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PROPOSED RESIDENTIAL DEVELOPMENT
LAND ADJACENT CHAWTON PARK ROAD, ALTON, HAMPSHIRE
Surface Water Drainage Strategy
Report No. 13-231-01
December 2013
PROPOSED RESIDENTIAL DEVELOPMENT
LAND ADJACENT TO CHAWTON PARK ROAD, ALTON, HAMPSHIRE
Odyssey Markides LLP
Tuscany House
White Hart Lane
Basingstoke
Hampshire
RG21 4AF
Tel: 01256 331144
Fax: 01256 331134
[email protected]
Project No. 13-231
December 2013
Proposed Residential Development,
Land adjacent to Chawton Park Road, Alton, Hampshire
13-231
December 2013
DOCUMENT CONTROL SHEET
REV
ISSUE PURPOSE
AUTHOR
CHECKED
REVIEWED
APPROVED
DATE
-
For review
TS
SJO
RS
BAC
Dec 2013
TS/ts/Report/13-231-01
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CONTENTS
PAGE
1.
Introduction
1
2.
Development Proposals
2
3.
Baseline Conditions
3
4.
Flood Risk Legislation and Policy Review
6
5.
14
6.
Foul Drainage Strategy
19
7.
Impact on Other Land
20
8.
Conclusions
21
APPENDICES
Figure 1
Site Location Plan
Appendix A
Proposed Masterplan
Appendix B
Topographical Survey
Appendix C
Groundwater and Flood Mapping - Environment Agency
Appendix D
Sewer Record Extracts – Thames Water Utilities Limited
Appendix E
Ground Investigation Extracts
Appendix F
Outline Drainage Strategy (Drawing no. 13-231-001)
Appendix G
Micro Drainage Surface Water Storage Calculations
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1.0
INTRODUCTION
1.1
Odyssey Markides LLP has been commissioned by BNP Paribas to undertake
a Surface Water Drainage Strategy (SWDS) to support a detailed planning application
for a new bowling club on the land adjacent to Chawton Park Road in Alton,
Hampshire. A site location plan is presented as Figure 1.
1.2
The existing site is approximately 0.5ha and is occupied with an open grass
field and trees. The proposals for the new Bowling Club comprise the construction of
a new sports club building, bowling green pitch, car park and associated access road
from a shared access serving the neighbouring Nursery & Girl Guide Centre. A copy of
the proposed site plan can be found in Appendix A.
1.3
This report comprises the following elements:

Review existing legislation, policy and supporting documents in relation to
flood risk and surface water drainage;

Demonstrate through use of an effective surface water drainage strategy,
incorporating sustainable drainage systems (SuDS), that any potential
flooding on this site can be safely mitigated in accordance with the
requirements of the National Planning Policy Framework (Communities and
Local Government, March 2012) (NPPF);

Prepare a surface water drainage strategy illustrating how the site can be
drained effectively and in accordance with the requirements of East
Hampshire District Council (EHDC), Hampshire County Council (HCC), the
Environment Agency (EA) and Thames Water Utilities Limited (TWUL).
1.4
This drainage strategy has been prepared in accordance with the requirements
set out in the NPPF and EA Guidance.
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2.0
DEVELOPMENT PROPOSALS
2.1
The development proposals comprise a new sports club building, bowling green
pitch, car parking and associated access road. A copy of the proposed masterplan can
be found in Appendix A.
2.2
Access to the new Bowling Club will be at the north eastern boundary via an
existing access road off Chawton Park Road, which also serves the Nursery and Girl
Guide Centre.
2.3
Surface water run-off will be managed using a SuDS management train making
use of infiltration trenches and permeable paving.
2.4
The foul water drainage system will be designed in accordance with the
requirements of Part H of the Building Regulations and will discharge to the existing
on-site public foul sewer in the north of the site, subject to agreement with TWUL. The
foul drainage strategy is discussed in detail in Chapter 6.
(2)
3.0
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BASELINE CONDITIONS
Sources of Information
3.1
The baseline conditions for this site have been established using the following
sources and references:

EA mapping;

TWUL Asset location plans;

British Geological Survey (BGS) mapping;

Existing Topographical Survey undertaken by Site Vision Surveys Limited;

EHDC’s Strategic Flood Risk Assessment (SFRA);

Phase 1 Desk Top Study by Soil Environment Services Ltd;

Trial Pits and Soakaway Tests by Geo-Environmental (ref:
GE9666/GR02/131108).
Site Description
3.2
The site is bounded to the north by Chawton Park Road, to the east by a
Nursery & Girl Guide Centre, to the west by a Cardiac Rehabilitation Centre and to the
south by Tennis Courts and open grass fields. The approximate centre of the site is at
Ordnance Survey (OS) Grid Reference 470770E, 138224N.
3.3
The site currently comprises of vacant an open grass field with trees.
Site Topography
3.4
The site generally slopes from south-west to north-east. The highest level on
the site is approximately 119.91 mAOD near the south-west boundary of the site, the
lowest level is approximately 116.43 mAOD in the north-east of the site.
topographical survey is presented as Appendix B.
(3)
The
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Geology
3.5
BGS mapping indicates that the bedrock beneath the site is the Holywell
Nodular Chalk Formation. No superficial geology has been recorded on this site.
3.6
Intrusive ground investigations including falling head infiltration testing has
been conducted on this site. Trial pits were excavated to a depth of 0.8m bgl (below
ground level). The results of the investigations indicate that the site is underlain by
clayey SILT and SAND HEAD DEPOSITS. A copy of the trial pit logs can be found in
Appendix E.
Hydrology
3.7
The EA’s Flood Map indicates that the site is located in Flood Zone 1. The EA’s
Flood Map is presented as part of Appendix C.
3.8
The Lavant Stream is the closest watercourse and is located approximately
300m south of the site.
Hydrogeology
3.9
Groundwater mapping published by the EA indicates that the site is located
over a Groundwater Vulnerability Zone designated Major Aquifer – High, with the
bedrock beneath the site designated as a Principal Aquifer. No superficial geology is
recorded. It is not located over a groundwater source protection zone; however, Zone
2&3 of a groundwater source protection zone are situated approximately 13m north of
the site boundary. The EA’s groundwater mapping is presented as part of Appendix
C.
3.10
EHDC’s SFRA indicates that there has been no known groundwater flooding
events within the vicinity of the site.
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Existing Surface Water Drainage Regime
3.11
The existing site generally falls from south-west to north-east, towards the
Chawton Park Road. As the site is open grass fields it is assumed that the existing
surface water run-off drains naturally to ground.
Existing Foul Water Drainage Regime
3.12
A foul sewer currently runs along Chawton Park Road conveying flows in an
easterly direction. There is an existing private 100mm diameter foul sewer located
within the site at the north eastern corner. It is assumed that this existing private
network currently serves the Nursery & Girl Guides Centre. Extracts from the TWUL
sewer records are presented as Appendix D.
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4.0
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FLOOD RISK LEGISLATION AND POLICY REVIEW
Legislation
Flood and Water Management Act 2010
4.1
The Flood and Water Management Act 2010 (FWMA) received Royal Assent on
th
8 April 2010. The Act was introduced to enforce some of the key proposals set out
within UK Government flood and water strategies along with the UK Government’s
response to Sir Michael Pitt’s Review of the summer 2007 floods.
4.2
Relevant to development sites, the FWMA is intended to encourage the uptake
of SuDS by removing the automatic right to connect to sewers and providing for
unitary and County Council’s to adopt SuDS for new developments.
4.3
The development proposals will adhere to the FWMA through the provision of
SuDS as a fundamental element of the surface water drainage system. Furthermore,
BNP Paribas are committed to working with the relevant stakeholders, such as the EA,
EHDC, HCC in implementing the requirements of the FWMA.
Flood Directive - The Flood Risk Regulations 2009
4.4
The Flood Risk Regulations 2009 came into force on 10 th December 2009,
transporting the European Floods Directive into domestic law. In essence the
Regulations require the EA to prepare flood risk assessments, maps and plans for sea,
main river and reservoir flood risk and will require lead local flood authorities (unitary
and county councils) to do the same for all other forms of flooding.
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National Policy
National Planning Policy Framework 2012
4.5
The National Planning Policy Framework 2012 (NPPF) replaced all planning
policy statements (including Planning Policy Statement 25: Development and Flood
Risk) upon publication in March 2012.
4.6
The NPPF sets out the Government’s planning policies for England and Wales,
and how these policies should be applied. The Technical Guidance to the NPPF (TG)
published in unison with the NPPF provides additional guidance and retains the key
elements of the now superseded PPS25.
4.7
The NPPF states that “inappropriate development in areas at risk of flooding
should be avoided by directing development away from areas of highest risk, but
where development is necessary, making it safe without increasing flood risk
elsewhere.”
4.8
When determining planning applications, local planning authorities should
ensure flood risk is not increased elsewhere and only consider appropriate
development in areas at risk of flooding where, following application of the Sequential
Test (and if required, the Exception Test) it can be demonstrated that:

