GUIDELINES

FOR

BENCHMARKING PERFORMANCE

IN THE

IRRIGATION AND DRAINAGE SECTOR

 

 

 

 

 

 

IPTRID Secretariat

FAO

Rome, Italy

December 2000

 

Summary

 

These guidelines are supplementary to the concept note entitled: Benchmarking performance in the irrigation and drainage sector.

The guidelines provide the detailed information required to collect, process and analyse data collected under the benchmarking programme.

 

 

 

 

 

 

 

 

 

Acknowledgements

 

Acknowledgements and thanks are extended to those authors and organizations mentioned in the bibliography that have provided assistance in the compilation of these guidelines.

 

Contents

Summary*

Acknowledgements*

Contents*

Introduction*

Purpose*

Context*

Categorization of schemes*

Data collection and analysis*

Data requirements*

Data capture*

Data units*

Data processing and analysis*

Partner benchmarking analysis*

Partner internal analysis*

Comparative analysis*

Programme implementation*

Data handling framework*

Central processing*

Data and information exchange*

Roles and responsibilities for implementation*

Selection of benchmarking partners*

Bibliography*

APPENDICES*

Appendix A1Performance indicators*

Appendix A2Protocols for data collection and processing*

Introduction

Purpose

The purpose of these guidelines is to assist in the process of data identification, collection, entry, processing and analysis for the irrigation and drainage benchmarking exercise.

The intention is that they will be used by those responsible for data collection, processing and analysis within the organization.

Context

These guidelines follow on from the benchmarking concept note prepared in October 2000. It is assumed that the concept note has been read.

The guidelines relate to the second and third stages (Figure 1) identified in the concept note, namely Data Collection and (Data) Analysis.

 

Figure 1: Stages of the benchmarking process

 

 

 

 

 

 

 

 

 

 

 

 

 

Categorization of schemes

So that comparisons may be made between irrigation and drainage schemes they need to be categorized into similar types. There are a variety of ways this can be done. Following are some typical categorization headings:

In order to group the schemes being benchmarked, background data are required as listed in Table 1 below. This table contains several system descriptors, which must be entered in the corresponding worksheet. Figure 2 shows the spreadsheet proforma for data entry.

 

Data collection and analysis

Data requirements

In any system, such as an irrigation network, there are:

In measuring performance we are interested in the efficiency with which we convert inputs to outputs, and the potential impacts that (a) the use of these inputs (resources) might have and (b) that the outputs might have on the wider environment. We are also interested in the efficiency with which the processes convert inputs to outputs.

 

There are a variety of irrigation domains (or systems) in which we are interested. The Concept Note outlined three that are of primary interest:

 

A more detailed discussion on these performance domains can be found in the accompanying document entitled Benchmarking performance in the irrigation and drainage sector.

Thus the performance indicators that are proposed for use in the benchmarking exercise are linked to these three domains, and their inputs, processes, outputs and impacts.

There are many performance indicators that might be used in this context. For the benchmarking exercise only key performance indicators will be used. These are indicators that, like the share price of a company on the stock exchange, give a usable indication of performance.

An additional factor, which needs to be considered, is the boundaries of the domains that are being benchmarked. The boundaries relate to the physical boundaries and to the depth or detail the indicators are considered. In general, to benchmark the physical boundary there will be a hydraulically independent system. Information will be summarized for the whole system.

The key performance indicators proposed for the benchmarking exercise are presented in Table 2.

 

 

Table 1: System descriptors

Code

Descriptor

Possible options

Location

 

D1

Country

D2

Continent

 

D3

Scheme name

D4

Latitude

 

D5

Longitude

 

Climate and soils

 

D6

Climate

  • Arid

  • Semi-arid

  • Humid

  • Humid tropics

D7

Average annual rainfall (mm)

D8

Average annual reference crop potential evapotranspiration, Etc (mm)

D9

Peak daily reference crop potential evapotranspiration, Etc (mm/day)

 

D10

Predominant soil type(s) and percentage of total area of each type

  • Clay

  • Clay loam

  • Loam

  • Silty clay loam

  • Sand

Institutional

 

D11

Year first operational

 

D12

Type of management

  • Government agency

  • Private company

  • Joint government/local organization/private
  • Water Users Association/Federation of WUAs

D13

Agency functions

  • Irrigation and drainage service

  • Water resources management

  • Reservoir management

  • Flood control

  • Domestic water supply

  • Fisheries

  • Other

D14

Type of revenue collection

  • Tax on irrigated area

  • Charge on crop type and area

  • Charge on volume of water delivered charge per irrigation

D15

Land ownership

  • Government

  • Private

Socio-economic

 

