Issue 01

25/06/18

Drainage Strategy

for

Michael Drayton School Extension

Warwickshire County Council

Drainage Strategy

MJC/KJD/171638/17-2 Reports/Drainage Strategy - Issue 01

Document History Issue Date Comment Author Chk’d 01 25/06/18 First Issue KJD JSW

Drainage Strategy

MJC/KJD/171638/17-2 Reports/Drainage Strategy - Issue 01

Contents

1.0 Introduction ....................................................................................................... 1

2.0 Site Setting ........................................................................................................ 1

Site Description and Location 1

Proposed Development 1

3.0 Existing Drainage .............................................................................................. 2

Foul Drainage 2

Surface Water 2

Possible Seven Trent Surface Water Sewer 2

4.0 Proposed Drainage ............................................................................................ 2

Proposed Foul Drainage 2

Proposed Surface Water 3

5.0 Seven Trent Development Enquiry Application ............................................. 4

6.0 Micro Drainage Windes Calculations ............................................................... 4

7.0 Rainwater Harvesting........................................................................................ 4

8.0 Pollution Control ............................................................................................... 4

Appendix A

Existing and proposed peak foul flow calculations in accordance with BS EN 12506-2

Appendix B

Proposed Phase One Foul Drainage Drawings

Appendix C

Existing green field run off rate for the development

Appendix D

Proposed phase two surface water drainage drawings

Appendix E

Surface water Miro Drainage Windes Calculations

Drainage Strategy

1 MJC/KJD/171638/17-2 Reports/Drainage Strategy - Issue 01

1.0 Introduction

Pick Everard have been appointed as to undertake the civil engineering design elements for

Michael Drayton Junior School in Nuneaton. This drainage strategy outlines the current

drainage systems on the site and how these will be affected by the project. This document

will also provide a guide of the proposed drainage for development.

2.0 Site Setting

Site Description and Location

The application site runs to 26,735m² / 2.764ha (6.6acres) and is located to the northern

side of Hartshill, Warwickshire, approximately 6km from Nuneaton. The site is bounded to

the east by the residential properties fronting Church Road, the main through road running

north out of Hartshill. The site is approximately centred on National Grid Reference

(NGR) 432555, 293977.

Proposed Development

It is proposed to construct a number of single storey extensions to the existing school and

undertake refurbishment of various sections. The project will be built in 2 phases. Phases

1includes the construction of a hall extension and various enabling works and phase 2

involves an extension that will create 4 new classrooms.

The proposed development is shown in Figure 2, below;

Figure 1 Proposed Development

Phase One Details

Phase one will include a small hall extension, approximately 33m2, to the front of the

school. The footprint of the extension will be constructed on existing hardstanding. The

hall construction works requires the existing foul drainage to be diverted around the

proposed hall footprint. Phase one also includes the enabling works for the temporary

Phase One Hall

Extension

Phase Two Year 4 Class Room Extension

Phase Two Year 5 and 6 Class Room Extensions

Temporary Class Room Location

Drainage Strategy

2 MJC/KJD/171638/17-2 Reports/Drainage Strategy - Issue 01

building. The temporary building will be constructed on the existing playground east of the

site in front of the year 4 classrooms.

Phase Two Details

Phase two will include 3 separate extensions to class rooms to the east of the site. The

largest of which will house 2 year 4 class rooms, a small toilet block, a staff room, group

working room and a reprographic centre. The total footprint new class room extensions

will be approximately 406m2.

The development of the year 5 and 6 classrooms will require the existing surface water

drainage to be diverted around the proposed footprint of the building.

3.0 Existing Drainage

A below ground utilities survey was carried out by Midlands Survey in May 2018. The

survey identified the existing on site drainage systems and services. A CCTV survey was

also carried out by Midlands Survey. It was found that the school has a separate surface

water and foul drainage system. Furthermore, the CCTV investigation found that most of

the drainage pipes are constructed from Pitch Fibre. Pitch fibre is a material common

construction material commonly associated with asbestos.

