HRA Email to RBWM Chief Executive rejecting the Thames Hospice Plans

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Thames Hospice Planning Application Sadly Agreed at Borough Meeting
We are extremely sorry to report that despite objections, and a petition, the RBWM Councillors on the Development Management Panel on 18th July 2017 voted 11 for and 2 against, so the application was granted subject to some traffic and height matters being clarified and / or improved.
Apart from objecting to the plan itself, we object to the flawed process of this Development Management Panel, in that a development is approved subject to some essential matters being sorted out. It is this sort of slapdash behaviour that has resulted in the deaths in the disastrous Grenfell Tower fire on 14th June 2017, and this country's building component fire regulations being unfit for purpose.
For this panel, the proper course of action is to reject until all design matters have been fully documented so that we know exactly what is being presented for approval.
There was acceptance that traffic is a problem, the A308 being narrow. The RBWM Highways representative trotted out the usual sop to those in the ruling class on this RBWM Council, that the increased traffic as a result would be only 3% so "NO PROBLEMO". If it had been 4% we heard a Councillor say, then it would have been a NO. The Highways group always conveniently disregard the fact that each successive development they approve that adds 3%, all together add up to much more.
One Councillor said that a road carrying as much traffic as the A308 should be a dual carriageway.
We know that there will be more developments affecting traffic on this road - these being those scheduled in the Local Development Plan on areas HA11, HA18, Monkey Island Lane, Racecourse Hotel, LEGOLAND and CrossRail.
So we look forward to Highways rejecting all of these future development proposals as the traffic from any one of them together with the Hospice Traffic will exceed 4%!!!!!!!!!!!!!!!!
We also have had, just yesterday, news of developers and / or landowners proposing yet again that they will build on "Lodge Farm", the area between Holyport Road, Ascot Road, Aysgarth Park and old Holyport. This area is not shown in the Borough Local Development Plan to be allowed for building - but who knows - it seems that this RBWM Planning lot is capable of anything.
Local RBWM Councillors did in the past propose that area for development - we stopped it. Then in the early stages of developing the Bray Parish Neighbourhood Development Plan up it came again - we stopped it. Then it was proposed by RBWM in their Edge of Settlement Analysis of 2014 - we stopped it.
We were disappointed that our local RBWM Councillor David Coppinger voted in favour of the plan. This was despite his statement of concern, that he had only discovered last week how difficult it is to turn out from a property onto the A308.
It was not surprising that our Bray Parish Councillor, Derek Wilson who is also the RBWM Lead Member for Planning voted for the development. Not only that, he proposed it be accepted. It is of course part of his Borough Local Plan!!
Below we show the presentation given by Anu Chawla our Vice Chair who presented on behalf of Windsor Road Residents who will be sorely afflicted by this development on Green Belt Flood Plain. We also show a full version of her description of the problems arising from this development - due to time restrictions, the meeting could not have the benefit of the full presentation.
We also show below our analysis of the flood report that was created on behalf of the Hospice. We consider that it is impossible to develop in this area without causing emerging water or flood water problems. Further we believe we have demonstrated that RBWM have contravened the NPPF requirements restricting building in Flood Plain 2 and 3.
We thank Ken Elvin, the Leader of Bray Parish Council - who also spoke eloquently against the application.
Apart from objecting to the plan itself, we object to the flawed process of this Development Management Panel, in that a development is approved subject to some essential matters being sorted out. It is this sort of slapdash behaviour that has resulted in the deaths in the disastrous Grenfell Tower fire on 14th June 2017, and this country's building component fire regulations being unfit for purpose.
For this panel, the proper course of action is to reject until all design matters have been fully documented so that we know exactly what is being presented for approval.
There was acceptance that traffic is a problem, the A308 being narrow. The RBWM Highways representative trotted out the usual sop to those in the ruling class on this RBWM Council, that the increased traffic as a result would be only 3% so "NO PROBLEMO". If it had been 4% we heard a Councillor say, then it would have been a NO. The Highways group always conveniently disregard the fact that each successive development they approve that adds 3%, all together add up to much more.
One Councillor said that a road carrying as much traffic as the A308 should be a dual carriageway.
We know that there will be more developments affecting traffic on this road - these being those scheduled in the Local Development Plan on areas HA11, HA18, Monkey Island Lane, Racecourse Hotel, LEGOLAND and CrossRail.
So we look forward to Highways rejecting all of these future development proposals as the traffic from any one of them together with the Hospice Traffic will exceed 4%!!!!!!!!!!!!!!!!
We also have had, just yesterday, news of developers and / or landowners proposing yet again that they will build on "Lodge Farm", the area between Holyport Road, Ascot Road, Aysgarth Park and old Holyport. This area is not shown in the Borough Local Development Plan to be allowed for building - but who knows - it seems that this RBWM Planning lot is capable of anything.