Within the site, the most vulnerable development is located in areas of
lowest flood risk unless there are overriding reasons to prefer a different
location; and,

Development is appropriately flood resilient and resistant, including safe
access and escape routes where required, and that any residual risk can
be safely managed, including by emergency planning; and it gives priority
to the use of Sustainable Drainage Systems. (NPPF, 2012)
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4.9
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All land in England and Wales is classified into three main Flood Zones which
refer to the probability of river or sea flooding (ignoring the existence of defences).
The TG identifies and describes the EA Flood Zones as:

Flood Zone 1: Low Probability defined as land assessed as having less
than 1 in 1,000 annual probability of river or sea flooding (<0.1%),

Flood Zone 2: Medium Probability defined as land assessed as having
between 1 in 100 and 1 in 1,000 annual probability of river flooding (1% 0.1%) or between 1 in 200 and 1 in 1,000 annual probability of sea flooding
(0.5% - 0.1%),

Flood Zone 3a: High Probability defined as land assessed as having a 1 in
100 or greater annual probability of river flooding (≥1%), or a 1 in 200 or
greater annual probability of sea flooding (≥0.5%),

Flood Zone 3b: The Functional Floodplain defined as land where water has
to flow or be stored in times of flood (as identified by local planning
authorities in their SFRA's).
4.10
In accordance with the NPPF. A site specific FRA is required for:

Proposals of 1 hectare or greater in Flood Zone 1,

All proposals for development in Flood Zones 2 and 3,

An area within Flood Zone 1 which has critical drainage problems,

Development or change of use to a more vulnerable class that may be
subject to other sources of flooding.
4.11
Given the above, the site does not require a site-specific FRA on the basis
that the site is less than one hectare and the area of development is located within
Flood Zone 1.
(8)
4.12
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Greenfield sites rely on natural drainage to convey or infiltrate rainfall.
In
general, site development can reduce the permeability of the site if not well designed,
increasing the volume and rate of surface water running off the site to nearby
watercourses. This in turn potentially increases flood risk to downstream areas.
Therefore appropriate drainage flow regulation arrangements may be required for new
developments to ensure that flood risk to others is not increased and attempts to
mimic the existing characteristics of the site in the form of Sustainable Drainage
Systems (SuDS) wherever physically possible.
National Standards for Sustainable Drainage Systems 2011
4.13
The National Standards for Sustainable Drainage Systems (NSSDS) was
published in draft format in December 2011. This Department for Environment, Food
and Rural Affairs (DEFRA) document provides guidance on designing, constructing,
operating and maintaining drainage for surface run-off.
4.14
The standards are to be used in order to manage surface run-off in accordance
with Schedule 3 of the FWMA.
4.15
The standards state the run-off destination should be considered in the
following order of preference:
4.16

Discharge into the ground (infiltration);

Discharge to a surface water body;

Discharge to a surface water sewer;

Discharge to a combined sewer.
Although yet to be formally adopted, the NSSDS provides guidance on run-off
destination, peak flow rate, volume and control of water quality and function.
(9)
4.17
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The NSSDS sets out the requirements in order to obtain approval from the
SuDS Approving Body (SAB) for operating and maintaining SuDS. In addition to the
standards, the Local Planning Authority may set local requirements for planning
permission that have the effect of more stringent requirements than that of the
standards.
East Hampshire District Strategic Flood Risk Assessment
4.18
East Hampshire District Council are required to produce a Strategic Flood Risk
Assessment (SFRA) in accordance with the now superseded Planning Policy
Statement 25 1 (PPS25) and; Development & Flood Risk, a Practice Guide Companion
to the PPS25.
The SFRA will “…inform the plan-making process of the a Local
Development Framework” and “…in particular inform the Core Strategy, the
Development Control Policies and the Development Provisions and Allocations
documents”.
4.19
The East Hampshire District Strategic Flood Risk Assessment (April 2008), a
living document, will inform Local Planning Authorities of flood related issues within the
District, aiding the decision process for development provision and allocations via the
Sequential Approach and Sequential Test as defined by NPPF.
4.20
The objective of the SFRA is to reduce the exposure of new developments to
flooding and minimise exacerbating risk to existing developments and reduce the
reliance on long-term maintenance of built flood defences.
4.21
The SFRA is a Level 1 study presented in a single main report document with
figures and appendices providing additional flood mapping information.
4.22
Tile Flood Maps A to E represent flood extents, produced by the Environment
Agency in December 2007 as derived from the ‘Jflow’ generalised computer modelling.
It should be noted that ‘Jflow’ is a ‘coarse modelling approach’ with a large number of
assumptions incorporated within the model. In some locations the river centreline
incorporated into Jflow modelling was found to be erroneous with the result that the
associated flood plains deviate from the natural valleys, as can been seen evident on
the tile flood maps.
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4.23
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The tile flood maps can still be used to identify locations of Localised Flooding
Areas (relate to historical flooding at individual locations), sewerage undertaker’s
sewer flooding incidents and flooding due to other sources.
The Water Industry Act 1991
4.24
The Water Industry Act 1991 (WIA) (HMSO, 1991) was introduced to
consolidate previous water supply and wastewater services enactments in the UK.
Section 94 sets out the principal duties and standards of performance to sewerage
undertakers which include the duty ‘to provide, improve and extend such a system of
public sewers (whether inside its area or elsewhere) and so to cleanse and maintain
those sewers as to ensure that that area is and continues to be effectually drained’.
4.25
Relevant to new development, Section 104 and Section 106 of the WIA
provides the framework for the adoption of sewers, subject to an agreement with the
sewerage undertaker, who in this case is TWUL.
4.26
Section 98 of the WIA provides the legal mechanism through which the
appropriate infrastructure can be requested (by the developer) and provided to drain a
specific location off-site through third party land.
4.27
Section 106 allows the sewerage undertaker a 21 day notice period prior to the
connection works being undertaken. During this time the application may be refused if
the undertaker considers that the connection mode or condition of the connecting
sewer does not satisfy the required standards.
The undertaker cannot refuse the
connection based on inadequate capacity.
Transfer of Private Sewers
4.28
It should be noted that the Water Industry (Schemes for Adoption of Private
Sewers) Regulations 2011 has transferred private sewers into the ownership of
statutory sewerage companies in England since October 2011. The Government are
also taking steps to stem the proliferation of newly built sewers in order to prevent the
recurrence of existing ownership/maintenance problems in the future.
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Pitt Review
4.29
In response to the severe flooding in the UK during the summer of 2007, the
government commissioned an independent review on lessons to be learned. The Pitt
Review was comprehensive and considered all stages of flooding - preparedness,
response and recovery - as well as the coordination, responsibilities, and legislation
necessary to ensure the UK can advance in the area of flood risk management.
Sewers for Adoption 7 th Edition
4.30
Sewers for Adoption (SFA) 7th Edition provides guidance for developers for the
design and construction of both surface and foul water sewers to be offered for
adoption. The guidance is provided in consultation with Water Undertakers. However,
please note that whilst SFA 7 th Edition is the latest publication, until Section 42 of the
FWMA is enforced SFA 6 th Edition can still be implemented.
4.31
The SFA places responsibility (in England and Wales) for existing and future
private sewers and lateral drains that connect to the public sewer system to the water
and sewerage companies.
4.32
The SFA will provide detailed guidance to support the Mandatory Build
Standard whereby; it will be mandatory for new sewers and lateral d rains (between the
sewer and the serviced property boundary) to be adopted to public status by the
sewerage undertaker.
4.33
The guidance for foul sewer design in Sewers for Adoption states:
‘The design of flows for gravity sewers for residential developments should be
4,000 litres/unit dwelling/per 24 hours.’
Building Regulations
4.34
Where drainage within a development is not to be adopted by the sewerage
undertakers, the so called private sewers will require to meet the standards as set out
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in Building Regulations 2002, Part H ‘Drainage and Waste Disposal’ guidance on the
design of private sewers.
4.35
Specific guidance can be found within the following sections of the Building
Regulations 2002 Part H.