Foul Drainage

The existing foul drainage flows, by gravity, to the front of the school and discharges into

the public sewer through the main school gate. The existing peak foul sewage flow of 4.1 l/s

has been calculated in accordance with BS EN 12506-2 based upon the number of wet

appliances to be installed in the building. Appendix A

Surface Water

A series of rain water pipes and land drains collect the surface water and discharges it in to

the surface water network. Similar to the foul the surface water drainage discharges from

site through the main school gate, to the north west.

Possible Seven Trent Surface Water Sewer

The topographical and CCTV survey found that there is a 300mm diameter surface water

pipe, possibly owned by Seven Trent Water, running underneath the existing building. The

new year 6 class rooms extension will be built over this pipe. A pre-development enquiry

has been submitted and the response will detail any Seven Trent owned sewers on site.

This will help Pick Everard to understand if a build over agreement is required.

4.0 Proposed Drainage

Proposed Foul Drainage

Due to the extent of the hall extension and associated foundations the foul and surface

water pipes will need to be diverted around the development. This is included within Phase

one. Phase one will also include the constructing of the permeant foul drainage which will

serve the small toilet block located within the new year 4 class rooms. The toilet block

within the extension will consist of 4 toilets and 4 sinks. The proposed peak foul sewage

Drainage Strategy

3 MJC/KJD/171638/17-2 Reports/Drainage Strategy - Issue 01

flow of 2.5l/s has been calculated in accordance with BS EN 12506-2 based upon the

number of wet appliances to be installed in the building, appendix A.

Before the occupation of the new extension a temporary building will be constructed and

will house no more than 4 toilets and 4 sinks. The foul drainage from the temporary

building will connect into the new permeant drainage to enable the school to drain the foul

water without installing a temporary septic tank or pump out the toilets with a tanker. This

will help to decrease the disturbances to the school during teaching hours.

The Phase one foul drainage drawings can be found in Appendix B

Proposed Surface Water

Infiltration testing

Infiltration testing was undertaken on 20 November 2017 by Nicholls Colton Group. The

tests were carried out in accordance with BRE digest 365. The initial feedback from

Nicholls Colton has proved that the ground is not suitable for drainage by infiltration as the

water level in the three trial pits did not decrease discernibly over a period of four to six

hours. Pick Everard are awaiting the final report.

Discharge Rates

The phases 2 development will increase the hardstanding from approximately 2750m2 to

3076m2 which is an increase of 326 m2. Warwickshire County Council Strategic Flood Risk

Assessment (SFRA) states “Surface water runoff from all new developments should be

attenuated to the Greenfield runoff rate for equivalent rainfall events up to and including the 1 in

100 year plus climate change.” The greenfield run off rate has been calculated using the UK

SUDs Greenfield Runoff Calculator. The catchment area for the proposed site was set to

0.1ha as this is the smallest area that could be inputted. The results are included in

Appendix C and summarised in Table 1 below.

Qbar (l/s) 0.47

1 in 1 year (l/s) 0.39

1 in 30 year (l/s) 0.93

1 in 100 year (l/s) 1.2 Table 1 Proposed Greenfield Run-off Rate Calculations

As restricting the run-off to the greenfield rates given above would require the flow to be

controlled to a rate well below the minimum practical piped controlled discharge of 5l/s.

The surface water discharge from the year 4 extension will be reduced to no more than

5l/s during the 1 in 100 year + 40% climate change storm.

Proposed Surface water Drainage System

The hall extension and year 5 and year 6 classrooms will be constructed on existing

hardstanding. Therefore, the surface water run off will discharge into the existing drainage

via rain water down pipes and land drains.

The existing carpark will be extended by 76m2 to accommodate correctly sizes disabled

spaces and 5 new parking spaces. The surface water drainage from new carpark extension

will discharge in to the existing drainage system.

The year 4 class room extension and proposed footpath will be constructed on existing

hardstanding and existing playing fields. The surface water discharge from the new class

Drainage Strategy

4 MJC/KJD/171638/17-2 Reports/Drainage Strategy - Issue 01

room and footpath will be collected in a series of rain water pipes and land drains and will

discharge in to a new length of 300mm dia pipe. An orifice plate will be placed within the

downstream manhole of the 300mm dia pipe. The orifice plate will restrict the surface

water discharge to no more than 5 l/s as it discharges in to the existing drainage system.

