1. Introduction

1.1 Background of the Study

Throughout history, water has been considered a natural resource critical to human

survival and human history can generally be considered to be water-centered. Human

survival and welfare generally depend on regular availability and control of water. The

people of developed countries has easily access to the pure and sufficient water usages

where the paradox of community water supply in developing countries is that everyone

has access to water supply, but in fact many people do not. They may have access to

water but only at a large walking distance, in too little volume or poor quality. A lot of

effort is made in the world to change this situation, but have we been effective and this

situation really- changing?

As a common characteristic of the urban areas of Bangladesh, accessibility to the suitable

quantity and quality of water is a major problem in KCC. Unplanned and improper

withdrawn of water is the main causes of the shortage of water. These shortages become

more acute when pumps are installed haphazardly. In some of the cases the supply system

suffers a gross water loss from old pipes, poor system control and excessive consumer

wastage. Sometimes, the consumers suffer frustration because of inadequate storage

capacity of the system and the intermittent supply.

In 1981, KCC was able to provide 5 million gallons of water in a day. But it is not

enough to serve the urban population because the total demand was 15 million gallons

(Islam, 1984). In the year 1991 water supply capacity rose to 8 million gallons but

demand rose even higher and KCC was able to supply only 34% of the total demand

(KDA, 1997). At present the total demand of water is about thirty million gallons but

the supply of water is half of this by which only 30% people are served (KCC, 2001).

About 90% of the total populations of the KCC area collect their drinking water from

shallow and deep tube wells instead of network water supply system from KCC (KCC,

1997). On the other hand, the water supply management of KCC is not systematic and

having limited expansion capabilities which requires designing, constructing and

managing to face future challenges.

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1.2 Importance of Groundwater

The fresh liquid water sources on land surface and in the ground constitute only 1% of

the total water on earth. These fresh water source have been formed by condensation of

water evaporated mainly from the oceans. Perhaps water is the frequently occurring

substance on the earth, but still evidence of recent estimate indicates that more than one

billion people do not access to safe water (World Bank, 1977). Lack of safe water is

more prominent in the third world countries.

Ground water is an important source of water supply throughout the world. Its use

irrigation, industries, municipalities and rural homes are increasing day by day. Two-

third of the total surface water of the earth is water, but the total surface water is not

suitable fort drinking and other purpose. Presently, 2.5% of the total water of the earth

drinkable (NGO Forum, 2003).

The main sources of water in Bangladesh are surface water in rivers, reservoirs, lakes,

canals and ponds and ground water in shallow and deep aquifers. The rain water is an

alternative source of water and has good potential for the water supply. Except for few

hilly regions Bangladesh is entirely under laid by eater bearing formation at depth

varying from 0 to 20 meters ground surface. The soil is mostly stratified and formed by

alluvial deposits of sand and silt having occasional lenses of clay. The main constituents

of the aquifer materials is the medium grained sand deposited at the lower reach by the

mighty rivers the Ganges, the Brahmaputra and the Meghna with their tributaries.

(Ahmed and Rahman, 2000)

Lack of safe water is more prominent in the third world countries. In Bangladesh, like

many developing countries, there is a great demand for safe water. Water is available in

country apparently almost everywhere but availability of safe water is the prime

question. Now, Khulna city faces the same problem. Khulna is the third largest city and

second seaport in Bangladesh. It is situated in southwestern part of Bangladesh along the

Bhairab and Rupsha rivers. These rivers are affected by tidal conditions and

contaminated by various industries and municipal untreated waste disposal. As a result,

surface water is not frequently used for various purposes. Ground water is available in

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and around Khulna city from the shallow and deep aquifers, Withdrawn of ground water

by well is the primary source of water for KCC water supply system.

The KCC water supply system is primarily based on small groups of production tube

wells and one surface water treatment plant. There are only five overhead tanks in the

city but two are not active. The total system has been developed over many years and

has been constructed using relatively small diameter pipes. Water Works Department of

KCC currently recovers its operating costs through the holding tax, connection fees for

new services and a flat monthly charge based on the size of service connection.

1.3 Objective of the Study

This study has intended with the followings objectives:

To evaluate the present aquifer status as a source of urban water supply.

To evaluate the existing water supply facilities in KCC area.

1.4 Literature Review

The water available in the saturation zone is known as ground water. The soil strata,

which contain groundwater and will readily, yield it to wells, are called aquifers. The

amount of ground water which can be obtained from an area depends on the

characteristics of the underlying aquifer and the extent and frequency of recharge. An

aquifer has interconnected pores filled with water, which may be considered as a

network of inter connected pipes through which water flows at a very show rate. These

interconnected pores provide both storage and flow or conduit function in an aquifers.

Ground water in Bangladesh except some place is available at a shallow depth.

