Policy 4c: Flood Risk and Sustainable Drainage

Object

Representation ID: 51848

Received: 31/07/2020

Respondent: Mrs Rachel King

The plan to relocate the sewage works from this brownfield site to another does not refer to the environmental harm this move will cause.

Support

Representation ID: 53718

Received: 04/10/2020

Respondent: Ms Clara Todd

sounds ok

Object

Representation ID: 53965

Received: 04/10/2020

Respondent: Mrs Tamsin Beevor

The development threatens the biodiversity of the river Cam, to claim that it considers the climate and ecological emergency is untenable.

Comment

Representation ID: 54496

Received: 05/10/2020

Respondent: Cambridge Cycling Campaign

Drainage should be managed in such a way that cycle and walking routes remain clear and accessible at all times of year and by all types of cycle, including in the case of a 1 in 100-year rain event.

Comment

Representation ID: 54742

Received: 05/10/2020

Respondent: Cam & Ely Ouse Catchment Partnership

The Cam and Ely Ouse Catchment Partnership suggests that great consideration should be given to surface water harvesting as a factor of surface water management in North East Cambridge, as mentioned in Policy 4c. Furthermore, considering an integrated approach to water management is vital to ensuring future resource sustainability within the Cam and Ely Ouse.

Object

Representation ID: 55617

Received: 29/09/2020

Respondent: Historic England

Flood Risk and Sustainable Drainage
Whilst we broadly welcome the inclusion of a policy in relation to sustainable drainage reference should be made to the need to consider archaeology in the design and layout of sustainable drainage systems.
Archaeology is an irreplaceable resource and should be conserved in a manner appropriate to its significance. Where a site on which development is proposed includes or has potential to include heritage assets with archaeological interest, local planning authorities should require developers to submit an appropriate desk-based assessment and, where necessary, a field evaluation. Reference could be made to this in sections 4.1 and 5 and Appendix A.
Buried waterlogged archaeology may be at particular risk from changes in the water environment. Consideration should be given to the most appropriate course of action to protect buried waterlogged archaeology though the design of Sustainable Drainage Systems. Waterlogged deposits, such as peat have the potential to preserve organic remains that are relatively rare in the archaeological record. They are of great importance for the information they provide about everyday objects such as drinking and eating vessels (wooden bowls, leather bottles, horn cups), clothing (fabric, shoes), modes of transport (boats, trackways) and equipment of subsistence (fishtraps). To maintain the preservation of organic materials, it is essential that the conditions which contributed to their survival (waterlogged; anoxic) remain the same. While saturated with water, oxygen is excluded which limits the presence/action of most soil fauna (insects, moulds, and micro-organisms) and fungi which feed on organic matter. The lowering of the water-table in an area could result in the remains becoming exposed to oxygen, which can enhance the degradation and loss of any remains that are present. We suggest that the SPD should discuss how these sorts of sites will be managed, which makes reference to the Historic England ‘Preserving Archaeological Remains’ guidance (2016): https://historicengland.org.uk/images-books/publications/preserving-archaeological-remains/
Reference should be made to the Ciria SuDS Manual which offers more guidance.
See our comments on historic environment policy framework in respect of archaeology.
Suggested Change:
Include reference to buried archaeology in relation to SuDs.

Object

Representation ID: 55667

Received: 02/10/2020

Respondent: St John's College

Agent: Savills

The draft policy states that “Proposals for non-residential development must achieve 5 BREEAM credits for water use (Wat 01), unless it can be demonstrated that such provision in not technically or economically viable”.

Current applications 20/03523/FUL (South Cambs) and 20/03524/FUL (Cambridge City) for Phase 1 at the St John’s Innovation Park will achieve 4 of the 5. The reason that 5 credits are not being targeted at this stage is due to the limitations of roof area available for rainwater harvesting on building 1 plus the additional sanitaryware fittings that would be included in the transport hub. As such the required flow rates to achieve a 55% reduction could be prohibitive from a performance perspective”.

It is agreed that a more ambitious target than the existing Local Plan target of 2 of the 5 should be included, but to enable balancing of different considerations, 4 out of 5 should be the minimum.

Comment

Representation ID: 55749

Received: 05/10/2020

Respondent: Brookgate

Agent: Bidwells

Neutral:
Policies 4a, b and c set standards and expectations for development across all
water related issues.
Brookgate broadly support these policies from a climate change resilience and in-combination
climate change impacts perspective. However, Policy 4c needs to be
aligned with Environment Agency guidance on climate change allowance:
(https://www.gov.uk/guidance/flood-risk-assessments-climate-change-allowances).

Comment

Representation ID: 55954

Received: 05/10/2020

Respondent: Natural England

The Cambridge water environment is under significant pressure from the demands of the existing
population. Groundwater abstraction to supply drinking water combined with surface and
wastewater discharges are impacting on groundwater levels, river flows and water quality; this is
already having an adverse effect on the natural environment, including several statutorily
designated nature conservation sites. Given the severity of the existing situation any new
development, including through NECAAP, will need to demonstrate, as a minimum, that water
supply and surface and waste water disposal demands can be met without further detriment to
groundwater levels, river flows and water quality. As a minimum development should seek to
achieve no further deterioration, however, the aim of any further development should be to reduce
these impacts and, as far as possible, deliver improvements in groundwater levels, river flows and
water quality. Proposed development will also need to ensure and demonstrate sustainable
drainage and flood risk management. These complex issues and deliverable solutions will need to
be addressed through the Integrated Water Management Study / Water Cycle Study (IWMS /
WCS) being undertaken to inform the Greater Cambridge Local Plan.
Whilst targets and requirements outlined in policies 4a -c are welcomed these policies should be
informed by the findings and recommendations of the IWMS/WCS. Any measures to mitigate
adverse environmental impact will need to be detailed and their viability assured, through the AAP.
Their delivery will need to be secured through robust policy requirements.

Object

Representation ID: 56015

Received: 05/10/2020

Respondent: Endurance Estates

Agent: Barton Willmore

Draft Policy 4c requires the implementation of a Sustainable Drainage System (SuDS) across NEC in accordance with the Cambridgeshire Flood and Water SPD in order to minimise the risk of flooding. The policy goes on to require priority to be given to the use of environmental improvements, with SuDS naturalised to enhance green and blue infrastructure.

The accompanying Cambridge Northern Fringe East Area Flood Risk Assessment confirms that pluvial flood risk will be a constraint on any development proposals and areas of open space will be required to manage this risk, which may have an impact on the deliverable density of any proposals. To address this, the separate report on Surface Water Drainage Space Allocation for Master Planning (2019) advises total storage requirements for the area of approximately 120mm per square meter of impermeable surface, depending on the type of feature. This would equate to between 10-15% of the overall development parcel with interception storage requirements met through green/blue roofs, rain gardens, permeable paving and other vegetated features. As the site has limited gradient, the majority of the features should be on the surface and swales used to convey the water long distances to minimise any pumping requirements.

Reliance on underground attenuation tanks will likely increase where densities are higher within the AAP and open space is limited. The overall quantum and density of development shown in the spatial framework raises the question of how the surface water demands of the AAP will be met satisfactorily when considering the preference shown by the LLFA on other sites for open surface solutions such as swales – an example being Land North of Cherry Hinton

Comment

Representation ID: 56138

Received: 05/10/2020

Respondent: U+I PLC.

Agent: We are Town

Reference to Strategic Flood Risk Assessment questioned – Strategic FRA very different to an FRA supporting a planning
application. The Strategic FRA would be at plan level and produced on behalf of GCSPS.