September, 2013

Management of Water Supply Pipe Networks II

Measures to Improve Water Supply Pipe Networks III

Present Conditions of Water supply I

contents

Outcomes & Problems III

Pipelines(㎞) Valves Hydrants Water Reservoirs Booster Stations

13,801 202,817 57,736 101/238million ㎥ 196

Supply facilities

Water Supply percentage : 100%

Population : 10.442 million Area : 605.21 ㎢

Facilities

- Water intake structure : 5 (712 million m3/day)

- Water purification center : 6 (435 million m3/day) (Advanced water Purification center with a capacity 70 million m3/day)

Production facilities

Water Production at present Annual Total Amount of Production : 117,722 million m3/year

Maximum Daily amount of Production : 358 million m3/day

Average Daily amount of Production : 322 million m3/day

Production facilities : 308 ℓ/day

Water Pipelines at present

- Length of Diameters(as of Dec. 2012 )

Classification total Under 50㎜

Between 80 And 350㎜

Between 400 And 1,000㎜

Over 1,100㎜

Length(㎞) 13,801 4,200 7,933 1,197 471

ratio%) 100 30.4 57.5 8.7 3.4

446 576

6,518

13,942

18,416

17,477

13,914 13,846 13,841 13,801

-

2,000

4,000

6,000

8,000

10,000

12,000

14,000

16,000

18,000

20,000

'56년 '60년 '70년 '80년 '90년 '00년 '09년 '10년 '11년 '12년

Length(km)

Inspection of water pipe conditions

Stage 3(2009~2013) small sized pipes (between 80㎜ and 350 ㎜)

Stage 2(2007) : medium sized pipes (between 400㎜ and 600 ㎜)

Inspection for

Stage 1(2006) : large sized pipes (700㎜ or larger pipes)

Replacement of worn-out Pipes

Under 80~700mm : Replacement of grey cast iron with ductile cast iron since 1984

Under 50mm : Replacement of galvanized steel pipe with stainless pipes since 1987

Over 800mm : replaced with PE pipe

Replacement of old pipes vulnerable to rust or leakage since 1984

- Closing/opening of valves

- Rust, water leakage, etc. in pipes and valves

- History of water leakage

- Sampling and measurement of flow, velocity, and pressure

< data >

pressure

velocity

flow

Drainage Method Sacrificial Anode Method Impressed Current Method

Installation of water pipe corrosion prevent systems

Types of corrosion prevention systems

Installed in 700mm or wider steel pipes vulnerable to galvanic corrosion

Durability maintenance through the prevention of galvanic corrosion of pipes

- Drainage method : prevention of corrosion by using electric railway

- Impressed Current Method : prevention of corrosion for the pipes without anti-corrosion systems -> existing water pipes

- Sacrificial Anode Method : prevention of galvanic corrosion in pipes -> newly installed water pipes

Establishment and Operation of GIS

Cycle of data update : data updated on a regular basis and upon facility changes

Data established

pipes

(㎞) Valves hydrants Meters

(thousand) reservoirs

Booster stations

Water Intake center

Water purification

center

13,801 202,817 57,736 1,968 101 196 5 6

-Water pipes : installation date, materials, diameters and other related information

Establishment of GIS

- General facilities : sizes, facilities, water supply area

- Major facilities with GIS

GIS block diagram

Water supply GIS

integrated DB

Construction DB

Network DB

Other DB

Basic map DB

Water supply DB

Land registration

DB

Field support system

Facility

management

Field management

Water supply GIS

Pipe network

management

Water supply

and repair

management

Repair

management Leakage/facility

management etc.