H1 – Foul water drainage

H2 – Wastewater treatment systems and cesspools

H3 – Rainwater drainage

H4 – Building over sewers

H5 – Separate systems of drainage

H6 – Solid waste storage
Pollution Prevention Guidance
4.36
For sewers not connected to a public adopted system, the Environment
Agency’s Pollution Prevention Guidance 4 (PPG4) ‘Treatment and Disposal of Sewage
where no foul sewer is available’ should be considered. However this guidance states
that “discharge to a foul sewer is the preferred option as the sewage is conveyed to a
purpose built and closely monitored sewage treatment plant, so development
proposals in sewered areas should connect to public sewers.”
(13)
5.0
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SURFACE WATER DRAINAGE STRATEGY
Sustainable Drainage Systems
5.1
The NPPF and EA guidance requires developments to employ SuDS
techniques where feasible in the management of site run-off and surface water
drainage on all new developments. Careful design of SuDS features can ensure that
the proposed surface water regime closely reflects the natural hydrology and
hydrogeology of the site.
5.2
The key benefits of the proposed SuDS on site are as follows:

Improving water quality over a conventional piped system by allowing the
settlement of pollutants.

Improving amenity through the provision of open green space and wildlife
habitat.

Enabling a natural drainage system which maintains the existing surface
water flow regime.
5.3
Source Control is a key element of SuDS and is now identified in Part H of the
Building Regulations 2002 as taking preference over conventional drainage systems.
Part H now states:
“Rainwater from a system provided pursuant to sub-paragraphs (1) or (2)
shall discharge to one of the following, listed in order of priority:
(a)
an adequate soakaway or some other adequate infiltration system;
or where that is not reasonably practicable,
5.4
(b)
a watercourse; or where that is not reasonably practicable,
(c)
a sewer.”
Source control systems treat water close to the point of collection, in features
such as soakaways, permeable pavements and dry swales.
(14)
As source control
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measures generally rely upon the infiltration of surface water to the ground, it is a
prerequisite that the ground conditions are appropriate. BGS mapping advises the
site is underlain by the Holywell Nodular Chalk Formation which is predominantly
Chalk.
5.5
The soakage potential of this strata is acceptable according to intrusive ground
investigations, extracts of which are presented as Appendix E. The infiltration rate
across this site averages at approximately 2.46.x10-5m/s.
5.6
The surface water run-off from the proposed development is proposed to be
managed using the following methods across the site.

The main access road and car park for the bowling club will be drained
using permeable paving with full infiltration to the sub-strata;

The roof drainage from the new sports club, surrounding small buildings
and hard standings will be collected and conveyed to discharge within
the permeable paving system in the adjacent car park;

The new bowling green will be drained in accordance with Sport
England recommendations with drainage trenches at the perimeter and
within the green at constant intervals. Surface water run-off is to
discharged directly into the ground with an overflow provision to the
permeable paving system in the adjacent car park.
5.7
Utilising permeable paving and infiltration trenches will help cleanse any
surface water of heavy metals, hydrocarbons, rubber dust, silts and other detritus by
settlement prior to entering into the sub-strata.
5.8
The proposed on-site surface water gravity sewer will be designed to cater for
the 1 in 30 year storm. Attenuation systems will store surface water run-off on-site
arising from flood events up to and including the 1 in 100 year plus 30% climate
change storm. A copy of the Surface Water Drainage Strategy drawing (13-231-001)
can be found in Appendix F.
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5.9
December 2013
The FWMA has amended Section 106 of the Water Industry Act to remove the
automatic right to connect surface water without prior consideration to SuDS.
5.10
SuDS will attenuate and treat surface water run-off at source (source control) in
line with the NPPF with its associated documents and the EA’s policies.
5.11
As part of the requirement of the Code for Sustainable Homes, SuDS will also
benefit the assessment of residential homes in the Code for Sustainable Homes rating
criteria.
Proposed Surface Water Discharge
5.12
The current drainage strategy seeks to discharge all surface water run-off on
site via infiltration techniques up to and including the 1 in 100 year plus 30% climate
change.
Proposed Design Criteria
5.13
Any design and assessment of the requirements for storm drainage will be
based on the following criteria:
Return Period
1 in 30
Flood Protection
1 in 100 year
Sensitivity Check
Climate Change to 30%
M5-60
19.90mm
Ratio R
0.35
Minimum Cover to Adoptable Pipes
1.2m
Minimum Velocity (Full Bore)
1m / Sec
Pipe Ks Value
0.6mm
5.14
Based upon the planning layout for the proposed development the impervious
surfacing consists of proposed roofs, roads, driveways and parking areas. T he total
impermeable area has been estimated as 0.2ha.
(16)
5.15
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Micro Drainage calculations have been prepared for the proposed catchment to
determine the total volume of storage and extent of permeable paving required on site
to accommodate the 100 year event plus 30% climate change in accordance with the
requirements of the NPPF. Micro Drainage surface water storage calculations are
provided in Appendix G.
5.16
To deal with the residual risk of blockage to all on-site drainage features, the
developer and end user will ensure maintenance of their respective drainage system in
line with the manufacturers’ recommendations by the production of a Maintenance
Management Plan. This will ensure that over the lifetime of the proposed development
the drainage system will be properly maintained to ensure continued functionality.
Contamination from Construction
5.17
The construction works must be undertaken in a manner to prevent pollution to
the Lavant Stream and any groundwater or aquifer which may lie beneath the site.
Contractors are to make reference to current legislation and EA guidelines in respect
of construction pollution prevention.
5.18
The contractor will be advised on the removal of any hotspots of contaminated
ground established through an intrusive soil investigation or during excavation works.
5.19
All stocks of materials, oils and fuels are to be stored in a manor preventing
spillage and seepage to ground.
Wastewater will not be freely discharged to the
ground or watercourses. All hydrocarbons and chemical spillages will be thoroughly
cleaned by excavation of the polluted ground and disposed of to a licensed waste
depot.
5.20
The list of guidelines below are initial recommendations and not exhaustive. It
will be the responsibility of the contractor to ensure they obtain and understand the
latest legislation and guidelines:

The Groundwater Directive 80/68/EEC. Office Journal of the European
Communities 1980.
(17)

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December 2013
Protection of Groundwater Against Pollution and Deterioration. Office
Journal of the European Union 2006.

Environmental Permitting (England and Wales) Regulations. Draft Statutory
Instruments 2010.

Waste Management – The Duty of Care: A Code of Practice. The Stationary
Office 1996.

Control of Water
Pollution from Construction Sites: Guidance for
Consultants and Contractors. CIRIA Report 532. 2001.

Waste Minimisation and Recycling in Construction – A Site Handbook.
CIRIA 1999.

Managing Materials and Components on Site. CIRIA 1998.

Safe Storage and Disposal of Used Oils: PPG8 Environmental Alliance
2004.

Underground, Under Threat. The State of Groundwater in England and
Wales. Environment Agency 2006.

