1. World Bank & Government of The Netherlands funded
Training module # 1
Understanding Conventional
and DWLR Assisted Water
Level Monitoring
New Delhi, March 2000
CSMRS Building, 4th Floor, Olof Palme Marg, Hauz Khas,
New Delhi – 11 00 16 India
Tel: 68 61 681 / 84 Fax: (+ 91 11) 68 61 685
E-Mail: dhvdelft@del2.vsnl.net.in
DHV Consultants BV & DELFT HYDRAULICS
with
HALCROW, TAHAL, CES, ORG & JPS

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Table of contents
Page
1. Module context 2
2. Module profile 3
3. Session plan 4
4. Main text 5
5. Overhead/flipchart master 6
6. Handout 7
7. Additional handout 8

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1. Module context
While designing a training course, the relationship between this module and the others,
would be maintained by keeping them close together in the syllabus and place them in a
logical sequence. The actual selection of the topics and the depth of training would, of
course, depend on the training needs of the participants, i.e. their knowledge level and skills
performance upon the start of the course. This is an independent module.

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2. Module profile
Title : Understanding Conventional and DWLR Assisted Water
Level Monitoring
Target group : Hydrogeologists, Asst-Hydrogeologists, Senior Technical Assistant
Duration : One Session of 30 minutes
Objectives : After the training the participants will be able to:
• Differentiate between conventional water level monitoring and
high frequency level monitoring.
Key concepts : • Prevalent water level monitoring
• High Frequency water level Monitoring
• True hydrographs
Training methods : Lecture
Training tools
required
: OHS
Handouts : As provided in this module
Further reading
and references
:

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3. Session plan
No Activities Time Tools
1 • Discuss the prevailing water level monitoring,
• Show the nature of the hydrograph emerging from
conventional monitoring
• Discuss the nature of aquifers being monitored,
• List the deficiencies of the conventional monitoring,
• Describe the advantages of dedicated piezometers over
hand dug wells
• Explain the need for high frequency monitoring and role of
DWLR,
• Explain a true hydrograph
15 min OHS
2 • Illustration 5 min OHS
3 Feedback 5 min
4 Wrap up 5 min

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4. Main text
Contents
1. Prevalent Monitoring 1
2. High Frequency Monitoring 2
3. True Hydrograph – What to do with it? 2

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Understanding Conventional and DWLR Assisted Water Level Monitoring
1. Prevalent Monitoring
Conventionally the groundwater monitoring in India has been conducted on the following
lines:
• Water levels are usually monitored in privately owned open dug wells tapping the upper
unconfined aquifers. These levels reveal the piezometric head/water table elevation of
the semi-confined/unconfined aquifers. However, the necessary well-aquifer hydraulic
connection is not always beyond suspicion.
• The frequency of monitoring has generally been restricted to four times in a year. These
times are rather arbitrarily selected during pre-monsoon, monsoon, post-monsoon and
winter seasons. It is presumed that these water levels represent the troughs and peaks
of the water table hydrograph. However, many a time these data may be too sparse to
yield reliable and credible water table hydrograph, as illustrated in figure 1. The figure
shows the true hydrograph (derived from high frequency DWLR data) superposed over
the corresponding hydrograph based upon four annual observations.
Fig 1: True Hydrograph from phreatic aquifer (Granitic rock), in Kattangur
Village, Nalgonda District Andhra Pradesh

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• Limited monitoring of the piezometric head of the deeper confined/leaky confined
aquifers has been carried out by some agencies, usually by observing the water level in
the deep production tube wells. The tube wells, many a time may not be adequately
isolated from (or worse, may even be tapping) the unconfined aquifer. Dedicated
piezometers tapping only the deeper aquifers and duly isolated from the unconfined
aquifer are almost non-existent.
The historical monitoring programmes though quite extensive and commendable in many
ways, have been deficit in several respects. The practising hydrogeologists have been
conducting the resource evaluations quite credibly in spite of these deficits. They have been
circumventing the problem by certain subjective practices based upon norms/past
experience or intuitive reasoning. Nevertheless, this has restricted their practice in many
ways. For example, no norms have been developed for estimating resource of the deeper
aquifers. (This estimation is no doubt difficult due to uncertainties regarding the recharge
zone, but lack of the piezometric head data has pre-empted its solution.) Similarly, since the
practitioners have never been able to view a true water table hydrograph, recharge
estimation by water balance of the unconfined aquifer gets uncertain in many ways. Further,
time series analysis of the water level data is not routinely done because the data at
necessary frequency are usually not available.
2. High Frequency Monitoring
The Hydrology Project has enabled construction of a large number of scientifically designed
piezometers tapping unconfined and the deeper aquifers. These piezometers have the
necessary hydraulic connection with the targeted aquifers and are suitably isolated from
overlying/underlying aquifers. Further, digital automatic water level recorders (DWLRs) are
installed in these piezometers. This ensures measurement of undistorted piezometric head
at the desired frequency, which may be much larger than the present frequency. In fact, the
frequency may be so high that the resulting piezometric hydrograph may almost be
continuous.
3. True Hydrograph – What to do with it?
With the high frequency and credible piezometric head data emanating from the
DWLRs, the groundwater practitioners in India shall have an access to true
piezometric head hydrographs, possibly for the first time. This is bound to inspire the
practitioners to enhance the scientific/technical content of their prevailing practice
and also to incorporate in it many new analyses. Some of the possibilities shall be
discussed subsequently.

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5. Overhead/flipchart master

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6. Handout

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7. Additional handout
These handouts are distributed during delivery and contain test questions, answers to
questions, special worksheets, optional information, and other matters you would not like to
be seen in the regular handouts.
It is a good practice to pre-punch these additional handouts, so the participants can easily
insert them in the main handout folder.