The proposed surface water drainage can be found in the Appendix D

5.0 Seven Trent Development Enquiry Application

A development application has been submitted to Seven Trent Water on the 18 of June

2018. Pick Everard are awaiting the response.

6.0 Micro Drainage Windes Calculations

The proposed drainage network has been input into WinDes drainage simulation software.

The 1 in 1 year, 1 in 2 year, 1 in 30 year and 1in 100 + 40% climate change events have

been simulated. The Windes Calculations can be found in Appendix E

7.0 Rainwater Harvesting

Rainwater harvesting has been considered but deemed not economically viable due to the

small number of new toilets in the proposed development.

8.0 Pollution Control

The Environment Agency sets out guidelines for many different pollution issues, pollution

prevention guidelines (PPG). PPG3 sets out guidelines for the use and design of oil

separators in surface water drainage systems. It states that “car parks typically larger than

800m2 in area or for 50 or more car parking spaces” will require a separator. This

redevelopment project is too small to require an oil interceptor.

Drainage Strategy

MJC/KJD/171638/17-2 Reports/Drainage Strategy - Issue 01

Appendix A

Existing and proposed peak foul flow calculations in accordance with

BS EN 12506-2

21/06/2018

BUILDING FOUL DRAINAGE BS EN 12506-2:2000 - SYSTEM III

Scheme: Michael Drayton

Ref: 171638

Building:

K

Frequency Factor: Frequent 0.7 e.g. Hospital, school, restaurant, hotel

Discharge

Appliance Unit (DU) No. Sum DUs Flow

(l/s)

I had a look Kerry

Basin 0.3 42 12.6 2.485

Sink 0.6 15 9 2.100

Shower 0.4 8 3.2 1.252

Urinal 0.4 17 6.8 1.825

Domestic Washing Machine 0.6 2 1.2 0.767

Dishwasher 0.2 1 0.2 0.313

Other:

Sum 33 4.02 l/s

Exsiting Foul Loading

21/06/2018

BUILDING FOUL DRAINAGE BS EN 12506-2:2000 - SYSTEM III

Scheme: Michael Drayton

Ref: 171638

Building:K

Frequency Factor: Frequent 0.7 e.g. Hospital, school, restaurant, hotel

Discharge

Appliance Unit (DU) No. Sum DUs Flow

(l/s)

I had a look Kerry

WC 1.8 6 10.8 2.300

Basin 0.3 6 1.8 0.939

Other:

Sum 12.6 2.48 l/s

Proposed Foul Loading

X001KJD-171638-17-1 Foul Load.xlsx 21/06/2018

Drainage Strategy

MJC/KJD/171638/17-2 Reports/Drainage Strategy - Issue 01

Appendix B

Proposed Phase One Foul Drainage Drawings

WAR007-PE-XX-ZZ-DR-C-0500_Proposed Drainage Layout - Phase One - Sheet 1 of 2_171638

WAR007-PE-XX-ZZ-DR-C-0501_ Proposed Drainage Layout - Phase One - Sheet 2 of 2_171638

100035

00

Year 4 class room extenstion

Existing School building

FWMH03

CL = TBC

IL = 140.213m AOD

FWMH01

CL = TBC

IL = 140.413

Proposed Foul Drainage to connect into the existing

drainage which flows the the public sewer.

CL = 140.860m AOD

IL = 139.580m AOD

FWMH02

CL = TBC

IL = 140.341m AOD

100mm dia Pipes

to SVP

1:40 Gradient

KEY:

- Proposed foul water sewer

- Proposed foul water manhole (1200mmØ PCC)

- Proposed foul water inspection chamber (475mmØ

- Proposed foul water internal gully (with trap)

- Proposed foul water gully (trapless)

- Proposed foul water stub pipe

- Existing foul drainage

-Existing foul drainage to be abandoned

G

IG

st

KEY:

- Proposed surface water sewer

- Proposed surface water manhole

(1200mmØ PCC)

- Proposed surface water inspection

chamber (475mmØ PPIC)

- Proposed surface water gully

- Proposed rainwater downpipe

- Proposed channel drain

- Existing surface water pipe

G

rwp

A1

Draft Planning IssueP01 15.06.18 KJDRevision Date Drn Chk

CDM - RESIDUAL HAZARDS

1

2

3 etc.