Groundwater levels are at or near ground levels during monsoon and post monsoon

period. Ground water raise as a result of recharge during may and usually reaches its

highest in late July in each year. Between July and October ground water levels are

constant and maintain a balance between surface water level and the fully recharge

aquifers. Ground water levels fall from October in response to rapid drainage of surface

water and changes in base levels. During the dry season most of the minor rivers are

sustained by groundwater outflows. The ground water withdrawn and recharge can be

increased approaching the potential limits by creating additional storage through

increased during the dry season. (Ahmed and Rahman, 2000)

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The available geological information and related studies have shown the two types of

aquifers exist in Bangladesh. a shallow aquifer, which has been termed “ main aquifer”

lies within 100 meter from the surface with an overlying clay/silt blanket, which is less

than 2 meter thick in the northwest and generally increases southward to mire than 50

meters. Other deep aquifer whose water development potentials is not known occurs at

depth between 300m and 2500m. (Ahmed and Rahman, 2000)

In the shallow aquifer groundwater flow from north to south localized in the major

rivers. Ground water gradient varies from 1:1000 in the northwest to 1:13000 in central

Bangladesh to less than 1:20000 in the coastal area. Permabilities of the main aquifers

are very high and vary from 10 to 200m/day. Transmissibility of the main aquifer range

from 100 to 10,000 m2/day with an average value of 2000 m2/day. Although the aquifer

has high transmissibility the horizontal flow of ground water gradient. The storage

capacity of the aquifer in Bangladesh increase with depth because to the increase in the

size of aquifer materials. The specific yield varies from 0.02 too 0.25. (Ahmed and

Rahman, 2000)

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2. Study Area

2.1 Location

The study area Khulna City Corporation (KCC) is an expanding center of

southwestern Bangladesh, which is being directly influenced by the tides. Khulna lies

at the point where the river Bhairab meets Sundarban route. The Bhairab in northern

side, Rupsha river in the middle side and Posur in the Southern side flows along the

western side of the city. Khulna is the third largest city in Bangladesh.

Geographically, Khulna lies between 22°49 / North latitude & 89°34/ East longitude

(Environmental Maps & Work book for Khulna City, 1999). Situated in flat terrain

with industrial activity in and around the city, it acts as a gateway to the nearby sea

port of Mongla. It is in the southwestern part of Bangladesh with its location on the

axis Jessore-Mongla port, the second largest seaport of the country. The location map

of Khulna district and study area has been shown in the Figure 1.

2.2 Regional Setting

Khulna city is located on the banks of the Rupsha and Bhairab rivers. It is in the south

west part of Bangladesh with it’s location on the axis of jessore-mongla port, the

second largest seaport of the country. Geographically, khulna lies between 22 o49/

north latitude and 89o34/ east longitude and it’s elevation is 7 feet avove MSL. Khulna

is bounded by the Bhairab and Fultala thana, on the east by the Rupsha river, on the

south by the Rupsha river and on the west Dumuria thana. Figure shows the location

of the Khulna city in context of Bangladesh and Khulna district. The Study area is

mainly covered by the Ganges deltaic deposits and paludal deposits of Quaternary age

(ALAM, et. al., 1990). The deltaic deposits comprise of tidal deltaic deposits, deltaic silt

deposits and mangrove swamp deposits. The southern part of the study area is low lying

area, whereas the land level of northern part is comparatively higher. The major portion

of the area lies between five and seven feet (1.5 and 2.1 meters) above the average sea

level. The northern part of the city is above the normal flood level. But the areas lying at

south east and west area usually inundated during the rainy season.

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- 6 -

Figure 1: Location of Khulna City Corporation in Bangladesh

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Bhairab River

Rupsha River

2.3 Geology of the Study Area

Khulna is situated in the delta region and delta is divided into moribund delta, central

delta, basin immature delta, mature delta and active delta. Khulna is in the immature

delta. It is possible that subsidence has played a major part in depressing this area There

are many evidences of it, such as large ruins in the heart of the swampy estuarine areas

such as at Shekertek and Bedkashi (Fawcus,1927), and presence of human artifacts and

tree stumps, buried in the alluvium many feet below the level of the sea. Hunter (1875)

recorded the presence of large tree trucks buried in the ground at Khulna town, indicating

subsidence of 6m.The Study area is covered by Holocene river alluvium comprising

deltaic, terrace meander, inter stream and swamp deposits. These Sediments continue to

accumulate from detritus deposits by the main river, particularly on the flood plain of

the Meghna. Tidal deltaic deposits are light to greenish gray, weathering to yellowish

gray, silt to clayey silt with lenses of very fine sand along active and abandoned

stream channels including crevasse splays, and contain some brackish water deposits.

