SPD-APCBTMP
Component 2 of Andhra Pradesh Community Based
Tank Management Project (APCBTMP)
Training Material for Training of
WUAs and PWs in Civil Works
TRAINING MODULE 2:
WATER BUDGETING &
CROP PLANNING
BANGALORE, ON BEHALF OF SPD-APCBTMP, I&CAD, GOVERNMENT OF ANDHRA PRADESH
PREPARED BY STEM - CENTRE FOR SYMBIOSIS OF TECHNOLOGY, ENVIRONMENT & MANAGEMENT,
SPD, PMU, APCBTMP~ STEM
INTRODUCTION
The ToT training is conceived to have components of imparting technical knowledge to the trainees, encouraging participation
and group activity, presentation by trainees for confidence building, demonstration through samples and field visits, field
exercises as a hands on training for the participants, feedback collection, participant assessment through quizzes and
observation on presentations made by them, documentation of these for each participant to assess their capability for
conducting training.
This training module 2 is of two days duration, a substantial part of it is devoted to learning by participation, group activity,
demonstration and quizzes/exercises. The program is designed to be as enjoyable as possible as against a drab lecture session.
The participants are expected to gain a near real life experience and actively participate, as there is no scope for passive
listening / being inattentive.
The program will in fact will be run by the participants with the resource persons being effective facilitators. The objective is to
inculcate an entrepreneurial attitude, actively participate, challenge and resolve practical issues.
The evaluation process for the ToT trainees will have elements of evaluating technical knowledge, comprehension and
communication skill, confidence to face an audience, handling questions, conduct himself / herself in an acceptable manner, so
that a team spirit is built in the whole process.
SPD, PMU, APCBTMP~ STEM
The evaluation process will have three components
(a) Quizzes – There will be quiz of 30 questions at the end of this module. The trainee will have 15 minutes to answer the
same. The quizzes will be based on only the sessions/PowerPoint concluded. The marks allotted for this component is 25
marks.
(b) Presentations – The purpose of organizing presentations by trainees / participants, groups will be formed of 4/5
persons each. Groups will be formed at the beginning of the training programme for each location and the group
composition will not be changed till the completion of the programme i.e., modules 1 to 5. The idea here is that each
trainee will have at least one opportunity to make a presentation which will be part of the evaluation. The marks allotted
for this component is 50 marks.
(c) Workbook exercise – After the training on module is concluded the trainees will conduct a field exercise and collect the
details as given in Part 1 Annexure 1. This will give the practical training of what is learned in the classroom. The marks
allotted for this component is 25 marks.
This module is divided into 2 parts
Part 1 – contains the programme schedule, session-wise plan and workbook exercise for module 2 which gives the
detailed agenda to train the FTs (WIs of SO) by STEM.
Part 2 – contains the programme schedule, session-wise plan and notes which the FTs will use/refer/follow to train the
WUAs/PWs.
SPD, PMU, APCBTMP~ STEM
ABBREVIATIONS
AE Assistant Engineer
AEE Assistant Executive Engineer
AP Andhra Pradesh
APCBTMP Andhra Pradesh Community Based Tank Management Project
APSRAC Andhra Pradesh State Remote Sensing Application Centre
CA Catchment Area
CE Chief Engineer
CIR Consumptive Irrigation Requirement
cm Centimetre
Cu Consumptive use of water
Cumec Cubic metre per second
Cusec Cubic feet per second
DPU District Project Unit
EE Executive Engineer
ft Feet
FTL Full Tank Level
GoAP Government of Andhra Pradesh
Ha Hectare
I&CAD Irrigation & Command Area Development
IS Indian Standards
m Metre
Mcft Million Cubic Feet
Mcum Million Cubic Metre
MI Minor Irrigation
PMU Project Monitoring Unit
PW Para worker
Re Effective Rainfall
SO Support Organization
SoI Survey of India
SPD State Project Director
Sq ft Square feet
SPD, PMU, APCBTMP~ STEM
TC Territorial Constituency
TOT Training of Trainers
WI Works Inspector
WUA Water Users Association
SPD, PMU, APCBTMP~ STEM
GLOSSARY
75% dependable yield – is the yield in which the reservoir receives the water
specified for 75 years out of 100 years.
Average Rainfall – The average of the previous 10 to 20 years rainfall.
Base period – The whole period of cultivation from the time irrigation water is first
issued, for the preparation of the ground for planting the crop to the last watering
before harvesting.
Capacity Table – it is the table which gives the volume of water stored in the
reservoir from full tank level to the minimum storage water.
Consumptive use of water - it is the amount of water required to meet evapo-
transpiration of crop.
Delivery method - The various delivery channels to be used such as presentation /
discussion / slide show/ role play/ demo.
Duration - estimated time in minutes for the session.
Keypoints - Describe what is to be said / knowledge to be imparted during
training.
Monsoon Period – June to December months of rainfall.
Resources, Visual aids required – Training resources such as White board /
Printed handouts / PowerPoint / Film / demo, site visit etc., required and kept ready
for use by the FTs in their training of WUAs and PWs
SOI Map – is a scale map (usually 1:50,000) developed by the Survey of India
indicating geographic features of the area such as tanks, roads, forest land, hills,
contours, drainage, etc., and available with the DPU.
Trainer’s note - Notes for the trainer to assist in delivery of module (eg. detailed
content/ knowledge to be imparted, etc.).
Yield from Rainfall: The quantity of water required received from its catchment at
a particular point of stream for rainfall of the year.
Part 1 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM
PART 1
Part 1 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM
PART 1 - CONTENTS
1. PROGRAMME SCHEDULE FOR THE 2-DAY TRAINING OF WIs ....................... 1
2. SESSION-WISE PLAN FOR THE 2-DAY TRAINING PROGRAMME.................... 7
Annexures
Annexure 1: Workbook Exercise ...................................................................... 21
Annexure 2: Feedback Form............................................................................ 23
Part 1 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM - 1
1. PROGRAMME SCHEDULE FOR THE 2-DAY TRAINING OF WIs
TRAINING MODULE 2: WATER BUDGETING AND CROP PLANNING
OBJECTIVE Impart knowledge on assessment of water availability for irrigation and planning of crop and
extent
DURATION 805 minutes
SESSIONS 11
NO. OF DAYS 2
PARTICIPANTS Works Inspectors
Part 1 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM - 2
Session
title and
No.
Key points Trainer’s note Delivery
method
Duration Resources,
Visual aids
required
Day 1
SESSION 1: Module 2
Brief of the Entire
Module 2
programme
The entire three day programme schedule will be
explained in brief. The objectives and desired outputs
of the module will be spelt out.
Presentation,
Discussion
30 Printed
Schedule
handout, PPT
SESSION 2: CATCH-MENT AREA
Calculation of
Catchment area and
yield from rainfall
If catchment area of the tank is missing from the tank
Particulars maintained by DPU, the same may be
ascertained from Survey of India (SoI) Map.
