Surface Water Drainage, Contamination and Flooding

Surface Water Drainage

The original drainage scheme proposed in the planning application drained water through outfalls into the sea. Not long before last summer’s planning committee they came up with an “indicative” scheme that included drainage into the canal as being “preferred”. It was later revealed this preference was because the Earl of Radnor owned the land below the high water line. The Environment Agency had always rejected the idea of drainage into the canal and prior to the meeting they formally objected. Nonetheless the planning committee resolved to grant planning permission in principle, subject to the EA withdrawing their objection.

Later the EA did withdraw their objection but as you will see from this letter they were very reluctant to do so and described the scheme as “just-about viable” and that discharge into the canal should be seen as an emergency fall back option only.

Today the majority of surface water drains downwards through the permeable landfill which acts like a sponge – but it will no longer do so after development since they have to capture all water (including that from the road) and discharge it somewhere. The drainage problem is caused therefore by the development itself. Instead of the road water draining directly to the beach under the promenade as now, the relocated road will exacerbate the amount drained into the pond before controlled discharge into the canal.

The drainage scheme requires an array of attention ponds/tanks and mechanical controls to regulate the flow of water into the canal. Reliability and maintenance will be issues. Blockages, chemicals for cleaning, pollutant-capture – all are glossed over. The scheme does not decrease the overall amount of water that drains into the canal , as implied, it simply regulates the flow rate by means of a high risk mechanical system to protect a development that need not be placed on Princes Parade.

Addendum page 195 shows just how close the road will be placed to the canal, several metres above the path and what is left of the embankment. Both will sit permanently in its shadow for the whole of the east of Seaview bridge. Neither humans nor wildlife will be impressed by that!

Do you recall the only reasonably large area of open green space, with play area, that was promised at the western end? Well about 1¼ acres of that will now be replaced by an open attenuation pool (bog) with some form of undescribed pollutant trap. (Addendum p134)

Some interesting responses from:

the Environment Agency Ea letter 12.6.19

Historic England HE Letter 19.6.19

KCC Archaeology KCC Archaeology 10.6.19

Hythe Town Council submitted an objection.

Previous Environment Agency Comments

The EA had objected to the latest plan to discharge the surface water into the canal EA – objection upheld letter

but in this letter EA letter 15.1.19 they say that they are satisfied that the secondary scheme now presented by the council (ie into the canal) represents a “just about viable” alternative to a direct discharge into the sea. On this letter Ea Letter 17.1.19 they confirm that they are withdrawing their objection.

You can read about the secondary scheme here Herringtons Report – Dec 2018

As this diagram from the report shows, the pond that is being proposed as part of this new solution will take up a lot of the open space.

The EA had previously suggested that all their other concerns are dealt with as conditions.

You can read what they had to say here:

EA 16.11.17

EA 10.4.18

EA 27.7.18

EA 31.7.18

This diagram shows how much of the western open space would be taken up by the drainage pond should the surface water be drained into the canal



You can view the Geo Environmental report that was included in the planning application here: Geo Environment

This seems to be based almost entirely on an earlier IDOM Merebrook contamination report  to the extent that para 1.1 is still referring to 36 new homes rather that the 150 new homes which are the subject of the planning application. This does rather cast doubt on the reliability of the rest of the report.

The earlier study comprised of  a phase 1 (non intrusive investigation) and a phase 2a ( preliminary exploratory investigation). The report acknowledges that intrusive locations were limited because of ecological considerations and dense vegetation. Hazardous gas testing was carried out in just 4 locations.
The report identifies a low risk to the health of current users from heavy metal and hydrocarbon contaminants buy they conclude that “as the majority of the site is heavily vegetated potential exposure to underlying made ground is significantly reduced. Therefore the risk to the general public and current site users is considered to be low.”

It identifies a low to moderate risk from the same contaminants for future residents and construction workers.

A moderate risk of groundwater contamination from vertical and horizontal migration is identified from all forms of contamination. The report proposes further monitoring.

A moderate risk was identified of hydrocarbons being able to permeate polymeric pipes which could have serious implication for drinking water supplies.

A low to moderate risk of elevated carbon dioxide has been identified and further monitoring recommended.
So the fact is that if the site is left undisturbed as open space no remediation will be required – remediation will only be necessary if the site is developed.

The planning department have commissioned a Formal Second Opinion from their own consultants RPS. You can read the letter here: RPS letter. RPS have identified further testing which needs to be done – either before the planning application is determined or as planning conditions should permission be granted.

We think contamination is too important to be left to the conditions stage and that further studies and a detailed remediation plan should be agreed before planning permission is granted.

History of the Landfill

In the archives in Folkestone library there is a very interesting account of the landfill site written by a local resident in 1968. She said that the dust carts had a regular dumping schedule but that local traders were also allowed to dump rubbish there too. Given that the site was open, does anyone really know what was dumped there?