Local RBWM Councillors did in the past propose that area for development - we stopped it. Then in the early stages of developing the Bray Parish Neighbourhood Development Plan up it came again - we stopped it. Then it was proposed by RBWM in their Edge of Settlement Analysis of 2014 - we stopped it.
We were disappointed that our local RBWM Councillor David Coppinger voted in favour of the plan. This was despite his statement of concern, that he had only discovered last week how difficult it is to turn out from a property onto the A308.
It was not surprising that our Bray Parish Councillor, Derek Wilson who is also the RBWM Lead Member for Planning voted for the development. Not only that, he proposed it be accepted. It is of course part of his Borough Local Plan!!
Below we show the presentation given by Anu Chawla our Vice Chair who presented on behalf of Windsor Road Residents who will be sorely afflicted by this development on Green Belt Flood Plain. We also show a full version of her description of the problems arising from this development - due to time restrictions, the meeting could not have the benefit of the full presentation.
We also show below our analysis of the flood report that was created on behalf of the Hospice. We consider that it is impossible to develop in this area without causing emerging water or flood water problems. Further we believe we have demonstrated that RBWM have contravened the NPPF requirements restricting building in Flood Plain 2 and 3.
We thank Ken Elvin, the Leader of Bray Parish Council - who also spoke eloquently against the application.
Presentation by Anu Chawla.
Chairman, Councillors, Ladies and Gentlemen
As the spokesperson for the residents of the area, I wish to state, we strongly object to the proposal. We submit that the proposal will have a detrimental impact on the residents health, wellbeing and properties; that it cannot pass the Exceptions tests and that Very special conditions are not met.
It is not possible to provide a detailed statement in 3 minutes so my full statement will be available on the Holyport Residents association website and to the press.
There is a growing nationwide concern that councils are not listening to residents’ concerns against bad planning. The area residents are concerned there is a predisposition to allow the proposal at any cost and without regard to the wellbeing of the existing residents.
This site has several significant issues against being developed, registered as double negatives on the council’s own Sustainability Appraisal.
We believe many of these issues have been underrated or understated in the case report to reduce their importance to allow Very special Consideration for the proposal.
- The land is Green belt and a hospice is not listed, as an appropriate exception in the NPPF, for construction is acknowledged
- However the importance to all residents and visitors, of the public amenity, the openness of the area and a landmark view from the road is completely undervalued. More than 200 people have signed a petition to ask for removal of this site from the development allocation.
- Traffic impact is underestimated. I refer the panel to the submitted photos of a typical peak period.
- The impact on the existing AQMA has not been addressed at all
- The impact of the height of the proposal (12 meters above raised ground) has been downplayed. 12 meters is twice the height of a house! The proposal is overbearing, will urbanise and completely dominate the neighbourhood.
- And critically this site has considerable issues with flooding. It is a flood plain!
Notwithstanding the value that the hospice movement provide to the community, the issue is whether this is the right site. We believe Very Special Conditions are not met. It is suggested that this is the only affordable site within their search but the search criteria submitted is neither extensive nor reasonable. We submit it is set specifically to target this site.
In today’s world driving 10 miles is not considered a long distance; imposing a 5 mile limit is placing unreasonable restrictions to reject any other sites.
The staff are located either in Windsor or Ascot, why is Windsor the epicenter of the search? Why not Ascot?
The constraint to combine all aspects of the charity headquarters maybe desirable but is not essential.
This site has only 6 useable acres due to flooding when the applicant is looking for a site of at least 8 acres.
It is ironic the applicant is looking for a semi rural area and then proposing to build industrial scale buildings which will dominate the area and remove its semi rural aspect.
In conclusion we urge the panel to dismiss the application and assist the hospice to find a more suitable alternative site, as there is severely detrimental impact on existing residents and properties, the Exception Tests cannot be passed and the very special conditions are also NOT met to allow the substantial harm to the Greenbelt.
ANU's full presentation
Chairman, Councillors, Ladies and Gentlemen
I am speaking on behalf of the residents of Windsor Road and surrounding areas, incorporating all their concerns, submitted as objections to the Planning Department. Over 55 households have objected so the actual number of people is around 110. None are in support of the suitability of this site for the Hospice. Additionally more than 200 people have signed a petition to ask for the site to be removed from the development allocation.
We the residents are concerned there is predisposition to allow the application at any cost, which is completely disregarding the welfare and wellbeing of the existing residents.
We believe this site is unsuitable for such a substantial development. The Flood Risk assessment report referenced by the case officer was only made available to the public last Friday. It has been carefully examined and due to lack of time provided, a report has been emailed directly to all the councillors by the chairman of the Holyport Residents Association. The analysis and questions raised conclude that the National Planning Policy Framework, NPPF and the PPG sequential and exception tests have NOT been met.
The local plan still has to undergo the test of soundness and legal compliance therefore has limited weight. In addition the council’s own Sustainability appraisal registers double negatives for water and flooding, Air and Noise Pollution, Use of Resources and landscape Quality.