Independent and incepted catchment calculations from
SoI toposheets
Interactive lecture
discussion &
presentation
45 SOI sheet duly
marking
catchment of
the tank,
Drawing Sheet
and sketch
pens, PPT
SESSION 3: Exercise 1 – CATCH-MENT AREA
Exercise on
Calculation of
Catchment area and
Problems on independent and incepted catchments Guidance by
faculty,
presentation of
30 SOI sheet duly
marking
catchment of
Part 1 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM - 3
yield from rainfall work done by
trainees and
discussion
the tank,
Drawing Sheet
and sketch
pens
SESSION 4:
TANK
Tank Area Capacity
table, working table
percolation,
evaporation losses
The capacity of the tank is the volume of water that
can be stored below the FTL. The block level plan of
reservoir foreshore with contours at 1 ft (or convenient
interval) intervals is called a block level map.
Evaporation and percolation losses should be taken into
consideration.
Interactive lecture
discussion &
presentation
45 Drawing Sheet
and sketch
pens, cello
tape, Reservoir
area and
Contour map of
tank, PPT
SESSION 5:
Exercise 2 -
TANK
Exercise on Tank
Area Capacity table,
working table
percolation,
evaporation losses
Problems on the volume of the tank will be calculated
by plotting contours and determining the area between
two successive contours and Month-wise evaporation
and percolation
Guidance by
faculty,
presentation of
work done by
trainees and
discussion
50 Drawing Sheet
and sketch
pens, cello
tape, Reservoir
area and
Contour map of
tank
SESSION 6: Extent of area under
irrigation utilizing
The WUA has to monitor the water inflow regularly to Interactive lecture
discussion &
45 Block command
area plan with
Part 1 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM - 4
AYACUT the tank water assess water quantity in the tank. Based on availability
of water, the crop plan is to be prepared. The WUA has
to facilitate the planning process. The TC member and
farmers of each TC have to discuss and plan the crops
for each survey number, of their segment. During the
planning, the water requirements of various crops, the
availability of water in the tank system has to be
considered
presentation distributaries,
Drawing sheets
and sketch
pens, cello
tape, PPT
SESSION 7:
CROP
WATER
REQUIRE-
MENT &
DUTY OF
WATER
Water requirement
for the crop period
It is the responsibility of WUA before onset of monsoon
to plan for crops to be grown under the ayacut, based
on the estimated yield during the monsoon period. For
carrying out this exercise, the SO helps in
supplementing the capacity table for the tanks, and
75% dependable yields for the monsoon period. The
quantity of yield available for utilization is assessed
from the area and rainfall.
Duty represents the irrigation capacity of a unit of
water. It is the relation between area of crop irrigated
Interactive lecture
discussion &
presentation
60 Sketch pens,
Drawing sheets
Cello tape, PPT
Part 1 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM - 5
and the quantity of irrigation water required during the
entire period of the growth of that crop.
Problems on crop water requirement, etc.
Day 2
SESSION 8:
Recap of
Day 1
Highlights of Day 1 Summary and Issues & Problems Interactive lecture
discussion &
presentation
15 Block command
area plan with
distributaries,
Drawing sheets
and sketch
pens, cello
tape, PPT
SESSION 9:
PRESENTA-
TIONS
Entire Module
Presentations by
Trainees as groups
Entire batch of 42 trainees will be divided into 9/10
groups with 4/5 members in each group. Each Trainee
group will present the entire module to the rest of the
participants, to get acquainted with the training
process and building confidence. It will also help
identify weak areas and clarify those. Nine or ten
persons will volunteer/will be assigned (the objective is
to allow each trainee present so that their training and
Presentation
(100%
participatory)
245 PPT, board,
screen and
anything else
to the
presenter’s
choice
Part 1 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM - 6
communication skills can be assessed. Improvements
can be suggested so as to maximize the value from the
ToT training programmes.) The mock presentation will
also give an opportunity to assess each trainee on their
assimilation and their suitability for conducting training.
Session 10 Quiz A quiz will be prepared with 30 questions. The trainee’s
absorption level will be assessed. The trainee will have
15 minutes to answer the same.
Pen and Paper
Individual
assignments
30 Randomly
selected from a
pool of four
prepared
quizzes
Session 11 Concluding Session Summary of all the days sessions
Opinion of Trainee’s on the Training programme -
Feed back form
Presentation,
discussion
30 PPT
Note: a total of 90 minutes on each day of training is allocated for lunch and two tea breaks (one in the forenoon and afternoon)
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2. SESSION-WISE PLAN FOR THE 2-DAY TRAINING PROGRAMME
SESSION 1: Brief on Module 2
Keywords:
Sessions Overview
Delivery methods
Topic: Brief on module 2
Objectives: To Provide overview of the Module 2
Expected Outcome: Clear understanding of the sessions and the training program
Time Required: 30 Minutes
Material Used: Power point presentation
Tips for Trainer:
Before the start of each session, make sure the material required is available (mentioned under materials required)
Methodology:
The Delivery Method used will be Presentation explaining the program schedule and the session wise topics
Part 1 - Training Material for TOT – Module 2
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SESSION 2: Catchment Area of Tank
Keywords:
Catchment Area
Yield from rainfall
Survey of India Map
Watershed
Mainstream
Calculation of catchment area
Topic: Calculation of catchment area and yield from rainfall
Objectives:
To understand and calculate the catchment area and yield from rainfall
Expected Outcome:
Knowledge about the catchment area.
Calculation of catchment area.
Understanding the concept and calculation of yield from rainfall.
Time Required: 45 Minutes
Material Required:
SOI sheet duly marking catchment of the tank,
Brown Sheet and
Sketch pens.
Tips for Trainer:
Make sure the material required is available.
Initiate discussions about the catchment area and understand their level of clarity.
Part 1 - Training Material for TOT – Module 2
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During the session, show and explain the SOI map and catchment area.
Conclude with the key words and their understanding on same.
Methodology:
The Delivery Method used will be interactive lecture, Discussion & presentation highlighting the following
The catchment area using SOI maps
The methods for calculating catchment area
The key words and their understanding on same
Part 1 - Training Material for TOT – Module 2
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Session 3: Exercise 1- Catchment Area
Give MI tank Map from SoI sheet
WI to draw the catchment for the tank- draw a line along the ridge of the basin and the point on the river when we work- catchment
Transfer the fan shaped area to a graph sheet and assess the are for the given in SoI sheet
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Session 4: Tank Area Capacity
Keywords
Catchment Area
Tank water spread Area
Surplus weir
Tank Sluice
Conveyance System
Tank Area Capacity table
Tank Working table
Evaporation losses
Percolation losses
Full tank level
Contour Map
Topic: Tank are capacity - Tank Area Capacity table, percolation, evaporation losses
Objectives:
To make them understand tanks and its components in detail
To obtain knowledge about the capacity of tank, evaporation and percolation losses
Expected Outcome:
Gain knowledge and to become familiar with
Tank and its component
Catchment Area
Tank Working table
Tank Area Capacity table
Evaporation losses
Percolation losses
Contour Map
Part 1 - Training Material for TOT – Module 2
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Time Required: 45 minutes
Material Required:
Powerpoint presentation,
Brown Sheet,
Sketch pens,
Cello tape,
catchment area map and
Contour map of tank
Tips for Trainer:
Make sure the material required is available.