We also have this eye witness account  from someone who “was a plumber apprentice with sharps the builders in Hythe from 1967-1978. Sharps ran the land fill site and I visited the site nearly every day dumping rubbish.In the sixties it was the height of the asbestos world in construction. Asbestos water tanks guttering roofing materials and worst of all the raw asbestos dust which was mixed into a paste and used for pipe lagging on large heating systems, schools large buildings etc. All this ended up in this site. All other domestic waste was dumped there, all untreated and unchecked. When we stopped for a lunch break to our amusement the seagulls flew around with empty tin cans stuck on there heads. I also remember some old muskets from Hythe museum being buried there. So what else is in that site, I wouldn’t know. Being I’ve been in the construction industry all my life the only way you could build on this site is for the total removal of the waste, which would contaminate the local area. So in my mind it would be best to leave this underground contamination well alone”

Response from David Monk

Here is a reply from David Monk about how the contamination risk will be dealt with:

Thank you for your query. I can confirm that that the issue of contamination will be addressed in detail in the Environmental Statement (ES) accompanying the, soon to be submitted, planning application within a chapter covering geo-environment , land contamination and ground conditions. This document will include a number of suggested remediation measures..

The information within the ES will be reviewed by the Environment Agency, as part of the statutory consultation process, and it is anticipated that they will suggest that a number of planning conditions be included as part of any planning permission. It is anticipated that such conditions will require further investigative work prior to the commencement of the development in order that the necessary remediation measures may be agreed and finalised. Such conditions are likely to require further survey work to be undertaken to establish, in more detail, the extent, scale and nature of the contamination as well as providing a further assessment of the risks to the following :-

Human health;
Property (existing or proposed) including buildings, crops, livestock, pets,
woodland and service lines and pipes,
Adjoining land,
Ground waters and surface waters,
Ecological systems,
Archaeological sites and ancient monuments.

Once this assessment has been undertaken it will be is necessary to a submit, to the Local Planning Authority for their approval, a detailed remediation scheme to bring the site to a condition suitable for the intended use by removing unacceptable risks to human health, buildings and other property and the natural and historical environment. Such a scheme will need to include details of all works to be undertaken, proposed remediation objectives and remediation criteria, a timetable of works, site management procedures and a verification plan.

Following the implementation of the remediation scheme, and prior to commencement of the main development, a verification report demonstrating completion of the works and the effectiveness of the remediation will need to be submitted to and approved in writing by the Local Planning Authority. The report will need to include the results of any sampling and monitoring carried out in accordance with the approved verification plan to demonstrate that the site remediation criteria have been met. It will also need to include details of longer-term monitoring of pollutant linkages and maintenance and arrangements for contingency action, as identified in the verification plan, and the mechanism for reporting of this to the Local Planning Authority.

I trust that information is of assistance and reassures you that there are sufficient checks and balances in place to ensure that the scheme will not pose a risk to the health and safety of local residents and visitors to the area.”


When the planning application was submitted  and according to the initial consultants’ report the Environment Agency classified the site as Flood Risk 3.

By the time the application was put on the agenda for the planning committee in Aug 2018, the site had apparently been reclassified as flood zone 1. However, all the surrounding area remains flood zone 3 so in a flood situation the proposed development would be marooned.

This is an extract from the consultants’ environmental report :

The location of the site within Flood Zone 3 means there would be a presumption against development for more vulnerable types of development (e.g. housing, schools) in favour of developing sites within the Shepway administrative area at lower risk of flooding.

Where SDC can demonstrate through application of the ‘sequential test’ and ‘exception test'(detailed in the National Planning Policy Framework (NPPF) that there are no other alternative or more suitable sites for development within the borough, then it would be possible to develop the site. Part of the evidence that would be used to inform the exception test would be data on the hazard to the site.

Should development of the site proceed based on the current SFRA Flood Zone 1 hazard classification of the site, data on the hazard should also be used to ensure the most vulnerable types of development are guided to the areas of lowest hazard within the site. Hazard mapping should be used to assist the siting of development types across the site, this would categorise the flood hazards present on the site arising from a flood (i.e breach of local coastal defences) enabling Master Planners to site vulnerable development types (e.g. housing) in those areas of the site with the lowest hazards, whilst areas of relatively greater hazard could be used for other low risk land uses such as car parks, leisure facilities or public open space.


