drainage strategy for land off eversley court at minera ...€¦ · priority level 5: surface water...

COOPERS is the trading name of Coopers (Chester) Limited.Company registered in England & Wales.

Company number 09730429.

tel: 01244 684 910web: www.coopers.co.uk

email: [email protected]

Park House, Sandpiper Court, Chester Business Park, Chester, CH4 9QU

Our ref: 6896DS

Drainage Strategy

for

Land off Eversley Court

at

Minera, Wrexham

For : Gower Homes 8 Temple Row Wrexham LL13 8LY 28 November 2018

For: Gower Homes Coopers (Chester) Ltd

Drainage Strategy for land off Everslet Court at Minera, Wrexham

Ref: 6896 DS Page 1 of 4 28 Nov 2018

Introduction Coopers have been instructed to produce a Drainage Strategy Report for a site in Minera, Wrexham. Gower Homes are planning the construction of 10 detached residential properties with associated access road, parking, vehicular access and landscaping subject to conditions. The site is greenfield and covers an area of 0.445ha. Site topography falls in a southerly direction with an average gradient of 1:25. Surface Water Drainage General The design for a surface water drainage system for the proposed development will be guided by the principles set out in the Welsh Government’s ‘Recommended non-statutory standards for sustainable drainage (SuDS) in Wales – designing, constructing, operating and maintaining surface water drainage systems’ (2017) The SuDS Standards Wales sets out the following hierarchy for surface water runoff destination: Priority Level 1: Surface water runoff is collected for use; Priority Level 2: Surface water runoff is infiltrated to ground; Priority Level 3: Surface water runoff is discharged to a surface water body; Priority Level 4: Surface water runoff is discharged to a surface water sewer, highway drain, or another drainage system; Priority Level 5: Surface water runoff is discharged to a combined sewer. Note that Priority Level 1 is the preferred (highest priority) and that 4 and 5 should only be used in exceptional circumstances. Existing Surface Water Drainage Surface water flows from the site currently drain to a shallow ditch located along the southern boundary. It is understood this then connects into a culverted watercourse routed through the housing estate to the south east of the site but details of the routes and connectivity are unclear. .



Ref: 6896 DS Page 2 of 4 28 Nov 2018

Existing Site Runoff The catchment surface area for the site and the proposed development is <50ha, therefore Micro Drainage software has been used to calculate the greenfield runoff for the site using the Interim Code of Practice (ICP) SUDS method. The outputs are provided in Appendix 2. The greenfield runoff rate has been calculated as QBAR of 4.2 litres / second Proposed Surface Water Drainage and Runoff Rates Priority Level 1 Whilst rainwater harvesting has been considered for the proposed development it should be noted that any device enabling water re-use cannot be taken into account when sizing attenuation as the storage facility may be full when a storm event occurs. Therefore, an over flow to an infiltration device (where ground conditions allow) or to a watercourse / sewer will be required. Gower Homes are not proposing to incorporate rainwater harvesting within the development, however they are proposing to install a water butt to each dwelling which will allow for water collection for garden re-use. Priority Level 2 No site investigation has been currently been undertaken but local geology plans show the site being underlain by glacial till, overlying Coal Measures bedrock. Therefore, we do not anticipate infiltration techniques as being suitable for disposal of surface water flows from the development. However, this will be reviewed further once the site investigation report is available. Priority Level 3 The site currently drains to a shallow ditch located at the southern boundary of the site. The proposed site layout does not allow for any drainage route to utilise this as a drainage outfall and it should be noted that levels would not allow for a connection without substantial uplift in ground levels in the southern portion of the site.



