CC/FM: Flooding and integrated water management

Support. there should be a blanket refusal of development within any floodplain. Developments should incorporate brown/green roofs (cedam) where practical.

There must be no development in flood prone or flood areas, and water management needs to be reintroduced. Regular cleaning of rivers, ditches and drains on roads and fields.

I am replying as part of my responsibilities as a Local parish Councillor for Heydon from feedback received via our Local Community led plan
I cannot find the appropriate place to comment on water supply .... as this is a key issue should you have somewhere more obvious to capture this topic?

Any way here is some feedback: Water supply is not sustainable in Cambridgeshire, the area is classified as semi arid and as such resources are stretched. Proposals for a feasibility study involving extra reservoirs are not appropriate. Reservoirs will only serve to store more of the water which is not currently sufficient to replenish Aquifers and Chalk Streams. This is a flawed solution proposal. The only real way to address this is through increased efficiency, less housing plans, and import of water from other areas. Reservours will exacerbate the issues not resolve them.

New development should not be permitted in Environment Agency Zone 3 flood risk areas.
Might there be something here about the types of storm that need to be accounted for in drainage calculations? Particular ref. to SUDS?

Agree with this Policy. It is of particular relevance to the proposed NECAAP proposals (Policy S/NEC) in the areas of highest density, i.e. 300/ha in the central areas, where appropriate SUDS will be needed and the large hard surface areas need to be permeable.
Regarding stormwater management parliament recently put a duty of Sewage Companies to reduce the storm overflows. Major developments, including their highways, should have dedicated separate road, roof and land drains run through balancing /attenuation ponds SUDS methods. as some recent new developments have not been affected by the recent stricture, CWWTP will need to build bigger storage and design it for future more intense rainfall. The stormwater in storage should then be fed back through the works after the storm has finished.

(Education) Policy CC/FM includes the expectation that developments will be required to provide integrated water management, including sustainable drainage systems (SuDS). The Council would be supportive of this being incorporated into the design of new schools. However, it should be acknowledged that this is likely to increase the size of the site required for a school. Currently, it is Council Policy to request the minimum site size required to enable delivery of a school which meets the standards set by the Department for Education (DfE), including suitable outdoor space to enable physical education in accordance with the school curriculum and to enable pupils to play outside. As this is a statutory requirement and delivered through the planning process via Sport England, there would be a statutory planning objection if not incorporated into the design. Including SuDS within the design would require an additional land allocation. Costs and space would also need to be incorporated into s106 agreements to ensure children’s safeguarding if, for example, SuDS ponds were to be on site rather than using attenuation tanks.
The Council therefore feels it would be most appropriate for any targets to be incorporated in policy to be the subject of a technical assessment on their achievability and cost, before being formally adopted.

(Flood Risk Team) The direction of the policy is going in a good direction, taking inspiration of the Cambridge City Local Plan 2018, as this holds good practice for the design of SuDS systems.
There should be an emphasis on managing surface water close to the source, on the surface and within open SuDS where practicable. I note it is included, but this should be the basis of all surface water schemes.
There is no mention of water quality in the proposed policy direction section. This should be included within the local plan as a standalone point within the flood management policy. This could include the use of terms such as the SuDS Management Train, focussing on providing multi stages of treatment through cascading structures. This is the way that developments should be going in managing their surface water.
While climate change is covered in Policy CC/DC, it would be worth including the surface water systems should be designed with an allowance of climate change included
The document is very much setting out the policy directions, it would be good to know the general set out of the proposed policy, as the listed versions of these policies are useful in interpreting, signposting and referring stakeholders to for information or as part of a scheme.
Reference should ideally be made to the Cambridgeshire Flood and Water Supplementary Planning Document (SPD), or any subsequent version of this, which is adopted South Cambs and Cambridge City individually.
It is noted that the policy will not need to repeat items covered by the NPPF, however, reference should be made to this within the document.

The Wildlife Trust support the inclusion of the policy and its proposed scope.

The inclusion of a policy on how development should address flood risk and implement integrated water management including sustainable drainage systems into the Plan is a sensible approach.

The inclusion of a policy on how development should address flood risk and implement integrated water management including sustainable drainage systems into the Plan is a sensible approach.

Huntingdonshire District Council support the proposed policy CC/FM which directs development to the areas with the least likelihood of flooding from all sources taking into account climate change. It is considered that integrated water management, including sustainable drainage systems (SuDS) should be applied where practicable to do so. Permeable surfaces, green roofs and run off rates requirements will also help to reduce the impact of flooding and water management.