Further possible control measures have been identified within the Design RiskAssessments which may help to mitigate these and other identified risksfurther during the construction / maintenance process.

S0 - Work in Progress

Client

Job No.

Suitability Status

Drawing Number

@ A1Scale

Project

Rev

NO DIMENSIONS TO BE SCALED FROM THIS DRAWING

This drawing is issued for the sole and exclusive use of the intended recipient and issubject to copyright in favour of Pick Everard. Pick Everard does not accept anyresponsibility or liability whatsoever for its use by a person other than the intendedrecipient.

Size

Drawing Title

T 0345 045 0050 www.pickeverard.co.uk

CDM - RESIDUAL HAZARDS The following are considered to be significant risksrelevant to this drawing, which could not be fully mitigated or removed throughdesign:

Project Code - Originator - Zone - Level - Type - Role - Number

171638 P02

Warwickshire County Council

Michael Drayton School

Proposed Drainage LayoutPhase OneSheet 2 of 2

1:50

WAR7-PEV-XX-ZZ-DR-C-0501

Planning IssueP02 25.06.18 KJD JSW

A

1

A

1

A

1

A

1

A

1

A

1

A

1

A

1

A

1

A

1

A

1

A

1

A

1

Existing Surface water RWP to be removed

Existing Surface pipe to be retained

Divert existing foul sewer

around the new extension

FWMH04

CL=TBC

IL= 139.270m

FWMH05

CL = TBC

IL = 139.120m

FWMH06

CL = TBC

IL= 139.099m AOD

EXMHF4

CL = TBC

IL = 139.340m

EXMHF3

CL = m

IL = 138.980m

Assumed 100mm dia Pipe

1:75 Gradient

From historical drawings

EXMHS11

CL = TBC

IL = 139.640m

EXMHS10

CL = TBC

IL = 139.213m

Invert of Existing SW

Approx 139.441m AOD

Invert of Existing SW

Approx 139.207m AOD

KEY:

- Proposed foul water sewer

- Proposed foul water manhole (1200mmØ PCC)

- Proposed foul water inspection chamber (475mmØ

- Proposed foul water internal gully (with trap)

- Proposed foul water gully (trapless)

- Proposed foul water stub pipe

- Existing foul drainage

-Existing foul drainage to be abandoned

G

IG

st

KEY:

- Proposed surface water sewer

- Proposed surface water manhole

(1200mmØ PCC)

- Proposed surface water inspection

chamber (475mmØ PPIC)

- Proposed surface water gully

- Proposed rainwater downpipe

- Proposed channel drain

- Existing surface water pipe

G

rwp

A1

Draft Planning IssueP01 15.06.18 KJDRevision Date Drn Chk

CDM - RESIDUAL HAZARDS

1

2

3 etc.

Further possible control measures have been identified within the Design RiskAssessments which may help to mitigate these and other identified risksfurther during the construction / maintenance process.

S0 - Work in Progress

Client

Job No.

Suitability Status

Drawing Number

@ A1Scale

Project

Rev

NO DIMENSIONS TO BE SCALED FROM THIS DRAWING

This drawing is issued for the sole and exclusive use of the intended recipient and issubject to copyright in favour of Pick Everard. Pick Everard does not accept anyresponsibility or liability whatsoever for its use by a person other than the intendedrecipient.