Ref: 6896 DS Page 3 of 4 28 Nov 2018

An ordinary watercourse runs along part of the eastern site boundary then continues east along Eversley House southern boundary before being culverted under Eversley Court and discharging into an open watercourse within the vicarage. Gower Homes are proposing to discharge all surface water flows from the development into the ordinary watercourse. Site levels do not allow for a direct connection into the open watercourse on the eastern boundary so we are proposing a gravity connection from the site to discharge into the culvert under Eversley Court. Flows will be restricted to 5 l/s using a vortex flow control fitted within the last manhole within the site boundary. This flow rate is slightly above the greenfield QBAR run-off rate for the site, but 5 l/s is generally considered the minimum practicable discharge rate to help prevent any future blockage and will also be acceptable to Welsh Water for adoption. Attenuation for the 30-year flood event will be provided within oversized pipes and manholes in the on-line sewer network being proposed within the road corridor. This network will be offered to Welsh Water for adoption under a S104 Agreement. The site layout does not allow for the incorporation of any surface features to provide attenuation so storage for the 100-year flood event plus a 30% allowance for climate change will be provided within off-line buried cellular crates (eg: Aquacell). This will be maintained by a management company details of which will be provided by Gower Homes at a future date. A SUDS management plan will be produced to address frequency and type of maintenance activities. Please refer to Coopers Drawing No. 6986-P03 for drainage proposals which have been designed using measured impermeable areas and modelled using MicroDrainage. Foul Drainage Following a review of Welsh Water sewers, we are proposing to connect into the public sewers in Eversley Court. A levels appraisal has confirmed a gravity connection from the site is achievable. All foul sewers serving more than 1 plot will be subject to a S104 Adoption Agreement with Welsh Water.



Ref: 6896 DS Page 4 of 4 28 Nov 2018

Conclusion It looks highly unlikely that the site will be suitable for infiltration techniques to dispose of surface water flows from the proposed development. However, this will be reviewed further when the site investigation report is available. Assuming ground conditions are unsuitable for infiltration we propose to discharge all surface water flows to the ordinary watercourse via a new connection into the culverted section under Eversley Court. Surface water flows will be restricted to 5 l/s which is considered the minimum practicable discharge rate. Surface water and foul networks will be offered for adoption to Welsh Water subject to a Section 104 Agreement A SUDS management plan will be produced at detailed design stage and a Management Company will take responsibility for the off-line attenuation components. Gower Homes will provide details of the management company prior to occupation.



Our Ref: 6896DS 28 Nov 2018

Appendix 1

Reference Drawings

Drawing No. Revision Title

6896 / P01 - Site Location Plan

6896 / P02 - Surface Water Impermeable Areas

6896 / P03 - Proposed Drainage Layout

NORTH

0 2000

S C A L E B A R (m)

200 400 600 800 1000 1500

28

52

532

7

51

26

National Grid referenceof the proposed site.

Drg No:

© Crown copyright. All rights reserved.Licence number AL 100005579.

DRAWN

CHEK'D

DATE

SCALE

The original of this drawing contained coloured symbols and/or features.Any black and white reproduction should not be relied upon. © Copyright

EVERSLEY COURT, MINERAWREXHAM

SITE LOCATION PLAN

6896 / P01

1:25000 @ A4

NOV 18

WC

AJ

SJ 270 520

SITE

50

Tel: 01244 684910Fax: 01244 684911Email: [email protected]: http://coopers.co.uk

Park HouseSandpiper Court

Chester Business ParkChester

CH4 9QU

2

R

1

B

Ch

R

7

6

C

8

C

3

R

4

10

B

9

H

Ch

5

SW AREAS

Plots 740

Garages 120

Driveways 280

Private Roads 0

Highway 1110

Total 2250

Client

DRAWING NUMBER

REVISION

CHECKED

DRAWN

DATE

SCALE at A2

Title

Project

GOWER HOMES

EVERSLEY COURT,

MINERA, WREXHAM

Proposed Drainage Plan

6896 / P02

1:250

NOV 18

WC

AJ

-

DO NOT SCALE




CH4 9QU

© Copyright

The original of this drawing contained coloured symbols and/or features.

Any black and white reproduction should not be relied upon.

Legend

Existing

Culverted Ordinary Watercourse

Open Channel Ordinary Watercourse

Combined Sewer

Highway Drain

Proposed

Site Boundary

Adoptable Surface Water Sewer

Adoptable Foul Sewer

Flow Control Manhole

Geocelluar Tank(100yr + 30%CC storage)