Water supply advanced water

supply system

As-built drawing

management system

Thematic map

management system

Access to integrated information

Pipe-related information

integration

Connection

between pipes and work

User interface

improvement

Links to other systems

Excavation date/permit

inquiry

Location of six underground

facilities

Links to other necessary

information

Seoul City GIS

- Underground

facilities

- Administrative

information

Road excavation

restoration

Pipe network interpretation

program

SDW

Online road construction

management system

Related DB

Completion of pipe networks necessary for water supply and durability improvement

Increase in revenue water rate through leakage reduction

Decrease in water leakage through repair and replacement of worn-out pipes

100% water supply

55.2

68.2 72.0

75.2

79.2

82.7 85.3

88.0 89.9

91.4 91.7 92.9 94.5

903

1077 1097 1106 1093 1104 1118 1125 1120 1114 1110 1110 1113

1635 1579 1523

1471 1379

1335 1311 1278 1246 1219 1211 1194 1177

50.0

55.0

60.0

65.0

70.0

75.0

80.0

85.0

90.0

95.0

100.0

800

1000

1200

1400

1600

1800

2000

2200

1989년 1999년 2000년 2001년 2002년 2003년 2004년 2005년 2006년 2007년 2008년 2009년 2012년

유수율 조정량 공급량 Water charge revenue water rate water Supply

Water supply pipe networks at present

Too wide or narrow pipes in use

Unsatisfactory water network systems for block network formation

Changes in the establishment of water supply pipe networks

- 1990s~2000s

- 1970s ~Early 1980s

- Mid-1980s

• maintenance focused on increasing revenue water rate

• management of worn-out pipes lacking corrosion resistance

• construction of water supply pipe networks in response to skyrocketing water supply demand

• installation of new pipes, and repair and replacement of worn-out pipes

Circumstantial changes

Need for reassessment of the life span of pipes that began to be replaced in 1984

Systematic maintenance and management of water supply pipe networks

Need for new paradigm to maintain of existing pipes

Inclusion of facility-related and other information for pipe network management

- Information provided: Installation date, materials, diameter, length, etc.

- Information to be added: Water flow, water pressure, water quality, flow rate,

scale, bio-film, etc.

- Condition assessment of time-worn pipes

- Adoption of the remote flow rate and valve control system

- Replacement based on materials and installation date

⇒ Objective management system establishment in accordance with pipe

condition assessments

- Replacement of worn-out pipes and water supply-oriented pipe network organization ⇒ Block system-oriented reorganization

Measures for Improvement

Establishment of water supply pipe networks for consistent, uninterrupted water supply

- Establishment of water pipe networks to link facilities

- Dual pipes in replacement of the single pipe that links the water purification center to reservoirs

• Consistent, uninterrupted water supply system even during pipe and valve maintenance

• Emergency water supply pipes in case of leakage and other urgent situations

• water purification center ⇔ water purification center, reservoir ⇔ reservoir

Trade off study of water supply pipe networks

- Analysis of the suitability of water pipe networks built in water supply areas

• Pursuance of energy-efficient facility operation

- Energy conservation through planned water production and supply

• Analysis of facility operation energy consumption

Pipe network management for energy conservation and green growth

- Measurement and management of velocity, flow, residual chlorine

- Analysis of economic feasibility by converting the flow rate of water supplied through large pipes into monetary terms (Korean won)

- Direct water supply to areas with pressurized water supply systems during off-peak hours

• Analysis of water usage per season and time zone

Asset management of water pipes

- Asset assessment and management of water pipes

• Classification of pipe assessment into various grades

- Creation of a database on the conditions of water pipes

Assessment and management of time-worn pipes beyond their life expectancy

- Application of depreciation cost depending on a pipe’s lifespan

• Information on the degree of corrosion, thickness of bio-film, velocity, flow, pressure, pH, residual chlorine, etc.

• Replacement of worn-out pipes

- Assessment of the condition of water supply pipes

• Utilization of GIS data on facilities and specimens collected in the field

Removal of the pipes with low velocity and completion of circular water supply networks

- Division of water pipes based on their function

Establishment of a block system with pipe networks

- Establishment of a circular water supply network with blocks in various sizes

- Establishment of an alternative water supply network for water supply to each block

- Plans for the establishment of block networks

Dualization of pipe networks based on the border between natural water supply areas and pressurized water supply areas

• Medium blocks : based on small blocks in 8 to 12 units

• Small blocks : based on 500~800 households

• Minor Pipes ⇒ water transfer to each household

• Large blocks : based on local reservoir

• Major Pipes ⇒ water transfer to small blocks