D16

(National) Gross Domestic Product (GDP)

 

D17

Farming system

  • Cash crop

  • Subsistence cropping

  • Mixed cash/subsistence

D18

Marketing

  • Government marketing board

  • Private traders

  • Local market

  • Regional/national market

D19

Pricing

  • Government controlled prices

  • Local market prices

  • International prices

Water source and availability

 

D20

Water source

  • Storage on river

  • Groundwater

  • Run-of-the river

  • Conjunctive use of surface and groundwater

D21

Water availability

  • Abundant

  • Sufficient

  • Water scarcity

D22

Number and duration of irrigation season(s)

Number of seasons

Number of months per season:

  • Season 1:
  • Season 2:
  • Season 3:

Size

 

D23

Commanded (irrigation) area (ha)

D24

Total number of water users supplied

D25

Average farm size (ha)

D26

Average annual irrigated area (ha)

D27

Average annual cropping intensity (%)

Infrastructure – Irrigation

 

D28

Method of water abstraction

  • Pumped diversion

  • Gravity diversion

  • Groundwater

D29

Water delivery infrastructure (length and %)

  • Open channel

  • Pipelines

  • Lined

  • Unlined

D30

Type and location of water control equipment

Type:

  • None
  • Fixed proportional division
  • Gated - manual operation
  • Gated - automatic local control
  • Gated – automatic central control

Location:

  • Control structure at main intake only
  • Control structures at primary and secondary level
  • Control structures at primary, secondary and tertiary level.

D31

Discharge measurement facilities location and type

Location:

  • None

  • Primary canal level

  • Secondary canal level

  • Tertiary canal level

  • Field level

Type:

  • Flow meter

  • Fixed weir or flume

  • Calibrated sections

  • Calibrated gates

Infrastructure – Drainage

 

D32

Area service by surface drains (ha)

D33

Type of surface drain

  • Constructed

  • Natural

D34

Length of surface drain (km)

  • Natural

  • Constructed

  • Open

  • Closed

D35

Area serviced by sub-surface drainage (ha)

 

D36

Number of groundwater level measurement sites

 

Water allocation and distribution

 

D37

Type of water distribution

  • On-demand

  • Arranged-demand

  • Supply orientated

D38

Frequency of irrigation scheduling at main canal level

  • Daily

  • Weekly

  • Twice monthly

  • Monthly

  • Seasonally

  • None

D39

Predominant on-farm irrigation practice

  • Surface – furrow, basin, border, flood, furrow-in-basin;

  • Overhead – raingun, lateral move, centre pivot

  • Drip/trickle

  • Sub-surface

Cropping

 

D40

Main crops each season with percentages of total command area

 

 

Figure 2: Proforma worksheet for entry of system descriptors

Data capture

To ensure consistency in the comparison of results, organizations joining the benchmarking programme will need to collect the data required for the calculation of the benchmarking indicators according to the specifications and protocols provided in Appendix A2.

Partner organizations will carry out the primary data processing to convert raw data into the format required for input into the benchmarking spreadsheet. This task must be carried out according to the instruction provided.

The spreadsheet workbook provided to benchmarking partners consists of six worksheets containing data in the following categories:

 

Indicator values in the summary worksheet are calculated automatically after the basic data are entered into the appropriate worksheet without user intervention.

Appendix A2 provides for each indicator the definition, measurement specification, processing needs and an example of the data entry spreadsheet.

Two types of indicators can be considered according to the type of data required:

  1. Indicators based on primary data

  2. Indicators based on secondary data

Some indicators are based on primary data that the organization must collect either as a normal part of its operation or for the specific purpose of benchmarking. Variables such as inflow volumes, revenues collected from water users, and total operation expenditure fall into this category.

Some other indicators rely on the use of secondary data for their calculation. For example, the calculation of evapotranspiration (Etc) relies on climatic data for the location of the irrigation scheme that must be provided in the format specified by the methodology for calculating Etc. This type of data may be collected either by the partner organization itself or an external organization. Wherever data are procured from an external organization special attention must be paid to the data processing methodology. This is particularly important when data auditing is necessary to trace possible calculation errors.

 

Data units

In order that the data can be compared across different irrigation systems the data should be presented in the units specified in the data protocol sheets in Appendix A2. Data may be collected and processed locally in different units, but should be converted into the required units before entering into the database.