The site is Green belt farming land, and therefore there is presumption against building here unless Very special conditions (VSC) can be proven. A hospice or care home is NOT listed in the NPPF as an appropriate exception for construction on Green Belt land.
The case officer has stated the scheme causes significant and substantial harm to the openness of the space by the locality of the site and its size and therefore the proposal is contrary to the Green belt policy.
Having read some of the literature accompanying the application and the case Officer’s report I wish to address Visual Impact, Flooding, Parking , Traffic, Pollution and Very Special Considerations,
Visual Impact
This substantial development, equivalent to a small hospital will urbanise the area and dramatically change its semi rural character.
The land, including the site, is the only open space remaining between the Braywick roundabout and Fifield Road. It is an area of recreation for many local residents and the general public. Bray Lake is a landmark! The view to the public, from the road, of Bray Lake is critical to the openness and the semi rural character of the area and cherished by the residents and visitors. Significant weight should be attributed to this loss.
Moreover in order to mitigate the flooding issues, the proposal is to raise the land where buildings are to be constructed. It is not specified ultimately where the ground level will be relative to the surrounding properties. This means that the three 2 storey buildings which are stated to be 12 meters high (twice the height of a house), on Ground level further raised, will be seen for miles. They will be out of place in their surroundings, completely dominating the neighbourhood and creating light pollution. It is ironic the Hospice is looking for a semi rural location and in the process turning the existing semi rural location to an urban one.
What is proposed amounts to overdevelopment.
Flooding
It is clear that the prospect of flooding is a substantial issue for the applicant.
The site allocated to the hospice is the worst possible on this land parcel, almost entirely in flooding zones 2 and 3, with high probability (75% chance) of ground water flooding within its vicinity and the facts are that part of the site regularly floods in the winter. The water table is very high. The proposed development will exacerbate the problem. This is an unsuitable site for development
The Environment Agency originally objected to the application on the basis that that the development would increase the risk of flooding elsewhere. Their latest cautious response of 10th July approving the development but imposing conditions which require minimum finished floor levels and compulsory flood plain storage serves to highlight the real risks of flooding attached to this site.
Given that the policy is to direct developments to areas at lowest probability of flooding, notwithstanding the benefit of the hospice to the community, it is submitted that this site cannot meet the Exceptional test because it will increase the risk of flooding to neighbouring properties.
I refer you to the analysis and conclusions presented by the HRA email to all councillors and urge the panel to take account of the residents’ knowledge of conditions on this site in wet weather and accept it is unsuitable
Traffic, Parking and Congestion
The Hospice will be relocating both sites therefore all its existing staff, patients and visitors will need to travel. It is already established that virtually everyone will drive.
Provision of 201 car parking spaces for 150 full time equivalent staff ie around 200 real people plus 500 volunteers, outpatients , weekly training sessions for up to 50 people, is inadequate parking provision.
Much of the traffic generated will be at peak periods when traffic is nose to tail. Exiting from our drives is difficult, we are dependent on motorists letting us out at peak times and one can’t turn right. I refer the panel to the pictures distributed and taken during one peak time at 6:20 pm.
The Highways report states that this narrow road already carries 18000 vehicles daily of transit traffic. This is looking at the increased traffic in isolation, without considering the further increase in traffic anticipated when crossrail is operational or due to houses already permitted to be built further down the road.
Highways estimate 574 additional daily vehicle trips based on FTE numbers to and from a single access point on this busy road and say as this is a 3% increase this is sustainable.
In absolute terms this is an additional 200 to 250 trips all starting/terminating at the same point on the road at each peak time. Traffic from all these people, service vehicles and ambulances, using a single access, all using the narrow A308 which is currently unable to meet existing demands make this an untenable proposal.
Air Pollution and AQMA (Air Quality Management area)
Increase in traffic means increase in Air pollution. Windsor Road already suffers from Air pollution due to the M4. ANY increase in traffic means increase in that pollution and if the open space which disperses these fumes is taken away that impact is multiplied.
We already have an AQMA in near proximity and a number of residents with asthma and lung related diseases. This issue has not even been addressed when planning policy states that Planning decisions should take account of the impact on air quality, supporting proposals which will result in the improvement of Air Quality Management Areas (AQMAs).
We submit that at present levels ANY increase is harmful.
Very Special Considerations
Notwithstanding the value that the hospice movement provide to the community, the issue is whether this is the right site. Whilst it is suggested that this is the only affordable site within their search, the search criteria submitted is neither extensive nor reasonable.
In today’s world driving 10 miles travel is hardly considered a long distance; 5 miles is placing unreasonable restrictions to reject any other sites.
When the staff are located either in Windsor or Ascot, why is Windsor the epicenter of the search? Why not Ascot? Or even a midpoint between Windsor and Ascot?
The applicant is looking for a site of at least 8 acres. This site has only 6 useable acres due to flooding.