Size

Drawing Title

T 0345 045 0050 www.pickeverard.co.uk

CDM - RESIDUAL HAZARDS The following are considered to be significant risksrelevant to this drawing, which could not be fully mitigated or removed throughdesign:

Project Code - Originator - Zone - Level - Type - Role - Number

171638 P02

Warwickshire County Council

Michael Drayton School

Proposed Drainage LayoutPhase OneSheet 1 of 2

1:75

WAR7-PEV-XX-ZZ-DR-C-0500

Planning IssueP02 25.06.18 KJD JSW

Drainage Strategy

MJC/KJD/171638/17-2 Reports/Drainage Strategy - Issue 01

Appendix C

Proposed green field run off rate for the development

This report was produced using the greenfield runoff tool developed by HR Wallingford and available at www.uksuds.com. The use of this tool is subject to the UK SuDS terms and conditions and licence agreement, which can both be found at http://uksuds.com/terms-and-conditions.htm. The outputs from this tool have been used to estimate storage volume requirements. The use of these results is the responsibility of the users of this tool. No liability will be accepted by HR Wallingford, the Environment Agency, CEH, Hydrosolutions or any other organisation for use of this data in the design or operational characteristics of any drainage scheme.

Greenfield runoff estimation for sites

www.uksuds.com │ Greenfield runoff tool

This is an estimation of the greenfield runoff rate limits that are needed to meet normal best practice criteria in line with Environment Agency guidance “Preliminary rainfall runoff management for developments”, W5-074/A/TR1/1 rev. E (2012) and the SuDS Manual, C753 (Ciria, 2015). This information on greenfield runoff rates may be the basis for setting consents for the drainage of surface water runoff from sites.

Site name:

Calculated by:

Latitude:

Longitude:

Reference:

Date:

Site coordinates

Site location:

Site characteristicsTotal site area (ha)

MethodologyQbar estimation methodSPR estimation method

Default Edited

SOIL typeHOST classSPR/SPRHOST

Hydrological characteristics Default Edited

SAAR (mm)Hydrological region Growth curve factor: 1 year Growth curve factor: 30 year Growth curve factor: 100 year

Notes:(1) Is QBAR < 2.0 l/s/ha?

(2) Are flow rates < 5.0 l/s?

(3) Is SPR/SPRHOST ≤ 0.3?

Greenfield runoff rates Default Edited

Qbar (l/s)1 in 1 year (l/s)1 in 30 years (l/s)1 in 100 years (l/s)

Methodology IH124

0.47

0.39

2

1.2

0.83 0.83

Lower consent flow rates may be set in which case blockage

4

0.1

2018-06-18T16:51:16

The Woodlands, Nuneaton

--- 5.0l/s if blockage from vegetation and other materials is possible.

1.5219° W

0.39

Michael Drayton

0.47

Kerry Dent

2.57

0.47

Calculate from SOIL type

52.54254° N

678678

44

1.2

2.57

Calculate from SPR and SAAR

4

---

0.93 0.93

2

6381924

work must be addressed by using appropriate drainage elements.

0.47

Where flow rates are less than 5.0 l/s consents are usually set at

Drainage Strategy

MJC/KJD/171638/17-2 Reports/Drainage Strategy - Issue 01

Appendix D

Proposed phase two surface water drainage drawings

WAR007-PE-XX-ZZ-DR-C-0502_Proposed Drainage Layout - Phase Two_171638

Michael Drayton

Junior School

100035

00

2000

3000

SWMH02

CL= TBC

IL= 140.492m AOD

SWMH03

CL= TBC

IL= 140.372m AOD

Proposed SW Drainage to connect into the

existing drainage which flows the the public

sewer.

CL= 140.880

IL = 139.230

300mm dia pipe used for

attenuation

Year 4 class room extenstion

Existing School building

SWMH04

CL=TBC

IL= 140.295m AOD

52mm dia Orifice Plate installed downstream

of the 300mm dia pipe to restrict the discharge

rate to:

1:1 year storm = 2l/s

1:30 Year storm = 3l/s

1:100 + 40% CC Storm = 4.7l/s

SWMH01

CL= TBC

IL= 140.618m AOD

SWMH05

CL= TBC

IL= 140.240m AOD

New manhole to divert existing drainage

around the proposed extension

SWMH06

CL= TBC

IL= 140.205m AOD

SWMH07

CL= TBC

IL= 140.149m AOD

EXSWMH01

CL= 140.870m AOD

IL= 140.260m AOD

New pipe to be laid to flow into

SWMH05

EXSWMH02

CL= 140.870m AOD

IL= 140.130m AOD

Existing surface water

pipe to be abandoned

and removed

Existing 300mm dia pipe

New foundations to bridge over pipe

Existing channel drain to be cleaned and unblocked

School drop off zone

surface water

drainage

KEY:

- Proposed foul water sewer

- Proposed foul water manhole (1200mmØ PCC)

- Proposed foul water inspection chamber (475mmØ

- Proposed foul water internal gully (with trap)

- Proposed foul water gully (trapless)

- Proposed foul water stub pipe

- Existing Foul Drainage

G

IG

st

KEY:

- Proposed surface water sewer

- Proposed surface water manhole

(1200mmØ PCC)

- Proposed surface water inspection

chamber (475mmØ PPIC)

- Proposed surface water gully

- Proposed rainwater downpipe

- Proposed channel drain

- Existing surface water pipe

- Existing surface water pipe to be

abandoned

G

rwp

P01 15.06.18 KJDRevision Date Drn Chk

CDM - RESIDUAL HAZARDS

1

2

3 etc.

Further possible control measures have been identified within the Design RiskAssessments which may help to mitigate these and other identified risksfurther during the construction / maintenance process.

S0 - Work in Progress

Client

Job No.

Suitability Status

Drawing Number

@ A1Scale

Project

Rev

NO DIMENSIONS TO BE SCALED FROM THIS DRAWING

This drawing is issued for the sole and exclusive use of the intended recipient and issubject to copyright in favour of Pick Everard. Pick Everard does not accept anyresponsibility or liability whatsoever for its use by a person other than the intendedrecipient.

Size

Drawing Title

T 0345 045 0050 www.pickeverard.co.uk

CDM - RESIDUAL HAZARDS The following are considered to be significant risksrelevant to this drawing, which could not be fully mitigated or removed throughdesign:

Project Code - Originator - Zone - Level - Type - Role - Number

171638 P02

Warwickshire County Council

Michael Drayton School

Proposed Drainage LayoutPhase Two

1:150

WAR7-PEV-XX-ZZ-DR-C-0502

Planning IssueP02 25.06.18 KJD JGWDraft Issue

Drainage Strategy

MJC/KJD/171638/17-2 Reports/Drainage Strategy - Issue 01

Appendix E

Surface water Miro Drainage Windes Calculations

Pick Everard Page 1

Halford House Michael Drayton SchoolCharles Street Phase 2Leicester LE1 1HA Surface Water SimulationDate 21/06/2018 Designed by KJDFile S001KJD-17-1-171638 -S...

Checked by JSWXP Solutions Network 2017.1.2

Existing Network Details for Storm

©1982-2017 XP Solutions

PN Length(m)

Fall(m)

Slope(1:X)

I.Area(ha)

T.E.(mins)

BaseFlow (l/s)

k(mm)

HYDSECT

DIA(mm)

Section Type

1.000 17.950 0.126 142.5 0.009 4.00 0.0 0.006 o 150 Pipe/Conduit1.001 20.850 0.120 173.8 0.009 4.00 0.0 0.006 o 150 Pipe/Conduit1.002 17.250 0.077 224.0 0.009 4.00 0.0 0.006 o 300 Pipe/Conduit1.003 16.521 0.015 1101.4 0.000 4.00 0.0 0.006 o 100 Pipe/Conduit

Network Results Table

PN US/IL(m)

Σ I.Area(ha)

Σ BaseFlow (l/s)

Vel(m/s)

Cap(l/s)

1.000 140.618 0.009 0.0 1.12 19.81.001 140.492 0.018 0.0 1.00 17.71.002 140.372 0.027 0.0 1.38 97.31.003 140.295 0.027 0.0 0.27 2.1

Pick Everard Page 2

Halford House Michael Drayton SchoolCharles Street Phase 2Leicester LE1 1HA Surface Water SimulationDate 21/06/2018 Designed by KJDFile S001KJD-17-1-171638 -S...

