Dr. A.F.M Afzal Hossain1, PEng.

Saad Siddiqui2 PEng.

Md. Jakir Hossain3

Zannatul Ferdous Haque4

1Deputy Executive Director (P&D); 2Principal Specialist, HRD; 3Senior Specialist, IRM, 4Junior Engineer, R&D

Dr. A.F.M Afzal Hossain1, PEng.

Saad Siddiqui2 PEng.

Md. Jakir Hossain3

Zannatul Ferdous Haque4

Introduction Groundwater has been the main source of irrigation and other

uses using a large number of deep (DTW) and shallow

tubewell (STW) both by public and private initiatives

In recent years, decline of groundwater table is observed in

some areas due to over-abstraction of groundwater

Lowering of groundwater table during dry months creates a

problem for operation of STW and hand tubewell (HTW)

Many ponds and tanks become derelict due to lowering of

groundwater table creating shortage of water for both

domestic use and use by the livestock population

Arsenic contamination is also observed in some places of

shallow groundwater along major river banks.

Policy Issues

There are various water policies such as

National Water Policy (NWPo)

Integrated Water Resources Management (IWRM)

National Environmental Management Action Plan

(NEMAP)

Integrated Water Resources Management (IWRM) is aprocess which promotes the coordinated development andmanagement of water, land and related resources in orderto maximize economic and social welfare in an equitablemanner, holistically without compromising thesustainability of vital ecosystems and the environment

Groundwater is a component of IWRM strategies althoughoften neglected. The three E’s of IWRM (Economicefficiency, Environmental sustainability and social Equity)are the drivers of water sector reform, includinggroundwater

Integrated Water Resources Management (IWRM)

Sectoral Use of Groundwater (GW)

Source: http://www.fao.org/nr/water/aquastat/data/query/results.html

Environment9%

Agriculture

32%

Water Supply 3%

Instream56%

Source: WARPO

Proportion of Water Demand (2025)

Trend of Irrigation Water use in Bangladesh

0

1000

2000

3000

4000

5000

6000

19

79-

80

19

80-

81

19

81-

82

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82-

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99-

00

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00-

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20

01-

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20

04-

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20

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20

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20

07-

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20

09-

10

20

10-

11

Irri

ga

tio

n C

ove

rage

('0

00

Ha

)

Year

Trend of Irrigation Development in Bangladesh

SW Irri, GW Irri. Total Irri

Source: BBS, BADC, DAE & BMDA

Geomorphic divisions of Bangladesh

Alam et al, 1990

Groundwater Resources Monitoring

Groundwater monitoring comprises the collection,

analysis and storage of data on a regular basis to

provide information for effective groundwater

management to a variety of stakeholders.

Why Monitor?

Assess and control the impacts and risks of human activities on groundwater quantity and quality

Detect changes in groundwater storage, flow and quality during well field operation.

Bridge knowledge gaps in the general understanding of the resource and its changes in time .

Groundwater is also an indicator of climate change. Monitoring of groundwater levels and recharge rates will help build greater understanding of the resource and the possible impacts of climate change upon it.

Effective Groundwater Monitoring Effective groundwater monitoring should be driven by

a specific objective and the data collected should be systematically stored for future use

The effectiveness of groundwater monitoring may be improved by careful attention to

a) data collection network design b) system implementation and maintenance c) data management, interpretation and use d) accessible monitoring stationse) use indicator determinants to reduce analytical costf) participatory monitoring amongst water users

Groundwater Level Monitoring BWDB has a network of GWL monitoring using 117

Observation wells

IWM conducted a study in 2000 that was funded by JICA

This study was to monitor the groundwater level scenario in

central Dhaka as well as groundwater level at the peripheral

rivers surrounding Dhaka city

It was observed that the

groundwater depletion in central

Dhaka is about 3m whereas at the

peripheral rivers, the groundwater

level depletes 1.5-2m in dry period

Total Groundwater Abstraction (699 Mm3) of

Dhaka City

74%

18%

4% 4%

Domestic supply

Commercial supply

Industrial supply

Community supply

Abstraction balance by subsurface inflow,

vertical recharge and mining

86.29%

13.71%Subsurface inflow and

vertical recharge

Mining

Groundwater Abstraction in Dhaka city (2004-05)