The constraint to combine all aspects of the charity headquarters maybe desirable but is not essential. Two smaller sites within close vicinity would fulfil the purpose.
The applicant is looking for a semi rural area and the application will remove the semi rural aspect of the existing area by industrial scale overbearing buildings which will dominate the entire area.
We submit that the entire search criteria and application is based specifically to target this site and to reject any alternatives. Therefore Very Special Conditions are NOT met.
I would urge the council to recommend that this application be dismissed and the District Council assist the hospice to locate a brownfield site nearer the urban area with better transport links for the staff and visitors using the facilities.
HRA Flood Risk Assessment
The following is the text of our comments against the Flood Risk Assessment provided by Thames Hospice. This assessment was sent by email to all RBWM Borough Councillors the day before the meeting. No-one mentioned it in the meeting.
There are particular points here that show that RBWM have contravened the NPPF in selecting this area in Flood Plain 2 and 3.
See the text and our comments against page 12 paragraph 5.3.
____________________________________________________
HRA considers that this Flood Risk Assessment fails to convince that development of this area is appropriate. Further the report reveals that the objectives of the NPPF and PPG Sequential and Exception Tests have not been met. In fact it appears that the Borough Council has predetermined that this development shall take place, in this mainly Flood Zone 2 area for reasons that are not supported by the NPPF requirements.
Our comments are shown in red with some underlining. The black text is abstracted from the Price an Myers document.
Page 3
Price and Myers say they were commissioned to produce this report. It should be confirmed that RBWM did not request or influence the production of this report.
Page 5
2.3 Thames Water have to pump new sewage from this development to a Windsor Road manhole.
Has Thames Water confirmed that their network has sufficient capacity? Who would pay for this?
Is this below the 24.5m AOD or below the 20.5m AOD?
Page 8
4
Drainage channel has to be maintained. It drains an area of 196 hectares to South of Windsor Road.
Has Thames Hospice committed to this maintenance?
Page 9 & 10
5.2 Flood Risk from Surface Water & Overland Flows
- Large catchment area to the South, - whose configuration channels the water underground under approximately 14 properties on the Windsor Road.
Have the 7 property owners each side of the pumping station (14 in all) under whose properties the catchment area lies been advised of the dangers of interfering with the existing drainage? In particular, has the blockage effect of installing underground storage tanks having an estimated volume of 1270.5 cubic metres been advised to them? If installed in the conformation of an approximate cube, the effective underground wall would have a width of 36 ft with a depth of 34.5 ft.
Page 11
Fig 5.4
The Historical Surface Water Flooding Map shows the extent of flooding in the past.
There are predictions of drastic sea level rises within 50 years. Has this been considered?
Page 12
Fig 5.5 Shows possible Surface Water flooding in the existing situation, with 7 Windsor Road properties affected.
Has the size of the new gully been designed to cope with not only such a spread of water, but also that arising in the future bearing in mind that the development will divert water from its normal course and that the sea level is rising?
5.3 Sequential & Exception Tests
In accordance with the NPPF and the PPG, the risk-based Sequential Test should be applied at all stages of the planning process. Its aim is to steer new development to areas at the lowest probability of flooding (Zone 1). Developments should not be permitted if there are reasonably available sites to accommodate the “proposed development" in areas with a lower probability of flooding.
It is clear that other sites are available in areas with a lower probability of flooding, in fact there are areas available with no probability of flooding; therefore the proposed development fails this test. The subject land is mostly Zone 2 with some Zone 3, so choosing to develop here does not comply with the NPPF.
The RBWMLP "Edge of Settlement Part 2 Constraints, Opportunities and Delivery Assessment", dated July 2016, assesses the site's (Parcel M35) potential for future development. The assessment identifies all constraints, including flooding, and concludes that "The Parcel has been promoted for residential use and is considered available".
It is clear that other sites are available in areas with a lower probability of flooding, therefore the Edge of Settlement conclusions are wrong, as the proposed development, and any development in this area, fails the sequential and exception test.
PPG (para 102) states two conditions for the Exception Test to be passed:
1. "It must be demonstrated that the development provides wider sustainability benefits to the community that outweigh flood risk, informed by a SFRA where one has been prepared".
As other sites are available in areas with a lower probability of flooding, the proposal has already failed and the above paragraph becomes irrelevant.
The RBWM Supplementary Planning Document - Planning for an Aging Population (Sept 2010) Requirement PAP11 Providing Care Homes or Housing for Older People in Areas with Restrictive Designations states, "The development , or redevelopment, of care homes or housing for older people may be acceptable within some restrictive designations where they will directly address a local need, as agreed by the council."
The Council have identified the need for a care home at this location which will benefit the local community. Therefore the development proposals meet the first part of the Exception Test.
Has the Council actually identified a need for a care home at this location? If so, such Council identification of a need for a care home at this location appears to be a specious and fallacious argument designed to mislead spectators into an acceptance of use of this land. This makes one suspect that there may be ulterior motives, or that planners or Councillors have been gulled into an unnecessary acceptance of use of this Green Belt flood plain land.