Deltaic silts are light gray to gray, fine sandy to clayey silt. Mangrove swamp deposits

are found in the southern margin of the study area. These are dark gray to black silt

and clay deposited in the active tidal zone which is dominated by woody organic rich

mangrove swamps. Marshy clay and peat deposits occur in the central, northeastern

and northwestern side of the study area. They are gray and black herbaceous peat and

yellowish grey silt. There is no specific evidence of wells in the Study area because of

there general similarity in Litho logy to Holocene sediments and lack of fossil

evidence although the Sediments become progressively older with depth.

2.4 Lithology

The litho logy of the various sediments referred to above varies from clay, through

silt, to fine, medium and occasionally coarse sand The geometry of individual

Sedimentary units is inevitably complex and there is a general lake of horizontal

continuity on a local scale. Also, there is an upward finding of the sequence, while the

degree of sorting decreases with depth. Table 1 Show an arbitrary subdivision of

subsurface strata of the study area based on lithology and electrical-log.

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Table 1: Stratigraphic Succession in Khulna

Age Study area Lithology Thickness

Quaternary Khulna

Clay, silty clay with occasional very fine

sand and traces of micas

13-65 m

Silt, silty sand, sandy clay, very fine to fine

sand, fine to medium sand

18-92m

Caly, silty clay, fine sandy clay 31-188m

Silty clay, fine to medium sand, medium

sand, some course sand

10-165m

(Source: ALAM, et al., 1990)

Peat is located in the deltaic pale is known from Kala Mouja in the Khulna district

(Ahmad, 1969): This peat bed has a thickness ranging from some few centimeters to about

3.5m. This type of peat is highly humified and its dark brown color indicates advanced

decomposition of the organic matter.

2.5 Hydrometeorology

The climatic condition of an area can be evaluated through analyzing the climatic and

hydrologic data. The climate and hydrologic data include rainfall, temperature,

humidity, atmospheric pressure, sunshine , wind speed, evaporation, transpiration, etc.

among which the rainfall, evaporation, transpiration component have a direct role in

the hydrologic balance and they are relevant to the hydrologic cycle of an area . The

climatic condition of an area has much influence on quality of water not only in

amount and kind, but also in the annual regime of water quality fluctuation (SANTOS

1972). Hassan (1992) constructed the following path of hydrologic cycle for South

part (Khulna, Jessore) of Bangladesh (Figure 2) and possibly it is the best fitted in

Bangladesh.

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T E

R E R E

E R

R-O R-O

I

Sp

EF INF

PC CP

O-F

Figure 2: Hydrological cycle for Bangladesh (Source: Hassan, 1992)

Explanation: R= Rainfall, R-0= Runoff, E= Evaporation, T= Transpiration, I= filtration, C= Percolation, EF= effluent, INF = Influent, O-F = out flow, Cp = Capillary Pressure and p = Seepage

2.5.1 Rainfall Distributions

Rainfall is an important component of hydrologic cycle. It is also the input component

of the hydrodynamic System of an area. Both the surface water and groundwater of an

area could be derived from this component alone. Less rain create imbalance in the

hydrologic budget of an area while heavy rains produce flush flood causing damage to

humidity i.e. agricultural products and others. Thus a long term rainfall distribution

statistics through out the year is very important for the local agro climatic condition

which will help in making the agricultural planning of an area (Hassan,1994).

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Atmosphere

Surface Oceans River

Soil

Groundwater

Khulna receives an average rainfall of about 1800mm. The main source of rainfall is the

southwestern monsoon. Nearly 81 per cent of total rainfall occurs during June-October.

During March-May some rainfall also occurs due to Nor'wester effect. Winter is the dry

period with little or nearly no rainfall. However, during the months of December and

January little rainfall is recorded. The monthly rainfall variation in Khulna city is shown

in the table.

The mean annual rainfall is 1692mm at Khulna. The mean monthly rainfall varies from

2mm to 341 mm. Other seasonal rainfall distributions on Khulna are represented in the

Table 2. About 90%of its mean rainfall in Khulna was received in May-October

(monsoon period) and rest 10% of rainfalls was received in November April (Non

monsoon period).

