Sistemas urbanos de drenaje sostenible y su aplicación en europa

Chris Jefferies, University of Abertay Dundee, ScotlandSustainable Cities Forum 3rd June 2010

Sustainable Surface Water Management in Cities

Professor Chris Jefferies

Urban Water Technology Centre

University of Abertay, Dundee


Sustainable Water Management in Cities

1. Drivers

2. Implementation – Timeline

3. Implementation – examples of good and bad practice

4. Performance assessment with university collaboration

5. Implements for encouraging SUDS

6. Concluding Remarks


SUDS Drivers in Cities

• Vietnam – Ho Chi Minh City – dying fish.

• China – Wuhan – polluted lakes and loss of fish.

• Brazil - Belo Horizonte – flooding and community.

• USA – Austin Texas – Long term community interest.

• Germany – Berlin – quality of water for swimming in lakes.

• Colombia – Bogota – wetland and species conservation

• Scotland – Dundee – protection of environmental quality.

Many cities worldwide are investing in sustainable drainage. Each has a different justification (driver)

Section 1

Basin in Ho Chi Minh City to preserve lake water quality











Wuhan - Infiltration and irrigation garden in high density housing. This area has a very high water table level

Down pipes from roofDisconnected











Belo Horizonte - Flood attenuation pond in park








• Colombia – Bogota – wetland and species conservation.



Austin filters – very expensive protection of groundwater

Barton springs – highly valued – must be protected











Berlin – street











Bogota – wetland (Humedal)

Bogota – treatment SUDS protecting wetland











Caption text


Implementation of SUDS in UK• 1997-8 Policy developed in Scotland.

• 2003 EU Water Framework Directive legislation.

• 2006 SUDS Required in all new developments.

• 2006 SUDS Design Manual.

• 2006 Scottish Water Technical Regulations released.

• 2010 SUDS being adopted by Scottish Water.

• 2010 Legislation in England.

• 2010 SUDS for Roads Manual (Scotland).

• 2011 SUDS used in all of UK.

Section 2


SUDS Numbers• Uptake was rapid in Scotland;

– 1997 – 79 systems; 2001 – 767 sites; 2004 – all new developments.

0

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2001 Data


SUDS Numbers• Uptake was rapid in Scotland;

– 1997 – 79 systems; 2001 – 767 sites; 2004 – all new developments.

S UDS s ites in S cotland by date, where known (01/01/2002)

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Implementation - Examples

Next I will discuss three categories of SUDS in Scotland

• Early sites in Scotland which had some problems.

• DEX – a nationally significant showcase site.

• Dundee – an alternative approach.

Section 3


There were some early implementation disasters

January 1998

September 1998 February 1999

Poor site management without sediment control


There were some early wrong solutions

Surface water system with discharge consentand underground filter system


And some over-enthusiasm not popular with residents

1999

2003

Pond serving 20 houses, later converted to a detention basin


Dunfermline Eastern Expansion Area (DEX)

• Wilcon Homes (Scotland) Lead developer – now part of Taylor

Woodrow.

• Major mixed use development totalling 354 Hectares.

• Periphery of one of Scotland’s ancient burghs.

• Ageing sewerage and stressed watercourses.

• Regional SUDS strategy was adopted.

• Seven retention ponds, many detention basins, swales, filter

drains and porous surfaces.

• The Treatment Train Concept was guiding principle


The middle of the development in 2004


Progressive development at DEX

WetlandSuperstore

Ponds199720002008


The sub – networks are designed as conventional systems


Conventional systems collectively drain to the SUDS ponds


Treatment Train starts with permeable paving


Treatment Train starts with permeable paving


Treatment Train includes detention basins


Treatment Train ends with a pond


SUDS at DEX has required different specialists to collaborate. Detention basin in a roundabout.