2. "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."
A sea level rise will change the situation. But apart from that we believe that this development will increase flood risk elsewhere. It cannot possibly reduce flood risk overall.
This FRA aims to assess the flood risk from all sources in order to ensure that the development will be safe from flooding, meeting the second part of the Exception Test.
As the Sequential and Acceptance tests have failed the remainder of this report is redundant. However, we have further criticism as follows.
Page 13
The area is subject to a greater than 75% Ground Water flood risk.
This in itself should be enough to stop consideration.
Page 17
Existing ditch to be redirected. Riparian owner has to keep the watercourse clear and Council can serve notices on riparian owner to deal with obstructions.
The document states;
“As the development is proposed in an undefended area of floodplain, which lies outside of the functional floodplain, the implications of ground raising operations for flood risk elsewhere needs to be considered. Raising existing ground levels may reduce the capacity of the floodplain to accommodate floodwater and increase the risk of flooding elsewhere due to flood water displacement.”
The last sentence is particularly of interest and relates to our comment on page 25 details.
Page 18
Warning and Flood Evacuation Plan to be prepared in liaison with the Local Authority and the Emergency Services.
Further expense – who is to pay for this?
Page 20
The proposed development will increase the impermeable areas on the site by 49% (1.55ha), therefore the peak surface water runoff rate and volume to the public sewer will be increased.
As if the above is not a sufficiently bad consequence of this development, the report continues;
However it must be noted that the northern part of the site will be flooded in a 1 in 100 year storm event and there will be no surface water runoff for such a storm event. The unmitigated peak runoff rate has been calculated using the Modified Rational methods.
Clearly, the above and previous are bad points that need to be highlighted.
Page 22
It is proposed that cellular storage tanks be used to provide onsite attenuation storage to reduce the peak surface water runoff rate from the development. Surface water runoff from the car parks and the buildings will be attenuated before being discharged to the lake.
Figure 8.2 - Attenuation Storage In accordance with the SFRA, the peak surface water runoff rates will be reduced to Greenfield runoff rates prior to discharge to the public sewer. As mentioned in section 6.1 the Greenfield runoff rate was found to be 16.21 l/s. The proposed landscaped areas will have a runoff rate of 8.12 l/s which will discharge freely into Bray Lake.
Microdrainage has been used to determine the total volume of attenuation storage required to reduce the overall peak surface water runoff rate to remaining allowance of 6.9 l/s, for a 1 in 100 year plus 20% climate change allowance storm event.
The preliminary calculations (Appendix B) assume that there will be two attenuation tanks with a combined storage volume of 884m³. It is proposed that these tanks be located at the northern side of the car parks beneath the paving. This will keep the tanks away from any building foundation structures.
Final dimensions for the attenuation tanks are to be determined once the architectural plans are finalised. Refer to Appendix C for an indicative drainage layout plan. The attenuated surface water will be discharged by gravity via a Hydrobrake to control the flow rate. The surface water will be passed through a petrol interceptor before discharged into Bray Lake.
Cellular storage tanks are proposed, having a storage volume of 884 cubic metres. This is equivalent to a cube of 9.597 metres or 31.5 feet. However, the thickness of the containing walls has not been mentioned, and these will presumably be approximately 0.75 meters so in plan the cube side becomes 11 metres (36 ft) with say a 10.5 metre (34.5 ft) depth – volume now 1270.5 cubic metres to be extracted from the water bearing capacity of the land.
Consider an area of land that currently has a certain capacity for drainage. Removal of 1270.5 cubic metres of that land will cause higher water levels in the area, an area in which in this case there is already cellar flooding in at least one older property. The creation of this 1270.5 cubic meters tank will assist the proposed development to drain its own area but will reduce the drainage rate in the surrounding area.
Further, the installation of underground storage tanks having an estimated volume of 1270.5 cubic metres could result in an effective underground wall of a width of 36 ft with a depth of 34.5 ft.
We believe that such devices are unhelpful and that development of this idea is a sophism, designed to gull planners and Councillors into accepting flood plain development.
Page 24
Property Owner is responsible for ensuring that the SuDS are maintained.
Will Thames Hospice commit to maintaining the SuDS (Sustainable Drainage System – the land lowering, new gulley and tanks)? And is the proposed SuDS fit for purpose? We say it is not, and that the barrier imposed by the underground tanks will possibly make the situation worse.
Page 25
Conclusions and Recommendations
This FRA related to fluvial flooding from Bray Lake. The site is located partially within Flood Zone 1 and 2. By raising the levels of the site, the development can be built and occupied with residual flood risk. The Hospice is proposed for allocation in the RBWMLP with the associated housing development to the west of the site.
As far as we know there has been no definite proposal for housing so this should not be mentioned here.
