Water Conservation

SHaC Video-conference

14 May 2008

Water in the built environment

• Water Supply

• Wastewater treatment

• Stormwater treatment

Judging Criteria

• RESEARCH & DESIGN & DEVELOPMENT 30%• 1. Teamwork and Collaboration within Tertiary organisation,

and with Industry, Local Government, and other Teams• 2. Project Management: Research, Planning and Process• COMMUNITY CONNECTION 25%• 3. Community Engagement• 4. Communication of design and rational to community• DESIGN AND ARCHITECTURE 45%• 5. Health• 6. Energy• 7. Material and Resource Use• 8. Water & Waste Management• 9. Site and Environment• 10. Architecture and Affordability

Hydrologic Cycle

Water Criteria

• 90 l/pp/pd design critera is achievable without supplementary supply

• Stormwater flows attenuated

• Wastewater reduced where possible

• Innovation being sought, in particular integration of water services.

What we are looking for• Safe and healthy water services to the home• Maximising water use efficiency• Providing resilience to the system through supplementary

supply• Retaining stormwater on-site, allowing infiltration• Integrating services where possible• Pushing the boundaries, gently; showing innovation• Understanding (not necessarily agreeing with) regulatory

constraints and working with regulators where required• Demonstrating how design criteria have been developed to

meet performance targets• Integrating the water services where possible and

considering whether integration with other services.

Social Considerations

• Less than 0.08% of all the Earth's water is available for biological life. Yet over the next two decades human use is estimated to increase by about 40%.

• Local Government Act requires thinking sustainably across the four pillars of wellbeing – cultural, environmental, social and economic.

Building resilience

• Reducing competing demands for water in parts of the Country where water resources are constrained.

• Reducing the need for further large water supply systems which cause changes to the water cycle and do not operate in harmony with natural water cycles and water catchments.

• Anticipating potential climate related changes and resulting water cycle disturbances

• Reducing the contribution of leaks and spills from wastewater on declining water quality in New Zealand

• Recognising that some water sources are not renewable in the short-term, for example groundwater is generally non-renewable for practical purposes

Cost savings

• Saving on capital costs through delaying or eliminating infrastructure development.

• Achieving cost savings in wastewater management through reducing the water that goes through the system.

• Saving cost associated with energy through reducing in-house hot water use.

• Saving costs associated with energy and maintenance in both the treatment of water to a potable standard and its reticulation.

• Saving energy and maintenance costs in the reticulation and treatment of wastewater.

life supporting resources

declining

consumption of life supporting resources

rising

“We can’t solve problems by using the same kind of thinking we used when we created them” Albert Einstein.

From this….

To this…

We could be going from: This…..

To this

Water Use Efficiency

Typical breakdown of domestic water use

Comparison of daily per capita water uses* =metered with volumetric pricing

Council Daily Per Capita Water Use Figure

Nelson 160*

Waitakere 167*

Rodney 179*

Metrowater (Auckland City) 184*

Manukau 189*

Papakura 190*

Kawerau 214

Upper Hutt 227

Tauranga 265*

Christchurch 333

South Taranaki 450

Kaikoura 648

Kapiti 650

Queenstown Lakes District 750

Current technologyTechnology including

Rainwater tanks

Greywater Reuse

Reduced or low flow devices

Pressure reducers

Tap aerators and flow restrictors

Dual flush/low flush toilet Water efficient appliancesWELS rating system should be in use this

year

Smarter use of Water

ProductsCosts

$sCosts with installation

Water savings % of

total use

Accumulative water savings %

of total use

Gismo 2 5-10 5Tap Aerators 10 5-10 10Outdoor hose washers

2 2-5 12-15

Low flow shower head75 150 10-15 22-30

Dual Flush Toilets

(<5l)225 300 10-15 27-40

4 star rated washing machine 1200 10 37-50

Rain barrel 400 litres or300 10-15 47-60

Rain tank

4500 litres or4000 4500 40-60 75 plus

Wastewater recovery system 3000 4000 20-40 60 plus

Relative increasing cost and difficulty

Tap aerators and shower flow restrictors

Stop household leaks

Dual flush toilet

Rainwater tank

Wastewater recycling and composting toilets

Rainwater barrels

Low flow shower head

Water conservation gardening

Water efficient appliances Water

conservation behavior

Wat

er u

se e

ffic

ienc

y

Schematic of DM options against cost and difficulty of implementation for the domestic user

Rainwater from all roofs is collected in this 25,000 litre tank. It is used for toilet flushing on ground floor, for urinals and for irrigation of glasshouses.