Where currency conversions have been made into United States dollars (US$) the rate and date should be provided in a footnote. If different rates and dates are used for individual calculations the rate and date for each should be shown.

Table 2: List of proposed key performance indicators

Domain

Performance indicator

Data required

Service delivery performance

Total annual volume of irrigation water delivery (m3/year)

Total daily measured water delivery to water users

Annual irrigation water delivery per unit command area (m3/ha)

Total daily measured water inflow to the irrigation system

Total command area service by the irrigation system

Annual irrigation water delivery per unit irrigated area (m3/ha)

Total daily measured water inflow to the irrigation system

Total annual irrigated crop area

Main system water delivery efficiency

Total daily measured water delivery to water users

Total daily measured water inflow to the irrigation system

Annual relative water supply

Total daily measured water inflow to the irrigation system

Total daily measured rainfall over irrigated area

Total daily/periodic volume of crop water demand, including percolation losses for rice crops

Annual relative irrigation supply

Total daily measured water inflow to the irrigation system

Total daily/periodic volume of irrigation water demand (crop water demand less excluding effective rainfall), including percolation losses for rice crops

Water delivery capacity

Current main canal capacity

Peak month irrigation water demand

Security of entitlement supply

System water entitlement

10 years minimum water availability flow pattern

Financial

Cost recovery ratio

Total revenues collected from water users

Total management, operation and maintenance (MOM) cost

Maintenance cost to revenue ratio

Total maintenance expenditure

Total revenue collected from water users

Total MOM cost per unit area (US$/ha)

Total management, operation and maintenance expenditure

Total command area serviced by the system

Total cost per person employed on water delivery (US$/person)

Total cost of MOM personnel

Total number of MOM personnel employed

Revenue collection performance

Total revenues collected from water users

Total service revenue due

Staffing numbers per unit area (persons/ha)

Total number of MOM personnel employed

Total command area serviced by system

Average revenue per cubic metre of irrigation water supplied (US$/m3)

Total revenues collected from water users

Total daily measured water delivery to water users

Productive efficiency

Total gross annual agricultural production (tonnes)

Total tonnage produced under each crop

Total annual value of agricultural production (US$)

Total annual tonnage of each crop

Crop market price

Output per unit serviced area (US$/ha)

Total annual tonnage of each crop

Crop market price

Total command area serviced by system

Output per unit irrigated area (US$/ha)

Total annual tonnage of each crop

Crop market price

Total annual irrigated crop area

Output per unit irrigation supply (US$/m3)

Total annual tonnage of each crop

Crop market price

Total daily measured water inflow to the irrigation system

Output per unit water consumed (US$/m3)

Total annual tonnage of each crop

Crop market price

Total volume of water consumed by the crops (ETc)

Environmental performance

Water quality: Salinity (mmhos/cm)

Electrical conductivity of periodically collected irrigation water samples

Total daily measured water inflow to the irrigation system

Electrical conductivity of periodically collected drainage water samples

Total daily measured drainage water outflow from the irrigation system

Water quality: Biological (mg/litre)

Biological load of periodically collected irrigation water samples

Total daily measured water inflow to the irrigation system

Biological load of periodically collected drainage water samples

Total daily measured drainage water outflow from the irrigation system

Water quality: Chemical (mg/litre)

Chemical load of periodically collected irrigation water samples

Total daily measured water inflow to the irrigation system

Chemical load of periodically collected drainage water samples

Total daily measured drainage water outflow from the irrigation system

Average depth to watertable (m)

Periodic depth measurement to watertable

Change in watertable depth over time (m)

Periodic depth measurement to watertable over 5 year period

Salt balance (tonnes)

Periodic measurement of salt content of irrigation water

Periodic measurement of salt content of drainage water

Data processing and analysis

Partner benchmarking analysis

Much of the data analysis involves compiling ratios of the data collected to produce the value of the required performance indicator. This task will be performed by the spreadsheet template provided. Partner organizations will be responsible for processing the raw data collected in conformance with the protocols outlined in Appendix A2. It is recognized that past data collected by partner organizations may have been collected in a variety of formats that may not necessarily comply with these specifications. In such cases, IPTRID will provide specialized assistance to ensure that data are processed in a comparable manner.

 

Partner internal analysis

In some cases the partner organization may wish to pursue the data analysis further by using statistical methods to analyse internal trends. This type of analysis may be especially useful in trying to explain causative factors of low performance. This might be the case, for example, with data on Delivery Performance Ratios (DPR) taken at tertiary off take points throughout the irrigation network, where the weekly average DPR values might be statistically analysed to obtain seasonal trends or variability (coefficient of variation). Whilst this analysis can be of considerable (internal) value to the partner organization, it is not required for establishing a comparative analysis with other organizations.