Indicative Plot Slab LevelFFL 00.00

COMBINED

HD HD

49.21 49.31

49.53

49.79

50.00

49.72

49.48 49.39

49.17

49.21

49.12 49.33

49.35

49.39

49.34

49.13

49.24

49.39

49.44

49.62

49.92

49.84

49.76

49.81 49.99

49.99

50.15

50.34

50.34

50.04

50.15

50.00

49.95 50.03

49.95

49.77

49.57

49.43

49.39

Base level48.950

COMBINED

COMBINED

CO

MB

INE

D

225 Ø @ 1:67

225 Ø

@ 1

:22

900

Ø @

1:4

00

900 Ø

@ 1

:400

900 Ø @ 1:400

225 Ø @ 1:165

CL = 53.00IL = 51.575

S1 1.5 Ø

CL = 52.70IL = 51.275

S2 1.5 Ø

CL = 51.20IL = 47.66

S3 1.8 Ø

CL = 50.75IL = 47.62

S4 1.8 Ø

CL = 50.25IL = 47.59

S5 1.8 Ø

S6(1.5 Dia. Flow Control Manhole)

Hydrobrake Optimum.5 l/s @ 1.35m design head

150 Ø @ 1:27

150

Ø @

1:2

8

150 Ø @ 1:32

150 Ø

@ 1

:38

150 Ø

@ 1

:29

CL = 51.20IL = 50.00

F2 1.2 Ø

CL = 52.70IL = 51.50

F1 1.2 Ø

CL = 50.60IL = 49.40

F3 1.2 Ø

CL = 50.40IL = 49.20

F4 1.2 Ø

CL = 50.00IL = 48.80

F5 1.2 Ø

SSSS

HD

HDHD

HDHD

HD

HD

HD

HD

HD

HDHD

HDHD

HDHD

225 Ø @ 1:165

150 Ø @ 1:37

Maintenance / Responsibilities

Sewers:All sewers to be offered to Welsh Water under a S104 Adoption Agreement.

Burried Geocellular crates:To be maintained by private 'Management Company' SUDS Management Planto be produced to address frequency and type of maintenance activities

CL = 49.50IL = 48.30

F6 1.2 Ø

CL = 49.40IL = 47.43

S7 1.2 Ø

Cellular attenuation tankproviding storage for a 100yr+ 30% CC storm event(30.4cu.m.)70m² x 0.4m deepAttenuation Location Option 1

CL = 50.00IL = 47.55

S6 2.4 Ø

CL = 48.287IL = 46.787

SJ27511997

1.2 Ø

CL = 48.237IL = 46.737

Existing

CL = 49.147IL = 47.947

Existing

BD

49.7

75

SSSS

1.2 Ø

375 Ø

CU

LV

ER

T

CL = 48.30IL = 47.20(Assumed IL)

S8 1.2 Ø

CO

MB

INE

D

CO

MB

INE

D

CO

MB

INE

D

FFL 53.70

FFL 54.15

FFL 54.00

FFL 52.80

FFL 52.50

FFL 51.90

FFL 51.50

FFL 51.25

FFL 50.30

FFL 50.15

FFL 52.50

FFL 50.00

FFL 50.15

Cellular attenuation tankproviding storage for a 100yr+ 30% CC storm event(30.4cu.m.)70m² x 0.4m deepAttenuation Location Option 2

Culvert (RouteUnconfirmed)

Client

DRAWING NUMBER

REVISION

CHECKED

DRAWN

DATE

SCALE at A1

Title

Project

GOWER HOMES

EVERSLEY COURT,MINERA, WREXHAM

Proposed Drainage Plan

6896 / P03

1:250

NOV 18

WC

AJ

-

DO NOT SCALE




CH4 9QU

© CopyrightThe original of this drawing contained coloured symbols and/or features.Any black and white reproduction should not be relied upon.

NORTH

RevisionRev Date By Appd.



Our Ref: 6896DS 28 Nov 2018

Appendix 2

Calculations

Greenfield Runoff Rate

Proposed Surface Water Drainage Calculations

Coopers Page 1Park HouseSandpiper CourtChester CH4 9QUDate 26/11/2018 17:00 Designed by ajonesFile Checked byMicro Drainage Source Control 2018.1.1

ICP SUDS Mean Annual Flood

©1982-2018 Innovyze

Input

Return Period (years) 1 Soil 0.500Area (ha) 0.445 Urban 0.000SAAR (mm) 1100 Region Number Region 9

Results l/s

QBAR Rural 4.2QBAR Urban 4.2

Q1 year 3.7

Q1 year 3.7Q30 years 7.4Q100 years 9.1

Coopers Page 1Park House Eversley Court, MineraSandpiper CourtChester CH4 9QU Surface Warter DesignDate 27/11/2018 15:07 Designed by CoopersFile 6896 SW03.MDX Checked by AJMicro Drainage Network 2018.1.1