Table 2: The monthly average climatic data in climatic in Khulna region

MonthRainfall(mm)

Temperature(oC) Relative

Humidity( %)Bright

sunshine (hr) Maximum Minimum

January 2 26.25 11.6 80.8 212.6

February 40 28.65 15.55 75.6 220.03

March 19.5 31.35 20.15 76.2 272.25

April 75.5 34.85 24.2 78.6 204.5

May 194 34.7 24.8 74.4 183.4

June 286 31.9 25.7 80.8 113.05

July 341 31.95 25.85 88.57 142.55

August 241 33.1 26.3 85 172.2

September 271.5 32.8 24.9 87.65 159.5

October 206 32.9 24.85 88.68 196

November 15.5 30.7 20.85 83.09 205.3

December 2 25.55 13.65 80.57 213.65

(Source: Meteorological department, Khulna, 2004-2008)

The recorded minimum mean monthly rainfall was in the month of December which is

0.12mm (0.12%of total rainfall) and the maximum mean monthly rainfall was in the

month of July which is 341mm (20.14% of total rainfall) About 80% of rainfalls were

received in annually within the Monsoon period(June to October) in Khulna .

Considering the rainfall intensity, it is seen that over 250mm/month of rainfall were

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received in the May-October months of the year and this duration may be termed as

wet month. The rest months of the year may be considered as non monsoon in which

less than 30 mm/month of rainfall were received from November to April.

2.5.2 Relative Humidity

Relative humidity is inversely proportional to the temperature. Higher the temperature

lesser will be the relative humidity of the atmosphere. The region has high relative

humidity. In Khulna area the mean monthly relative humidity varies from 90.15Qune)

% to 70.90% (February) and the mean annual is 81.35%. T a b l e 2 gives the mean

monthly relative humidity in percent of Khulna and Figure 6. shows the monthly

relative humidity variation and Figure: 7 the relationship between relative, humidity

and temperature of Khulna.

2.5.3 Wind Speed

Wind speed data at the meteorological office is reported as an average for the day in

Knots for the predominant wind direction of at 10m height. The records indicate a

significant variation in the mean wind speed across the region. The monthly distribution

of the wind speed also varies.

2.5.4 Bright Sunshine Hours

Bright sunshine is the important parameter in controlling the climatic condition of an

area. The air pressure of an area depends on the bright sunshine and thus it control the

wind blow(Direction and speed), evaporation rate etc .The mean monthly bright

sunshine in Khulna varies from 113.05 hours to 272.25hours in June and March

respectively. The mean monthly bright sunshine in Khulna is given in the Table 2.

The Study area experiences a wide variation in the distribution of sunshine hours,

ranging from a mean annual minimum of 5.2 hours of to a maximum of 7.0 hours. As

would be expected the sunshine hours in the monsoon from June to September are much

lower than during the rest of the year where in excess of 8.5 hours of sunshine are not

uncommon.

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2.5.5 Evaporation and Evapotranspiration

The evaporation and transpiration data along the rainfall are required to study the

hydrologic balance of an area. Evaporation is depended upon the temperature condition

of the atmosphere and it is directly proportional to the temperature i.e., higher the

temperature greater the evaporation. The estimated mean maximum evaporation in Khulna

area was 4.33mm/d (April), and the mean annual evaporation was 2-mm/d. The Khulna

area, the mean monthly evapo-transpiration varies from 2.67 mm/d (January to 5.12mm/d

(April) and the mean annual is 3.49mm/d.

2.6 Hydrogeology

Hydrogeology is the Study of geological factors relating to the earth's Water. The

traditional Studies in hydrogeology focused on either the mathematical treatment of flow

through porous media or on a general geological description of the distribution of rock

formation in which ground water occurs. Therefore the optimum development and

management of groundwater resource for mitigation human requirements must be

dependent on the proper investigation of the water bearing formations on an area and its

properties and characteristics (Bowen, 1986).

2.6.1 Drainage Pattern

The Study area is mainly drained by the Bhairab, Rupsha, and Pasur river and numerous

minor tidal; streams. These (Bhairab, Rupsha, and Pasur) are actually a same river course

but have different names in different locations during their courses and gradually found

their way by a Southerly route to the Bay of Bengal. The Bhairab River, the most

important river of the Study area, enters the Study Area from the north near Phultala and

flows in a south easterly course at the northern part of Khulna district. It then passes to

the south, discharging a great part of its water into the Rupsha or Pasur, while the main

channel runs to the Southeast part Fakirhat and Bagerhat and joins the Madhumatiat

Kachua near Khulna. Bhairab is joined by the Atharabanki which covers the surplus

Water of the Madhumati into the Bhairab.

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3. Methodology

The paper is developed on secondary data. The data were collected from various

secondary sources. Hydrologic data are collected from the Water Supply Authority

of Khulna, Bangladesh Water Development Board, Khulna City Corporation,

Khulna Development Authority and Bangladesh Meteorological Department. Data

of water withdrawn from aquifer with were collected from KCC, KDA and BWDB.

Meteorological data were collected from BMD Khulna office. Maps are collected

form the KCC. Relevant documents and journals are collected from different

published and unpublished sources. Literature review and other literature were

collected from different books. Various maps are also collected from KCC, KDA

authority. River related data are collected from the BWDB office.