Initiate discussions about the Tank area, losses and the keywords and understand their level of clarity on keywords
Make list of points/ views raised and address them in detail.
During the session, show and explain with the maps of contour level map of tank.
Methodology:
The Delivery Method used will be interactive lecture, Discussion & presentation highlighting the following
The tank with the help of map.
Contour map, explain contour level map of tank, ayacut.
The method for calculating the capacity of the tank
The water losses in the tank due to percolation and evaporation
Month-wise percolation and evaporation losses from tank
The key words and their understanding on same.
Part 1 - Training Material for TOT – Module 2
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Session 5: Exercise 2 - Tank area capacity table, working table percolation, evaporation losses
Part 1 - Training Material for TOT – Module 2
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SESSION 6: AYACUT
Keywords:
Ayacut
Ayacut Contour Map
Extent of area under irrigation utilizing the tank water
Objectives: To understand the ayacut area
Expected Outcome: Gain Knowledge and familiarity of ayacut area
Time Required: 45 minutes
Material Required:
Command area plan with distributaries
Brown sheets
Sketch pens
Cello tape
Tips for Trainer:
Make sure the material required is available.
Discuss about the Ayacut and understand their level of clarity.
During the session, show and explain the Ayacut Contour Map.
Methodology:
The Delivery Method used will be interactive lecture, Discussion & presentation highlighting the following:
The Ayacut in detail with the help Ayacut contour map.
Key words and their understanding on same.
Part 1 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM - 15
SESSION 7: CROP WATER REQUIREMENT AND DUTY OF WATER
Keywords:
Crop planning
Water requirement for the crop period
Effective Rainfall
Consumptive irrigation requirement
Crop period
Base period
Duty of water
Different expressions of Duty of water
Factors affecting the duty
Objectives:
To have an understand on crop planning and water requirement for crop
To understand the different expressions of duty of water
To be familiar with the factors affecting the duty of water
Expected Outcome:
Planning of the pattern of crop and water requirement of crop
Familiarity to different expressions of duty of water
Time Required: 60 minutes
Material Required:
Sketch pens,
Brown sheets
Cello tape
Part 1 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM - 16
Tips for Trainer:
Make sure the material required is available.
Discuss about the crop planning.
List out the views and opinions on Brown sheet or board.
Methodology:
The Delivery Method used will be interactive lecture, Discussion & presentation highlighting the following
Crop planning
The effective rainfall and consumptive irrigation requirement for assessing the water requirement for crop
The concept of Duty of water with an illustration
The factors affecting the Duty
Conclude with the key words and their understanding on same.
Part 1 - Training Material for TOT – Module 2
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SESSION 8: Recap of Day 1
Summary and Issues & Problems:
Ayacut
Ayacut Contour Map
Catchment Area
Tank water spread Area
Surplus weir
Tank Sluice
Conveyance System
Tank Area Capacity table
Evaporation losses
Percolation losses
Time Required: 15 min
Material Required:
Powerpoint Presentation
Sketches
Brown Sheets
Sketch pens
Part 1 - Training Material for TOT – Module 2
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SESSION 9 : Presentations by Trainees as groups
Entire batch of 42 trainees will be divided into 9/10 groups with 4/5 members in each group.
Each Trainee group will present the entire module to the rest of the participants, to get acquainted with the training process and building confidence.
It will also help identify weak areas and clarify those. The groups will volunteer/will be assigned (the objective is to allow each trainee present so that their training and communication skills can be assessed).
Improvements will be suggested so as to maximize the value from the ToT training programmes.
The mock presentation will also give an opportunity to assess each trainee on their assimilation and their suitability & interest for conducting training.
Part 1 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM - 19
SESSION 10: Quiz
A quiz will be prepared on 30 questions. The trainee’s absorption level will be assessed. The trainee will have 15 minutes to answers the same.
Part 1 - Training Material for TOT – Module 2
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SESSION 11: Concluding Session
1. Summary on the sessions briefing the following:
Catchment Area ,Tank , Ayacut
Calculation of catchment area, yield from rainfall
Water requirement of crop
Duty of water
2. Workbook (Annexure 1)
Each trainee is required to fill the workbook exercise by visiting threetanks near his home location and the same will be submitted before the start of the next training programme i.e. after three weeks.
3. Feedback from the trainees is collected through a form (Annexure 2)
Part 1 - Training Material for TOT – Module 2
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Annexure 1: Workbook Exercise
Prepare working table for MI tank
Given:
1. Area capacity table
2. Monthly irrigation requirement - based on crop water requirement
3. Inflows - (take average of last 2 years)
4. Assume evaporation losses
MI TANK WORKING TABLE 2010-2011 (WATER YEAR)
Sl.No Month Tank at Start
Inflow
OutflowsEvapo-ration
Tank level
at End
Remarks
Irrigated Surplus Total
1 June1FN +135 - - - - - 1352FN +135 10 2 - -
2 July1FN +136 10 42FN 5 4
3 August1FN +137 30 52FN 45 5
4 September1FN +139 25 52FN 20 5
5 October1FN +140 - 52FN &T2 - 6
6 November1FN +139 - 62FN - 6
7 December1FN +137 - 52FN - 2
8 January1FN +136 -2FN -
9 February1FN -2FN -
10 March1FN +136 -2FN -
11 April1FN -2FN -
12 May1FN +137 -2FN -
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Sl.No Crop
Av. Water depth reqd. (in cm)
Kharif Crops1 Maize, high yielding 452 Bajra (spiked millets, or pearl millets), high yielding 303 Juar (Great millets), high yielding 304 Gound-nut 455 Cotton 25-406 Pulses like Arhar, etc 307 Transplanted Rice (Paddy), high yielding 125-1508 Til -
Rabi Crops1 Wheat (ordinary) 37.52 High yielding Wheat 453 Gram (high yielding) 304 Barley 302 Potatoes 60-906 Tabacco 607 Linseed i.e. Alsi 45-508 Mustard 45
Overlapping crop but generally classified under Rabi crop
1 Sugarcane 90
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Annexure 2: Feedback Form
TRAINING OF TRAINERS (TOT)ON
Component II of APCBTMP FOR WORKS INSPECTORS
Module Name Module number
Location Date
COORDINATOR: MR. BV SURANJAN REDDYMR. THIRUPAYYA
DURATION: 12TH – 14TH OCT,2009
NO. OF PARTICIPANTS:
FEEDBACK(Please do not write your name on the form)
Tick ( ) the following grade to fill the form
CONTENTS &COVERAGE
A –EXCELLENT B – GOOD C – AVERAGE D – NOT SATISFIED
TIME ALLOTTEDA – MORE B –ADEQUATE C –NOT ADEQUATE
1. EVALUATION OF COURSE SESSIONS
S. No. Session TopicRating
Contents & Coverage
Time Allotted
Day 1 A B C D A B C
1 Session 1: Brief on Module 2
2 Session 2: Catchment Area
3 Session 3: Exercise on Catchment Area
4 Session 4: Tank
5 Session 5: Exercise on Tank Area
6 Session 6: Ayacut
7 Session 7: Crop water requirement and duty of water
Day 2
8 Session 8: Recap of Day 1
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S. No. Session TopicRating
Contents & Coverage
Time Allotted
9 Session 14: Presentations by participants
10 Session 15: Quiz
11 Session 16: Concluding Session
2. EVALUATION OF FACULTY / RESOURCE PERSONS
Tick ( ) the following grade to fill the form
A – EXCELLENT B – GOOD C – AVERAGE
S.NO.
