Water Supply Network

Water Supply Network System Content 1.0 Introduction. 2.0 Sources of water. 2.1 Surface Source. 2.2 Ground Water. 3.0 Water demand and Quantity of Urban Water Supply. 4.0 Quality of Water. 5.0 Distribution of Water supply. 5.1 Distribution system characteristics. 5.2 Distribution system. 5.3 Water treatment plants. 5.4 Norms of water supply. 6.0 Present Scenario of Water-Distribution of Surat City. 7.0 Perspective Planning For Implementation of the Projects. 8.0 Conclusion. 9.0 References.

1.0 Introduction.

ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

Water supply system in urban area should be developed in a proper way to meet the demand and at the same time, quality of water should also be maintained with in standard prescribed limits. Thus the quality of water and the distributions are the important issues for urban water supply system. Provision of an adequate quantity of water has been a matter of concern since the beginning of civilization. Even in ancient cities, local supplies were often inadequate and aqueducts were built to convey water from distant sources Services and network for the health, safety and convenience of the urban population advanced further in the last century. The rich developed countries and the poor developing countries showed distinct paths of progress in finding solutions to these concerns. The state of the art on these concerns may be broadly defined under a subject title “networks and services”. Networks and services can be studied with respect to region, block district and state as well as for a town and a village; the coverage of the topics under urban networks and services are vast. It includes water supply, sanitation, drainage, solid waste disposal, fire services, telecommunication, health care and educational system. The level of public utilities and services in any city reflects its quality and governance. The public utilities and services growth in any city has generally kept pace with the population growth. The primary objective of water supply system is to take water from the best available source and to subject it to processing which will ensure water of good quality, free from unpleasant taste or odour and containing nothing which might be determined to health, and to distribute it top meet the requirement of the town or the city. Any public water supply scheme should meet the following requirements:  Ensured quality of water supply for its intended use like drinking or industrial use.  Ensured sufficient quantity of supply.  Ensured convenient and easy accessibility of water supply distribution.  Ensured economic and financial viability of water supply product such that the capital and recurring cost falls with in the affordable limits of the consumers of the system.

2.0 SOURCES OF WATER.

2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

The main source of water is river ‘Tapti’. The head works for the water supply are located at ‘Nana Varachchha’. The water is being obtained from river Tapti, by three different methods in the following manner: 1. Through the infiltration wells located at the river – bed. 2. Through tube – wells at ‘Varachchha’. 3. Through the surface purification plant by the treatment of raw water. 2.1 Surface Source: Surface water is water in a river, lake or fresh water wetland. Surface water is naturally replenished by precipitation and naturally lost through discharge to the oceans, evaporation and sub-surface seepage. There are two major water works on the tanks on the river tapi (N-E Corner of the city).the water released from the Ukai dam.100 Km upstream is drawn at varachha, and sarthana water works for treatments 2.2 Ground Water: Sub-Surface water, or groundwater, is fresh water located in the pore space of soil and rocks. It is also water that is flowing within

aquifers

below

the

water

table.

Sometimes it is useful to make a distinction between sub-surface water that is closely associated with surface water and deep

sub-surface water in an aquifer

Due to the seasonal character of river tapi, ground water exploitation through French wells infiltration wells as well as tube wells take place even at the two water works. Of the total area about 55.60 Sq.Km. areas, which was added to the city in 1986, is not covered by a rectangular distribution network. In these areas SMC operates about 50 bore wells, serving a population of approximately 65,000 persons. Water from the bore wells is pumped into overhead tanks, which are connected to stand pots. In some cases water is directly pumped into stand pots. 3.0 FACTORS AFFACTING WATER DEMAND AND QUANTITY OF URBAN WATER SUPPLY. a) Factors affecting the quantity of water supply are: 2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

• Pollution and their characteristics • Climatic conditions • Size and type of city • Standard of living • Quality of water • Pressure in the supply • System of supply • Rates of water • Type of sewerage system • Metering • Fire fighting requirement • Number and type of industries • Area under public gardens • Policy regarding the metered supply • Potential sources of water supply • Age of community b) Design period: For water supply projects, a 30 years design period is assumed. Population forecast for this period take into consideration the potential of various sectors of urban economy and regional physical and economic linkages. c) Per capita rate of water supply: The following per capita rates have been recommended as the minimum requirement for the design of public water supply in India:  For design population up to 5,000 → 90 lpcd per person  For design population up to 5,000 to 20,000 → 110 lpcd per person  For design population up to 20,000 to 50,000 → 125 lpcd per person  For design population above 50,000 to 2, 00,000 → 200 lpcd per person. c) Rate of water supply: The consumption of water during the year is not always at a constant rate. There will be seasonal, monthly, daily, and hourly variation. d) Peak factor: The distribution system shall be design to satisfy the peak demand of the population. The recommended peak factors for India are: City size (Population) Up to 50,000