STORM SEWER DESIGN by the Modified Rational Method

Design Criteria for Storm


Pipe Sizes STANDARD Manhole Sizes STANDARD

FSR Rainfall Model - England and WalesReturn Period (years) 1 PIMP (%) 100

M5-60 (mm) 18.000 Add Flow / Climate Change (%) 0Ratio R 0.330 Minimum Backdrop Height (m) 0.000

Maximum Rainfall (mm/hr) 0 Maximum Backdrop Height (m) 0.000Maximum Time of Concentration (mins) 30 Min Design Depth for Optimisation (m) 1.200

Foul Sewage (l/s/ha) 0.000 Min Vel for Auto Design only (m/s) 1.00Volumetric Runoff Coeff. 0.750 Min Slope for Optimisation (1:X) 400

Designed with Level Soffits

Network Design Table for Storm

PN Length(m)

Fall(m)

Slope(1:X)

I.Area(ha)

T.E.(mins)

BaseFlow (l/s)

k(mm)

HYDSECT

DIA(mm)

Section Type AutoDesign

1.000 19.000 0.300 63.3 0.040 5.00 0.0 0.600 o 225 Pipe/Conduit1.001 38.000 1.500 25.3 0.040 0.00 0.0 0.600 o 225 Pipe/Conduit1.002 18.000 0.045 400.0 0.045 0.00 0.0 0.600 o 900 Pipe/Conduit1.003 10.000 0.025 400.0 0.045 0.00 0.0 0.600 o 900 Pipe/Conduit1.004 16.000 0.040 400.0 0.045 0.00 0.0 0.600 o 900 Pipe/Conduit1.005 60.000 0.353 170.0 0.000 0.00 0.0 0.600 o 225 Pipe/Conduit

Network Results Table

PN Rain(mm/hr)

T.C.(mins)

US/IL(m)

Σ I.Area(ha)

Σ BaseFlow (l/s)

Foul(l/s)

Add Flow(l/s)

Vel(m/s)

Cap(l/s)

Flow(l/s)

1.000 0.00 5.19 51.575 0.040 0.0 0.0 0.0 1.65 65.5 0.01.001 0.00 5.44 51.275 0.080 0.0 0.0 0.0 2.61 103.8 0.01.002 0.00 5.63 47.660 0.125 0.0 0.0 0.0 1.56 992.7 0.01.003 0.00 5.73 47.615 0.170 0.0 0.0 0.0 1.56 992.7 0.01.004 0.00 5.90 47.590 0.215 0.0 0.0 0.0 1.56 992.7 0.01.005 0.00 6.91 47.550 0.215 0.0 0.0 0.0 1.00 39.8 0.0


Manhole Schedules for Storm


MHName

MHCL (m)

MHDepth(m)

MHConnection

MHDiam.,L*W

(mm)PN

Pipe OutInvert

Level (m)Diameter(mm)

PNPipes InInvert

Level (m)Diameter(mm)

Backdrop(mm)

S1 53.000 1.425 Open Manhole 1200 1.000 51.575 225

S2 52.700 1.425 Open Manhole 1200 1.001 51.275 225 1.000 51.275 225

S3 51.200 3.540 Open Manhole 1800 1.002 47.660 900 1.001 49.775 225 1440

S4 50.750 3.135 Open Manhole 1800 1.003 47.615 900 1.002 47.615 900

S5 50.250 2.660 Open Manhole 1800 1.004 47.590 900 1.003 47.590 900

S6 50.000 2.450 Open Manhole 2400 1.005 47.550 225 1.004 47.550 900

48.300 1.103 Open Manhole 1200 OUTFALL 1.005 47.197 225


PIPELINE SCHEDULES for Storm

Upstream Manhole


PN HydSect

Diam(mm)

MHName

C.Level(m)

I.Level(m)

D.Depth(m)

MHConnection

MH DIAM., L*W(mm)

1.000 o 225 S1 53.000 51.575 1.200 Open Manhole 12001.001 o 225 S2 52.700 51.275 1.200 Open Manhole 12001.002 o 900 S3 51.200 47.660 2.640 Open Manhole 18001.003 o 900 S4 50.750 47.615 2.235 Open Manhole 18001.004 o 900 S5 50.250 47.590 1.760 Open Manhole 18001.005 o 225 S6 50.000 47.550 2.225 Open Manhole 2400