FACULTY / RESOURCE PERSON RATING
A B C
1 Mr. Suranjan Reddy
2 Mr. Thirupayya
3
3. EVALUATION OF COURSE
S.NO.
FACULTY / RESOURCE PERSON RATING
A B C
1 Teaching of the Course
2 Course Material Provided
3 Relevance of the Course for your Job
4 How Useful this Course been to Specific Requirements of your Job
5 Have your Expectations, which you had when you joined the course, fulfilled
4. FACILITIES PROVIDED
S.NO.
FACILITY RATING
A B C
1 Arrangements made
2 Support from Staff
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5. YOUR SUGGESTIONS TO IMPROVE THE COURSE
Part 2 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM
PART 2
Part 2 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM
CONTENTS
1. PREAMBLE ............................................................................................26
2. PROGRAMME SCHEDULE......................................................................28
3. CHECK LIST OF MATERIAL REQUIRED.................................................31
4. WORK PLAN..........................................................................................31
5. SESSION-WISE PLAN ...........................................................................32
6. NOTES...................................................................................................42
6.1. Water Budgeting.................................................................................... 42
6.1.1. Introduction .................................................................................... 42
6.1.2. Catchment Area of Tank .................................................................. 43
6.1.2.1. Calculation of Catchment Area ............................................................44
6.1.3. Tank ............................................................................................... 46
6.1.3.1. Block Levels ......................................................................................46
6.1.3.2. Capacity of a tank..............................................................................46
6.1.3.3. Losses ..............................................................................................47
6.1.4. Ayacut ............................................................................................ 48
6.2. Crop Planning........................................................................................ 49
6.2.1. Introduction .................................................................................... 49
6.2.2. Water Requirement for Crop............................................................. 50
6.2.3. Different expressions of Duty of water .............................................. 50
6.2.4. Factors Affecting Duty...................................................................... 51
6.2.4.1. Methods and System of Irrigation........................................................52
6.2.4.2. Mode of Applying Water .....................................................................52
6.2.4.3. Method of Cultivation .........................................................................52
6.2.4.4. Time and Frequency of Tilling .............................................................53
6.2.4.5. Type of the crop ................................................................................53
Part 2 - Training Material for TOT – Module 2
SPD, PMU, APCBTMP ~ STEM
6.2.4.6. Basic period of the crop......................................................................53
6.2.4.7. Climatic condition of the area..............................................................53
6.2.4.8. Quality of water.................................................................................53
6.2.4.9. Method of Assessment .......................................................................53
6.2.4.10. Canal Condition .................................................................................54
6.2.4.11. Character of Soil and Sub Soil of Canal and Irrigative fields ...................54
6.2.4.12. Topography of the land ......................................................................54
6.3. Water Charges....................................................................................... 55
6.4. Assessment methods ............................................................................. 56
6.5. References ............................................................................................ 58
6.6. Conversion Factors ................................................................................ 58
List of Tables and Figures
Table 1: Tank Duties for MI Works...................................................................... 45
Table 2: Average Evaporation Losses from AP Tank (Month-Wise) ....................... 47
Table 3: Monsoon Rainfall and No. of Fillings....................................................... 48
Figure 1: MI Tank Features................................................................................. 42
Figure 2: Catchment Plan ................................................................................... 43
Figure 3: SoI Map showing Catchment Area ........................................................ 46
Figure 4: Block Level Map of the Tank................................................................. 48
Figure 5: Ayacut Contour Map ............................................................................ 49
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1. PREAMBLE
I&CAD Department has initiated a programme to benefit 2.5 lakh ha of irrigated area
under 3000 minor irrigation tanks, at an estimated cost of Rs. 1000 crores, with
financial assistance from the World Bank and the Government of India, under the AP
Community Based Tank Management Project (APCBTMP).
The SPD, APCBTMP, I&CAD, has contracted STEM for “Conducting ToTs related to
Component-II of the APCBTMP Project”. Under this engagement, one of the items in
the ToR, is to review and revise the five training modules and material for
training WIs prepared by the PMU, as the PMU felt the need for the same.
The five modules are
o Joint azmoish, demand raising and collection of water charges
o Crop planning and water budgeting
o Works management
o Supervision of civil works, quality control / SEMF forms 4 and 6
o Awareness on O&M of irrigation system
This document on Module 2 describes crop planning and water budgeting which
includes Catchment area; Tank area; Ayacut; Crop Water Requirement; and Duty of
Water.
This training of WIs under the ToT is conceived to have sufficient material for the
FTs to train the WUA & PWs. The knowledge will be imparted to the trainees
through methodologies such as discussion cum presentation and demonstration
through, exercises, presentations by the trainees, so as to have hands on training
for the participants.
This training on module 2 is designed as a one-day programme, a substantial part of
it is devoted to learning by participation, demonstration and exercises. The training
is designed to be as enjoyable as possible as against a drab lecture session.
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Guidelines provided will enable the FTs to in turn deliver the content, to capacitate
the WUAs and PWs, to carry out their duties during the implementation as well as
the maintenance phase of the project.
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2. PROGRAMME SCHEDULE
OBJECTIVE Impart knowledge on assessment of water availability for irrigation and planning of crop and extent
DURATION 360 minutes
SESSIONS 6
NO. OF DAYS 1
PARTICIPANTS WUA Managing Committee and Water Management Sub-Committee
Session title and
No.Key points Trainer’s note
Delivery method
TimeResources, Visual aids required
SESSION 1: CATCH-MENT AREA
Calculation of Catchment area and yield from rainfall
If catchment area of the tank is missing from the tank particulars maintained by DPU, the same may be ascertained from Survey of India (SoI) Map. Independent and incepted catchment calculations from SoI toposheets
Interactive lecture discussion & presentation
45
SOI sheet duly marking
catchment of the tank,
Brown Sheet and sketch
pens
SESSION 2: Tank Area Capacity table, working table
The capacity of the tank is the volume of water that can be stored below the FTL. The block level plan of
Interactive lecture discussion &
45 Brown Sheet and sketch
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Session title and
No.Key points Trainer’s note
Delivery method
TimeResources, Visual aids required
TANK percolation, evaporation losses
reservoir foreshore with contours at 1 ft (or convenient interval) intervals is called a block level map. Evaporation and percolation losses should be taken into consideration.
presentation pens, cello tape, Reservoir
area and Contour map of
tank
SESSION 3: AYACUT
Extent of area under irrigation utilizing the tank water
The WUA has to monitor the water inflow regularly to assess water quantity in the tank. Based on availability of water, the crop plan is to be prepared. The WUA has to facilitate the planning process. The TC member and farmers of each TC have to discuss and plan the crops for each survey number, of their segment. During the planning, the water requirements of various crops, the availability of water in the tank system has to be considered.
