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Sustainable Strategic Drainage Studies

Dr Doug Lewis

Technical Manager

Grontmij Water Engineering

What are I going to say?Introduce a couple of fascinating projects that demonstrates the potential of stakeholdersworking together to deliver integrated sustainable solutions to complex urban situations:

1) Tyneside Strategic Sewerage Studies for NWL

2) South Dalmarnock, Glasgow, Strategic Studies for Clyde Gateway & GCC

Future Impacts on Sewer Systems in England and Wales2

• Modelling review of 10 yr RP to determine the impact of climate change,population and creep in impermeable areas up to 2040, Ofwat July 2011

• 100 drainage catchments used from the ten water companies

• Unconstrained growth – in which new development is allowed to discharge inaccordance with current legislation (PPS25)

• Predicts significant increase insewer flooding using existing network

• Recommends ‘sustainable’ modifications to the catchment to reduce need tomodify the network, and a need for strategic studies to deliver these changes intime to prevent an increase in flooding

Median increase % 50th percentile

Population growth 5Property creep 12Climate change 27Combined 51

Tyneside Strategic Sewerage Studies3

• Six pilot studies into sustainable sewerage solutions using constrained growth

• Grontmij are investigating Gateshead, North Shields and Hebburn DA’s

• Used by the partners to inform future planning by promoting the ‘bestopportunities’ for customers and the environment

• Three stage approach aligned with the principles of SWMP:

Stage 1 - Collection, collation and analysis of detailed information to identifypotential flooding locations ,dependencies and interactions;

Stage 2 - Focus on the application of a risk based approach to identify andassess sustainable drainage options; and

Stage 3 - Investment planning.

Model Build and Future Scenarios Models4

Hebburn Drainage Area Overview5

River Don

MonktonBurn

Bede’s BurnCulvert

Interceptor Sewer

Drainage AreaExtents

A19

A165

TyneTunnel

Pelaw

MonktonVillage

Planned Development6

Lukes Lane2020: 378

Bedwell Ind Est2020: 353

Sth TynesideCollege2020: 100

H Mullins Earby2050: 55

HebburnCivic Centre2020: 79

Blackett St2012 : 172050: 88

HawthorneLeslie2050: 67

RiversideVillage2012: 2072020: 115

South Dr /Victoria Rd W2050: 305

School St2012: 131

Hedgely Ct2012: 2212020: 1102050: 7

Key201220202050

Stage 1 Issues & Flooding7

Key

Lukes LaneEstate

Campbell Pk

College Rd /Finchale Rd

Walsh AveStage 1 IssuesEA 30 Yr FloodNWL Reported

Model Predicted Flooding – 2012 v 2050 Situation8

Key275%

68%

140%

40%

10%

17%

20%

15%

15%15% 2012 FloodLocations

2050 FloodIncrease2050 New FloodLocations

Opportunities Overview9

Opportunity Area 1: Lukes Lane

Opportunity Area 2: Bede’s Burn

Opportunity Area 3: Walsh Avenue

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Opportunity Area 1: Lukes Lane

Source Control

Ditch & Field DrainConverted to Swale

Detention Ponds

Re-profileMonkton Burn

Existing SW Sewer

Opportunity Area 1: Lukes Lane11

1.

1. 2.

2.

Ditch & Field DrainConverted to Swale

Detention Ponds

Opportunity Area 1: Lukes Lane12

3.

Re-profileMonkton Burn

3.

13

4.

4.

4.Source Control and/or Runoff Reduction

4.

Opportunity Area 1: Lukes Lane

Tyneside SSS results and recommendations14

Stage 1 Sage 3

• At 2050 design horizon, 40% reduction in total spill occurrence and spill volume, for 5yr RP

• 5% reduction in peak flows in the sewer system providing improved capacity

• 12% reduction in number of properties in the worst and medium risk bands for floodrisk

• Provision of landscaped water features – amenity and biodiversity benefits;

• Evidence base for future investments for all partners

• Requirements for storage conveyed into proposed development plans

South Dalmarnock, Glasgow,Strategic Integrated Urban Infrastructure

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Stage 1 Sage 3

South Dalmarnock, Context16

Stage 1 Sage 3

•River Clyde, Celtic Park, Games Village, NISA,

Cunningar Loop, Glasgow Green

South Dalmarnock, Stakeholders & policy/guidelines17

Stage 1 Sage 3

In addition to Clyde Gateway and land owners, the statutorystakeholders are:

•Scottish Government (SPP, FRM & SUDSfRoads)

•SEPA (SPP7 & CAR)

•Glasgow City Council (Env3 Flood Prevention and LandDrainage, RCFM)

•Scottish Water (Sewers for Scotland 2nd Edition)

•Metropolitan Glasgow Strategic Drainage Plan

South Dalmarnock, Flooding18

Stage 1 Sage 3

•200 yr plusclimate changeevent affectsClyde GatewayandCommonwealthGames Villagesites

South Dalmarnock, Flooding multiple developmentimplications

19

Stage 1 Sage 3

•Land raisingof both sitesincreases floodrisk from RiverClyde

•Floodalleviationschemerequired forboth sites

South Dalmarnock, 2D Infoworks surface water flows20

Stage 1 Sage 3

•M200-120critical stormevent

•Springfield roadand Dalmarnockcross inundated

South Dalmarnock, Natural flows & extensive catchment21

Stage 1 Sage 3

•Natural flow sub-catchments dictateSUDS locations

•Commonwealth villagesite hydrologicallyseparate

South Dalmarnock, East End Regeneration Road22

Stage 1 Sage 3

•Issues with new road levels and railway crossing

South Dalmarnock, Utilities & railways23

Stage 1 Sage 3

•Deep sewersto WwTW

•Dalmarnockroad andrailwayconstraints

South Dalmarnock, Aspirations24

Stage 1 Sage 3

• Create an infrastructure framework for the regeneration of the area

• Separate surface water from combined sewers and free up WwTW capacityfor development

• Establish Operational Frameworks and agreements between maininfrastructure Stakeholders

• Establish Design Codes for Developers

• Encourage and improve Cycle Path /Pedestrian links

• Encourage view corridors to the river, safe play and recreation areas

• Create multi-functional urban corridors

South Dalmarnock, Integrated urban infrastructure25

Stage 1 Sage 3

•Integrating bluespace (SUDS)green space(amenity) andmovement(brown)

South Dalmarnock, SUDS elements26

Stage 1 Sage 3

•Development blocksource controlsleading to local orregional structures

South Dalmarnock, SUDS elements27

Stage 1 Sage 3•Flood Strategy1 in 200 yearevent

South Dalmarnock, SUDS elements28

Stage 1 Sage 3•Flood Strategy1 in 200 yearevent plusclimate change

South Dalmarnock, SUDS Model29

Stage 1 Sage 3

•InfoworksCS/2D model

•Strategicoptioneeringtool

•1%reduction inpass forwardflows

South Dalmarnock, Pond elements30

Stage 1 Sage 3• Regionalstructure not SfSstandards asspace limited

South Dalmarnock, Park elements31

Stage 1 Sage 3

•Riverside &railway parks

South Dalmarnock, Masterplan32

Stage 1 Sage 3

•RIBA Stage Boutline design

•Infrastructure ledMasterplan

•Winner of 2011Scottish designawards forMasterplaning

South Dalmarnock, Revised SUDS route33

Stage 1 Sage 3

• Carrier drain following Dalmarnock Road until Springfield Road

• RIBA C detailed design for Riverside Regional SUDS and localSUDS

• Reduced from four to three development fingers

South Dalmarnock, Revised SUDS model34

Stage 1 Sage 3

•Potentialretrofitareas

•Threedevelopmentblockfingers

South Dalmarnock, Revised SUDS detail35

Stage 1 Sage 3

•TraditionalWindesmodelling

•Source,local andregionalcontrols

South Dalmarnock, Success factors36

Stage 1 Sage 3

•Determined and integrated design team

•Stakeholders will to succeed

•Worthwhile objectives - increased environmentalquality and amenities

South Dalmarnock, Results37

Stage 1 Sage 3

•Integrated Masterplan basedon IUI

•Developer interest

•Statutory approval ongoing

•Exemplar design

•Riverside area and carrier draincurrently being progressed

South Dalmarnock, SWMP/Masterplan/IUI38

Stage 1 Sage 3• Thank you