Dundee has adopted the philosophy that the water must be visible as much as possible

Conveyance Swale


Dundee has adopted the philosophy that the water must be visible as much as possible

Roadside Swales


Performance assessmentUndertaken with the collaboration of four universities

• Hydrological – predictable performance– Reduction of percentage runoff– Attenuation of peak flows– Reduction of flow volumes

• Water Quality – surprisingly good performance– Reduction of peak concentrations– Good pond outlet qualities– Source control systems particularly effective

• Social Acceptability– Seen as positive– Fewer barriers than initially feared.

Section 4


Hydrological BehaviourTypical Hydrograph at a pond

High peak, low volume 55% reduction;

Low peak, large volume 39% reduction


Field study of soil in a basinContaminant concentration in two soil layers

TPH TPH

Copper Copper


Field study results in a highway basinContaminant concentration in two soil layers


Field study results in a highway basin

Contaminant concentration in two soil layers


Water Quality at Linburn PondLinburn pond: TSS (mg/l) at inlets (11/4/02 @ 16:35 to 11/4/02 @ 21:55)

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c (m

g/l)

NE TSS(mg/l) N1A TSS l(mg/l) N1B TSS (mg/l) E TSS (mg/l)

Linburn pond: TSS concentrations and flows at outlet (11/04/02 @ 05:25 to 06/05/02 @ 13:00)

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TSS (mg/l) flow (l/s)

Pollutant BudgetVery difficult due to number of inflows and duration of study needed.

Monitoring results - Linburn Pond inflow TSS

Monitoring results - Linburn Pond outflow TSS


Water Quality at Halbeath Pond

Inlet Quality Outlet Quality


Social - Perceived Advantages

Perception of SUDS

0.00%

10.00%

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60.00%

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Perceived advantages of SUD ponds

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cent

age

of r

epso

nses

Attracts w ildlife

Adds to the aesthetic value of thearea

Recreation/Amenity facilities

Pet w alking area

Avoidance of f loods

Creation of a new habitat

None

Educational for children

Re-establishes the lost contactw ith nature


19.6%

18.5%

17.5%

15.2%

10.8%

6.8%

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3.8%

2.2%

1.1%0.5%

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Perc

enta

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of r

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onse

s

1

Barriers as indicated by professionals

Barriers to SUDS application

Adoption of maintenance

Developers & Plannersreluctance to apply SUDS

Landtake

Not enough knowledge,training & experience amongstSUDS specialistsWater authorities reluctance toaccept SUDS

Cost

Public perception & publiceducation

Safety

Bad practice examples

Improper planning &landscaping

Increased rainfall due toClimate Change

Social – Barriers to SUDS

Safety


Results from monitoring - Adoption Issues

• Management train which reinforces and follows the natural pattern of drainage should be used where possible.

• Desilting is required 2 months prior to vesting.

• Preference will be detention ponds, then detention basins and finally underground storage.

• For most applications, detention ponds (1xVt) will be used. Only where there are more risks of pollution will retention ponds (4xVt) be used.

• SUDS will normally only be adopted after the development has been completed and all properties connected.


Results from monitoring - Sedimentation

• Sediment problems found from construction phase runoff.

• Most filter drains and infiltration trenches were affected by

construction sediment.

• Long term sedimentation rates very slow, particularly where

there is a treatment train.

• There is little sedimentation where the contributing catchment

is fully developed.

• It is very unlikely that SUDS sediment from non-industrial

locations will become badly contaminated.


Detention basins remove sediment effectively

Oct 1999 Dec 2001

Oct 2000 Feb 2002


Will sediment be contaminated?This basin serves highway in USA with 300,000 vehs. per day

No perceived contaminated sediment problem.

UK requires a

different

approach but

still the

sediments are

not

contaminated


Maintenance and costs

• Much maintenance is carried out is to keep up a good appearance.

• Maintenance roles have not been clarified – neither in England or in Scotland.

• Asset and maintenance costs are principal concern.

• Whole life Costing tool under development by HRWallingford.

