a water efficiency calculator (https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/504207/BR_PDF_AD_G_2015_with_2016_amendments.pdf) report, or equivalent information, at the planning stage to demonstrate compliance with such a policy.

Achieving 110 litres/person/day can be done with existing technology by installing efficient showerheads, spray taps and low flush toilets. Complex greywater recycling and rainwater harvesting schemes are not typically required to adhere to this water efficiency standard.