Interactive lecture discussion & presentation
45
Block command area plan with distributaries, Brown sheets and sketch
pens, cello tape
SESSION 4: WATER
REQUIRE-MENT FOR
CROP
Water requirement for the crop period
It is the responsibility of WUA before onset of monsoon to plan for crops to be grown under the ayacut, based on the estimated yield during the monsoon period. For carrying out this exercise, the SO helps in supplementing the capacity table for the tanks, and 75% dependable yields for the monsoon period. The quantity of yield available for utilization is assessed from the area and rainfall.
Interactive lecture discussion & presentation
45
Sketch pens, Brown sheets
Cello tape
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Session title and
No.Key points Trainer’s note
Delivery method
TimeResources, Visual aids required
SESSION 5: DUTY OF WATER
Area that can be irrigated
Duty represents the irrigation capacity of a unit of water. It is the relation between area of crop irrigated and the quantity of irrigation water required during the entire period of the growth of that crop.
Interactive lecture discussion & presentation
45
Sketch pens, Brown sheets
Cello tape
SESSION 6: EXERCISE
Crop water requirement
1. Making of catchment area on the map and calculation of runoff
2. Calculation of Tank area and capacity3. Duty of water calculation and area that can be
irrigatedNote: copies of required maps (the participants will be divided into groups of 5 each headed by PWs)
Interactive discussion and
calculation135
SoI map, Tank maps
(contour), block command
area plan, graph paper
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3. CHECK LIST OF MATERIAL REQUIRED
Material required
1. SOI sheet duly marking catchment of the tank see notes
2. Tank area and Contour map of tank see notes
3. Block command area plan with distributariessee notes
4. Graph paper
5. 4 nos. Brown sheets
6. Sketch Pens (2 colours)
7. Cello Tape (1 roll)
8. Scissors (1 no)
4. WORK PLAN
Particulars/ Action to be
taken
Time in minutes-5 45 90 135 180 225 270 315 360
Introduction to ModuleSession 1 –Catchment AreaSession 2 -TankSession 3 -AyacutSession 4 – Crop Water RequirementSession 5 – Duty of WaterSession 6 -
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5. SESSION-WISE PLAN
SESSION 1: Catchment Area of Tank
Keywords:
Catchment Area
Yield from rainfall
Survey of India Map
Watershed
Mainstream
Calculation of catchment area
Topic: Calculation of catchment area and yield from rainfall
Objectives:
To understand and calculate the catchment area and yield from rainfall
Expected Outcome:
Knowledge about the catchment area.
Calculation of catchment area.
Understanding the concept and calculation of yield from rainfall.
Time Required: 45 Minutes
Material Required:
SOI sheet duly marking catchment of the tank,
Brown Sheet and
Sketch pens.
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Tips for Trainer:
Make sure the material required is available.
Initiate discussions about the catchment area and understand their level of clarity.
During the session, show and explain the SOI map and catchment area.
Conclude with the key words and their understanding on same.
Methodology:
The Delivery Method used will be interactive lecture, Discussion & presentation highlighting the following
The catchment area using SOI maps
The methods for calculating catchment area
The key words and their understanding on same
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Session 2: Tank Area Capacity
Keywords
Catchment Area
Tank water spread Area
Surplus weir
Tank Sluice
Conveyance System
Tank Area Capacity table
Tank Working table
Evaporation losses
Percolation losses
Full tank level
Contour Map
Topic: Tank and its components - Tank Area Capacity table, percolation,evaporation losses
Objectives:
To make them understand tanks and its components in detail
To obtain knowledge about the capacity of tank, evaporation and percolation losses
Expected Outcome:
Gain knowledge and to become familiar with
Tank and its component
Catchment Area
Tank Working table
Tank Area Capacity table
Evaporation losses
Percolation losses
Contour Map
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Time Required: 45 minutes
Material Required:
Brown Sheet
Sketch pens,
Cello tape,
catchment area map and
Contour map of tank
Tips for Trainer:
Make sure the material required is available.
Initiate discussions about the Tank area, losses and the keywords and understand their level of clarity on keywords
Make list of points/ views raised and address them in detail.
During the session, show and explain with the maps of block level map of reservoir.
Methodology:
The Delivery Method used will be interactive lecture, Discussion & presentation highlighting the following
The tank with the help of map.
Contour map, explain block level map of tank,ayacut.
The method for calculating the capacity of the tank
The water losses in the tank due to percolation and evaporation
Month-wise percolation and evaporation losses from tank
The key words and their understanding on same.
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SESSION 3: AYACUT
Keywords:
Ayacut
Ayacut Contour Map
Extent of area under irrigation utilizing the tank water
Objectives: To understand the ayacut area
Expected Outcome: Gain Knowledge and familiarity of ayacut area
Time Required: 45 minutes
Material Required:
Block command area plan with distributaries
Brown sheets
Sketch pens
Cello tape
Tips for Trainer:
Make sure the material required is available.
Discuss about the Ayacut and understand their level of clarity.
During the session, show and explain the Ayacut Contour Map.
Methodology:
The Delivery Method used will be interactive lecture, Discussion & presentation highlighting the following
The Ayacut in detail with the help Ayacut contour map.
Key words and their understanding on same.
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SESSION 4: CROP WATER REQUIREMENT
Keywords:
Crop planning
Water requirement for the crop period
Effective Rainfall
Consumptive irrigation requirement
Objectives:
To have an understand on crop planning and water requirement for crop
Expected Outcome:
Planning of the pattern of crop and water requirement of crop
Time Required: 45 minutes
Material Required:
Sketch pens,
Brown sheets
Cello tape
Tips for Trainer:
Make sure the material required is available.
Discuss about the crop planning.
List out the views and opinions on Brown sheet or board.
Methodology:
The Delivery Method used will be interactive lecture, Discussion & presentation highlighting the following
Crop planning
The effective rainfall and consumptive irrigation requirement for assessing the water requirement for crop
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SESSION 5: DUTY OF WATER
Keywords:
Crop period
Base period
Duty of water
Different expressions of Duty of water
Factors affecting the duty
Objectives:
To understand the different expressions of duty of water
To be familiar with the factors affecting the duty of water
Expected Outcome:
Familiarity to different expressions of duty of water
Time Required: 45 minutes
Material Required:
Sketch pens
Brown sheets
Cello tape
Tips for Trainer:
Make sure the material required is available.
Discuss about the different ways of expressing the duty of water
Explain the keywords with help of example.
List out the views and opinions on Brown sheet or board.