 

Comparative analysis

The essence of the benchmarking process is to provide organizations with the ability to compare their performance in relation to similar organizations or similar processes. The comparative analysis will consist primarily of ranking performance levels for individual indicators both numerically and graphically. Table 3 and Figures 2, 3, 4, and 5 provide an example of comparative analysis carried out by the Australian benchmarking programme. A similar type of analysis will be carried out in this programme.

Table 3: Selection of data collected and analysed in Australian benchmarking exercise (ANCID, 2000)

Scheme

name

 

 

 

Irrigable area

 

 

ha

Area irrigated

 

1998/99

ha

Irrigation deliveries

 

1997/98

ML

Irrigation deliveries

 

1998/99

ML

Main system water delivery efficiency

%

Gross revenues

1998/99

 

000 A$

Total number of MOM personnel

No.

Average depth to water-table

m

Cost recovery ratio

 

 

Operating cost/ Revenue

 

%

Maintenance cost/ Revenue

 

 

%

Total cost of water supply

 

A$/ML

Average depth delivered to users

m

Gross revenue per unit area

 

A$/ha

Coleambally

97 000

68 694

445 673

457 000

81.2

6 530

46

3.3

0.665

0.10

Jemalong

18 334

14 940

62 795

42 423

70.9

1 522

7

3.3

1.23

52

8

29.14

0.284

0.10

Murray Irrigation

796 764

0

1 045 658

1 167 755

79.5

19 125

124

3.6

1.37

29

28

14.5

0.000

0.00

Murrumbidgee

480 000

180 000

949 935

823 229

79.7

28 225

243

n/a

1.23

24

24

32.3

0.457

0.16

West Corurgan

212 000

21 000

84 372

66 178

87.5

1 926

9

4

1.17

63

5

24.23

0.315

0.09

Barker-Barambah

0

8 650

9 285

100

199

3

n/a

82

73

62.14

0.107

0.02

Boyne River

0

3 265

6 412

63.6

130

4

n/a

5

14

22.77

0.196

0.04

Bundaberg

55 579

59 200

144 352

91 605

100

6 550

37

n/a

26

42

64.4

0.155

0.11

Burdekin River

23 980

47 846

430 002

375 233

87.4

10 104

41

4

28

23

21.24

0.784

0.21

Condamine

0

11 500

58 354

100

433

6

n/a

2.38

75

45

14.34

0.507

0.04

Dawson

7 021

7 529

40 089

14 622

100

153

11

n/a

290

277

88.98

0.194

0.02

Emerald

19 054

23 509

168 760

79 263

98.6

3 663

20

n/a

8

24

25.05

0.337

0.16

Eton

12 000

15 000

37 711

1 789

43.8

802

11

n/a

32

719.67

0.012

0.05

Logan

4 000

3 996

4 072

100

449

4

n/a

51

97.47

0.102

0.11

Lower Mary River

5 110

6 190

20 337

1 928

92.8

207

3

n/a

43

133

283.71

0.031

0.03

Mareeba-Dimbulah

15 415

22 140

119 044

72 531

67.1

4 004

26

n/a

24

30

38.5

0.328

0.18

Pioneer Valley

0

0

12 111

1 047

100

6 189

4

n/a

1.54

5

1

459.41

0.000

0.00

Prosperine

9 000

11 250

1 039

100

1 229

2

n/a

3

9

288.95

0.009

0.11

South Burdekin

27 450

13 428

67 432

32 964

41

1 505

6

n/a

0

0.245

0.11

St George

13 084

17 289

60 697

98 987

91.8

1 654

20

n/a

40

32

14.96

0.573

0.10

 

Warrill

8 170

8 170

4 986

100

503

5

n/a

58

22

120.55

0.061

0.06

Central Irrig. (SA)

11 000

11 000

87 000

94 553

99.1

5 797

23

n/a

1.52

21

18

51.22

0.860

0.53

Golden Heigths

738

723

6 029

6 531

100

816

4

1.5

1.4

0

0.903

1.13

Lower Murray

0

0

56 000

100

0

9

n/a

0.93

0

0.000

0.00

Sunlands

900

794

6 700

8 255

100

918

5

1.2

1.1

75

7

89.42

1.040

1.16

Cressy-Longford

4 000

2 000

6 182

3 821

100

207

3

n/a

0.53

135

54

102.07

0.191

0.10

Southeast (Tas)