• Ground levels will need to be raised for the buildings falling within the Flood Zone 1 and 2. Ground levels will be lowered within the site to mitigate the displacement of flood water into the neighbouring properties and surrounding areas. This will be on a volume for volume basis.
We see no indication in the plans as to where or how this lowering will take place. No figures are given for the volume referred to. It seems impossible to make such a reduction. The report says on page 5 Para 2.4 that the water table is at only 900mmm below the surface. Lowering below the normal water table is clearly not allowable in making this benefit, and any lowering close to the water table will result in muddy areas.
• The FFLs of the proposed buildings will be set at 23.170m AOD which meets the minimum required 300mm freeboard above the 1 in 100 year plus 35% climate change allowance design flood level of 22.809. This will also allow the FFLs to remain above the flood level for a 1 in 100 year plus 70% climate change allowance design flood level of 23.168m AOD;
• There will be an increase in impermeable areas on site and therefore an increase in the surface water runoff rates or peak volumes;
This will result in an increase in the water table height, not only to the detriment of adjacent areas, but will further reduce the depth to which the intended land lowering may extend.
• Rainwater will be stored onsite and surface water discharge will be restricted to 16.63l/s;
• If possible, permeable paving, green roofs and rainwater harvesting will be included in the development proposals;
The words “if possible” are not acceptable – do the plans include it or not?
• The drainage strategy will seek to restrict peak flows via an attenuation tank system (designed for the 1 in 100 year plus 20% climate change allowance storm event) before discharging to the nearby water body (Bray Lake);
See comment below.
• An attenuation volume of 884m³ will be required to achieve a total proposed runoff rate of 16.63l/s;
Cellular storage tanks are proposed, having a storage volume of 884 cubic metres. This is equivalent to a cube of 9.597 metres or 31.5 feet. However, the thickness of the containing walls has not been mentioned, and these will presumably be approximately 0.75 meters so in plan the cube side becomes 11 metres (36 ft) with say a 10.5 metre (34.5 ft) depth – volume now 1270.5 cubic metres to be extracted from the water bearing capacity of the land.
Consider an area of land that currently has a certain capacity for drainage. Removal of 1270.5 cubic metres of that land will cause higher water levels in the area, an area in which in this case there is already cellar flooding in at least one older property. The creation of this 1270.5 cubic meters tank will assist the proposed development to drain its own area but will reduce the drainage rate in the surrounding area.
Further, the installation of underground storage tanks having an estimated volume of 1270.5 cubic metres could result in an effective underground wall of a width of 36 ft with a depth of 34.5 ft.
We believe that such devices are unhelpful and that development of this idea is a sophism, designed to gull planners and Councillors into accepting flood plain development.
• Therefore, the proposed development has an acceptable flood risk within the terms and requirements of NPPF, the EA and the SFRA.
Not agreed.
The following is the text of our comments against the Flood Risk Assessment provided by Thames Hospice. This assessment was sent by email to all RBWM Borough Councillors the day before the meeting. No-one mentioned it in the meeting.
There are particular points here that show that RBWM have contravened the NPPF in selecting this area in Flood Plain 2 and 3.
See the text and our comments against page 12 paragraph 5.3.
____________________________________________________
HRA considers that this Flood Risk Assessment fails to convince that development of this area is appropriate. Further the report reveals that the objectives of the NPPF and PPG Sequential and Exception Tests have not been met. In fact it appears that the Borough Council has predetermined that this development shall take place, in this mainly Flood Zone 2 area for reasons that are not supported by the NPPF requirements.
Our comments are shown in red with some underlining. The black text is abstracted from the Price an Myers document.
Page 3
Price and Myers say they were commissioned to produce this report. It should be confirmed that RBWM did not request or influence the production of this report.
Page 5
2.3 Thames Water have to pump new sewage from this development to a Windsor Road manhole.
Has Thames Water confirmed that their network has sufficient capacity? Who would pay for this?
- The water table is stated to be at 900 mm.
Is this below the 24.5m AOD or below the 20.5m AOD?
Page 8
4
Drainage channel has to be maintained. It drains an area of 196 hectares to South of Windsor Road.
Has Thames Hospice committed to this maintenance?
Page 9 & 10
5.2 Flood Risk from Surface Water & Overland Flows
- Large catchment area to the South, - whose configuration channels the water underground under approximately 14 properties on the Windsor Road.
Have the 7 property owners each side of the pumping station (14 in all) under whose properties the catchment area lies been advised of the dangers of interfering with the existing drainage? In particular, has the blockage effect of installing underground storage tanks having an estimated volume of 1270.5 cubic metres been advised to them? If installed in the conformation of an approximate cube, the effective underground wall would have a width of 36 ft with a depth of 34.5 ft.
Page 11
Fig 5.4
The Historical Surface Water Flooding Map shows the extent of flooding in the past.
There are predictions of drastic sea level rises within 50 years. Has this been considered?
Page 12
Fig 5.5 Shows possible Surface Water flooding in the existing situation, with 7 Windsor Road properties affected.