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Methodology:
The Delivery Method used will be interactive lecture, Discussion & presentation highlighting the following
The concept of Duty of water with an illustration
The factors affecting the Duty
Conclude with the key words and their understanding on same.
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SESSION 6: EXERCISE
Contents/Keywords:
Crop water requirement
Preparation of Catchment area map
Calculation of runoff
Calculation of Tank area and capacity
Duty of water calculation and area that can be irrigated
Objectives:
To understand the different expressions of Duty of water
To be familiar with the factors affecting the duty of water
Expected Outcome:
Crop water requirement
Contents:
Preparation of Catchment area map
Calculation of runoff
Calculation of Tank area and capacity
Duty of water calculation and area that can be irrigated
Time Required: 45 minutes
Material Required:
SoI map
Tank maps (contour)
Block command area plan
Graph paper
Carbon paper
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Tips for Trainer:
Make sure the material; copies of required maps are available.
Methodology:
The participants will be divided into groups of 5 each headed by PWs
Explain how to mark catchment area on the map
After marking the catchment area explain how to calculate runoff
Give an exercise for the calculating runoff
Explain the methods for calculating tank area and capacity, duty of water, and area that can be irrigated
Give an exercise for calculation of the above
Clarify the doubts if any in calculation
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6. NOTES
Key Words: Water budgeting, catchment area, survey of India map, monsoon rainfall, runoff,
coefficient of runoff, intercepted catchment areas, rainfall, tank, contour (block level) map, capacity
of tank, losses, ayacut, crop planning, water requirement of crop, duty of water, water charges,
assessment methods of water charges.
6.1. Water Budgeting
6.1.1. Introduction
The water budgeting is the process of keeping an account of irrigation water
available in the tank, and its utilization (ayacut) through regulation (See Figure 1).
The main objectives of the water budget are to:
a) Provide irrigation to the entire command area
b) Ensuring equity and dependability in water supplies, to all the farmers, in all
the reaches, in the command
c) Optimize production per unit quantity of water
Figure 1: MI Tank Features
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For efficient regulation and distribution of water, the WUA should have an idea of
the measurements of water required, distributed etc., through the water releasing
points. The project will install such measuring devices in all the tanks, and the
concerned competent authority and the SO staff, will impart training to the para-
worker for water management, in taking the measurements. Simultaneously, the SO
will also impart training on crop water requirements to the WUA members, to
facilitate preparation of cropping plan for the tank.
Water distribution at the field level is the most important issue that needs to be
planned and managed efficiently by the WUA. The water availability in the tank is
transparent and the farmers see inflows. In the project, it is proposed to strengthen
WUA with adequate capacity, to deal with the issue, under the existing traditional
practice. Based on the water available in the system, the water management Sub-
committee shall prepare the water distribution plan, in accordance with the demand
of the farmers.
The Subcommittee gets endorsement of plan from management committee. The
plan can be implemented through the lashkar (watermen). These watermen can be
government employees or traditional practitioner (Neeradi or Neeruganti).
6.1.2. Catchment Area of Tank
Figure 2: Catchment Plan
Mainstream
Tank location
Watershed
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Catchment area is the watershed area of a particular stream, at a particular point,
from which the rainfall is collected/stored (See Figure 2).
6.1.2.1. Calculation of Catchment Area
If catchment area of the tank is missing from the tank particulars (memoirs)
maintained by DPU, the same may be ascertained from Survey of India (SoI) Map
(See Figure 3).
The Average Rainfall of the area may be obtained from Rain gauge stations
/Isohyets given in IS Codes.
The yield from catchment may be determined from standard procedures available in
Chapter 2-Estimation of yield of V(b) Technical Operation Manual.
Normally the yield from catchment will be assessed from rain fall run-off relation,
taking the coefficient of run-off as 0.50 (as recommended by DPU).
Example 1: For an average monsoon, rainfall during (June to December) of 750
mm and Catchment Area (CA) of 1 sq km, the yield will be
= CA x average rainfall x coefficient of run-off
= 1000 x1000 x.750 x 0.50 = 0.375 Mcum (13.24 Mcft)
If there is another tank in the upstream of the tank, the area of catchment of the
upstream tank is called intercepted catchment area of this tank. For arriving at the
yield of this tank, 1/5 of the intercepted catchment area may be taken as free
catchment area, and may be added to the catchment area of tank under
consideration, for purpose of calculating yield.
Example 2: Suppose for the above example, there is also 5 sq km of incepted
catchment, than 1 sq km will get added as the free catchment area, and the total
catchment area for the tank will be 1+1 sq km (=2 x 106 sq m = 2 M sq m),
and hence the yield will be = 0.375 *2 = 0.750 Mcum (26.48 Mcft)
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Alternative: Instead of applying arbitrarily any factor of conversion from
intercepted catchment to equivalent free catchment, assume the whole Catchment
Area (CA) to be free and deduct the actual upper utilizations. Since the Master Plan
of each basin has already been prepared, this should be applied to in all cases. The
upper and lower utilizations may be calculated on the basis indicated below
(Table 1). The same basis was adopted while calculating yields in the Master Plan
records of various basins.
Table 1: Tank Duties for MI Works
Type of Crops Acre/Mcft Ha/Mcum
(i) For Irrigated wet crops (Kharif)
Upto 15"/38 mm Monsoon Rainfall 3 ½ 50
Above 15"/38 mm and up to 20"/50 mm 4 57
Above 20"/50 mm and upto 25"/64 mm 4 ½ 64
Above 25"/64 mm and upto 30"/76 mm 5 71
Above 30"/76 mm and upto 32.5"/82 mm 5 ½ 79
Above 32.5"/82 mm and upto 35"/89 mm 6 86
Above 35"/89 mm and upto 37.5"/95 mm 7 100
Above 37.5/95 mm and upto 40"/102 mm 7 ½ 107
Above 40"/102 mm and above 8 114
(ii) For irrigated Dry crops (kharif) upto 25"/64 mm monsoon rainfall 15 214
(iii) Above 25”/64 mm rainfall for irrigated Dry crops (kharif) 20 285
Note: Monsoon rainfall relates to rainfall occurring between months June to December both months inclusive.)
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Figure 3: SoI Map showing Catchment Area
6.1.3. Tank
A tank is a water body, where water gets collected from the catchment area and
stored. The physical structure of a tank consists of an earthen bund to store water, a
surplus system to let off excess flows safely, sluices to release water for irrigation,
and a tank bed to cover the water spread when the tank is full. The canal system
comprises of a main canal to carry water for irrigation of required discharge, and
field channels that carry water to the farmers’ field. In the present project only
minor irrigation tanks with more than 40 hectares of ayacut have been considered
for the restoration.
6.1.3.1. Block Levels
The block level plan of reservoir foreshore with contours at 1 ft (or convenient
interval) intervals is called a block level map (See Figure 4).
6.1.3.2. Capacity of a tank
The capacity of the tank is the volume of water that can be stored below the FTL. It
is generally expressed as Mcft or Mcum.