Peak factor 3 Times the average

rate 50,000 to 2, 00,000

2.5 Times 2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

2, 00,000 and above

2 Times

e) Water meters: the policy whether meters will be installed is a critical decision. This involves expenditure on salary of municipal employees who read meters, as well as revenue from consumers and some control on water use. 4.0 QUALITY OF WATER. The following are the important parameters: a) Temperature: the drinking water should be cool. Desirable is bet. 10c to 15.6 c. b) Turbidity: turbidity is on account of suspended and colloidal inorganic matter such as silt, clay and mud particle. It should be between 2.5 -10 ppm. c) Odour and Taste: substance that produce and odour will almost invariably impart a taste as well as odour in drinking water may be due to the presence of microscopic organic matter or inorganic substance such as iron, sodium carbonates and sulphates. d) Colour: for drinking purpose the colour of water should be preferably be less than 10ppm. e) Alkalinity: alkalinity is mainly because of carbonates, bicarbonates and hydroxides. It helps in the process of coagulation while purifying the water. f) Hardness: hardness of water is due to the presence of bicarbonates sulphates and chlorides of calcium carbonate.hardness of water should be between 75-115 ppm for domestic purpose. g) pH value: pH value is a symbol of presence of positive hydrogen iron concentration in a sample of water. Water containing alkali will have OH ions, while water containing an acid will have more H+ ions. The ph value of water for domestic use shall be from 6.5 to 8.

5.0 DISTRIBUTION OF WATER-SUPPLY. Distribution of water is very much important in any water supply network. Water supply distribution is designed to satisfy the demand placed by different land use densities and fire fighting requirements all the time. Piping systems, pumping stations, storage facilities fire hydrants, house connections, water

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

meters constitute the entire distribution system. The distribution system normally costs 60 to 70% of the total cost. Municipal water supply system consists of the following units: •

Collection works

•

Transmission works

•

Purification works

•

Distribution works

5.1 Distribution system characteristics The configuration The configuration of the system is dictated primarily by the street pattern, topography, degree and type of development of the area and location of treatment and storage work. Topography and distribution If there is a change in topography, the distribution system is divided into zones. This will preclude extreme high pressure at lower area and maintain reasonable pressure at higher elevation. Grid and branching system: The distribution system may be generally classified as grid system, branching system or some other combination. Pipe specification: Distribution pipes shall not be less than 150 mm in diameter in the Indian metropolitan cities to meet fire-fighting requirements. In other urban areas the minimum pipe diameter shall be 100 mm. Pressure specification The minimum residual pressure at the time of two store houses,17 meters for three store house and 22 mt for four store houses.

5.2 Distribution system The spatial distribution of water consumption can be estimated by studying population demand and commercial and industrial water use patterns. Predicted hydrograph for each zone is required for assessing the combined peak, flow requirement. There are four principal methods of laying out distribution system: 2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

1. Dead-End System or Tree System:- In this system, one main pipelines runs through the center of the populated area and sub mains take off from this to both the sides. It is suitable for towns that have one several road and by lanes without regularity. The main is a larger diameter at the beginning and it becomes smaller as it goes further from the sources of water supply. The pipe, which connects house within main pipe in the streets, is known as services pipe having 100 to 200 mm or even 300 mm dia. Here less numbers of valves are required, but if there is case of repairs to any sections, the supply of the branch has to be cut off giving inconvenience to the majority. The discharge available for fire fighting in the streets will be limited. 2. Grid – Iron System or Reticulation System:-If the dead ends of the precious system are inter-connected, water can be made to circulate continuously through the whole of the distribution system. This system is therefore also known as the interlaced system. Here, the main supply pipe runs through the center of the rectangular area and sub mains take off from these in perpendicular directions. This system is ideal for cities laid out on rectangular plan. There is free circulation of water, without any stagnation. In case of repairs, only very small area of distribution system is affected, but here large numbers of cut off required. The systems require longer pipes lengths and bigger diameters. The cost of laying water pipe is more. 3. Circular System or Ring System:- This system is most suitable for the town or area having well planned streets and roads. In this system, the supply main forms a ring around the distribution district. In case of fire, a large quantity of water is available. 4. Radial System:- This system is just the reverse of the circular system. In this system, whole area is divided in to a number of distribution districts. Each district has a centrally located distribution reservoir from where distribution pipes run radially towards the periphery of the distribution district. This system gives quick service, without much loss of head. 5.3 Water treatment processes: •

The purpose of water treatment is to remove all those impurities, which are objectionable, either form taste or odour point of view or from public health point of view.