Without conjunctive use1997 - Max depth, 25m

GW - 98%

Without conjunctive use2016 - Max depth, 45m

Population - 9.74 mill Abstraction - 507 Mm3

DTW - 387 Nos

Without conjunctive use2006 - Max depth, 35m

Population - 7.74 mill Abstraction - 408 Mm3

DTW - 312 Nos

With conjunctive use1997 - Max depth, 15m

SW - May-OctGW - Nov-Apr

-1500

-1000

-500

0

500

1000

1500

mm

1997

20062016

-3000

-2000

-1000

0

1000

2000

3000

4000

mm

19972006

2016

-1500

-1000

-500

0

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1000

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mm

20162006

1997

-3000

-2000

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0

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2000

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mm 1997

20062016

-800

-600

-400

-200

0

200

400

600

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mm

19972006

2016

-2500-2000-1500-1000-500

0500

10001500200025003000

mm

1997

20062016

-1500

-1000

-500

0

500

1000

1500

2000

2500

1 2 3

Abstraction

Recharge

Surplus

Deficit

Groundwater Balance of Dhaka City

Trend of Groundwater Development in Northwest Region

•Groundwater use for agricultural

production has significantly been

increased over the time in North-

west region

• The other areas where

groundwater is widely used are

the domestic and drinking

purposes

•Contribution of groundwater for

domestic water supply in rural

and urban towns in northwest

region is about 97%

•The wide spread use of

groundwater for drinking purpose

has resulted in significant

reduction in water borne diseases

like cholera, diarrhea, dysentery,

typhoid etc

•In some places of the north-west region, depth to groundwater table goes below 7.0

to 20.0 m

•During the peak time of recharge, groundwater table almost regains to its original

positions except some places of the area such as Tanore Thana

•In these areas, recharge is less compared to the total abstractions

•Decline of groundwater table is mainly occurred due to higher abstraction round the

year

Groundwater Level Monitoring in Coastal Region

-1.3

-1.1

-0.9

-0.7

-0.5

-0.3

-0.1

16-Mar-13 23-Mar-13 30-Mar-13 6-Apr-13 13-Apr-13 20-Apr-13 27-Apr-13

WL (

mP

WD

)

Date

Water LevelObservation Well no: 15, Well ID: KO_L_2_3

Groundwater Quality Monitoring

BWDB has a network of GWQ monitoring using 117 Observation wells

Similarly DPHE, BMDA and BADC have their own monitoring system

IWM installs and collects data from observation well using field kit and lab tests measuring the values of different parameter

The values of each parameter compared with standard for agriculture and drinking to see whether the qualities are within safe limits

In the north-west (NW) region a study was conducted by IWM

There is no Boron and Fluoride toxicity in the NW region

Manganese concentration is high in some places which might

create potability and palatability problems

Nitrate contamination in groundwater is noticed in areas where

open latrine is located in the vicinity of drinking water sources

such as a hand tube well

The study area possess no salinity problem except in a pocket

area of Manda Upazila under Naogaon district

In the early 90’s Arsenic contamination was observed in few

HTWs of Chapai-Nawabgonj district in the southwestern part

of the Barind area. However, in other part of the area, the

arsenic content of groundwater from DTWs is <0.01 mg/L

Groundwater Quality Monitoring in Coastal Region

500

1000

1500

2000

2500

21-Mar-13 28-Mar-13 4-Apr-13 11-Apr-13 18-Apr-13 25-Apr-13

EC

(µ

s/C

m)

Date

Electric Conductivity (EC)Observation Well no: 14, Well ID: KO_L_2_2

4000

4250

4500

4750

5000

5250

5500

5750

6000

1-Jan-13 16-Jan-13 1-Feb-13 16-Feb-13 4-Mar-13 19-Mar-13 4-Apr-13 19-Apr-13 5-May-13

EC

(µ

s/C

m)

Date

Electric Conductivity (EC)Observation Well no: 40, Well ID: KA_R_2_1

Under Joint Action Research project IWM collects data from observation wells

Constraints to GW use

Hard to Reach Areas for Water Supply in Bangladesh

Source: WSP, 2012

Relationship between Arsenic distribution and Geology of Bangladesh

BGS-DPHE, 2001 ; Alam et al. 1990

Distribution of Arsenic in Bangladesh

Source: DPHE/BGS/DFID, 2000

Groundwater Quality

Source: NWRD, WARPO, 2003

Why Use Groundwater Model

Groundwater models are mainly used for resource assesment

Groundwater models are also used to represent the naturalgroundwater flow in the environment