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The volume of the tank will be calculated by plotting contours and determining the
area between two successive contours. The volume or quantity between two
successive contours is given by
C= I/6 ∑ (A1 + A2 +√ (A1A2)) cubic units
Where C=Capacity of the tank in units (cubic feet)
A1 & A2 are the areas of two successive contours in Sq ft and I is the contour
interval in feet. Area capacity table shall be prepared for the tank and used for water
budgeting.
6.1.3.3. Losses
Evaporation and percolation losses should be taken into consideration. Table 2 gives
the loss of water from tank due to evaporation in mm month-wise.
Table 2: Average Evaporation Losses from AP Tank (Month-Wise)
Month Evaporation in mmJan 100Feb 100Mar 175Apr 225May 250Jun 175Jul 150Aug 150Sep 150Oct 125Nov 100Dec 100Annual loss 1800
Based on the yield calculations, the capacity of the tank shall be fixed as per
Table 3.
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Table 3: Monsoon Rainfall and No. of Fillings
Monsoon rainfallNo. of fillings
Areas influenced by NE Monsoon
Other areas in A.P.
38 mm (15”) 1 1
38-50 mm (15”-20”) 1 ¼ 1 ¼
50-64 mm (20”-25”) 1 ½ 1 ½
64-76 mm (25”-30”) 1 ¾ 1 ¾
76-89 mm (30”-35”) 2 2
89-102 mm (35”-40”) 2 ½ 2
Above 102 mm (>40”) 2
6.1.4. Ayacut
Ayacut is the area that can be irrigated from the water of the tank (See Figure 5).
Figure 4: Block Level Map of the Tank
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Figure 5: Ayacut Contour Map
The calculation for water requirement for the ayacut is present under duty of water
in the following section – crop planning.
6.2. Crop Planning
6.2.1. Introduction
The WUA has to monitor the water inflow regularly to assess water quantity in the
tank. Based on availability of water, the crop plan is to be prepared. The WUA has to
facilitate the planning process. The TC member and farmers of each TC have to
discuss and plan the crops for each survey number, of their segment. During the
planning, the water requirements of various crops, the availability of water in the
tank system has to be considered.
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6.2.2. Water Requirement for Crop
It is the responsibility of WUA before onset of monsoon to plan for crops to be
grown under the ayacut, based on the estimated yield during the monsoon period.
For carrying out this exercise, the SO helps in supplementing the capacity table for
the tanks, and 75% dependable yields for the monsoon period. The quantity of yield
available for utilization is assessed from the area and rainfall. The quantity of water
required for irrigating one hectare of land is based on type of crop, type of soils and
type of irrigation methods and base period of crops. Eg., (1) wet crops like paddy
require more water than dry crops like maize (2) sugarcane requires more water
than paddy per hectare.
In order to determine the irrigation requirements of a certain crop, the following
terms are defined
(1) Effective rainfall (Re) – Effective rainfall is that part of precipitation falling
during the growing period of the crop, that is available to meet the evapo-
transpiration needs of the crop.
(2) Consumptive Irrigation requirement – this is defined as the amount of
irrigation water, that is required to meet the evapo-transpiration needs of the
crop during its full grow.
CIR = Cu –Re
Cu is consumptive use of water
In addition to the above, water is lost in percolation in the field water course, field
channels & field application, and conveyance loss in the distributaries. The gross
irrigation is the sum of water required to satisfy the field irrigation requirement and
water lost, as conveyance losses in distributaries.
6.2.3. Different expressions of Duty of water
Duty represents the irrigation capacity of a unit of water. It is the relation between
area of crop irrigated and the quantity of irrigation water required during the entire
period of the growth of that crop.
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Delta is the total depth of water required by a crop during the entire period. The
crop is in the field and is denoted by the symbol ∆.
Example: If a crop requires about 12 waterings at an interval of 10 days and a
water depth of 10 cm in every watering, then the ∆ for that crop will be 12 x 10 =
120 cm = 1.2 m.
If the area of the crop is A hectares, the total quantity of water required will be 1.2 x
A = 1.2 A hectare-m in a period of 120 days.
Crop period is the time in days that a crop takes from the instant of its sowing, to
that of its harvest.
Base period – The whole period of cultivation by the time irrigation water is first released for the preparation of the ground for planting the crop, to the last watering before harvesting.
Kor Depth and Kor Period: The distribution of the water during the crop period isnot uniform. Crops require maximum water during first watering before sowing and after crops grow a few centimeters. There after, water requirement graduallyreduces and is least when crop gains maturity, the first watering is known as Kor watering and depth applied is known as Kor depth. The portion of the base period in which Kor watering is needed is known as Kor period. The discharge in the canal is maximum during this period and the capacity of this canal shall be designed to meet the requirement.
Duty of water is reckoned in the following 4 ways
(1) No. of hectares/acres that one cumec/cusec can irrigate i.e., (a) 1700 hectares per cumec (b) 120 acres per cusec
(2) By total depth of water 1.2 m or 43”
(3) No. of hectares/acres that can be irrigated by 1 Mcum/ 1 Mcft of stored water. This system is used for tank irrigation.
(4) By no. of hectare-m/acre-ft expanded by per hectare/acre irrigation.
6.2.4. Factors Affecting Duty
The duty of water of canal system depends upon variety of the factors. The Principal factors are:
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1) Method and System of Irrigation
2) Mode of applying water to the Crops
3) Methods of Cultivation
4) Time and Frequency of Tilling
5) Type of Crop
6) Base Period of the Crop
7) Climatic Condition of the Area
8) Quality of Water
9) Method of Assessment
10)Canal Conditions
11)Character of Soil and Subsoil of the Canal and Irrigated Fields
12)Topography of the Irrigated area
6.2.4.1. Methods and System of Irrigation
In the Perennial Irrigation System, soil is continuously kept moist and water required for initial saturation is less. Due to shallow depth of water table deep percolation losses are less. Inundation Irrigation system, there is wasteful use of water flow. This system has lower duty due to conveyance losses in the network of the canals.
Lift Irrigation system has higher duty as the command area is close to the water source.
Tank Irrigation gives higher duty due to rigid controls.
6.2.4.2. Mode of Applying Water
Flood irrigation system has lesser duty than the furrow system. Sub Irrigation system gives still higher delay. The basin Irrigation and uncontrolled flooding gives less duty.
6.2.4.3. Method of Cultivation
If the land is properly ploughed and made quite loose before irrigating, the soil will have higher water retention capacity in its unsaturated zone. Thus the number of waterings can be reduced, increasing the duty.
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6.2.4.4. Time and Frequency of Tilling
Frequency of cultivation reduces the loss of moisture through weeds. Soil structure affects the plant growth to a very great extent. A good structure (good arrangementof soil particles in relation to one another) is called good tilts of soil. When the soil is in good tilts, evaporation losses from the surface of soil is less, soil becomes properly aerated and yield of crop is better
6.2.4.5. Type of the crop
The duty varies from crop to crop and Kharif to Rabi.
6.2.4.6. Basic period of the crop
If the base period of crop is more, the amount of water required will be high, hence the duty will be low and vice-versa.