Following are purposes of water treatment: 2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

1. To remove colour, dissolved gas and murkiness of water. 2. To remove objectionable tastes and odour. 3. To remove the disease-producing micro-organisms so that water is safe for drinking purposes. 4. To remove hardness of water. For surface waters, following treatment processes are generally adopted. 1. Screening 2. Aeration 3. Sedimentation With or Without Coagulants. 4. Filtration 5. Disinfections 6. Miscellaneous Processes

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

Fig. Schematic layout of water treatment plant.

5.4 Norms of water supply:The recommended norms for per capita supply, treatment capacity, distribution and proportion of supply, have been wondered for estimating the total requirements while the unit costs and O & M expenditure has been used to asses the financial situation and requirements for the future. Table: Norms for water supply network Sr. No. 1 2 3 4 5 6 7

Category Water Supply (lpcd) Distribution network coverage (%) Total storage required (%) Storage capacity ratio Total treatment req. (%) Population dependent on House Service Connection Person per stand post/Hand Pump

Avg. 150 77 30 90 80 590 127

Min. 135 74 25 42 75 36 54

Max. 180 79 40 199 100 78 227

The present supply by SMC is an average is 85 lpcd; but these do not meet the standard, as can be shown in the table below: Institutions/ committees

Levels 2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

Ministry of urban affairs &employment

150 lpcd

CPHEEO Eight five year plan

150-200 lpcd 125 lpcd

TCPO

180 lpcd

6.0 PRESENT SCENARIO OF WATER SUPPLY SYSTEM IN SURAT CITY.

2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

The Surat city is second largest city of Gujarat and is one of the fast developing cities. Surat Municipal Corporation has the responsibility of supplying water to the residents of the city. Presently SMC is serving 92% of the total area 90% of the population. The city has a well established water supply and distribution system in the walled town, but the distribution system in the extended areas beyond the walled town was extended on adhoc basis as and when new areas were added and the population spread increased. Therefore, the corporation had taken up a

2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

comprehensive programme estimated to the cost of Rs. 1026 lacs to improve the distribution system of the city including the extended area. The scheme was designed keeping in mind the anticipated population of the year 2001. The main line was designed for 30 years. The water supply scheme is designed to give 275 liters of water per capita per day. Present Yield of Water Works: Water Works

Present Yield (in MLD)

(1) Varachha Water Works

30

(2) Sarthana Water Works

280

(3) Katargam Water Works

220

(4) Rander Water Works

150

Total Present Yield

680

Present status of Water Supply: (May 2008) Description

Old Area

New Area.

112.27

334.27

Sq.Km

Sq.Km.

Total population (As per 2001 census)

24.34 Lacs

28.77 Lacs

Area covered by piped water supply (in %)

95 %

38 %

Population coverage of piped water supply (in %)

97 %

*

Total water supply installed capacity

828 MLD

*

Total average water supplied at present

680 MLD

*

148 Lpcd

*

Total Length of Pipelines (75 to 900 mm)

2550 Km.

*

Total Nos. of Water Connections: (All size)

3,27,000

*

Area of City

Per Capita Water Supply in lpcd (Net after losses & industrial supply)

* At present, water supply in the extended parts of the city is being catered as per their existing water supply systems and not from SMC water works. After the implementation of new water supply Master Plan, new area will be covered under water supply network. Present Storage Capacity Storage Capacity in Lac Liters at Water Distribution Stations

2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

Sr.No.

Location

Nos of UGSR

UGSR Cap.

ESR Cap.

TOTAL Cap.

1

Khatodara

3

450.0

22.5

472.5

2

Umarwada

3

337.5

22.5

360.0

3

Katargam

3

450.0

22.5

472.5

4

Althan

2

225.0

--

225.0

5

Athwa 1

2

315.0

--

315.0

6

Udhna

3

335.0

--

335.0

7

Dumbhal 1

3

297.0

--

297.0

8

Pandesara

3

450.0

15

465.0

9

Joganinagar 1

2

450.0

--

450.0

10

Udhna Sangh

1

140.0

--

140.0

25

3449.50

82.5

3532.0

SUB-TOTAL (A)

Storage Capacity in Lac Liters at Water Works 1

Varachha

3

295.0

37.5

332.5

2

Sarthana

3

562.5

--

562.5

3

Katargam

3

675.0

--

675.0

4

Rander

2

435.0

--

435.0

11

1967.5

37.5

2005.0

SUB-TOTAL (B)

Total Storage Capacity in Lac Liters GRAND TOTAL (A+B)