Groundwater Protection: Policy and Practice Document GP3. Environment
Agency 2006.
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6.0
FOUL DRAINAGE STRATEGY
6.1
TWUL are the governing water authority for the area.
Any proposed
connections or changes to the existing discharge rates must be approved by TWUL
prior to commencement of any construction works.
6.2
Foul flows generated by these proposals will be conveyed through the site via
gravity drains to the existing private foul water sewer located in the north east of the
site. The new foul network will be designed to meet the requirements of Part H of the
Building Regulations. The final connection to the existing foul water lateral will need to
be agreed with TWUL under a Section 106 Agreement.
6.3
The final foul discharge rate will be determined upon confirmation of the
internal layout of the club house showing numbers of toilets, showers and sinks.
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7.0
IMPACT ON OTHER LAND
7.1
The development proposals will limit surface water run-off from the
development to that of existing greenfield run-off rates. The proposals will provide
surface water infiltration and attenuation on-site to accommodate flood events up to
and including the 1 in 100 year plus 30% climate change flood event in the form of
permeable paving and infiltration trenches.
7.2
As the proposals utilise infiltration where possible and there is no record of the
site flooding, the development should not cause any adverse effects to the existing
off-site flood risk downstream or on adjacent land.
(20)
8.0
CONCLUSIONS
8.1
Information provided by the
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December 2013
EA indicates the site is located within
Flood Zone 1, at low risk of flooding.
8.2
The proposed development area is less than 1 hectare in size and therefore in
accordance with the NPPF will not require a Site Specific Flood Risk Assessment in
support of the development proposals and planning submission.
8.3
A Surface Water Drainage Strategy has been prepared to demonstrate that the
proposed surface water run-off from the development can be accommodated within the
site for all storm events up to and including the 1 in 100 year plus 30% climate change
in accordance with the requirements of the NPPF and the EA.
8.4
The proposed Surface Water Drainage Strategy includes permeable paving
allowing full infiltration for full discharge to the ground. The sub-base will provide
attenuation for storms in excess of the natural infiltration rates up to an including the 1
in 100 year event plus 30% climate change.
8.5
Any on-site surface water sewers will be designed to accommodate flows from
the 1 in 30 year storm event, and all surface water attenuation systems will be
designed to accommodate the 1 in 100 year plus 30% climate change storm.
8.6
The proposed foul water drainage scheme will include a network built to meet
the requirements of Part H of the Building Regulations and connect into the existing
foul sewer crossing the north east of the site. TWUL approval will need to be obtained
prior to any new connections or alterations in drainage flows to the public sewers.
8.7
The proposed development will provide means to conveying overland flow
during extreme flood events away from buildings along the car park and access road
by way of the detailed level strategy design.
8.8
The site satisfies the requirements of NPPF with regard to flood risk, surface
water run-off management and the Sequential Test.
(21)
FIGURE 1
Site Location Plan
Burgess Hill
SITE
Reproduced from Ordnance Survey with the permission
of the Controller of Her Majesty's Stationery Office, Crown
Copyright Reserved.
Odyssey
Markides
Tuscany House
White Hart Lane
Basingstoke
Hampshire
RG21 4AF
Job Title
LAND AT CHAWTON PARK ROAD,
ALTON
Client
1:25000 @A4
Drawn
Drawing Title
Telephone: 01256 331144
Fax: 01256 331134
e-mail: [email protected]
web: www.odysseymarkides.com
Site Location Plan
Date
Scale
Job No
AA
13-231
DEC 13
Checked
Figure No
TS
Designed
Approved
FIGURE 1
AA
BAC
Rev
-
APPENDIX A
Proposed Masterplan
CH
AW
TO
grass
I
I
I
I
I
I
I
I
fence
I
I
I
I
I
I
I
I
N
PA
RK
RO
AD
I
I
hedge
I
grass
+117.40
ditch
I
I
117.30+
path
+117.60
I
I
+117.65
I
I
I
fence
hedge
path
I
ditch
I
I
grass
grass
I
I
17
BOWLING GREEN
ditch
path
I
1 in 3
grass bank
I
38.4 X 38.4m
I
fence
I
hedge
5no. new trees
turning zone for
fire appliance /
refuse vehicle
footpath
I
I
5no. trees to
be removed
6m wide
access road
I
I
I
I
I
I
access
road
vehicle height
restriction
barrier
I
I
centre line of bowling green
I
I
117.30+
+117.60
I
path
steps
+117.65
eqp't
ramp
+117.95
steps
disabled
ramp
VIEWING TERRACE
lawn
steps
car park
I
CAR PARK
I
CARDIAC
REHABILITATION
CENTRE
8
ditch
+117.40
I
I
25no. spaces
(inc. 2no. disabled)
I
I
possible
future
club house
extension
lawn
I
+118.00 FFL
BINS / CYCLES
underground water
storage tank
I
I
STORES
CLUB HOUSE
gates
I
retaining wall
I
I
I
I
I
I
I
hedge
access for
future
development
I
I
I
I
I
I
I
I
I
I
fence
NURSERY & GIRL GUIDE CENTRE
A
TENNIS COURTS
DEC '13
REVISION
DATE
ISSUED FOR PLANNING
SS/PF
COMMENTS
AUTHOR / CHECKED
TITLE
CHAWTON PARK ROAD, ALTON
grass
NORTH
DETAIL
1
0
1
2
3
4 5
10
15
20 m
PROPOSED SITE PLAN
DATE
Ordnance Survey, (c) Crown Copyright 2010. All rights reserved. Licence number 100020449
LHC GROUP
www.lhc.net
EXETER
PLYMOUTH
SOUTHAMPTON
01392
01752
08450
444334
669368
714565
SCALE
OCT 2013
1:200 @ A1
DRAWING No.
REV.
13091 - P.03
A