6.2.4.7. Climatic condition of the area
The climatic conditions which affect duty are
i) Temperature
ii) Wind
iii) Humidity
iv) Rainfall
Due to high temperature and wind, evaporation losses will be more and duty will be less. Rainfall during crop period will reduce the irrigation water requirement and duty will thus be higher. Duty exclusive of rainfall may also be considered.
6.2.4.8. Quality of water
If the harmful salt content and alkaline content of water is more, water will have to be applied liberally so that the salts are leached off. These will in turn reduce duty. More fertilizing matter in water will cause less consumption of water and increase duty.
6.2.4.9. Method of Assessment
Volumetric method of assessment always leads to higher duty. This is because the farmer will use water economically. It the method of assessment is based on the area under cultivation, the farmer will have a tendency to use more water and the duty will be low.
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6.2.4.10. Canal Condition
In the unlined canals, the seepage and percolation losses will be high, resulting in low duty. For lined canals the losses will be less and duty will be high. The dispersion of the Irrigated areas with respect to the canal tends to reduce the duty.
6.2.4.11. Character of Soil and Sub Soil of Canal and Irrigative fields
If the soil and sub soil of canal/field is coarse grained, seepage/percolation losses will be high. Fine grained soils reduces the seepage, losses will be low and hence the duty will be higher.
6.2.4.12. Topography of the land
If the filed is not level the lower portion get more water, the higher portion may remain drier. In order to supply water to the higher patches, more water will be used and the duty will be reduced.
Example: If 75% dependable inflow during the monsoon period is 5 Mcum, then
the capacity of the tank shall be 2.5 Mcum taking into consideration two fillings.
The area that can be irrigated with 5 Mcum for various crops are given below.
Kharif paddy 71 Ha/Mcum 5x71=355 Ha
Rabi paddy 36.64 Ha/Mcum 5x36.64= 183 Ha
Sugarcane 29.16 Ha/Mcum 5x29.16 = 145 Ha
Therefore the area to be irrigated will depend on the volume of water available and
crops planned. The WUA in its General Body Meeting, before monsoon, decides the
period of crop and estimate of water required, and accordingly inform the concerned
PW for regulation of water.
Example: In AP, Paddy will be grown under Tank irrigation. The duty for Paddy will
be expressed as follows.
1. 1 cusec discharge – Irrigates 50 Acres
2. Water at 0.43 “/day during crop period i.e., 100 days
The water required for 1 acres is 0.43/12x100 x 4840x9 = 156090 cft
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Considering evaporation and conveyance losses 1.2 x 156090 = 0.20 Mcft. The Duty for Paddy is 0.20 MCFT /acres. Similarly the duty for sugarcane,which needs water for 365 days is
The stored water can Irrigate = 34.84 / 0.20 = 174.20 acres
If Command area is more than this, we have to go in for change in cropping Pattern.
Taking the No. of fillings during Monsoon as 2, the capacity of tank shall be= 34.84 / 2 =17.42. Considering dead storage as 10% the Gross storage of Tank =17.42 x 1.10 =191.20 Say 200 Mcft
The WUA review the inflows, outflows and storage of tank every fortnight and
suitable remedial measures are taken to save water, if there is a shortfall in inflows
or extra area is irrigated, if water is available.
6.3. Water Charges
Before harvesting, the WUA and the AE/AEE will have joint inspection and prepare
the list of survey number-wise extent of crop irrigation, in that Fasli (year). This list
includes registered and unregistered ayacut. The list will be sent to EE for raising the
water tax. The EE after verifying the area based on remote sensing maps of
APSRAC, send the list to the revenue department for raising the demand and
collection of tax. This listing is called Joint Ajmoish (Please refer module1).
The water bodies i.e. the tanks, are the property of Government. Therefore the
water which has been supplied for irrigation to the farmers is at the Government’s
expense. Some nominal charges must therefore be paid by the farmers for using this
water. The fixation of such charges is known as assessment of irrigation water. The
return on capital investment is based upon such water charges.
The charges are levied on the farmer for the following reasons
(1) To recover cost of construction of the tank and the associated infrastructure i.e., repayment of loan
(2) To meet O&M cost of works
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(3) To check cultivation against uneconomical and careless use of water
The methods of assessment are
(1) Crop wise area basis
(2) Volumetric assessment
(3) Seasonal basis
(4) Composite rate basis
(5) Permanent assessment
Penalties (for unauthorized irrigation) may go up to 6 times normal charges.
Almost all tank irrigated lands are assessed for water on crop wise area basis. The
rates for different crops have been fixed on the basis of
(1) Cash value for crops and its paying capacity
(2) Water requirement of crops
(3) Time of demand for water (available, supplies in tank i.e., monsoon and non-monsoon).
The normal rates of water tax1 are
(1) Wet crop Rs. 100/acre - Kharif
(2) Wet crop Rs. 100/acre – Rabi
(3) Dry crop Rs. 60/acre - Kharif
(4) Dry crop Rs. 60/acre – Rabi
(5) Two wet crops Rs. 350/acre
6.4. Assessment methods
Following are the usual methods used to arrive at water charges
(1) The system of assessment on the area basis has the following disadvantages.
The cultivator near the head reaches, use more water and deprive the
1 Fixed by the Government
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cultivators at tail-end reaches. Since the charges are not levied on the basis of
actual quantity of water used the cultivator makes wasteful use of water.
(2) Volumetric assessment involves charges on actual volume supplied. It has
disadvantages of meters having to be fixed, meters not working properly,
meter readings to be taken and pilferage of water.
(3) Season based assessment on the type of crop grown and crop season.
(4) Composite rate basis is a combination of water charges and the land revenue.
Some states prefer to collect both revenues together and hence the name.
(5) Permanent assessment by betterment levy basis – the farmers of that area
where the water body is improved, will be levied at a fixed rate every year for
such provisions for some years.
(6) The water tax collected must at least be sufficient to maintain the regular
O&M works under that water body. 90% of water tax is ploughed back to the
WUA, for maintenance of O&M works.
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6.5. References
1) Civil Engineers Hand Book, Association of Engineers I & CAD-1998
2) Irrigation and Water Power Engineering, Dr.B.C.Punmia & Dr. Pande, B.B.Lal
3) APCBTMP- Operational Manuals Volume I WUA manual- Annexure I
a. Volume I WUA Manual – Annexure I
b. Volume Vb Technical Manual – Chapter 2 Estimation of Yield
6.6. Conversion Factors
1. Length1 inch = 25.4 mm1 foot = 0.3048 metres1 metre = 3.280 ft1 mile = 1.609 km
2. Area =1 sq.ft = 0.092903 sq.m1 sq.m = 10.7639 sq ft1 hectare = 2.4711 acres1 acres = 0.4046 hectares1 sq.mile = 2.5889 sq.km
3. Volume1 cft = 0.028317 cu.m1 Cum = 35.315 cft1 TMC (thousands million cft) = 28.317 mcum (million cubic metre)1 cumec (cubic metres per sec) = 35.315 cubic ft per second