As a neighbouring district with areas at risk of flooding, it is considered that careful flood and water management will be beneficial to not just Greater Cambridge, but also facilitate benefits and minimise impacts in the surrounding districts.

The requirements for hard surfacing to be permeable should ensure that they meet the requirements of the Local Highways Authority for adoptable road standards.

We support the proposed policy

In addition to requiring that the risk of flooding is not increased elsewhere as a result of new development (including peak runoff rate should be no greater for the developed site than it was for the undeveloped site), in setting out the approach to runoff rates, the Plan should be clear there should be no reduction in runoff rates under non-flood circumstances.
This is to ensure biodiversity in downstream watercourses that is dependent on such flows is not adversely impacted, and similarly the amenity of flowing streams and rivers is not compromised by upstream developments.

Repeating myself here but Grey Water should be used where possible.

Regarding Flooding, before any work starts anywhere with historic flooding, flood management must be implemented before work is started and approved by independent experts. In the past, SCDC have approved plans where residents have informed them of flooding issues and within a year, area has flooded. Maybe use simulations (via independent experts).

Applications approved experiencing flooding Hunters Close Impington, Park Primary, Histon as example. Approved, residents expressed concerns, now flooding, nothing happening to fix.

CC/FM: Flooding and integrated water management

4.22. The emerging policy sets a requirement for new development to provide integrated water management, including SuDS, where surface water is managed close to its source and on the surface where possible. In addition, potential flood risk from developments will need to be fully addressed and account for potential climate change impacts.
4.23. North Cambourne is located in Flood Zone 1, so is at low risk of flooding from rivers and the sea. However, there are some isolated areas of the site at risk of surface water flooding, adjacent to existing watercourses. Through an integrated sitewide SuDS strategy, this risk will be mitigated within public open spaces and potentially mitigated through a centralised rainwater harvesting system to reduce potable water consumption.
4.24. The SuDS strategy will aim to ensure that the peak runoff rate post development is no greater than that which currently exists on the site.

The whole plan is proposed despite the knowledge that in the short-, medium-, and long-term ongoing growth will cause further disruption to the chalk aquifer and habitats on which we all depend. Until an approach to dealing with this is found, a massive development on this scale cannot take place without inevitable and irreversible damage to the water ecosystem.

The fields south of the city are already flooded over the winter months. I have attached photos from January 2021 which show extensive surface water across the fields. With climate change this is set to get worse. Permission for development was rejected for the 2018 Plan because of flooding. Why would this have improved now?

Policy CC/FM doesn’t take adequate account of the local heavy clay soil.

A better drainage recommendation is needed for low infiltration areas, together with stronger planning review and enforcement.
If the recommendation includes surface features such as swales, lower housing density may be required to allow sufficient space. This should be explicitly recognised, and this space should be distinct from areas set aside as Public Open Space.

Made more aware of increasing intensity of summer storms and severity of summer droughts.

Marshall agrees with this policy and is fully supportive. Cambridge East lies within Flood Zone 1 and is therefore at a low risk of fluvial flooding. The potential for all flood sources, including pluvial (overland surface water runoff), will be fed through design development, ensuring that flood risk is not increased elsewhere and that the development itself remains safe. This will be an integral part of the green infrastructure strategy, with ‘blue corridors’ maintained for preferential exceedance flow routes. This will ensure natural flood management is provided, in line with the principles of the Local Plan. This will ensure that the development is future proofed, and that water management is integrated within the emerging vision.

Cambridge East’s vision is for an exemplary water management strategy, ensuring that surfaces remain permeable where feasible, and that runoff rates are not increased above those existing. This is in line with the Local Plan proposals. Rainwater harvesting is top of the drainage hierarchy and is being explored in detail at Cambridge East, with potential discharge into and extraction from the aquifer using innovative techniques to maximise wider benefits, including for biodiversity. Further discussions will be held with WRE, the EA, and Anglian Water. Marshall also agrees that the future of SuDS within developments needs to be defined, and in line with the Local Plan proposals we will put in place robust management and maintenance plans to ensure that the highly sustainable water management strategy functions as intended for the lifetime of the development.

Regarding “The plan will set out the approach to runoff rates, including that peak runoff rate should be no greater for the developed site than it was for the undeveloped site.” Whilst we support this, there may be cases where flooding is already a problem and the development provides an opportunity to reduce flood risk, in such cases we would hope that there would be a policy requirement to reduce runoff rates from pre-development levels. For example, a development in the upper water catchment that is subject to flash flooding.

