Presented to The University of Auckland, ENVENG 244

Presented by Priscilla Chung, Water Supply Planning Engineer

Date 3 August 2006

Water Supply - Water Distribution

• Introduction

• Water Supply Challenges

• NZ Framework

• Water Distribution Projects

• Case Studies

Presentation Outline

Three Parts to Water Supply

1. Source

2.Treatment 3.DistributionNZWWA (2004) The Story of Drinking Water, Auckland

Distribution main

Water Distribution Systems

Reservoirs

Trunk main

Boosted WS Areas

Pumps

Pressure Reducing

Valves

Pressure Reduced

WS Areas

Gravity

WS Areas

Bulk Water

Meter

Water Supply Challenges

• Population Growth & Urbanisation

– 9 billion by 2050

– Out of balance megacities - 80% of world’s population will

be in countires least capable of supporting further growth

• Prolonged Life Expectancy

– Today’s children may live until age of 120

Boulos. P (2006), Our Infrastructure Challenges of Tomorrow And the Latest Advances in Modeling Technology, MWH Soft, Auckland

NZWWA (2004) The Story of Drinking Water, Auckland

Water Supply Challenges (Continue…)

• Availability of Clean Water

– > 2 billion people do not have clean reticulated water supply

– 1/2 world population will be water stressed

• Energy Usage & Stress

• Increased Customer Expectations

• Stringent Environmental Regulations

Boulos. P (2006), Our Infrastructure Challenges of Tomorrow And the Latest Advances in Modeling Technology, MWH Soft, Auckland

NZWWA (2004) The Story of Drinking Water, Auckland

Water Supply Challenges (Continued…)

• Aging Workforce and Infrastructure

Boulos. P (2006), Our Infrastructure Challenges of Tomorrow And the Latest Advances in Modeling Technology, MWH Soft, Auckland

Drinking Water Infrastructure

Composition

Pipe Deterioration Rate

USAWaterborne Disease

Outbreak

- 30% associated with

distribution system

deficiencies

- Avg 200 illnesses per

outbreak

New Zealand

Approximately 1,165,000 people (29% of NZ) were supplied

with drinking-water that failed to comply bacteriologically.

Water Supply Challenges (Continued…)

ESR (2003) Annual Review of Drinking-water Quality in New Zealand 2003, Ministry of Health, New Zealand

Boulos. P (2006), Our Infrastructure Challenges of Tomorrow And the Latest Advances in Modeling Technology, MWH Soft, Auckland

New Zealand Framework

• NZ Statistics

– 87% supplied from reticulated distribution network

– 2016 Water Treatment Plants

– Average daily usage 240 litre / person / day

NZWWA (2004) The Story of Drinking Water, Auckland

ESR (2003) Annual Review of Drinking-water Quality in New Zealand 2003, Ministry of Health, New Zealand

New Zealand Framework

• National Level

– The Ministry for the Enviroment

– The Ministry of Health

• Regional Level

– Regional Councils

• Local Level

– Territerial Local Authorities e.g. District or City Councils

New Zealand Framework (Continue…)

South IslandNorth Island

ESR Water Group (2004) New Zealand Community Drinking-Water Supplies, New Zealand

New Zealand Framework (Continue…)

• NZ Statutes / Regulations

– Local Government Act 2002

– Resource Management Act 1991 & Resource Management Amendment

Act 2005

Local

Government

Act

Resource

Management

Act

Inform future

planning and

outcome

identification

Long Term

Council

Community

Plan (LTCCP)Policy

Statements

and Plans

Integrated Monitoring

Strategy - social, economic, environmental

and cultural reporting

New Zealand Framework (Continued…)

• Other Relevant Code of Practices and Guidelines

– Drinking-Water Standards for New Zealand 2005

– New Zealand Fire Services Fire Fighting Water Supplies Code of Practice

SNZ PAS 4509:2003

– NZWWA Guidelines for Modelling Water Distribution Systems, April 2004

Water Distribution Projects

• Planning & Studies

– Asset Management Planning

– Security of Supply

– New Developments

• Operation and Maintenance

– System Shutdowns

– Flushing Programs

– Condition Assessment of Buried Infrastructure

– Water Quality Assessment

• Design and Capital Works

Case Study 1 - Asset Management Planning

in Thames - Coromandel District (TCDC)