Checked by JSWXP Solutions Network 2017.1.2

Area Summary for Storm

©1982-2017 XP Solutions

PipeNumber

PIMPType

PIMPName

PIMP(%)

GrossArea (ha)

Imp.Area (ha)

Pipe Total(ha)

1.000 - - 100 0.009 0.009 0.0091.001 - - 100 0.009 0.009 0.0091.002 - - 100 0.009 0.009 0.0091.003 - - 100 0.000 0.000 0.000

Total Total Total0.027 0.027 0.027

Free Flowing Outfall Details for Storm

OutfallPipe Number

OutfallName

C. Level(m)

I. Level(m)

MinI. Level

(m)

D,L(mm)

W(mm)

1.003 EXSITING 141.130 140.280 140.280 100 0

Simulation Criteria for Storm

Volumetric Runoff Coeff 0.750 Additional Flow - % of Total Flow 0.000Areal Reduction Factor 1.000 MADD Factor * 10m³/ha Storage 2.000

Hot Start (mins) 0 Inlet Coeffiecient 0.800Hot Start Level (mm) 0 Flow per Person per Day (l/per/day) 0.000

Manhole Headloss Coeff (Global) 0.500 Run Time (mins) 60Foul Sewage per hectare (l/s) 0.000 Output Interval (mins) 1

Number of Input Hydrographs 0 Number of Storage Structures 0Number of Online Controls 1 Number of Time/Area Diagrams 0Number of Offline Controls 0 Number of Real Time Controls 0

Synthetic Rainfall Details

Rainfall Model FSR Profile Type SummerReturn Period (years) 100 Cv (Summer) 0.750

Region England and Wales Cv (Winter) 0.840M5-60 (mm) 20.000 Storm Duration (mins) 30

Ratio R 0.400

Pick Everard Page 3

Halford House Michael Drayton SchoolCharles Street Phase 2Leicester LE1 1HA Surface Water SimulationDate 21/06/2018 Designed by KJDFile S001KJD-17-1-171638 -S...

Checked by JSWXP Solutions Network 2017.1.2

Online Controls for Storm

©1982-2017 XP Solutions

Orifice Manhole: SWMH04, DS/PN: 1.003, Volume (m³): 2.1

Diameter (m) 0.052 Discharge Coefficient 0.600 Invert Level (m) 140.295

Pick Everard Page 4

Halford House Michael Drayton SchoolCharles Street Phase 2Leicester LE1 1HA Surface Water SimulationDate 21/06/2018 Designed by KJDFile S001KJD-17-1-171638 -S...

Checked by JSWXP Solutions Network 2017.1.2

Summary of Critical Results by Maximum Outflow (Rank 1) for Storm

©1982-2017 XP Solutions

Simulation CriteriaAreal Reduction Factor 1.000 Additional Flow - % of Total Flow 0.000

Hot Start (mins) 0 MADD Factor * 10m³/ha Storage 2.000Hot Start Level (mm) 0 Inlet Coeffiecient 0.800

Manhole Headloss Coeff (Global) 0.500 Flow per Person per Day (l/per/day) 0.000Foul Sewage per hectare (l/s) 0.000

Number of Input Hydrographs 0 Number of Storage Structures 0Number of Online Controls 1 Number of Time/Area Diagrams 0Number of Offline Controls 0 Number of Real Time Controls 0

Synthetic Rainfall DetailsRainfall Model FSR Ratio R 0.400

Region England and Wales Cv (Summer) 0.750M5-60 (mm) 20.000 Cv (Winter) 0.840

Margin for Flood Risk Warning (mm) 300.0Analysis Timestep 2.5 Second Increment (Extended)

DTS Status ONDVD Status ON

Inertia Status ON

Profile(s) Summer and WinterDuration(s) (mins) 15, 30, 60, 120, 180, 240, 360, 480, 600,

720, 960, 1440Return Period(s) (years) 1, 2, 30, 100

Climate Change (%) 0, 0, 0, 40

PNUS/MHName Storm

ReturnPeriod

ClimateChange

First (X)Surcharge

First (Y)Flood

First (Z)Overflow

OverflowAct.