36

5417.0

120

5537.0

NOTE: * Not including Work of ESR of 22.5 Lac Liters capacity in progress

Alternative supply methods Water is also supplied from umarwada station by tankers of 1000 liters each.the supply details are as below:

Mode of supply

Alternative supply details Tankers

No. of trips

140

Quantity of water supplied

1.40 MLD

Period of supply

All Season

Mains areas supplied to

Udhana, Umra, Piplod, Pandessara & 2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

Khatodra

7.0 PERSPECTIVE PLANNING FOR IMPLEMENTATION OF THE PROJECTS. To meet the demands of the growing population SMC has been the implementation a water supply project, which is divided into two phases: phase – I is from 2001-2011 and phase-II from 2011-2021. the demand of water will be 820 MLD by 2021 as per the projection. Some works have been taken up on a priority basis, in order to provide immediate relief (by 2001) to certain areas, at a restricted cost. Head/Year

Priority

Phase – I

Phase-II

phase 2001 Population (Lacs) 26 Water Demand (mld) 490

2011 35 660

2021 43 820

@190 lpcd Storage capacity (ml)

330

328

160

A separate treatment plant for the other areas could be located at Sarthana and Katargam there will be 80% satisfaction of demand in 2001 and 100% satisfaction in year 2011. In order to augment supplies, a weir has been constructed on Tapi River, near Singanpore. The purpose of weir is to increase the surface water availability. The impoundage caused by the weir may result in an increase in the yield of French wells at Sarthana and infiltration wells at Varachha by about 50 MLD. Two additional surface water treatment plants of 50 MLD are under construction at Varachaha. It is proposed to augment the supply by 60 MLD at Rander giving a total supply of about 320 to 370 MLD in the priority phase. The present storage capacity will be upgraded from 91 MLD to 328 MLD by end of phase II in 2021. The city has been divided into 6 water zones. North, west, central, east,s outh and south west .in order to meet the requirements of the year 2011-21 additional distribution stations are proposed at Singanpor , Ved.Rander, Jahangirpur, Jahngirabad, Limbayat, Athwa, Aithan, Sagarampura, Udhana and Bhestan. 2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

Following is an abstract of the zone wise. Water demand for the three phases Zone West S-W North Central South East

Demand (MLD) 2011 131 118 162 151 195 183 940

2001 79 64 107 137 138 145 670

2021 180 167 239 165 240 219 1210

A new source at katargam by construct the surface purification plant of 240 MLD capacity has been developed and it will be commissioned shortly.furthe the top priority works like athwa water supply system with Booster Station Rander –Adajan water supply system with Booster Station and udhana-pandesara water supply system have also been recently completed. The SMC intends to seek financial assistance from the World Bank or any other Financial Institutional for implementing the water supply project to alleviate water shortage and cater the remaining areas of the city. Benefits: The proposed water supply project will ensure safe potable water to the uncovered areas within the city limit. The 4.34 million projected population of the year 2021 is proposed to be covered there by replacing conventional methods. Due to strengthen the system, even the existing consumers in old city will get water with adequate pressure. People in new areas (most of the slum-dwellers) will also get safe drinking water at their doorstep. Resultantly, people will stop using water from unsafe sources. Due to availability of ample water supply, people will be induced to grow more trees, resulting in overall healthy environment and this will also stop storing and wastage of water. 8.0 CONCLUSION: Today urban population is increasing at a rapid rate and so at the same time the demand of water also increasing. Many cities are not able to meet the demand and sometimes to meet the demand they are not able to keep control over the quality of water. Thus to maintain good quality of water, with high supply efficiency, collective action is required to meet this challenges. Contributionof urban inhabitants 2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

is required to meet the capital and reaming expenditure for water supply system and large capital requirement.

9.0 REFRENCES Books:  Punamia B.C. and Jain Ashok K., “Water Supply Engineering”, (1999), Laxmi Publications PVT.LTD, New Delhi.  B.S. Raju ,”Water supply and Waste water engineering”, (2001),Tata Macgraw-Hill Publishing CO. LTD, New Delhi.  Deswal S.S. and Deswal S.,” Environmental Engineering”, (2001), Dhanpatrai And CO. PVT. LTD., Delhi.  Sharma B.K. and Kaur H.,” Environmental Chemistry”, (1995), GOEL Publishing House, Meerut.  Gohil M.B.,Popat A.K. and Gohil D.P.,” Essential Of Environmental Engineering”,(2004) Atul Prakashan,Ahemedabad. Web Sites: 2ND SEM, M-TECH(PLANNING),YEAR-2008-09

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ELEMENTS OF WATER SUPPLY NETWORK SYSTEM

•

http://www.suratmuniciple.org.

•

http://www.envfor.nic.in

•

http://www.neeri.nic.in/

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