Landcare’s water management

Kapiti Coast District Council

• Public education

• Wide ranging education progs

• & free services,eg. green gardener

& plumber, and garden show

• Subdivision Code of Practice promoted low impact urban design

• Proposed a District Plan change- two acceptable solutions which promote water conservation

• But: no metering and still have 650 l/pp/pd

0

50

100

150

200

250

300

350

400

450

Business As Usual 12000 litre raintank(toilet, laundry and

outdoors)

4420 litre raintank(toilet, laundry) and

greywater (outdoors)

Wa

ter

us

ag

e (

l/p

/da

y)

Leakage (assuming popn of 36000)

Commercial use (assuming popn of 36000)

Residential use

Modeled water reduction for Kapiti

Composting Toilets

·

·      

Wastewater Management

Stormwater Managament

Prevention Techniques

• Landscaping– rain gardens, swales, absorbent materials

• Green Roofs

• Pervious Pavement

• Ponds and Wetlands

• Infiltration Trenches

Common site-level Best Management Practices

Water Quality Friendly Streets

Source: City of Portland Water Quality Friendly Streets Program. http://www.portlandonline.com/bes/index.cfm?c=32066

The Kapiti Coast District Council experience in changing the rules of

the game for subdivision & development

Out with the old and in with the newOut with the old and in with the new

• Living areas face the street• Permeable fences• Houses facing reserve/public

open space• Located on site for solar

access• Each house has private space

outside to rear or back of property

• Narrower carriageways• Located near planned railway

station• Building materials chosen for

long term durability

On the ground change

• Low flow showerheads• Watersmart two tank

system– Rainwater for use in gardens– Town supply for use in

house• Greywater collected for

watering lawns• Uses covenants on the title

to ensure systems are maintained

On the ground change

Example of 500m2 lots

SMA 254%

61%

61%

48%

61%

53%

55%

Permitted Activity Route, North Shore

• “Off-the-shelf” standard solutions

• SMA & Activity

• Preferred mitigation methods

• Rain tanks

• Bio-retention

• Provide multiple benefits

• Practice notes to aid with design (Source:Maplewood, Minisata)

Bio-retention• Rain gardens, SW planters, Bio-retention swales, Tree Pits• Benefits:

– Water volume reduction, – Peak flow control, – Water quality, – Amenity

• Min Design • Requirements:

– Min depth 600mm of planting soil– 8% of area (or 5%)

• Practice note to help with design• Gardens not treatment devices

Water Quality Friendly Streets

Curb Cut w/Pad

Council documentation

– Engineering standards

– Council Engineering Manuals

– Verification Methods and

Acceptable Solutions

– Information Pamphlets and

Brochures

– Practice Notes/Design

Guidelines

Based on work of Prof Hans Schreier

A Traditional Approach

• >Impervious Surfaces• < Buffer Zones• Stormwater Piping• Large scale infrastructure• End of Pipe Treatment• Point Source Pollution• Expanding Water Supplies• Focus – Single Pollutants• Water Use of Human

Activities• Government Management

A Sustainable Approach

• < Impervious Surfaces• > Buffer Zones• Creating biological solutions• On-site solutions• Detaining Stormwater• Non-Point Source Pollution• Controlling Demand• Source Control• Water for Environmental

Services• Community Involvement

Design Criteria• Water efficient fittings and appliances• On-site water capture and reuse• Water supply flow rates optimised to balance required

performance and conservation • Local retention of stormwater runoff, stormwater treatment

train with consideration of raingardens, roofgardens and swales

• Wastewater minimised and/or reused; information on water use readily available

• In-house water supply flow rate optimised• Plumbing system designed for water and energy efficiency• Site design recognition of local soil and climate conditions

and low water use garden design applied.

Website resources• http://www.level.org.nz• http://www.sustainablehouseholds.org.nz/actionpdfs/

save_water_action.pdf• http://www.smarterhomes.org.nz/water/• http://www.ecobob.co.nz/EcoBusiness/Browse.aspx also good

for products and services• http://www.waitakere.govt.nz/CnlSer/wtr/wtrsavetips.asp• http://www.ecomatters.org.nz/09_Water/091_Water/

091d_Water_06_top_10_tips.htm • http://www.ecan.govt.nz/Our+Environment/Energy/YourHome/

homeimprovement/hot-water.htm for hot water saving tips• http://www.bethedifference.gw.govt.nz• http://www.ccc.govt.nz.waterwause/story2.497.cfm?• http://www.greenpagesaustralia.com.au• http://www.consumerbuild.org.nz/publish/maintenance/kitchen-

bathroom-plumbing.php

Definitions

Residential Built Environment

“The residential built environment consists of the buildings and supporting infrastructure that together constitute the surroundings in which people dwell. It includes, therefore, not only people’s dwellings but other neighbourhood buildings. It also includes the arrangement of infrastructure that service dwellings and the neighbourhoods in which those dwellings are situated.”

Sustainability and Affordability

“In achieving sustainability of residential built environments the focus is on the sustainability of individual dwellings but also the neighbourhoods in which they are situated. The goal is to make improving the sustainability of dwellings and neighbourhoods both affordable and cost-competitive.”

Systems

Industry,

Infrastructure,

Government,

Consumers

Pull based on market and needs

Energy

Water

IEQ

Pull based on prioritised systems and HSS

Market Transformation – pan communication and alignment

Policy and Regulation – pan regulatory involvement

Beacon’s Operating Model

Neighbourhoods

New Homes

Retrofit Homes

BEACON WATER TARGETS

1. All Homes - reducing per capita demand

for reticulated water by 40% and council

mains supply by 50%.

2. All Homes & Neighbourhoods – Effective

management of three waters to create a

more resilient water system

Nation

Region

Neighbourhood

Home

City