Water Level(m)

1.000 SWMH01 15 Summer 100 +40% 100/15 Summer 141.1281.001 SWMH02 15 Summer 100 +40% 30/15 Winter 141.1231.002 SWMH03 15 Summer 100 +40% 30/15 Winter 141.1221.003 SWMH04 30 Winter 100 +40% 1/15 Summer 141.113

PNUS/MHName

SurchargedDepth(m)

FloodedVolume(m³)

Flow /Cap.

Overflow(l/s)

PipeFlow(l/s) Status

LevelExceeded

1.000 SWMH01 0.360 0.000 0.32 5.6 FLOOD RISK1.001 SWMH02 0.481 0.000 0.57 9.1 FLOOD RISK1.002 SWMH03 0.450 0.000 0.15 10.1 FLOOD RISK1.003 SWMH04 0.718 0.000 2.06 4.7 FLOOD RISK

Pick Everard Page 5

Halford House Michael Drayton SchoolCharles Street Phase 2Leicester LE1 1HA Surface Water SimulationDate 21/06/2018 Designed by KJDFile S001KJD-17-1-171638 -S...

Checked by JSWXP Solutions Network 2017.1.2

Rainfall Hyetograph for 15 minute 100 year Summer I+40%for Pipe 1.000 (Storm)

©1982-2017 XP Solutions

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

1 46.489 4 69.905 7 314.575 10 158.945 13 58.2322 51.117 5 92.770 8 488.233 11 92.770 14 51.1173 58.232 6 158.945 9 314.575 12 69.905 15 46.488

Pick Everard Page 6

Halford House Michael Drayton SchoolCharles Street Phase 2Leicester LE1 1HA Surface Water SimulationDate 21/06/2018 Designed by KJDFile S001KJD-17-1-171638 -S...

Checked by JSWXP Solutions Network 2017.1.2

Rainfall Hyetograph for 15 minute 100 year Summer I+40%for Pipe 1.001 (Storm)

©1982-2017 XP Solutions

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

1 46.489 4 69.905 7 314.575 10 158.945 13 58.2322 51.117 5 92.770 8 488.233 11 92.770 14 51.1173 58.232 6 158.945 9 314.575 12 69.905 15 46.488

Pick Everard Page 7

Halford House Michael Drayton SchoolCharles Street Phase 2Leicester LE1 1HA Surface Water SimulationDate 21/06/2018 Designed by KJDFile S001KJD-17-1-171638 -S...

Checked by JSWXP Solutions Network 2017.1.2

Rainfall Hyetograph for 15 minute 100 year Summer I+40%for Pipe 1.002 (Storm)

©1982-2017 XP Solutions

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

1 46.489 4 69.905 7 314.575 10 158.945 13 58.2322 51.117 5 92.770 8 488.233 11 92.770 14 51.1173 58.232 6 158.945 9 314.575 12 69.905 15 46.488

Pick Everard Page 8

Halford House Michael Drayton SchoolCharles Street Phase 2Leicester LE1 1HA Surface Water SimulationDate 21/06/2018 Designed by KJDFile S001KJD-17-1-171638 -S...

Checked by JSWXP Solutions Network 2017.1.2

Rainfall Hyetograph for 30 minute 100 year Winter I+40%for Pipe 1.003 (Storm)

©1982-2017 XP Solutions

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

Time(mins)

Rain(mm/hr)

1 12.494 6 41.702 11 121.527 16 224.946 21 95.228 26 40.3832 30.695 7 46.856 12 150.599 17 206.590 22 72.965 27 40.3673 38.446 8 57.054 13 180.722 18 180.722 23 57.054 28 38.4464 40.367 9 72.965 14 206.590 19 150.599 24 46.856 29 30.6955 40.383 10 95.228 15 224.946 20 121.527 25 41.702 30 12.493