Results were produced from the analysis of secondary data collected from different

sources. Data were analyzed with the help of software like Microsoft Excel.

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4. Results and Discussions

The secondary data were analyzed and the following results were made on the

basis of the given data.

4.1 Evaluation of Existing Water Sources in KCC Area

Oceans and seas are the main source of water but they are not potable. Fresh liquid

water sources from land surface and in the ground constitute only 1 % of the total water

on earth. In Bangladesh, safe water for drinking and other needs is available in surface

water of rivers, canals, ponds, reservoirs and lakes and ground water in shallow and

deep aquifers; ground water is the most important source of water supply in our country

rather than surface water and for the salinity the water supply system of KCC is mainly

dependent on the ground water.

In Khulna city, the quality of drinking water is apparently a more serious issue than the,

supply water. The primary source of water supply in KCC area is mainly from the

ground water extracted through production and hand tube wells. The secondary source

of water supply is surface water extracted from rivers, ponds and wells etc.

4.1.1 Surface Water Sources

Every year vast quantity of surface water from the Ganges and its distributaries flows

through two-river system in and around Khulna city, viz. Rupsha and Bhairab for 6

months. Beyond this period i.e. in the dry season the river water flow is reduced and

affected by saline water intrusion from the sea. Dakatia Beel has also been included as a

source of surface water supply. There are other numerous ponds which are used as

surface water sources in KCC area. The existing ponds in KCC area is shown in the

Figure 3.

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Scale1:25,000

Figure 3: Location of ponds of KCC (Source: KCC, 2000)

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4.1.2 Ground Water Sources

Ground water in and around Khulna is available in both shallow and deep aquifers. The

shallow aquifers are extended towards north of Khulna town and well developed in the

west of Dumuria thana. The depth of shallow aquifers varies from 0~100 m. Phultala

and Rupsha areas have a good potential for abstracting shallow ground water with

acceptable iron content. The Jessore-Khulna-Bagerhat ridge running almost parallel to

the river Bhairab and having a maximum width of 6 km, has hydrological relationship

with the adjacent depressed lands known as Dakatia Beel.

The deep aquifers are generally present below 150-300m. Water from deep aquifers is

almost pure and safe for drinking purpose and less vulnerable to pollution from

industrial waste and spillage. The contents of iron and manganese are within

permissible limits of WHO or Bangladesh standard Investigations suggest that untapped

ground water supplies are available from around Khulna city, particularly Dumuria

area.

4.1.3 Production Sources of KCC Water Supply

There are currently 43 production wells in operation. Total installed capacity of the

wells is in excess of 35,000 m3/ day but the yield to the system is considered

significantly less because of operating condition. Most of the wells with some few

exceptions in shallow aquifer are 150mm diameter deep tube wells at an average depth

of 275meters. Service is intermittent as the pumps are operated for a maximum of 13

hrs in a day divided into two shifts. These service periods are frequently interrupted,

which reflects reduced supply and level of service to the consumers. An inventory of

production wells was undertaken in 1994 which resulted that there is a need for

consideration of either rehabilitation or replacement of worst performing wells in KCC.

Production wells in KCC area are indicated in Table 3 and drinking water production

tube wells are indicated in figure 4.

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Table 3: Deep aquifer water production wells

Serial no

Location of well Well no.Year

installedTotal depth

(m)

Pump capacity m3/hour

1. Khalispur-1 1 1963 85 682. Khalispur-3 3 1973 238 683. Gollamari 10 1981 276 1364. DPHE/Rupsha-1 16 1982 201 685. R&D Compound 18 1982 253 686. Azam khan comm.college 19 1983 276 327. Circuit house 22 1983 198 688. Feri ghat-2 23 1983 256 689. Bagmara 24 1983 265 6810. Pollimangal 25 1984 262 6811. Khalispur pourashava 26 1984 226 6812. Taltala city college 27 1984 210 6813. DPHE/Rupsha-2 28 1985 197 4514. Hadis Park 29 1986 210 6815. Khalispur-5 30 1987 247 6816. Islamabad comm. Center 31 1987 270 6817. Sheikh para-2 32 1988 169 6818. Tutpara well field-1 33 1987 201 6819. KDA Nirala-1 34 1987 251 6820. KDA Nirala-2 35 1987 232 6821. KDA Nirala-3 36 1988 253 6822. Tutpara well field-2 37 1988 198 10223. Tutpara well field-3 38 1986 274 7024. Mujganni well field-1 39 1986 290 7025. Mujganni well field-2 40 1986 253 7026. Mujganni well field-3 41 1987 281 6827. Sisu park-2 42 1988 234 7028. Shonadanga 43 1987 283 6829. Arambag 45 1987 286 7030. Tarerpukur-2 46 1994 250 6831. Municipal tank road 47 1994 281 6832. Khalispur sewerage 47 1994 268 6833. Khalispur TV center 48 1994 254 6834. DPHE/Rupsha-3 49 1994 212 6835. Nurnagar 50 1994 245 6836. Zilla high school 51 1995 245 7037. Islamabad comm. Center 52 1995 274 7038. East Baniakhamar 53 1995 285 13039. Feri ghat 54 1994 323 7040. Khalispur (near club) 55 1995 266 6841. Alia Madrasa compound 56 1994 282 6842. Mosselman para 57 1994 214 6843. Sonadanga near police fari 58 1994 245 68