AUTHOR \ CHECKED
SS/PF
DRAWING-STATUS
CONTRACTORS MUST CHECK ALL DIMENSIONS ON SITE. ONLY FIGURED DIMENSIONS ARE TO BE WORKED FROM. DISCREPANCIES MUST BE REPORTED TO THE ARCHITECT BEFORE PROCEEDING. C THIS DRAWING IS COPYRIGHT.
APPENDIX B
Topographical Survey
BT
W
T
BW
2W
5d
0.4
2W
BT W
BT
BT
225
BT
BT
BT
BT
0d
0.5
5d
0.8
T
B
OSA
SHEET LAYOUT
5d
0.4BT
W
1
5d
0.7
W
W
W
W
W
LEGEND
W
E
HV
W
GAS
W
RA
RT
GP W
E
d
.70 W
W
EOT
0.4
E 5d
BT
1W
PIPE
W
0d
0.8
V
F
VR
BT
W
T
FO
U
EOT
0.4
BT
5d
BT
A
O
V
F
W
T
EO
1W EMPTY 0.45d
W
BT W
0
CE
d
d
0.50 .E
0 45
1W
0
15
1W EMPTY 0.45d
BT
A
O
W
BT
W
CATV
CCTV
BT
OSA
E
HV
W
W
OSA
Foul Drainage
Surface Drainage
Combined Drainage
Electricity
Electricity High Voltage
Gas
Water
Cable Television
Close Circuit Television
Communication
British Telecom
Compressed Air
Offset Fill-Line
Oil Pipe
Pipe
Ventilation
Fuel Line
Vapour Recovery
Gauge Line
Telemetry
Fibre Optics
Unknown
Historical by Layer
End Of Trace
W
BT
W
OSA
T
T
FO
U
W
BT
TANK * - W= Water U=Unknown
F=Foam
P=Product
Trial Pit Location
C=Concrete
Do Not Drill / Banded Pipes
0
E
150
15
BT
5
BT
E
BT
5d
0.4
5d
0.8
W
Borehole / SVS
W
STANTION
W
BT
A/R
BOLL
ILLU BOLL
BH
BTIC
C/BOX
C/B FENCE
CR
CTV
CP
CONC
CL
D
D/CHAN
DP
EIC
ER
EP
EOT
F/BED
FH
FS
GV
G
G-RUN
HT
IC
IL
LP
MH
MKR
MTR
MW
OH
E
W
IN TRENCH
SCAR
5d BT
0d W
0.9 E
5d
0.3
0.4
BT
W
BT
5
22
E
W
5d
E
W
BT
E
W
0.4
0d
W
0.8
PE WATER
SUPPLY TO
REHAB CENTRE
NO SIGNALS
5d T
0.6 B
E
T
0.6
E
1W
2W
BTW
W
EO
5d
EOT
T
5d B
0.6
2W W
0d E
0.8 30d
0.
PUMP ISLAND
LEGEND
BT
W
T
W
W
BT
*
100
0.4
0
d
22
2
100
BT
PE WATER
SUPPLY TO
NURSERY
NO SIGNALS
BTW
ASSUMED ROUTE
BOLLARD
ILLUMINOUS BOLLARD
BOREHOLE
BRITISH TELECOM COVER
CONTROL BOX
CLOSEBOARD FENCE
CABLE RISER
CABLE TV
CATCHPIT
CONCRETE
COVER LEVEL
DEPTH / DEEP
DRAINAGE CHANNEL
DOWN PIPE
ELECTRICITY COVER
EARTH ROD
ELECTRICITY POLE
END OF TRACE
FLOWER BED
FIRE HYDRANT
FIRE SWITCH
GAS VALVE
GULLY
GULLY RUN
HEIGHT
INSPECTION COVER
INVERT LEVEL
LAMP POST
MANHOLE
MARKER
METER
MONITORING WELL
OVERHEAD
OSA
OSBM
PR
P&R FENCE
RET WALL
RE
RS
RWP
S/A
SAP
S/C
SEC FENCE
SL
SP
ST
STN
SV
SVP
TBM
TFR
THL
TL
TP
UTL
UTR
UTS
UTT
VR
VP
WM
WFC
WP
U/S
OFF SURVEY AREA
ORDNANCE SURVEY BENCH MARK
PIPE RISER
POST & RAIL FENCE
RETAINING WALL
RODDING EYE
ROAD SIGN
RAIN WATER PIPE
SOAK AWAY
SAPLING
SOUND CONNECTED
SECURITY FENCE
SPOT LIGHT
SOIL PIPE
STOP TAP
STATION (DATUM POINT)
STOP VALVE
SOIL VENT PIPE
TEMPORARY BENCH MARK
TAKEN FROM RECORDS
THRESHOLD LEVEL
TRAFFIC LIGHT
TELEGRAPH POLE
UNABLE TO LOCATE
UNABLE TO RAISE
UNABLE TO SURVEY
UNABLE TO TRACE
VAPOUR RECOVERY
VENT PIPE
WATER METER
WATER FILLED CHAMBER
WASTE PIPE
UNDERSIDE
DIAMETER
E
BT
R
d
W
45
E
0. 00d
1.
d
5
4
BT
0.
W E
A
SC
W
E
W
E
BT
D
EN
OF
W
E
THE ELECTRIC SUPPLY TO REHAB CENTRE ENTERS BUILDING
AND IS FED FROM OUTSIDE THE SURVEY AREA.
UNABLE TO LOCATE ROUTE OF GAS TO REHAB CENTRE.
ADVISED ON SITE THAT NURSERY HAS NO GAS SUPPLY.
NURSERY BT IS SUPPLIED OVERHEAD.
BT
BT
E
BT
BT
W
UTILITY NOTES
E
BT
BT
5
22
0.7 0d
0.3
W
BT
BT
5d
0d
E
5d
0.4
0.6
BT W
BT
W
BT
W
AS
BT
BT
W
E
E
BT
NO
L
E
0
AR
A
GN
SI U
U
10
ED
M
SU U
S
GA
BT
U
BT W
SC
CH U
E
BT
U
5
25
OSA
B
W
0.
d
45
W
E
BT
d
65
0. 0d
.0
1
T
BT
EN
TR
E
BT
BT
W
E
BT
W
E
BT
OSA
BT W
E
BT
BT
TOPOGRAPHICAL NOTES
THE TOPOGRAPHICAL SURVEY WAS SUPPLIED BY SHAW COLGATE LTD
BT
BT
0d
0.5
BT
DESCRIPTION
DATE
REV
BT
BT
0
10
NO OUTLET
VISIBLE
BT
OSA
OSA
OSA
SURVEYS
UNABLE TO
LOCATE WATER
SUPPLY TO
WATER FEATURE
ASSUMED PE
SITE VISION SURVEYS LIMITED
S
UTILITY
TOPOGRAPHICAL
MAPPING
T: 01788 575036 W: SVSLTD.NET
E
CR
WATER
FEATURE
CLIENT:
Shaw Colgate Ltd
REHAB CENTRE
SITE LOCATION:
10
Chawton Park Road
Alton
Hampshire
0
DRAWING TITLE:
Utility Survey
OSA
DISCLAIMER: The location of under ground services shown on this drawing has been determined using electro-magnetic (and/or ground probing radar, where requested) techniques and visual observations. the limitations of this drawing
should be realised and no guarantee can be given that all services have been identified. This drawing may not include the location of all public services that may cross the site and therefore the relevant service drawings should be
obtained from the appropriate utility company and used in conjunction with this drawing. Additional services, structures or other below ground obstructions not indicated on this drawing may be present on site. reference should be
made to historical plans and as built drawings. Excavations in the vicinity of services should be carried out with due diligence ref: HSG47 document "avoiding dangers from underground services". Location accuracy is determined by
refering to manufacturers guidelines for the systems deployed. Reference should be made to the latest version of SVS Ltd site procedures document for utility location surveys.
SURVEYED BY:
RM
DRAWN BY:
DRAWING NO:
RM
1:200 @A1
PC
SURVEY DATE:
1013-SCL-7009
SCALE:
APPROVED BY:
10-10-13
SHEET NO:
1 OF 2
REV:
APPENDIX C
Groundwater and Flood Mapping – Environment Agency
Flood Zone Map created 17/12/13
Legend
0
95
190
285 m.
© Environment Agency copyright and / or database rights 2014. All rights reserved. © Crown Copyright and database right 2014. Ordnance Survey licence number 100024198.
Flood Map for Surface Water 1_30
Legend
0
95
190
285 m.
Flood Map for Surface Water 1 in 200 chance created 17/12/13
Legend
0
95
190
285 m.
Environment Agency - What's in your backyard?
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Other topics for this area...
Groundwater
X: 470,889;Y: 138,119 at scale 1:10,000
Groundwater