Downstream Manhole

PN Length(m)

Slope(1:X)

MHName

C.Level(m)

I.Level(m)

D.Depth(m)

MHConnection

MH DIAM., L*W(mm)

1.000 19.000 63.3 S2 52.700 51.275 1.200 Open Manhole 12001.001 38.000 25.3 S3 51.200 49.775 1.200 Open Manhole 18001.002 18.000 400.0 S4 50.750 47.615 2.235 Open Manhole 18001.003 10.000 400.0 S5 50.250 47.590 1.760 Open Manhole 18001.004 16.000 400.0 S6 50.000 47.550 1.550 Open Manhole 24001.005 60.000 170.0 48.300 47.197 0.878 Open Manhole 1200

Free Flowing Outfall Details for Storm

OutfallPipe Number

OutfallName

C. Level(m)

I. Level(m)

MinI. Level

(m)

D,L(mm)

W(mm)

1.005 48.300 47.197 0.000 1200 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 Offline Controls 0 Number of Time/Area Diagrams 0Number of Online Controls 1 Number of Storage Structures 1 Number of Real Time Controls 0

Synthetic Rainfall Details

Rainfall Model FSR Profile Type SummerReturn Period (years) 1 Cv (Summer) 0.750

Region England and Wales Cv (Winter) 0.840M5-60 (mm) 18.000 Storm Duration (mins) 30

Ratio R 0.330


Online Controls for Storm


Hydro-Brake® Optimum Manhole: S6, DS/PN: 1.005, Volume (m³): 19.9

Unit Reference MD-SHE-0100-5000-1350-5000Design Head (m) 1.350

Design Flow (l/s) 5.0Flush-Flo™ CalculatedObjective Minimise upstream storage

Application SurfaceSump Available YesDiameter (mm) 100

Invert Level (m) 47.550Minimum Outlet Pipe Diameter (mm) 150Suggested Manhole Diameter (mm) 1200

Control Points Head (m) Flow (l/s) Control Points Head (m) Flow (l/s)

Design Point (Calculated) 1.350 5.0 Kick-Flo® 0.829 4.0Flush-Flo™ 0.400 5.0 Mean Flow over Head Range - 4.4

The hydrological calculations have been based on the Head/Discharge relationship for the Hydro-Brake®Optimum as specified. Should another type of control device other than a Hydro-Brake Optimum® be utilisedthen these storage routing calculations will be invalidated

Depth (m) Flow (l/s) Depth (m) Flow (l/s) Depth (m) Flow (l/s) Depth (m) Flow (l/s) Depth (m) Flow (l/s)

0.100 3.3 0.800 4.2 2.000 6.0 4.000 8.3 7.000 10.90.200 4.6 1.000 4.4 2.200 6.3 4.500 8.8 7.500 11.20.300 4.9 1.200 4.7 2.400 6.5 5.000 9.2 8.000 11.60.400 5.0 1.400 5.1 2.600 6.8 5.500 9.7 8.500 11.90.500 5.0 1.600 5.4 3.000 7.3 6.000 10.1 9.000 12.20.600 4.8 1.800 5.7 3.500 7.8 6.500 10.5 9.500 12.6


Storage Structures for Storm


Cellular Storage Manhole: S5, DS/PN: 1.004

Invert Level (m) 48.600 Safety Factor 2.0Infiltration Coefficient Base (m/hr) 0.00000 Porosity 0.95Infiltration Coefficient Side (m/hr) 0.00000

Depth (m) Area (m²) Inf. Area (m²) Depth (m) Area (m²) Inf. Area (m²) Depth (m) Area (m²) Inf. Area (m²)

0.000 70.0 0.0 0.900 0.0 0.0 1.800 0.0 0.00.100 70.0 0.0 1.000 0.0 0.0 1.900 0.0 0.00.200 70.0 0.0 1.100 0.0 0.0 2.000 0.0 0.00.300 70.0 0.0 1.200 0.0 0.0 2.100 0.0 0.00.400 70.0 0.0 1.300 0.0 0.0 2.200 0.0 0.00.401 0.0 0.0 1.400 0.0 0.0 2.300 0.0 0.00.600 0.0 0.0 1.500 0.0 0.0 2.400 0.0 0.00.700 0.0 0.0 1.600 0.0 0.0 2.500 0.0 0.00.800 0.0 0.0 1.700 0.0 0.0