(Source: KCC, 2001)

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4.1.4 Tube-Wells

The KCC statistical current information shows that KCC have 5650 hand tube wells of

which 3800 are shallow and the remaining 1850 are deep tube well. The yields of these

tube wells were estimated by Haskonning 1981 as 3.3 m3/day for the shallow wells and

6.6 m3/day for the deep tube wells estimates with this consultant concerns. The Table 4

reflect the total picture of tube wells.

Table 4: KCC Hand Tube wells

Description No. of wells Capacity (m3 /day)

Deep Tube well 1910 6.6

Shallow Tube well 3875 3.3

Total 5785

Source: KCC (2006)It can be observed from the accompanying table that more than 4% of both shallow and

deep tube wells of KCC are not working. The status of shallow and deep tube wells is

shown in Table 6.

4.1.5 Daily Extraction from Aquifer

From the above data it can be calculated that the total water extracted by the production

and deep tubewells are coming from the deep aquifers and the total amount of water is

35006.5 m3/day. And by extraction of shallow tubewells from shallow aquifers is 3.3

m3/day. So the total water withdrawn from the deep and shallow aquifers is 35009.8m 3/

day. The table 5 shows the calculated data.

Table 5: Daily total aquifer water extraction for water supply

(Source: calculated from the data)

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Description Capacity (m3 /day)

Deep aquifer extraction 35006.5

Shallow aquifer extraction 3.3

Total 35009.8

Table 6: Status of Tube wells

Ward No.

Deep Tube wells Shallow Tube wells

Working Not workingWorking Not working

1 5 256 22 3 254 13 3 332 14 39 72 15 3 190 26 3 246 27 3 173 48 7 164 99 61 7 2

10 30 11

128 511 3 1 153 412 14 1 131 413 3 134 314 84 8 315 25 61 1016 82 13 -17 76 30 318 57 3 4 -19 43 7 21 420 57 5 35 821 42 3 68 1222 76 4 66 823 47 2 64 124 71 4 33 825 52 1 16 126 46 2 22 l27 57

25756

4529__ _ _

5__28 56 1 29 2

29 44 21 430 64 3 45 1431 83 7 2 4

Total 123953

53 2761 128(Source: Water Works Department, 2000)

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4.2 Storage and Distribution

4.2.1 Storage Facilities Reservoirs

There are five elevated water storage tanks with a total capacity of 2815 m 3 but

now three are running. The location of tanks is shown in Figure 4 and Table 7

shows the inventory of existing overhead storage tanks in KCC area.

Table 6: Inventory of Existing Overhead Tanks

SL. No. Location

Height of tank fromGL(m)

Maximumwater

level(m)

Storagecapacity(m3)

Material ofconstruction

1 Water Works 15.2 19.2 91 Steel

2 Ferry ghat 23 27.4 909 R.C.

3 H&S New colony 18.3 22.0 680 R.C.

4H&S Khalispur lal

hospital18.3 22.6 455 R.C.

5 DPHE 26.2 28.7 680 R.C.

Total 2815

(Source: KCC, 2001)

The main sources of water supply in KCC area are ground water. Above 90 percent

usage water is extracted from the ground with the help of production tube-wells, deep

and shallow tube-wells and other private tube-wells. There are only one surface water

treatment plant which generates 450 m3 /day and 43 production tube-wells. Besides,

there are five overhead tanks and 262 km of distribution lines.

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(Source: Water Works Department, 2000)

Figure 4: Location of overhead tanks and Deep water production well

- 22 -

N

4.3 Aquifer in Khulna City Corporation

The primary source of water supply in KCC area is mainly from the groundwater

extraction through production and hand tubewells. Only 30% of the house holds in KCC

area have access to the piped water supply, 64% have access to the hand tubewells and

only 6% use water from secondary sources. Groundwater in and around Khulna is

available in both shallow and deep aquifers. The depth of shallow aquifer varies from 0

to 100 meters and the deep aquifer varies from 150 meters to above 300 meters. Water

form deep aquifer is almost pure and free from salinity problem but the water of shallow

aquifers is highly saline and unfair for drinking purpose (KDA, 2005)

4.3.1 Aquifer Properties

Aquifer parameter data for the Study area are relatively Sparse. Based on Pump test

Data the aquifer properties of the upper aquifer namely transmissivity of Khulna city

area is 3900m3 and the Storage co-efficient is 2.O× 10 -3. Based on litho logy the

Specific yield of upper aquifer is 16.60%.