Data search
Text only version
Groundwater source
protection zones

Inner zone
(Zone 1)
Outer zone
(Zone 2)
Total catchment
(Zone 3)
Special interest
(Zone 4)
Aquifer Maps Superficial Deposits
Designation
Principal
Secondary A
Secondary B
Secondary
(undifferentiated)
Unknown (lakes and
landslip)
Aquifer Maps - Bedrock
Designation
Principal
Secondary A
Secondary B
Secondary
(undifferentiated)

Groundwater
Vulnerability Zones
Major Aquifer High
Major Aquifer
Intermediate
Major Aquifer Low
Customers in Wales - From 1 April 2013 Natural Resources Wales (NRW) will take over the responsibilities of the Environment Agency in Wales.
© Environment Agency copyright and database rights 2013. © Ordnance Survey Crown copyright. All rights reserved. Environment Agency, 100026380.
Contains Royal Mail data © Royal Mail copyright and database right 2013.
This service is designed to inform members of the public, in line with our terms and conditions. For business or commercial use, please contact us.
More about Groundwater
British Geological Survey Aquifer data:
The Aquifer Extents are not displayed at scales greater than 1:75,000 (Ordnance Survey 1:250,000 scale) as the data
was only modelled to this level and is not accurate pass this.
Minor Aquifer High
Minor Aquifer
Intermediate
Minor Aquifer Low
New BGS Aquifer Designation Maps
From 1st April 2010 new aquifer designations replace the old system of classifying aquifers as Major, Minor and NonAquifer. This new system is in line with our Groundwater Protection Policy (GP3) and the Water Framework Directive
(WFD) and is based on British Geological Survey mapping.
Groundwater Source Protection Zones data:
The Source Protection Zones are not displayed at scales greater than 1:20,000 (Ordnance Survey 1:50,000 scale) as
the data was only modelled to this level and is not accurate pass this. They should not be compared against field
boundaries.
Groundwater Source Protection Zones
Groundwater provides a third of our drinking water. We ensure that your water is safe to drink defining Source
Protection Zones. These zones help to monitor the risk of contamination from any activities that might cause pollution
in the area.
Facts and figures of our groundwater resources
Find out more about groundwater and groundwater levels.
http://maps.environment-agency.gov.uk/wiyby/wiybyController?x=471500.0&y=139...
16/12/2013
APPENDIX D
Sewer Record Extracts – Thames Water Utilities Limited
%
SU7038SE
14
0
Asset Location Search Sewer Map - ALS/ALS Standard/2013_2607948
!
7302
O SE !
L
C
0
5
6301
H 1150
!
T
7303
U
!
!
MO6315
S
T
00
17
5R
1O
15
5
22
%
%
%
%%
6
8202
!
2
1
%50% 22
1
8201
ESS
5
22
5
!
!
6210
%
6204
K
AR
P
7202
!
0
15
%
6206
!
08
!
%
7201
6202
!6205
!6207
TO
W
A5
CH22
!
!
6209
N
R
D 22
OA
!
Indoor Bowli
!
5
Club
%
!
%
7204
5
22
!
7203
%
6201
Girl Guide (HQ)
!
CR
Cardiac Rehabilitation Centre
Tennis Courts
id
M
nt
Ha
s
R
lw
ai
ay
d
ar
W
y
Bd
Games Courts
Tennis
Courts
o
Sp
rts
Pa
n
lio
i
v
The width of the displayed area is 218m and the centre of the map is located at OS coordinates 470778,138222
The position of the apparatus shown on this plan is given without obligation and warranty, and the accuracy cannot be guaranteed. Service pipes are not shown but their presence should be anticipated. No liability of
any kind whatsoever is accepted by Thames Water for any error or omission. The actual position of mains and services must be verified and established on site before any works are undertaken.
Based on the Ordnance Survey Map with the Sanction of the controller of H.M. Stationery Office, License no. 100019345 Crown Copyright Reserved.
Page 7 of 10
NB. Levels quoted in metres Ordnance Newlyn Datum. The value -9999.00 indicates that no survey information is available
Manhole Reference
Manhole Cover Level
Manhole Invert Level
8201
8202
8301
6208
6209
6206
6315
6301
6202
6207
6204
6210
6205
7303
7302
7204
7202
7201
6201
7203
114.25
114.32
113.83
n/a
n/a
n/a
116.67
116.71
116.55
n/a
n/a
n/a
n/a
116.51
116.59
115.68
115.33
114.75
116.33
115.95
113.46
113.42
112.82
n/a
n/a
n/a
115.53
115.14
114.65
n/a
n/a
113.5
n/a
115.56
115.29
114.28
114.1
113.79
114.76
114.3
The position of the apparatus shown on this plan is given without obligation and warranty, and the accuracy cannot be guaranteed. Service pipes are not
shown but their presence should be anticipated. No liability of any kind whatsoever is accepted by Thames Water for any error or omission. The actual position
of mains and services must be verified and established on site before any works are undertaken.
Page 8 of 10
ALS Sewer Map Key
Public Sewer Types (Operated & Maintained by Thames Water)
Foul: A sewer designed to convey waste water from domestic and
industrial sources to a treatment works.
Sewer Fittings
Other Symbols
A feature in a sewer that does not affect the flow in the pipe. Example: a vent
is a fitting as the function of a vent is to release excess gas.
Symbols used on maps which do not fall under other general categories
/
Public/Private Pumping Station
Air Valve
Change of characteristic indicator (C.O.C.I.)
Dam Chase
Surface Water: A sewer designed to convey surface water (e.g. rain
water from roofs, yards and car parks) to rivers or watercourses.
Invert Level
Combined: A sewer designed to convey both waste water and surface
water from domestic and industrial sources to a treatment works.
M
Fitting
Summit
Meter
Areas
Vent Column
Lines denoting areas of underground surveys, etc.
Trunk Surface Water
Storm Relief
Trunk Foul
Operational Controls
Agreement
A feature in a sewer that changes or diverts the flow in the sewer. Example:
A hydrobrake limits the flow passing downstream.
Operational Site
Trunk Combined
Control Valve
P
P
Bio-solids (Sludge)
Vent Pipe
Chamber
Drop Pipe
Tunnel
Ancillary
Proposed Thames Surface
Water Sewer
Proposed Thames Water
Foul Sewer
Gallery
Foul Rising Main
End Items
Combined Rising Main
End symbols appear at the start or end of a sewer pipe. Examples: an
Undefined End at the start of a sewer indicates that Thames Water has no
knowledge of the position of the sewer upstream of that symbol, Outfall on a
surface water sewer indicates that the pipe discharges into a stream or river.
Surface
Main
Water
Rising
Sludge Rising Main
Proposed Thames Water
Rising Main
Vacuum
Conduit Bridge
Weir
Other Sewer Types (Not Operated or Maintained by Thames Water)
3) Arrows (on gravity fed sewers) or flecks (on rising mains) indicate direction of
flow.
Combined Sewer
Gulley
W
Culverted Watercourse
Proposed
Undefined End
Abandoned Sewer
Notes:
2) All measurements on the plans are metric.
Surface Water Sewer
Outfall
Inlet
1) All levels associated with the plans are to Ordnance Datum Newlyn.
Foul Sewer
6) The text appearing alongside a sewer line indicates the internal diameter of
the pipe in milimetres. Text next to a manhole indicates the manhole
reference number and should not be taken as a measurement. If you are
unsure about any text or symbology present on the plan, please contact a
member of Property Insight on 0845 070 9148.
4) Most private pipes are not shown on our plans, as in the past, this information has