Has the size of the new gully been designed to cope with not only such a spread of water, but also that arising in the future bearing in mind that the development will divert water from its normal course and that the sea level is rising?
5.3 Sequential & Exception Tests
In accordance with the NPPF and the PPG, the risk-based Sequential Test should be applied at all stages of the planning process. Its aim is to steer new development to areas at the lowest probability of flooding (Zone 1). Developments should not be permitted if there are reasonably available sites to accommodate the “proposed development" in areas with a lower probability of flooding.
It is clear that other sites are available in areas with a lower probability of flooding, in fact there are areas available with no probability of flooding; therefore the proposed development fails this test. The subject land is mostly Zone 2 with some Zone 3, so choosing to develop here does not comply with the NPPF.
The RBWMLP "Edge of Settlement Part 2 Constraints, Opportunities and Delivery Assessment", dated July 2016, assesses the site's (Parcel M35) potential for future development. The assessment identifies all constraints, including flooding, and concludes that "The Parcel has been promoted for residential use and is considered available".
It is clear that other sites are available in areas with a lower probability of flooding, therefore the Edge of Settlement conclusions are wrong, as the proposed development, and any development in this area, fails the sequential and exception test.
PPG (para 102) states two conditions for the Exception Test to be passed:
1. "It must be demonstrated that the development provides wider sustainability benefits to the community that outweigh flood risk, informed by a SFRA where one has been prepared".
As other sites are available in areas with a lower probability of flooding, the proposal has already failed and the above paragraph becomes irrelevant.
The RBWM Supplementary Planning Document - Planning for an Aging Population (Sept 2010) Requirement PAP11 Providing Care Homes or Housing for Older People in Areas with Restrictive Designations states, "The development , or redevelopment, of care homes or housing for older people may be acceptable within some restrictive designations where they will directly address a local need, as agreed by the council."
The Council have identified the need for a care home at this location which will benefit the local community. Therefore the development proposals meet the first part of the Exception Test.
Has the Council actually identified a need for a care home at this location? If so, such Council identification of a need for a care home at this location appears to be a specious and fallacious argument designed to mislead spectators into an acceptance of use of this land. This makes one suspect that there may be ulterior motives, or that planners or Councillors have been gulled into an unnecessary acceptance of use of this Green Belt flood plain land.
2. "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."
A sea level rise will change the situation. But apart from that we believe that this development will increase flood risk elsewhere. It cannot possibly reduce flood risk overall.
This FRA aims to assess the flood risk from all sources in order to ensure that the development will be safe from flooding, meeting the second part of the Exception Test.
As the Sequential and Acceptance tests have failed the remainder of this report is redundant. However, we have further criticism as follows.
Page 13
The area is subject to a greater than 75% Ground Water flood risk.
This in itself should be enough to stop consideration.
Page 17
Existing ditch to be redirected. Riparian owner has to keep the watercourse clear and Council can serve notices on riparian owner to deal with obstructions.
The document states;
“As the development is proposed in an undefended area of floodplain, which lies outside of the functional floodplain, the implications of ground raising operations for flood risk elsewhere needs to be considered. Raising existing ground levels may reduce the capacity of the floodplain to accommodate floodwater and increase the risk of flooding elsewhere due to flood water displacement.”
The last sentence is particularly of interest and relates to our comment on page 25 details.
Page 18
Warning and Flood Evacuation Plan to be prepared in liaison with the Local Authority and the Emergency Services.
Further expense – who is to pay for this?
Page 20
The proposed development will increase the impermeable areas on the site by 49% (1.55ha), therefore the peak surface water runoff rate and volume to the public sewer will be increased.
As if the above is not a sufficiently bad consequence of this development, the report continues;
However it must be noted that the northern part of the site will be flooded in a 1 in 100 year storm event and there will be no surface water runoff for such a storm event. The unmitigated peak runoff rate has been calculated using the Modified Rational methods.
Clearly, the above and previous are bad points that need to be highlighted.
Page 22
It is proposed that cellular storage tanks be used to provide onsite attenuation storage to reduce the peak surface water runoff rate from the development. Surface water runoff from the car parks and the buildings will be attenuated before being discharged to the lake.
Figure 8.2 - Attenuation Storage In accordance with the SFRA, the peak surface water runoff rates will be reduced to Greenfield runoff rates prior to discharge to the public sewer. As mentioned in section 6.1 the Greenfield runoff rate was found to be 16.21 l/s. The proposed landscaped areas will have a runoff rate of 8.12 l/s which will discharge freely into Bray Lake.
Microdrainage has been used to determine the total volume of attenuation storage required to reduce the overall peak surface water runoff rate to remaining allowance of 6.9 l/s, for a 1 in 100 year plus 20% climate change allowance storm event.
The preliminary calculations (Appendix B) assume that there will be two attenuation tanks with a combined storage volume of 884m³. It is proposed that these tanks be located at the northern side of the car parks beneath the paving. This will keep the tanks away from any building foundation structures.