Table 8: Aquifer properties of The Upper aquifer of the study area:

Location

Derived from Litho-

logyDerived from pumping test

Specific yield in %Transmissivity in -

m2/dayStorage co-efficient×10 -3

Khulna 16.60 3900 2.0

(Source: HASSAN, 1992 GWC, BWDB, 1985 &1986)

4.3.2 Factors relating to the Water Potentiality of aquifers

The occurrence movement and storage of ground water are governed by the Litho

logy, geological structure, thickness and depth of occurrence of different geological

formation along with the tectonic activities prevailing in the area. The ultimate source

of most dissolved ions in water is the mineral assemblage in rocks near the land surface.

The purity of crystal -size of minerals, the rock texture and porosity, the regional structure,

the degree of fissuring and a good number of other factors might influence the

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composition of water passing over and through the rock (Hem, 1970).An understanding of

Landscape and its formation is essential for the demarcation of catchments boundaries,

assessment of surface and subsurface water resource and the planning of water

development projects for irrigation development. All these are relates with geology of that

area. Hence the important role of geology in assessing the hydrology and hydrochemistry

of an area cannot be over emphasized.

4.3.3 Natural Recharge of Aquifers

In the contest of the alluvial aquifer of Bangladesh, the usual method of evaluation of

available ground water resources is based on a calculation of recharge. Recharge is the

process by which water infiltrates during the wet season and restores in the groundwater

levels to field capacity. It is usually expressed as a depth of water per unit area, or as a

seasonally available volume. The groundwater System in the Study Area is considered to

be in hydrodynamic equilibrium condition, that is, the annual discharge is approximately

equal to the annual recharge. Recharge exceeds the discharge during the monsoon period

and the ground water rises but during the dry season recharge is considerably less than

discharge and then the ground water levels decline. The Area under study, the primary

source of natural research are taken to be direct infiltration of rainfall and flood waters

during monsoon, other potential sources such as ground water inflows are considered to be

negligible (UNDP,1982: MPO/Harza, 1986). This water infiltrates. and fills the

unsaturated zone created by the dry season groundwater level recession. The following

component and processes are involved in recharge and discharge mechanism of the

ground water System of the study area as well as Bangladesh (Hassan, 1992).

Recharge (R): Input

Components Processes

Rainwater: Runoff, infiltration and percolation

Floodwater: Runoff, infiltration and percolation

River water: Infiltration and percolation

Seepage water: Infiltration and percolation

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Discharge (D): out put

Components Processes

Artificial flow: By using different types of tubewells.

Natural Flow: By Steam flow activity (to river ponds and canal etc)

Capillary rise: By differential atmospheric pressure

Evapo-transpiration: By heat, temperature and light.

In Bangladesh , about 26% of the total annual groundwater recharge is being lost by

discharging into cannels, streams and rivers before the start of the irrigation season in the

month of November (KARIM, 1982) The runoff has been estimated as 20% to 40% of the

excess (P-PF) rain fall (UNUP, 1982).Considering the topographic configuration of the

study area it may be assume as minimum of 20% runoff of the excess rainfall that is

equivalent to 138.53 mm/anam.

The estimated annul ground water recharge of the study area is about 196.2 million cubic

meter, it can be considered as actual ground water research of the study area. The

available ground water recharge within this period can be calculated by 26% deducted

from the annual ground water recharge that is equivalent to 145.18 million cubic meter of

the area.

4.4 Other potential aquifer water sources near KCC area

Ground water in and around Khulna is available in both shallow and deep aquifers. The

shallow aquifers are extended towards north of Khulna town and well developed in the

west of Dumuria Upazilla and the deep aquifers are generally present below 150 to 300

m. The deep aquifer has been intensively exploited by production wells of KCC and to

some extent by industrial well and private hand tubewells.

Ground water supplies are available from the following sources within reasonable

distance from Khulna city which are shown in Figure 9.

(i) Khulna city area

The previous modeling study monitoring data suggest that a continuous abstraction of

59000m3/d of fresh water could be maintained for decades. However, at present the

shallow aquifer is only a reasonable source in the northern half of the city. The shallow

aquifer has been developed by a few production wells, numerous hand tubewells and

many private motorized tubewells.

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(Source: KCC, 2001)

Figure 5: Potential aquifer water sources in and around Khulna city

(ii) Rupsha area

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There are shallow ground water resources in this area. This area is expected to grow

rapidly after construction of the proposed Rupsha Bridge over the Rupsha river.