not been recorded.
5) ‘na’ or ‘0’ on a manhole level indicates that data is unavailable.
Page 9 of 10
APPENDIX E
Ground Investigation Extracts
HP2
HP1
HP3
All positions are approximate
Project:
Chawton Park Road, Alton
Title
Exploratory Hole Location Plan
Client:
BNP Paribas
Ref No:
GE9666
Revision: 0
28 Crescent Road, Brighton, BN2 3RP
Drawn:
GR
Date:
01/11/2013
T: 01273 699 399 F: 01273 699 388
Figure:
1
Scale:
Not To Scale
E: [email protected] W: www.gesl.net
Geo-Environmental Services Ltd
STRATA
SAMPLING & TESTING
STRATA DESCRIPTION
Legend
mOD
mBGL
Water
S/Pipe
Grass overlying dark brown slightly silty clayey TOPSOIL with
abundant roots.
(0.30)
0.30
Brown slightly sandy very clayey SILT with occasional medium to
coarse subangular flint gravel.
(0.70)
1.00
End of Trial Pit at 1.00 m
SAMPLES: D=disturbed B=bulk U=undisturbed TESTS: MAC=macintosh IVAN=vane HPEN=penetrometer SPT=split-spoon CPT=cone WATER:
Stability:
Type:
Method:
Project:
Remarks:
Client:
Position:
GE9666
Start:
Finish:
Plant:
=rest OTHERS: (2.00)=strata
Ref:
Hand Excavated Trial Pit
Groundwater:
No Groundwater Encountered
=strike
Filled:
Eng:
04/11/2013
04/11/2013
04/11/2013
JO
Drawn:
BNP Paribas
Ckd:
HP1
Scale: 1:25
Size:
Depth:
Level:
Figure:
JO
Sheet:
1.00mBGL
FIG
Sheet 1 of 1
STRATA
SAMPLING & TESTING
STRATA DESCRIPTION
Legend
mOD
mBGL
Grass overlyingdark brown silty clayey TOPSOIL with abundant roots,
brick fragments and occasional coarse flint gravel.
Water
S/Pipe
(0.25)
0.25
Brown very clayey silty SAND with occasional medium to coarse
subangular flint gravel.
(0.55)
0.80
Stability:
Type:
Method:
Project:
Remarks:
Client:
Position:
GE9666
Start:
Finish:
Plant:
Ref:
Groundwater:
=strike
Filled:
Eng:
04/11/2013
04/11/2013
04/11/2013
JO
Drawn:
BNP Paribas
Ckd:
HP2
Scale: 1:25
Size:
Depth:
Level:
Figure:
JO
Sheet:
0.80mBGL
FIG
Sheet 1 of 1
STRATA
SAMPLING & TESTING
STRATA DESCRIPTION
Legend
mOD
mBGL
Water
S/Pipe
Grass overlying black clayey silty TOPSOIL with abundant roots and
occasional fine to medium subangular flint gravel.
(0.30)
0.30
Dark brown very clayey silty fine SAND with abundant fine to medium
calcareous inclusions and occasional fine to medium subangular
flint gravel.
(0.30)
0.60
Stability:
Type:
Method:
Project:
Remarks:
Client:
Position:
GE9666
Start:
Finish:
Plant:
Ref:
Groundwater:
=strike
Filled:
Eng:
04/11/2013
04/11/2013
04/11/2013
JO
Drawn:
BNP Paribas
Ckd:
HP3
Scale: 1:25
Size:
Depth:
Level:
Figure:
JO
Sheet:
0.60mBGL
FIG
Sheet 1 of 1
28 Crescent Road, Brighton,
East Sussex, BN2 3RP
Tel : 01273 699 399
Fax : 01273 699 388
Soakaway Test Results (after BRE Digest 365)
Project Name : Chawton Park Road, Alton
Client : BNP Paribas
Pit reference
Pit depth (m)
Pit width (m)
Pit length (m)
Depth to standing water (m)
Test 1
Time (min)
0.0
1.0
2.0
3.0
4.0
5.0
10.0
20.0
30.0
60.0
90.0
120.0
Job No. :
GE9666
Date :
08/11/2013
HP1
1.00
0.30
0.30
Test 2
Time (min)
Depth (m)
0.42
0.42
0.45
0.47
0.48
0.50
0.51
0.56
0.60
0.75
0.88
0.96
Test 3
Time (min)
Depth (m)
Depth (m)
0.00
0.10
0.20
Depth (m)
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
0
30
60
90
120
150
180
Time (mins)
Test 1
Max. depth (m)
Test 2
Test 3
1.00
1.00
1.00
Effective depth (m)
75% effective depth (m)
t75 (min)
t50 (min)
t25 (min)
0.58
0.57
0.71
0.86
22.00
52.00
85.00
1.00
0.25
0.50
0.75
1.00
0.25
0.50
0.75
Vp 75-25
ap 50
tp 75-25
0.03
0.438
63.00
0.05
0.69
0.00
0.05
0.69
0.00
Soil infiltration rate (m/s)
Soil infiltration rate (mm/hr)
1.6E-05
-
-
5.68E+01
-
-
Tel : 01273 699 399
Fax : 01273 699 388
Pit reference
Pit depth (m)
Pit width (m)
Pit length (m)
Test 1
Time (min)
0.0
1.0
2.0
3.0
4.0
5.0
10.0
20.0
30.0
Job No. :
GE9666
Date :
08/11/2013
HP2
0.80
0.27
0.27
Test 2
Time (min)
Depth (m)
0.17
0.22
0.25
0.27
0.30
0.32
0.41
0.54
0.72
Test 3
Time (min)
Depth (m)
Depth (m)
0.00
0.10
0.20
Depth (m)
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
0
5
10
15
20
25
30
35
40
45
50
55
Time (mins)
Test 1
Max. depth (m)
Test 2
Test 3
0.80
0.80
0.80
0.63
0.33
0.49
0.64
6.00
17.00
27.00
0.80
0.20
0.40
0.60
0.20
0.40
0.60
Vp 75-25
ap 50
tp 75-25
0.02
0.4131
21.00
0.03
0.5049
0.00
0.03
0.0729
0.00
4.4E-05
-
-
1.59E+02
-
-
Effective depth (m)
t75 (min)
t50 (min)
t25 (min)
60
Tel : 01273 699 399
Fax : 01273 699 388
Pit reference
Pit depth (m)
Pit width (m)
Pit length (m)
Test 1
Time (min)
0.0
1.0
2.0
3.0
4.0
5.0
10.0
20.0
30.0
60.0
80.0
Job No. :
GE9666
Date :
08/11/2013
HP3
0.60
0.27
0.27
Test 2
Time (min)
Depth (m)
0.15
0.19
0.20
0.21
0.22
0.22
0.25
0.31
0.35
0.46
0.50
Test 3
Time (min)
Depth (m)
Depth (m)
0.00
0.10
0.20
Depth (m)
0.30
0.40
0.50
0.60
0.70
0.80
0.90
1.00
0
10
20
30
40
50
60
70
80
90
100
110
Time (mins)
Test 1
Max. depth (m)
Test 2
Test 3
0.60
0.60
0.60
0.45
0.26
0.38
0.49
12.00
40.00
75.00
0.60
0.15
0.30
0.45
0.60
0.15
0.30
0.45
Vp 75-25
ap 50
tp 75-25
0.02
0.3159
63.00
0.02
0.3969
0.00
0.02
0.3969
0.00
1.4E-05
-
-
4.95E+01
-
-
Effective depth (m)
t75 (min)
t50 (min)
t25 (min)
120
APPENDIX F
Outline Drainage Strategy (Drawing no. 13-231-001)
OSA
DRAINAGE STRATEGY SPECIFIC NOTES:
N
1. ALL BELOW GROUND DRAINAGE TO COMPLY WITH PART
H OF THE BUILDING REGULATIONS.
NOTES
1. DO NOT SCALE FROM THIS DRAWING.
225
W
ExF 2
2
8 0
2.SURROUNDING TOPOGRAPHICAL DATA AND
SERVICES SURVEY HAS BEEN PROVIDED BY SITE
VISION SURVEYS LTD IN DRAWING 1013-SCL-7009.
ODYSSEY MARKIDES CONSULTING ENGINEERS DOES
NOT TAKE RESPONSIBILITY FOR THE ACCURACY OF
THE SURVEY INFORMATION.
225
2. PROPOSED CONNECTION TO THE EXISTING FOUL
WATER NETWORK SUBJECT TO A SECTION 106
AGREEMENT WITH THAMES WATER.
OSA
OSA
OSA
BT
W
0d BT
W
0d
0.8
0.4
22
5
3. MAXIMUM GRADIENT OF PERMEABLE PAVEMENT
FORMATION TO BE <1 IN 100. STEPPED FORMATIONS /
CHECK DAMS TO BE CONSIDERED IN CONSTRUCTION OF
PERMEABLE SUB-BASE. MIN THICKNESS OF CLEAN
GRANULAR PERMEABLE SUB-BASE TO BE 450MM.
BT
W
W
ExF 01
82
5d
0.3
BT
5d
W 0.9
BT
W
OSA OSA
0.4
BTW
0d
E
d
5
0.9
0d
0.5
E
E
d
0.7
5
BT W
5d
0.8
6. THE CONTRACTOR IS REMINDED OF HIS OBLIGATION
TO VERIFY THE ROUTE OF ALL SERVICES ON SITE
PRIOR TO THE COMMENCEMENT OF THE WORKS.
E
BT
W
5. THE AVOIDANCE AND PROTECTION OF SERVICES
DURING THE WORKS IS THE RESPONSIBILITY OF THE
CONTRACTOR.
OSA
100
T
EO
5d
0.4
0
10
BTW
BT W
5. BOWLING PITCH DRAINAGE TO CONSIST OF DRAIN
TRENCHES AT 5M CENTERS TO ''SPORT ENGLAND''
REQUIREMENTS, SUBJECT TO DETAILED DESIGN
REQUIREMENT. DEPTH OF DRAINAGE TRENCHES,
SUBJECT TO SUITABLE SUB-STRATA TO ALLOW FOR
INFILTRATION.
100
150
T
BW
BT
W
225
4. PROPOSALS ARE INDICATIVE ONLY TO
DEMONSTRATE THE PRELIMINARY DRAINAGE
STRATEGY AND ARE SUBJECT TO EVOLVE IN LINE
WITH DETAILED DESIGN REQUIREMENTS FOLLOWING
PLANNING PERMISSION.
OSA
0d
0.5 E
BTW
150
4. SURFACE WATER RUN OFF FROM ROOF AND
SURROUNDING HARDSTANDING AREAS TO DISCHARGE
TO PERMEABLE PAVING VIA DIFFUSER UNITS, SUBJECT
TO DETAILED DESIGN DEVELOPMENT. PERMAVOID OR
SIMILAR APPROVED. SIZE AND EXTENT OF DIFFUSER UNIT
ARE SUBJECT TO DETAILED DESIGN.
3. SITE LAYOUT HAS BEEN PROVIDED BY LHC GROUP
ARCHITECTS IN DRAWING 13091 - P.03 REV A
BT
W
BT
W
2W
BT
BT
BT
BT
100
OVERFLOW FROM PITCH
DRAINAGE TO PERMEABLE
PAVING SYSTEM
70
0.
OSA
W
W
W
0d
0.5
5d
0.8
W
d
W
BT
BT
0
CE
RA
RT
GP W
E
W