2 year Return Period Summary of Critical Results by Maximum Level (Rank 1) for Storm


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


Synthetic Rainfall DetailsRainfall Model FSR M5-60 (mm) 18.000 Cv (Summer) 0.750

Region England and Wales Ratio R 0.334 Cv (Winter) 0.840

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

DTS Status OFFDVD 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) 2, 30, 100

Climate Change (%) 0, 0, 30

PNUS/MHName Storm

ReturnPeriod

ClimateChange

First (X)Surcharge

First (Y)Flood

First (Z)Overflow

OverflowAct.

Water Level(m)

SurchargedDepth(m)

FloodedVolume(m³)

1.000 S1 15 Winter 2 +0% 51.623 -0.177 0.0001.001 S2 15 Winter 2 +0% 51.326 -0.174 0.0001.002 S3 60 Winter 2 +0% 100/15 Summer 48.014 -0.546 0.0001.003 S4 60 Winter 2 +0% 30/60 Winter 48.014 -0.501 0.0001.004 S5 60 Winter 2 +0% 30/60 Winter 48.014 -0.476 0.0001.005 S6 60 Winter 2 +0% 2/15 Summer 48.014 0.239 0.000

PNUS/MHName

Flow /Cap.

Overflow(l/s)

PipeFlow(l/s) Status

LevelExceeded

1.000 S1 0.10 6.1 OK1.001 S2 0.11 11.2 OK1.002 S3 0.02 9.3 OK1.003 S4 0.02 8.7 OK1.004 S5 0.02 9.7 OK1.005 S6 0.13 4.9 SURCHARGED












Inertia Status ON




PNUS/MHName Storm

ReturnPeriod

ClimateChange

First (X)Surcharge

First (Y)Flood

First (Z)Overflow

OverflowAct.

Water Level(m)

SurchargedDepth(m)

FloodedVolume(m³)

1.000 S1 15 Winter 30 +0% 51.643 -0.157 0.0001.001 S2 15 Winter 30 +0% 51.350 -0.150 0.0001.002 S3 60 Winter 30 +0% 100/15 Summer 48.529 -0.031 0.0001.003 S4 60 Winter 30 +0% 30/60 Winter 48.527 0.012 0.0001.004 S5 60 Winter 30 +0% 30/60 Winter 48.527 0.037 0.0001.005 S6 60 Winter 30 +0% 2/15 Summer 48.527 0.752 0.000

PNUS/MHName

Flow /Cap.

Overflow(l/s)


LevelExceeded

1.000 S1 0.19 11.5 OK1.001 S2 0.24 23.7 OK1.002 S3 0.03 18.0 OK1.003 S4 0.03 14.2 SURCHARGED1.004 S5 0.03 14.9 SURCHARGED1.005 S6 0.13 4.9 SURCHARGED












Inertia Status ON




PNUS/MHName Storm

ReturnPeriod

ClimateChange

First (X)Surcharge

First (Y)Flood

First (Z)Overflow

OverflowAct.

Water Level(m)

SurchargedDepth(m)

FloodedVolume(m³)

1.000 S1 15 Winter 100 +30% 51.664 -0.136 0.0001.001 S2 15 Winter 100 +30% 51.375 -0.125 0.0001.002 S3 120 Winter 100 +30% 100/15 Summer 49.350 0.790 0.0001.003 S4 120 Winter 100 +30% 30/60 Winter 49.350 0.835 0.0001.004 S5 120 Winter 100 +30% 30/60 Winter 49.350 0.860 0.0001.005 S6 120 Winter 100 +30% 2/15 Summer 49.350 1.575 0.000

PNUS/MHName

Flow /Cap.

Overflow(l/s)


LevelExceeded

1.000 S1 0.33 19.3 OK1.001 S2 0.40 39.7 OK1.002 S3 0.03 20.5 SURCHARGED1.003 S4 0.06 27.1 SURCHARGED1.004 S5 0.03 18.5 SURCHARGED1.005 S6 0.15 5.7 SURCHARGED

drainage strategy for land off eversley court at minera ...€¦ · priority level 5: surface water...

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