CIRIA WSUD Workshop Cardiff

Water Sensitive

Urban DesignDeveloping our approach in Wales

Aaron Burton

March 2012

Outline

Drivers in Wales

Pilots/ case studies

The future

Housing challenge

Additional 200,000

new homes by 2025

Additional 30,000

new homes in

Cardiff by 2025

80% of existing homes remain by 2050

DCWW

Water Resources

(context – Cardiff daily household

use is around 50 Ml/d)

Deficit zones:

SEWCUS: -12 to -104 Ml/d

Pembrokeshire: -13 to -19 Ml/d

Brecon: -1 Ml/d

NEYM: +2.9 to -5 Ml/d

Water and carbon connection

5% UK annual carbon

Emissions

(~3% in Wales)

1% UK annual carbon

emissions

Flooding – Surface water

Majority of surface

water problem locations

are in SE Wales

Scott (2011) Surface water management in a changing legislative framework, Presented at ICE Wales Flooding conferencehttp://www.ice.org.uk/getattachment/20b63757-2855-43c2-98e0-8ca42da77696/Wales-Flooding-Conference-2011-Dominic-Scott.aspx

NEF - Ecosystem services

Ecosystem Service Green roofs/ walls

Street trees Wetlands Rainwater harvesting

Water and energy efficiency

Rain gardens/ bioretention

Reduce flood risk

Offset urban heat island

Reduce energy demand

Reduce noise/ air pollution

Support biodiversity

Recreation/ leisure

Reduce water use

Reduce wastewater flows

Reduced CO2

Reduced water and energy bills

Adapted from GLA (2011) Managing risks and increasing resilience – The Mayor’s Climate Change Adaptation Strategy, p. 90,

http://www.london.gov.uk/sites/default/files/Adaptation-oct11.pdf (Accessed 05/11/12)

Pilots/

Case Studies

Water Sensitive Brynheulog

Site issues:

•Blocked

drainage

•Erosion and

WQ

•Flooding past

issue/ road

surface issues

Before

WSUD Measures Bioretention Systems

Slotted kerb opening and grate (Docklands, Melbourne)Kerb opening through lintel (Ku-ring-gai Council)

Road

Footpath

Slot in kerb

Stormwater drainage (eg 375 mm pipe)

0.5 – 1.5 m

0.5 - 1m Filter media

0.1 m Transition layer (sand)

0.15 m Drainage layer, with perforated pipes (gravel)

Impervious liner

0.1 - 0.3 m Temporary ponding

Overf low pit

Rain gardens

Wetlands at differing scales

Wetlands Wetland

/raingarden Raingardens/ RWH

Welsh Housing Quality Standard

16% of households in WalesSAP rating for energy (space and water heating)Responsible for “environment” and landscapesEAW & EST Guidance to support WHQS (based on pilot study & survey)

WC partnerships

Refurbishment

Voids and maintenance

WSUD Guidance and Pilot Studies

Community based schemes

Reeds used to cut pollution in

Llanfyllin's River Cain

Caearau & Brynglas SUDS Pilot

0

20

40

60

80

100

120

140

Baseline RWH with

Traditional

Solution

RWH with

traditional

solution

(new tech)

RWH with

traditional

solution

RWH with

traditional

solution

SuDS only SuDS +

1500l RWH

SuDS +

1500l RWH

new tech

SuDS + 300l

RWH

SuDS + 100l

RWH

Option

To

tal em

issio

ns -

wate

r, s

ew

era

ge, su

rface w

ate

r, S

uD

S,

RW

H e

mb

od

ied

(tC

o2e)

NO14 (464 props) BY21 (278 Props) BP04 (1 school + 10 props)

Broader costs and benefits? Maintenance, adoption,

uptake rates etc…

Water Sensitive Communities

Value of Water and behaviour change

0

20

40

60

80

100

120

140

All In-home Mail, events,

telephone (1)

Mail, events,

telephone (2)

Mail, events,

telephone (3)

Advice method

Carb

on

Savin

g k

gC

O2/y

r

0

5

10

15

20

25

Wate

r savin

g (

m3/y

r)

Average saving per customer (CO2 heating + embodied) Kg CO2/yr Average water saving (m3/yr)

Future work

WSUD Programme Board

To guide decision making and resource input as we develop our approach to Water Sensitive Urban Design in Wales. WSUD

WR

WFD

Land Man

Groundwater

Biodiversity

FRCM

Climate Change

Air Quality

WQ

Planning

Academic:

Retrofit2050

PREPARED

TSB Future Cities

Industry:

CIRIA Scoping Study

SuDS Wales Groups

IWA Future Cities

Pilots:

Bryheulog

Cardiff tbc

Caerau & Brynglas

CCW - NER

Wetland Mapping

HA Water Pilot

Living Wise Cardiff

Policy:

SPPSoW

Housing Bill

Planning Bill

Building Regulations

WHQS

SuDS Guidance

/SABs

Programmes:

Periodic Review

WRMP

DCWW SWEAR

DCWW SDPs

EAW CFMPs

LA SWMPs

Diffuse Pollution AP

FUTURE:

•WSUD Guidance

•Pilot technology

•Sector wide

learning programmes

(LZCH?)

•Community 1st

•EU Life+

Overview of activities in Wales Feb 2012