1W
0.4
E 5d
BT
E
150
5
BT
5d
E
0.4
BT
0.8
5d
S5
0
KEY
W
SITE BOUNDARY
W
100
0.4
0d
0
15
22
W
W
BT
W
W
BT
BT
OSA
EOT
FW
Ex 0.450d 1
7BT2 .80d
T
1W EMPTY 0.45d
W
BT W
d
.70 W
0
15
d E
d
0.50 .4
0 5
1W
EO
EOT
W
BT
W
W
E
BT
W
BT
BT
d
E
W
5d
PROPOSED FOUL
WATER NETWORK
PROPOSED SURFACE
WATER NETWORK
PROPOSED DRAINAGE
TRENCHES
E
E
W
BT
EXISTING (PUBLIC) FOUL
WATER NETWORK
PROPOSED
PERMEABLE BLOCK
W
0
0.4
PROPOSED CONNECTION TO
EXISTING PRIVATE FOUL NETWORK
SUBJECT TO CONDITION SURVEY
OF DOWNSTREAM LATERAL AND
SECTION 106 AGREEMENT WITH
THAMES WATER.
5d BT
0.4W
F
0d W
x
0
E .09 45dE
2
W7 0.3
BT
5
22
OSA
IN TRENCH
SCAR
W
W
9. DRAINAGE STRATEGY SUBJECT TO DETAILED
DESIGN DEVELOPMENT.
W
OSA
OSA
1W EMPTY 0.45d
E
BT
W
OSA
8. THE CONTRACTOR SHOULD NOTE THAT THE
SERVICES SHOWN ARE NOT TO BE CONSIDERED
EXHAUSTIVE. PRIVATE SERVICES MAY BE PRESENT
WITHIN THE LIMIT OF WORKS AND CARE SHOULD BE
TAKEN TO LOCATE AND AVOID THESE DURING
CONSTRUCTION.
W
E
BT
W
W
E
BT
W
5d
BT
5
22
W
7. THE CONTRACTOR SHOULD ALLOW FOR ANY
NECESSARY LIAISON WITH THE STATUTORY UTILITIES
DURING THE COURSE OF THE WORKS TO AVOID ANY
DISRUPTION TO EXISTING CUSTOMER SUPPLIES.
0 .7
BT
5d
0.7
E
6. PERMEABLE PAVING AND INFILTRATION TRENCH TO BE
A MINIMUM OF 5m FROM ANY PROPOSED / EXISTING
BUILDING FOUNDATIONS OR PUBLIC ROADS.
T
BW
E
d
5
0.4
2W
BT W
5d
0.4BT
W
0.8
0.6
NURSERY & GUIDE CENTRE
BTW
E
OF
EN
BT
W
W
E
W
W
W
WATER LINE
BT
BT
BT
BT LINE
OVERHEAD LINES
d
45
0.
E
BT
E
S4
BT
BT
BT
W
E
E
ELECTRICAL LINE
NU
0
10
BT
W
E
S3
W
E
U
BT
W
&
G
E
BT
D
d
45
0. 00d
1.
U
G
E
BT
BT
R
A
SC
E
BT
BT
W
E
W
E
RY
E
RS
BT
BT
RL
E
ID
CE
I
BT
BT
5
22
E
0d
BT
W
5d
0.4
5d
0.7 0d
W
0.3
E
0.6
BT W
SURFACE WATER
DIFFUSER UNIT
E
TR
N
5d T
0.6 B
E
E
1W
2W
BTW
W
T
EO
5d
EOT
T
5d B
0.6
2W W
0d E
0.8 30d
0.
BT W
B
W
45
0.
d
REFER TO DRAINAGE
STRATEGY NOTE 4 FOR
DETAILS.
BT
d
65
0. 0d
.0
T 1
BT
E
REFER TO DRAINAGE
STRATEGY NOTE 5 FOR
DETAILS.
BT
SW STUB FOR FUTURE
CONNECTION FROM
EXTENSION
BT
BT
Rev
BT
Amendments
Drn Chk App
Date
BT
BT
S2
0d
0.5
BT
BT
BT
BT
S1
E
CR
Telephone: 01256 331144
Fax: 01256 331134
E: [email protected]
W: www.odysseymarkides.com
Tuscany House
White Hart Lane
Basingstoke
Hampshire RG21 4AF
0
10
WATER
FEATURE
Job Title
LAND AT CHAWTON PARK ROAD,
ALTON
Drawing Title
OUTLINE DRAINAGE STRATEGY
REHAB CENTRE
Client
0
10
P:\13-231 - Land at Chawton Park Road, Alton\Tech\Acad\Drawings\13-231-001 Outline Drainage Strategy.dwg
E
BT W
E
OSA
Scale
Date
1:250 @A1
Drawn
Designed
DEC '13
Checked
AA
Job No
TS
Approved
TS
BAC
Drawing No
13-231
Rev
13-231/001
-
APPENDIX G
Micro Drainage Surface Water Storage Calculations
Tuscany House
White Hart Lane
Basingstoke RG21 4AF
Date 18/12/2013 16:55
File PERMEABLE PAVING...
Micro Drainage
Page 1
Land adjancent to
Chawton Park Road
Designed by TS
Checked by
Source Control 2013.1.1
Summary of Results for 100 year Return Period (+30%)
Half Drain Time : 101 minutes.
Storm
Event
15
30
60
120
180
240
360
480
600
720
960
1440
2160
2880
4320
5760
7200
8640
10080
15
30
60
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
Max
Level
(m)
Summer 116.538
Summer 116.630
Summer 116.710
Summer 116.756
Summer 116.755
Summer 116.736
Summer 116.692
Summer 116.650
Summer 116.616
Summer 116.588
Summer 116.540
Summer 116.469
Summer 116.396
Summer 116.342
Summer 116.270
Summer 116.224
Summer 116.192
Summer 116.168
Summer 116.149
Winter 116.580
Winter 116.693
Winter 116.817
Storm
Event
15
30
60
120
180
240
360
480
600
720
960
1440
2160
2880
4320
5760
7200
8640
10080
15
30
60
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
Max
Max
Max
Depth Infiltration Volume
(m)
(l/s)
(m³)
Status
0.538
10.6
67.8
0.630
12.2
87.6
0.710
12.2 103.1 Flood
0.756
12.2 110.5 Flood
0.755
12.2 110.4 Flood
0.736
12.2 107.4 Flood
0.692
12.2
99.8
0.650
12.2
91.8
0.616
12.1
84.6
0.588
11.6
78.5
0.540
10.6
68.2
0.469
9.2
52.8
0.396
7.8
37.6
0.342
6.7
28.1
0.270
5.3
17.5
0.224
4.4
12.1
0.192
3.8
8.9
0.168
3.3
6.7
0.149
2.9
5.3
0.580
11.4
76.8
0.693
12.2 100.0
0.817
12.2 118.9 Flood
Rain
Flooded Time-Peak
(mm/hr) Volume
(mins)
(m³)
Summer 121.761
Summer 81.796
Summer 52.391
Summer 32.351
Summer 24.014
Summer 19.302
Summer 14.207
Summer 11.411
Summer
9.619
Summer
8.361
Summer
6.696
Summer
4.887
Summer
3.559
Summer
2.838
Summer
2.059
Summer
1.638
Summer
1.372
Summer
1.188
Summer
1.052
Winter 121.761
Winter 81.796
Winter 52.391
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
18
32
60
92
126
160
228
294
356
420
548
794
1148
1504
2208
2944
3672
4408
5136
17
31
60
©1982-2013 Micro Drainage Ltd
O K
O K
Risk
Risk
Risk
Risk
O K
O K
O K
O K
O K
O K
O K
O K
O K
O K
O K
O K
O K
O K
O K
Risk
Tuscany House
White Hart Lane
Date 18/12/2013 16:55
Micro Drainage
Page 2
Land adjancent to
Chawton Park Road
Designed by TS
Checked by
Summary of Results for 100 year Return Period (+30%)
Storm
Event
120
180
240
360
480
600
720
960
1440
2160
2880
4320
5760
7200
8640
10080
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
Max
Level
(m)
Winter 116.893
Winter 116.879
Winter 116.831
Winter 116.742
Winter 116.670
Winter 116.618
Winter 116.580
Winter 116.517
Winter 116.428
Winter 116.340
Winter 116.281
Winter 116.209
Winter 116.168
Winter 116.141
Winter 116.122
Winter 116.108
Storm
Event
120
180
240
360
480
600
720
960
1440
2160
2880
4320
5760
7200
8640
10080
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
min
Max
Max
Max
Depth Infiltration Volume
(m)
(l/s)
(m³)
Status
0.893
12.2 126.8 Flood
0.879
12.2 125.6 Flood
0.831
12.2 120.6 Flood
0.742
12.2 108.4 Flood
0.670
12.2
95.8
0.618
12.2
85.1
0.580
11.4
76.8
0.517
10.2
63.1
0.428
8.4
43.9
0.340
6.7
27.7
0.281
5.5
18.9
0.209
4.1
10.5
0.168
3.3
6.8
0.141
2.8
4.8
0.122
2.4
3.6
0.108
2.1
2.8
Rain
Flooded Time-Peak
(mm/hr) Volume
(mins)
(m³)
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
Winter
32.351
24.014
19.302
14.207
11.411
9.619
8.361
6.696
4.887
3.559
2.838
2.059
1.638
1.372
1.188
1.052
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
100
136
174
248
314
378
444
572
822
1172
1528
2244
2944
3672
4400
5080
Risk
Risk
Risk
Risk
O K
O K
O K
O K
O K
O K
O K
O K
O K
O K
O K
O K
Tuscany House
White Hart Lane
Date 18/12/2013 16:55
Micro Drainage
Page 3
Land adjancent to
Chawton Park Road
Designed by TS
Checked by
Rainfall Details
Rainfall Model
FSR
Winter Storms
Yes
Return Period (years)
100
Cv (Summer) 0.750
Region England and Wales
Cv (Winter) 0.840
M5-60 (mm)
19.900 Shortest Storm (mins)
15
Ratio R
0.350 Longest Storm (mins) 10080
Summer Storms
Yes
Climate Change %
+30
Time Area Diagram
Total Area (ha) 0.347
Time (mins) Area
From:
To:
(ha)
0
4 0.347
Tuscany House
White Hart Lane
Date 18/12/2013 16:55
Micro Drainage
Page 4
Land adjancent to
Chawton Park Road
Designed by TS
Checked by
Model Details
Storage is Online Cover Level (m) 117.000
Porous Car Park Structure
Infiltration Coefficient Base (m/hr) 0.08856
Width (m) 16.0
Membrane Percolation (mm/hr)
1000
Length (m) 62.0
Max Percolation (l/s)
275.6
Slope (1:X) 100.0
Safety Factor
2.0 Depression Storage (mm)
5
Porosity
0.30
Evaporation (mm/day)
3
Invert Level (m) 116.000
Cap Volume Depth (m) 0.450

bristol railhub

Transcription

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