Policy should recognise the value of SuDS for the provision of natural green space and biodiversity and encourage above ground SuDS for this reason. We have seen a number of development proposals where SuDS have been located surrounded by roads, this is problematic because it encourages semi-aquatic wildlife to cross the roads and risk being crushed (eg spawning amphibians) and it fails to recognise ecological principles of connecting habitat (not isolating it with roads). We would welcome wording in the draft Plan that discourages this type of design.

Policy needs to meet requirements of Environment Agency, Lead Local Flood Authority and water companies

TMLC supports the integration of water management within new developments and in-accordance with Policy CC/WE.

Policy CC/FM states that development will be directed to the areas with the least likelihood of flooding from all sources and taking into account climate change. The Policy also states that development will be required to provide integrated water management, including SuDS. Land West of London Road, Fowlmere proposes to include SuDS and will adhere to Policy CC/FM.

Greater Cambridge Local Plan Strategic Spatial Options Assessment (November 2020)
The Greater Cambridgeshire Local Plan is supported by a Greater Cambridge Local Plan Strategic Spatial Options Assessment (November 2020).

The Assessment identifies that current over-abstraction of the Chalk aquifer is having a detrimental impact on environmental conditions. It acknowledges that none of the Councils’ growth strategies offer an opportunity to mitigate the existing detrimental impacts and there is no environmental capacity for additional development in the new Local Plan to be supplied with water by increased abstraction from the Chalk aquifer.

Major new water supply infrastructure is proposed and will be operational in mid-2030s, however, development in the interim will need to reduce abstraction through the implementation of ambitious targets for water efficiency. Such targets will be required to be addressed across all new developments.

It is understood that all development within Greater Cambridgeshire will need to adhere to such ambitious water efficiency targets and therefore there is no growth strategy that has a lesser water usage impact than another.
In so far as utilising recycling systems, the Assessment suggests that large sites are able to successfully use recycling to reduce demand for potable water. We disagree with this statement. Whilst retrofitting developments may be expensive, new development (regardless of scale) is able to adopt rainwater recycling systems. It is unclear why the statement specifically restricts water recycling usage to “large developments”. Land West of London Road, Fowlmere, is able to adopt a rainwater recycling system if this is a requirement set by Local Policy.
The Assessment also identifies the potential for introducing flood management and SuDS schemes to deliver multifunctional benefits including biodiversity enhancements. Land West of London Road, Fowlmere presents an opportunity for delivering a scheme which includes SuDS that provide multifunctional benefits including an opportunity to benefit and enhance designated wildlife sites.

Overall, however, the Assessment recommends that growth should be concentrated in new settlements or urban extensions that avoid high flood risk and have high standards for the design of flood risk management, water usage and re-use, and blue-green infrastructure.

This recommendation follows a Location Opportunities and Constraints Categorisation and Scoring which assesses and score each of the proposed growth strategies.

Minor Rural Centres (including Melbourn) and Group Villages (including Fowlmere) is assessed as having a red rating for flood risk due to potential existing fluvial flood and surface water flood risk. Wastewater and Quality are assessed as amber, subject to local WRC capacity. The red flood risk rating is despite Paragraph 4.2.1 of the Assessment stating “flood risk does not differentiate between the growth scenarios”.

Land West of London Road, Fowlmere is located within Flood Zone 1 with low risk of surface water flooding, which is a sequentially preferable location for development as supported by the NPPF (2021). In this regard the Site should be assessed as having a Green or Amber Flood Risk rating. In either instances, this Site should be given a total constraints score of -6. This score would result in the same overall scoring as the proposed recommended growth strategy of locating growth within new settlements or urban extensions. This amendment would also introduce criterion “Good opportunities”, thereby also improving the overall combined constraints and opportunities score for development within Minor Rural Centres and Group Villages.

It is therefore disputed as to why development within the Minor Rural Centres and Group Villages have been disregarded as an appropriate growth strategy if they are able to meet the ambitious water usage targets and implement water recycling systems.

Policy CC/FM states that development will be directed to the areas with the least likelihood of flooding from all sources and taking into account climate change. The Policy also states that development will be required to provide integrated water management, including SuDS.
Land to the East Side of Cambridge Road, Melbourn is proposed to deliver a scheme that implements SuDS and an integrated water management system that takes into account climate change. Such SuDS will also be multifunctional, providing both biodiversity and amenity benefits.