Final dimensions for the attenuation tanks are to be determined once the architectural plans are finalised. Refer to Appendix C for an indicative drainage layout plan. The attenuated surface water will be discharged by gravity via a Hydrobrake to control the flow rate. The surface water will be passed through a petrol interceptor before discharged into Bray Lake.
Cellular storage tanks are proposed, having a storage volume of 884 cubic metres. This is equivalent to a cube of 9.597 metres or 31.5 feet. However, the thickness of the containing walls has not been mentioned, and these will presumably be approximately 0.75 meters so in plan the cube side becomes 11 metres (36 ft) with say a 10.5 metre (34.5 ft) depth – volume now 1270.5 cubic metres to be extracted from the water bearing capacity of the land.
Consider an area of land that currently has a certain capacity for drainage. Removal of 1270.5 cubic metres of that land will cause higher water levels in the area, an area in which in this case there is already cellar flooding in at least one older property. The creation of this 1270.5 cubic meters tank will assist the proposed development to drain its own area but will reduce the drainage rate in the surrounding area.
Further, the installation of underground storage tanks having an estimated volume of 1270.5 cubic metres could result in an effective underground wall of a width of 36 ft with a depth of 34.5 ft.
We believe that such devices are unhelpful and that development of this idea is a sophism, designed to gull planners and Councillors into accepting flood plain development.
Page 24
Property Owner is responsible for ensuring that the SuDS are maintained.
Will Thames Hospice commit to maintaining the SuDS (Sustainable Drainage System – the land lowering, new gulley and tanks)? And is the proposed SuDS fit for purpose? We say it is not, and that the barrier imposed by the underground tanks will possibly make the situation worse.
Page 25
Conclusions and Recommendations
This FRA related to fluvial flooding from Bray Lake. The site is located partially within Flood Zone 1 and 2. By raising the levels of the site, the development can be built and occupied with residual flood risk. The Hospice is proposed for allocation in the RBWMLP with the associated housing development to the west of the site.
As far as we know there has been no definite proposal for housing so this should not be mentioned here.
• Ground levels will need to be raised for the buildings falling within the Flood Zone 1 and 2. Ground levels will be lowered within the site to mitigate the displacement of flood water into the neighbouring properties and surrounding areas. This will be on a volume for volume basis.
We see no indication in the plans as to where or how this lowering will take place. No figures are given for the volume referred to. It seems impossible to make such a reduction. The report says on page 5 Para 2.4 that the water table is at only 900mmm below the surface. Lowering below the normal water table is clearly not allowable in making this benefit, and any lowering close to the water table will result in muddy areas.
• The FFLs of the proposed buildings will be set at 23.170m AOD which meets the minimum required 300mm freeboard above the 1 in 100 year plus 35% climate change allowance design flood level of 22.809. This will also allow the FFLs to remain above the flood level for a 1 in 100 year plus 70% climate change allowance design flood level of 23.168m AOD;
• There will be an increase in impermeable areas on site and therefore an increase in the surface water runoff rates or peak volumes;
This will result in an increase in the water table height, not only to the detriment of adjacent areas, but will further reduce the depth to which the intended land lowering may extend.
• Rainwater will be stored onsite and surface water discharge will be restricted to 16.63l/s;
• If possible, permeable paving, green roofs and rainwater harvesting will be included in the development proposals;
The words “if possible” are not acceptable – do the plans include it or not?
• The drainage strategy will seek to restrict peak flows via an attenuation tank system (designed for the 1 in 100 year plus 20% climate change allowance storm event) before discharging to the nearby water body (Bray Lake);
See comment below.
• An attenuation volume of 884m³ will be required to achieve a total proposed runoff rate of 16.63l/s;
Cellular storage tanks are proposed, having a storage volume of 884 cubic metres. This is equivalent to a cube of 9.597 metres or 31.5 feet. However, the thickness of the containing walls has not been mentioned, and these will presumably be approximately 0.75 meters so in plan the cube side becomes 11 metres (36 ft) with say a 10.5 metre (34.5 ft) depth – volume now 1270.5 cubic metres to be extracted from the water bearing capacity of the land.
Consider an area of land that currently has a certain capacity for drainage. Removal of 1270.5 cubic metres of that land will cause higher water levels in the area, an area in which in this case there is already cellar flooding in at least one older property. The creation of this 1270.5 cubic meters tank will assist the proposed development to drain its own area but will reduce the drainage rate in the surrounding area.
Further, the installation of underground storage tanks having an estimated volume of 1270.5 cubic metres could result in an effective underground wall of a width of 36 ft with a depth of 34.5 ft.
We believe that such devices are unhelpful and that development of this idea is a sophism, designed to gull planners and Councillors into accepting flood plain development.
• Therefore, the proposed development has an acceptable flood risk within the terms and requirements of NPPF, the EA and the SFRA.
Not agreed.