Therefore, the ground water resource can be developed in the future for the local needs.

(iii) Dumuria area

Both deep and shallow ground water are available in central Dumuria. At present

shallow tube-wells are used for irrigation purpose, which indicate, that there is a very

high productive shallow aquifer in the west of Dumuria. This source has probably

highest potential ground water resources around Khulna city (MSP, 1997).

(iv) Khalishpur-Phultala area

Both deep and shallow aquifers are available in the same area within a strip of a few

kilometers wide from the northern part of Khulna city to Phultala and beyond towards

Jessore. The shallow aquifer runs almost parallel to the river Bhairab and on either side

of the Khulna-Jessore road. The water quality in both aquifers is good. The transmission

distance and pipe lines to augment city water distribution system will be less and so the

development of ground water resources (both deep and shallow) in the area will be most

economic option for meeting the city demand. Short and medium term needs of the city

can be met by developing new wells in the area.

4.5 Discussion

Due to lack of sufficient data it is too tough to calculate the total aquifer status. But from

the collected data it can be calculated the daily extracted of water from the deep and

shallow aquifers. From the data it is found that the total water supply system is

depended on the aquifer water extraction. The extraction rate is sufficient and the total

water supply is dependent upon it. But considering the growing demand of water should

encourage people for more extraction of deep aquifer so that the shallow water is not

potable in every where.

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5. Development Strategy for Aquifer Water Sources

General strategy for further water sources development by the authority should follow

the following principles:

(i) Short term (0 to 5 years)

• Continuation of use ground water from the deep aquifer in and around Khulna.

• Development of new well fields for extracting water from the aquifers north of

Khulna in Khalishpur and Phultala area.

• Monitoring and evaluation of the impact of ground water development and increasing

abstraction.

(ii) Medium term (6 to 15 years)

• Increased withdrawal from the shallow and / or deep aquifers.

• Further development of new wells fields for extracting water from the aquifers north of

Khulna in Khalishpur and Phultala area.

• Continued monitoring and evaluation of the impact of ground water development and

increasing abstraction.

(iii) Long term (over 15 years)

• Further exploitation of available aquifer water resources in and around Khulna.

• Continued monitoring and evaluation of the impact of ground water development and

increasing abstraction.

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6. Conclusion

In this study it is found that the shallow aquifers are fully recharged during the rainy

season, and the major concerns with the shallow aquifer are the possibilities of salt

water intrusion and contamination of the aquifer by effluent released at the surface or to

leach pits. The major concern with the deep aquifer is that withdrawals should not

exceed die safe yields of the aquifer. To be environmentally sound, the impacts of water

withdrawal on the aquifer should be carefully monitored over the short term to

determine the impacts of sustained abstraction. But hydro-meteorological analysis

shows that Khulna having a tropical monsoon climate characterized by high

temperature, heavy rainfall, often excessive humidity and fairly marked seasonal

variations. The mean annual 1997 to 2001 rain fall is 1692.5 mm about 90% of the

annual rainfall were received from May to October.

For the development and management of aquifers of the study area, A detailed

climatologically, hydrological, and hydro-geological subsurface mapping is necessary to

be considered. The tropical monsoonal climate characterized by relatively high

temperature, heavy rainfall, excessive humidity etc is suitable for the ground water

potentiality.

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7. References

1. Ahmed, M. Feroze and Rahman. Md Mujibur, (2000). Water Supply &

Sanitation, ITN. Bangladesh. Publ, 1st Edition, p. 304-328.

2. Nazim Uddin. M., (2002), “A Study on water supply system of Khulna City.”

Environmental Science Discipline, KhulnaUniversity, Khulna. (Thesis Paper).

3. Sultana Nasrin, (2003). “Physico-chemical and Microbiological Aspects of

Drinking water- A Case Study on Khulna City Corporation, Khulna,

Bangladesh”. Environmental Science Discipline, Khulna University, Khulna.

(Thesis Paper).

4. KDA, (2000). Structure Plan, Master Plan and Detailed Area Plan for Khulna

City.

5. KCC, (2003). Monitoring Report, Water Supply Department.

6. NGO Forum, (2003). For drinking water supply and sanitation.

7. Hassan, M.Q, (1994). Long term rainfall distribution: A correlation between

1968 and 1990-72 periods of Jessore Khulna Region, southwest Bangladesh.

University press limited.

8. Brammer, H., (1996). The Geography of the soils of Bangladesh, The

University Press Limited.

9. Todd, D.K, (1980). Groundwater Hydrology, University of California,

Berkeley, John Wiley & Sons Publ, 2nd Edition, p. 267-312.

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