Groundwater models try to predict the fate and movement ofthe chemical

The models may be used to predict the effects of hydrologicalchanges (like groundwater abstraction or irrigationdevelopments) on the behavior of the aquifer

Groundwater models are used in various water managementplans for urban areas

Being able to model groundwater systems can be

tremendously useful for a wide range of applications

Using a model helps people visualize a system which they

cannot see, and it can illustrate key points of interest or be

used to gather information about a system

People who have difficulty understanding water use

policy and other issues sometimes benefit from instruction

with a groundwater model in which issues are visually

illustrated

Groundwater Modelling Tools:

IWM uses three complete packages of mathematical modelling. These are:

MIKE SHE

MODFLOW

FEFLOW

MIKE SHE is a fully distributed, physically-based

hydrologic model that can simulate water movement over

and under the earth's surface

MIKE SHE can be used for the analysis, planning and

management of a wide range of water resources and

environmental problems related to surface water and

groundwater

Five basic modules of MIKE SHE water movement are:

Overland Flow, Channel/River Flow, Evapotranspiration,

Unsaturated Flow and Saturated/Groundwater Flow

Evapotranspiration

Overland Flow

River Flow

Flow in Unsaturated Zone

Groundwater Flow

Approach

•US Geological Survey (USGS) originated Visual MODFLOW is

an easy-to-use modeling environment for practical applications in

three-dimensional groundwater flow and contaminant transport

simulations

• It is a finite difference model, which solves a system of

equations describing the major flow and related processes in the

hydrological system

• Visual MODFLOW simulates three-dimensional ground-water

flow through a porous medium by using a finite-difference

method

FEFLOW

FEFLOW is the first complete groundwater modeling

software package to successfully combine powerful graphical

features with sophisticated analysis tools and robust numerical

algorithms for:

Density-dependent flow (salt water intrusion)

Transient or steady-state flow

Saturated and unsaturated flow

Multiple free surfaces (perched water table)

Mass and heat transport

FEFLOW has been specifically designed to meet the advanced

technology requirements of expert modeling professionals

involved in complex groundwater modeling projects

B a y o f B e n g a l

Fourth Dhaka Water

Supply Project

Meghna Dhonagoda

Irrigation Project

North Bangla Deep

Tube Well Project

Modelling Technique used in Selected GW Projects

Conjunctive use Model

for SW/GW interaction in

CAD Project for Teesta Barrage

Pilot Conjunctive use Model

for SW/GW interaction in

lower Atrai

Deep Tube Well Installation

Project in Barind Area

BMDA Unit 2

BMDA Phase-III

Coverage of Coarse Groundwater Models at IWM

Case Study on GW Model in Barind Area (Phase-1)

Project Map of 25 Thana in Rajshahi, Nawabganj & Naogaon Districts

Project Covers 25 thana

of Rajshahi, Nawabganj

& Naogaon Districts

Total Area = 750,000 ha

Cultivable Area = 595,760 ha

Population = About 2 million

Rainfall ~ 1200 to 1700 mm

Nos of DTW = 6047

Nos of STW ~ 70,000

Data Collection & Processing

Topography, Cross Section Survey & Geo-referencing

Hydro-meteorological & Hydrological Data

Hydro-geological Investigation

Soil Sample Testing & Analysis

Percolation and Seepage in the Paddy Field

Hydro-Geochemical Investigation

Land Use and Vegetation

Water Abstraction and Irrigation by Different Modes

Objectives of the study

•Assessment of Thana wise available safe groundwater

resources and recharge potential using groundwater model

•Development of guidelines for effective Groundwater

Monitoring System

•Development of Management Information System to store,

review and analyze time series and spatial data

•Irrigation adoption based on model results for an efficient

planning and management of the groundwater resources

Model Calibration

.