The latest (July 2015) flood risk assessment for Shepway still shows the site in flood zone 3:—Phase-II-SFRA-July-2015/pdf/Shepway_District_Council_-_Phase_II_SFRA-July15-FINAL_ISSUE.pdf

and the flood map:

and the flood hazard map:

The flood risk report included in the planning application admits that Princes Parade is in flood zone 3. The report argues that Princes Parade lies in zone 3a (high probability of flooding) as opposed to zone 3b (the functional floodplain). It claims that the Environment Agency flood maps are “high level” and do not take into account things like local flood defences. The report claims that according  to more detailed studies, Princes Parade lies in a less hazardous part of flood zone 3a. (Where there is a shortage of developable land , local authorities are allowed to consider development in the less riskier flood zone areas – the “sequential test”.)

If a zone 3a site passes the sequential test then the exception test has to be applied where the development is considered more vulnerable. Housing falls into the more vulnerable category. To pass this test the applicant has to prove that the wider sustainability benefits to the community outweigh the flood risk and and also has to carry out a site specific risk assessment to show that the development will be safe thoughout its lifetime and won’t increase the flood risk elsewhere.

The report then looks at all the possible different sources of flooding and concludes that the only main risk is wave overtopping.

The report recommends : that the finished floor level of all buildings should be at least 600mm above the level of the promenade; flood resilience measures should be incorporated into the design of the building – eg high quality door and window fittings; the occupants should sign up to the Environment Agency flood warnings.

The plan was that the surface water would be discharged into the sea.  Kent County Council had agreed with this approach – you can read their letter here: KCC Suds

However the new documents published in July 2018 state that the plan is now to discharge the surface water into the canal:

additional – covering letter

additional -surface water drainage

The Herrington’s study referred to in the covering letter has not been supplied to the planning officers.


You can read the full report here:Flood Risk Report

Here are the comments we submitted to the planning application on the subject of flooding:

The NPPF states that only where there are no reasonably available sites in Flood Zones 1 and 2, should decision makers, consider the suitability of Flood Zone 3, taking into account the flood risk vulnerability of land uses, and applying the Exception Test if required.

The Exception Test is required if following the application of the Sequential Test it is not possible or consistent with wider sustainability objectives for the development to be located in zones of lower probability of flooding , the Exception Test can be applied. The siting of dwellings and hotels in flood zone 3a requires that the Exception Test is applied.

For the Exception Test to be passed, there are 2 criteria that must be satisfied, and these are listed below;

  • It must be demonstrated that the development provides wider sustainability benefits to the community that outweigh flood risk, informed by a Strategic Flood Risk Assessment where one has been prepared, and
  • A site specific Flood Risk Assessment must demonstrate that the development will be safe for its lifetime taking  account of the vulnerability of its users , without increasing flood risk elsewhere and where possible will reduce flood risk overall. (source: Shepway District Council SFRA July 2015)

The Council has carried out both a Sequential Test and an Exception Test in relation to this proposal. However, in submitting this application, rather than pursuing the allocation of the land through the Development Plan process they have not demonstrated that there are no other sites in less vulnerable flood zones where the these uses could be accommodated. The Council’s evidence has not been tested through public consultation or Public Inquiry. There are clearly other housing sites available with consent or allocated which meet the Councils housing need now. Additionally there is another site identified for a leisure centre at Nicholls Quarry. There is therefore no need to develop on this site which has a high probability of flooding.

In relation to the Exception Test it is recognised that the provision of housing and a leisure centre can be a community benefit .However in relation to housing,  Shepway has more than sufficient land to meet its housing need now. In relation to the leisure centre the Council does not know whether the use is viable, and there is an alternative site in any case. Therefore this proposal does not provide sustainability benefits for the community.  

 To overcome the risk to buildings and people on the site itself, it is proposed in the application to create a plinth 1.1m above the existing promenade off which all development will be constructed. This may have the unfortunate consequence of pushing flood water elsewhere and creating a greater depth of flood on adjoining land which would be in conflict with the advice contained in para 100 of the NPPF. The Council’s Flood risk assessment states that this will not happen but does not explain why not.

There is additionally, the question of drainage. As the site is a former tip, the site cannot be drained into the ground, using soakaways because of the contamination. It is proposed to tank the hard surfaced areas, and drain them, via pipes to the beach. The buildings would be drained by pipes directly to the beach. Such an approach is satisfactory during normal weather conditions, but if heavy rain is combined with a high sea level and overtopping, will it prevent water from the site draining to the sea, and actually cause flooding on the site?  

Given the Council’s conclusions on the acceptability of development on Princes Parade, it is odd that the development of the golf course land which is also in flood zone 3a is unacceptable because of flood risk. In the absence of the testing of the evidence that supports the Council’s sequential test as to whether there are preferable sites, little weight should be given to it.

This proposal results in vulnerable land uses, being sited in an area of a high probability of flooding. The Council cannot demonstrate that the uses cannot be accommodated in less vulnerable locations because they clearly can be, and they have not demonstrated an overriding need. This proposal is in conflict with the advice contained in the NPPF.