The Greater Cambridgeshire Local Plan is supported by a Greater Cambridge Local Plan Strategic Spatial Options Assessment (November 2020).
The Assessment identifies that current over-abstraction of the Chalk aquifer is having a detrimental impact on environmental conditions. It acknowledges that none of the Councils’ growth strategies offer an opportunity to mitigate the existing detrimental impacts and there is no environmental capacity for additional development in the new Local Plan to be supplied with water by increased abstraction from the Chalk aquifer.
Major new water supply infrastructure is proposed and will be operational in mid-2030s, however, development in the interim will need to reduce abstraction through the implementation of ambitious targets for water efficiency. Such targets will be required to be addressed across all new developments.
It is understood that all development within Greater Cambridgeshire will need to adhere to such ambitious water efficiency targets and therefore there is no growth strategy that has a lesser water usage impact than another.
In so far as utilising recycling systems, the Assessment suggests that large sites are able to successfully use recycling to reduce demand for potable water. We disagree with this statement. Whilst retrofitting developments may be expensive, new development (regardless of scale) is able to adopt rainwater recycling systems. It is unclear why the statement specifically restricts water recycling usage to “large developments”. Land to the East Side of Cambridge Road, Melbourn, is able to adopt a rainwater recycling system if this is a requirement set by Local Policy.
The Assessment also identifies the potential for introducing flood management and SuDS schemes to deliver multifunctional benefits including biodiversity enhancements. Land to the East Side of Cambridge Road, Melbourn presents an opportunity for delivering a scheme which includes SuDS that provide multifunctional benefits including an opportunity to benefit and enhance designated wildlife sites.
Overall, however, the Assessment recommends that growth should be concentrated in new settlements or urban extensions that avoid high flood risk and have high standards for the design of flood risk management, water usage and re-use, and blue-green infrastructure.
This recommendation follows a Location Opportunities and Constraints Categorisation and Scoring which assesses and score each of the proposed growth strategies.
Minor Rural Centres (including Melbourn) are assessed as having a red rating for flood risk due to potential existing fluvial flood and surface water flood risk. Wastewater and Quality are assessed as amber, subject to local WRC capacity. The red flood risk rating is despite Paragraph 4.2.1 of the Assessment stating “flood risk does not differentiate between the growth scenarios”.
Land to the East Side of Cambridge Road, Melbourn is located within Flood Zone 1 with low risk of surface water flooding. In this regard the Site should be assessed as having a Green or Amber Flood Risk rating. In either instances, the Site should be given a total constraints score of -6. This score would result in the same overall scoring as the proposed recommended growth strategy of locating growth within new settlements or urban extensions. This amendment would also introduce the summary of “Good Opportunities” thereby also improving the overall combined constraints and opportunities score for development within Minor Rural Centres and Group Villages.
It is therefore disputed as to why development within the Minor Rural Centres and Group Villages have been disregarded as an appropriate growth strategy if they are able to meet the ambitious water usage targets and implement water recycling systems.

The RSPB supports the principles set out for this policy, particularly with reference to source control. Our experience is that this is often an element which is not implemented well due to supposed practical constraints which are not necessarily justified. We believe that Greater Cambridge have an opportunity to push the boundaries to make this a standard practice in new development. We suggest that references to green roofs should be changed to biodiverse and/or biosolar (to preclude the use of sedum roofs which have limited utility). Where use of permeable surfaces is not practicable, source control should again be implemented.

Great Shelford is already at risk of flooding. Therefore flood plains need to be managed and not built upon.

Cambourne Town Council understands the need for this policy as it addresses the aims contained in the vision.

The availability of water supply and the pressure on the existing environment due to the low level of existing water resource is a key issue for the area. The scale of envisaged growth and development is out of line with the water resources available, and in terms of sewage capacity and nutrient burdens from discharges. This should be an intrinsic consideration throughout the Local Plan. The Local Plan needs to be future-proofed and requires agility to respond to the changing and increasing pressures that are likely to come forward for the water environment over the plan period.

Support the inclusion of specific local policy content on flood resilience and integrated water management.

Section 3.1: Climate Change

COMMENT

Section 3.1 set out the approach to tackling climate change and includes the following policies:

Policy CC/NZ: Net Zero Carbon New Buildings: The promoted development will be net zero carbon in operation, taking a holistic approach that implements energy efficient buildings alongside a dedicated solar farm and solar PV on roofs. Given the fast pace of technological advancement and evolution, the development will assess the available options at the time of construction so as to be able to deliver a sustainable, viable, project.

Policy CC/FM: Flooding and Integrated Water Management: The prevailing surface water strategy to be adopted is a network of positive drainage consisting of, and not limited to, the following SuDS features:
• Open swales / rills;
• Living Roofs
• Blue Roofs (these can also be used in areas of Living Roof)
• Attenuation Basins (with some localised pond/wetland features);
• Porous Paving (where feasible);
• Bio-retention areas; and
• Rainwater Harvesting.