Groundwater Level

Calibration Period: 1997-2003

INDIA

BMDA GW Well

BWDB GW Well

IWM GW Well

Model Calibration

Groundwater Level

Calibration Period: 1997-2003

INDIA

BMDA GW Well

BWDB GW Well

IWM GW Well

ObservedSimulated

Model Validation

Groundwater Level

Validation Period: 2004-2005

INDIA

BMDA GW Well

BWDB GW Well

IWM GW Well

Simulated Observed

FindingsThana Area (km2)

Available

Resource (mm)

Useable

Resource (mm)

Irr Requirement

Year: 2005 (mm)

Remaining

Water (mm)

Atrai 284 931 838 399 439

Badalgachi 214 607 546 437 109

Bagha 184 369 332 207 125

Bagmara 363 725 653 422 231

Bholahat 124 696 626 377 249

Charghat 165 343 309 368 -59

Dhamoirhat 301 296 266 462 -196

Durgapur 195 734 661 414 247

Godagari 472 231 208 295 -87

Gomastapur 318 189 170 180 -10

Mohadebpur 398 305 275 482 -208

Manda 376 553 498 251 247

Mohonpur 163 619 557 345 212

Nachole 284 405 365 206 159

Naogaon 276 564 508 455 53

Nawabganj 452 913 822 134 688

Niamatpur 449 236 212 290 -78

Paba 280 542 488 287 201

Patnitala 382 331 298 286 12

Porsha 253 335 302 105 197

Puthia 193 461 415 380 35

Raninagar 258 740 666 521 145

Sapahar 245 510 459 193 266

Shibganj 525 586 527 280 247

Tanore 295 180 162 280 -118

Conclusions of Case Study

It is beneficial to augment surface water irrigation. Groundwater condition is

greatly improved by augmented recharge from surface water irrigation

During peak time, groundwater table almost regains to its original positions

except some areas such as Tanore Upazilas. This is mainly due to higher

abstraction in monsoon period. At the same time, recharge is also less compare

to the total abstractions in these areas

Present withdrawals of groundwater to fulfill the requirement of Boro in excess

of potential recharges and available resources have created the tendency of

continuous lowering of groundwater level in some Upazilas. Monitoring of

groundwater level in these Upazilas need to be carefully continued for future

action

•Major knowledge gaps have been observed on uncertainty in the water

availability under climate change consideration, uncertainty in the upstream

withdrawal, occurrence of Arsenic, water utility, natural and environmental

water requirements

•Many research has already been conducted on Arsenic occurrence and

possible solutions, there are still considerable gaps in the understanding of

release mechanism

•Key areas for high priority research are implications for food safety of

irrigation with Arsenic contaminated water; the horizontal and vertical extent

of contamination;

•Another major issue is prediction of whether aquifer contamination will

change with time, cost-effective solutions for immediate mitigation and long-

term solutions

•The utility of groundwater depends on its quality, the level

from which it must be pumped and its sustainable yield

•Remarkable growth in groundwater use over the last two

decades, both for domestic and irrigation use, implies that

important planning considerations may be explored further

•Relationship between water and the natural environment is not

well understood

•The knowledge gaps exist in both national and basin level

• Filling gaps is seen as an essential and integral component to

meet the basin level water scarcity in future

•Groundwater

quality

particularly

salinity is a major

issue in the

coastal region as

well as in the pilot

areas

• An assessment

of the present

state of ground

water salinity has

been performed

using available

secondary source

data GW Salinity, Dry & Wet Period 2011-2012

Depth upto 150, Pilot Area-1

GW Salinity, Dry & Wet Period 2011-2012

Depth upto 150, Pilot Area-2

Database Development

Location of Nest Wells

Concluding Remarks

As groundwater resource is limited both qualitative and

quantitative monitoring of groundwater is required

Qualitative monitoring is required to assess whether the

groundwater recharge is adequate or not

If recharge is less than withdrawal then there will be

chance of groundwater mining which is alarming

Qualitative monitoring is required to assess whether all

the parameters are within the range or not

It is recognized that water resources problems cannot be

treated in isolation

The problems are seldom isolated and their solution

requires a holistic approach to water management that

must address different, often conflicting, demands for

water

Problems like wetland protection or the conjunctive use of

surface water and groundwater resources require the

integrated management of surface water and groundwater

together with the water chemistry and ecology

Regional model for Surface water is available. But there is no regional model for groundwater

Groundwater model for whole Bangladesh is required for coupling surface water and groundwater model

This will help predicting future scenario of groundwater resources