• Objective:

– To update the network capacity

planning issues for TCDC water asset

management plan (AMP)

• Key drivers:

– Significant increases to the future

population projections

– Network changes - recent capital

works and renewal projects

• Scope:

– Hydraulic modelling to predict critical

areas in the network and asess optimal

upgrade solutions

MatarangiWhangamata

WhitiangaCoromandel

TairuaPauanui

Thames

23

12

6

2

6

17

0

6.6 7.2

5.8

3.2

5.8 6.7

0

0.0

5.0

10.0

15.0

20.0

25.0

"Future Development Potential Document April 2005" - Extracted

Information

2026 Peak Occupancy Rate

Ratio of summer population to permanentpopulation (2001)

Case Study 1 - Asset Management Planning

in Thames - Coromandel District

Medium Projected growth (2001-2021)

63.6%

17.6%

42.3%

16.8%

3.8%

20.0% 20.0%

0.0%

10.0%

20.0%

30.0%

40.0%

50.0%

60.0%

70.0%

Whitianga

Whangamata

PauanuiTairua

Thames

Coromandel

OnemanaHahei

Matarangi

“Future Development Potential Document April 2005” - Extracted Information

Case Study 1 - Asset Management Planning

in Thames - Coromandel District

Case Study 1 - Asset Management Planning

in Thames - Coromandel District

Whitianga

Hydraulic

Model

Water Treatment

Plant

Storage

Tank

Trunk Mains

Distribution Mains

Storage Tanks

Pump stations

Green nodes:

Supply points /

Hydrants /

Isolation Valves

Case Study 1 - Asset Management Planning

in Thames - Coromandel District

Water Treatment

Plant

Storage

Tank

Trunk Mains

WTP Clarifier

Flow Control Valve

WTP Storage Tank

WTP Pumps

Case Study 1 - Asset Management Planning

in Thames - Coromandel District

Pump Curve

Water Consumption Time Series Data

Control Mechanisms

e.g. Treatment Plant Booster Pump turns

on when the storage tank level drops

below 3.8m

Case Study 1 - Asset Management Planning

in Thames - Coromandel District

Minimum Pressure (m)

Whitianga

- Model Simulation

Prediction in Year 2026

Area highlighted red are

critical areas where

minimum pressure is

below TCDC water

supply level of service

requirement of 10m

Case Study 1 - Asset Management Planning

in Thames - Coromandel District

Whitianga - Fire Supply Simulation Prediction

• Checking against Fire Code 1992 or SNZ PAS

4509:2003

• Residential Fire Flow Requirement: 25L/s shared

by two hydrants in a max radial distance of 270m

apart

• Maintaining a residual pressure of 100kPa

Case Study 1 - Asset Management Planning

in Thames - Coromandel District

Whitianga

- Upgrade Solutions

Different options are

trialled in the hydraulic

model to obtain optimum

system improvement

(best hydraulic results +

minimum cost)

Installation of new pipes

recommended in town (RED)

Case Study 2 -

Metrowater Shutdown Tracing Tool

• System Shutdown

– Planned shutdown: E.g. Routine maintenance of pipes, valves,

pumps…etc

– Emergency shutdown: E.g. Pipe bursts

• Objective

– To identify the most efficient way of shuting down certain section of a

network -> which isolation valves to close in the field

– To identify the customers affected and the extent of area involved

Case Study 2 -

Metrowater Shutdown Tracing Tool

Shutdown Tracing

Simulation

in the Control

Room

Maps showing location of

isolation valves to be shut

List of customers affected

and their contacts

Field Operation

personnel receive

maps through

pocket PC

Customer

notification

Case Study 2 -

Metrowater Shutdown Tracing Tool

Isolation Valves

- Red Nodes

Pipe burst

outside

engineering

school

Case Study 2 -

Metrowater Shutdown Tracing Tool

Case Study 2 -

Metrowater Shutdown Tracing Tool

Case Study 2 -

Metrowater Shutdown Tracing Tool

Case Study 2 -

Metrowater Shutdown Tracing Tool