• Scottish Water will be adopting joint detention basins and ponds from a date yet to be set under strict conditions.

• They must be designed & detailed to ‘Sewers for Scotland’ –which is at consultation stage.

• Outlet detailing and treatment train is the key.


DEX Maintenance Activities

DEX Ponds Maintenance Activities

Litter Picking27%

Pruning / Trimming

10%

Grass Cutting13%

Weeding22%

Fence / Sign Erection

Aquatic Plant Aftercare

4%

Algae Removal / Straw Bales

6%

Inspection8%

In/Out Maintenance

2%

Filter Drain Maintenance

2%

Silt Removal2%

Grass Cutting Costs 1999 - 2003

Halbeath28%

Pond 719%

Linburn10%

Pond 613%

Wetland30%


DEX Maintenance Activities


Frequency of Maintenance Activities for a Pond (Months). Similar data will be available from UKWIR soon

Low Medium HighRoutine MaintenanceInspection, Reporting & Information Management

36 6 1

Litter / minor debris removal 12 1 .25Grass Cutting 36+ 12 4Pruning Nil 3 1Weeding beside Retention Ponds 36+ 12 4Silt Removal 24 12 6Algae Removal in first five years 6 4 2Aquatic Vegetation Management 120 48 12Corrective MaintenanceIntermittent Facility Maintenance (Excluding Sediment Removal)

Varies Varies Varies

Sediment Dewatering & Removal for Retention Ponds: Main Pool

600 300 120


Outcomes of performance assessment

• Confidence about which SUDS work in the local conditions.

• Design parameters applicable for local conditions.

• Identification of many operation and maintenance issues.

• A clear understanding of ownership issues.

• Young graduates who were knowledgeable about SUDS.

• Well documented showcase examples of SUDS developed.


Implements for encouraging SUDS

I will finally address some different organisational benefits for

SUDS. Examples from;

• Emschergenossenschaft, Germany – financial instrument

• Glasgow, Scotland – Strong multi-stakeholder partnership.

• Water Vision Documents – from Netherlands.

Section 5


Emschergenossenschaft Fee concept

• Emschergenossenschaft is a main drainage authority in

Germany

• Local streams are very polluted due to discharge of excess

surface water.

• Land is low lying and there were high pumping costs.

• Reduction in connection fee for disconnecting surface water


Disconnection fee diagram (EG)


Emschergenossenschaft Fee concept

Housing companies now look for ways to disconnect.


Glasgow – a partnership approach to SUDS

• Glasgow is a major urban area in Scotland.

• Approximately 200 unsatisfactory combined sewer overflows.

• Chronic water pollution in receiving main river.

• $Billions - cost of implementing conventional solutions.

• Below ground solutions cannot be implemented without above

ground solutions.


Glasgow – a partnership approach to SUDS

• Joint implementation of above/ below ground solutions

• Formal partnership formed to underpin drainage solutions

MGSDP (Metropolitan Glasgow Strategic Drainage

Partnership).

• Partnership includes;

– Four local municipalities.

– Scottish Water Company.

– Environmental Regulator.

– Major development organisations (with public finance).

– NGOs.


Water Visionfor Johnstone 2007


The Water Vision: Assisting Water and Planning

• A document to raise awareness to ALL Stakeholders.

• It shows options how Johnstone’s stressed watercourses might

be improved.

• It is a co-ordinated vision that can be put into practice.

• It shows Stakeholders where they ‘fit in’ to the bigger picture &

help with choosing solutions that benefit all

• Opportunity to establish a Common Goal.

• It helps co-ordinate resources for cost effective solutions.


Thank You

Sustainable Surface Water Management in Cities

Sistemas urbanos de drenaje sostenible y su aplicación en europa

Documents

university of abertay

loss of fish

suds drivers

china wuhan polluted

sustainable water management

sustainable drainage

colombia bogota wetland

implementation of suds