3 800

1 373

2 490

2 280

100

422

2

n/a

0.28

283

50

616.23

0.166

0.31

Winnaleah

5 967

1 226

4 844

3 485

100

236

2

n/a

2.56

239

17

173.6

0.284

0.19

First Mildura

8 058

6 667

51 077

54 307

81

4 586

27

n/a

1.2

20

15

67.17

0.815

0.69

G-MW Murray Valley

128 268

81 410

342 612

374 519

69.5

8 736

46

3.1

1.25

18

19

18.61

0.460

0.11

G-MW Shepparton

82 460

54 140

211 352

174 904

66.5

4 994

31

3.4

0.96

20

30

31.03

0.323

0.09

G-MW Cent. Goulburn

172 131

119 592

472 618

410 623

69.6

10 830

65

2.3

1.07

19

27

29.07

0.343

0.09

G-MW Rochester

117 066

66 730

263 233

225 007

87.8

4 930

39

2.5

1.08

22

20

27.6

0.337

0.07

G-MW Pyramid-Boort

186 481

109 018

277 672

230 555

81.3

4 716

32

1.9

0.8

28

27

25.64

0.211

0.04

G-MW Torrumbarry

173 366

130 152

479 173

551 619

72.9

11 418

81

1.5

1.19

20

18

19.22

0.424

0.09

G-MW Nyah

1 616

1 035

6 196

6 755

91.1

508

6

n/a

1.26

37

18

59.22

0.653

0.49

G-MW Tresco

1 902

884

4 946

5 431

94.3

403

2

1.5

1.29

27

25

67.02

0.614

0.46

G-MW Woorinen

2 804

0

6 522

6 489

69

540

3

1.5

1.11

17

45

84.3

0.000

0.00

Bacchus Marsh

1 834

1 300

4 520

2 688

68.8

501

3

n/a

18

18

218.01

0.207

0.39

Macalister

55 000

37 387

133 000

138 150

62.3

5 525

31

n/a

19

19

37.96

0.370

0.15

Werribee

3 366

3 010

11 212

9 009

82.7

1 370

7

n/a

14

15

156.9

0.299

0.46

Sunraysia

10 672

10672

102 410

85 278

81.2

11 382

60

3.1

1.48

27

19

91.49

0.799

1.07

Wimmera-Mallee

3 100

0

19 584

17 183

54.2

15 123

7

2

1.44

14

16

110.7

0.000

0.00

Carnarvon

2 000

950

2450

1 400

88.9

2 829

16

n/a

0.88

62

0

630.63

0.147

2.98

Ord River

13 000

13 000

180 000

210 000

75

1 600

18

4

43

42

5.48

1.615

0.12

South West (WA)

112 000

9 780

81 176

83 098

71.5

4 072

27

n/a

1.31

25

19

32.41

0.850

0.42

Note: A$1 = US$0.55 (2000 prices)

 

Figure 3: Example of comparative plot of irrigation water delivery

Figure 4: Example of comparative plot of water delivery efficiencies

 

Figure 5: Example of comparative plot of gross revenue per unit irrigated area

Figure 6: Example of comparative plot of cost recovery ratios

Programme implementation

Data handling framework

There will be two levels of data handling within the benchmarking programme, which will involve the partner organization itself and the Central Database and Processing Unit (CDPU). Basic data will be collected and processed by the partner organization before it is entered into the benchmarking database according to the protocols provided in Appendix A2.

The relation between partner organizations and the CDPU is depicted in Figure 7. This structure is designed to maximize the flexibility of data collection and the ability to share data between the partner organizations. It is envisaged that data sharing through the CDPU will subsequently encourage "one-to-one" exchange of data and information between the partner organizations. The CDPU will host a Website that will be maintained by IPTRID and IWMI.

Partner organizations will have two options to capture data either:

  1. directly into the tailor-made benchmarking template via the Internet, or

  2. into a tailor-made benchmarking template provided on a computer disk.

Once the data have been entered on the disk the disk can be sent via the Internet or posted to the CDPU and will become part of the IPTRID central benchmarking database.

The CDPU will have two functions:

    1. warehousing benchmarking databases from partner organizations to enable data sharing; and,

    2. host software and carry out comparative performance analysis.

At least in the initial stages of the programme, the CDPU will periodically be required to produce printed reports, which will be made available to those benchmarking partners, which may not have access to Internet facilities.

 

Central processing

Data and information exchange

The main aim of the benchmarking programme is to enable the partner organizations to access data and information that has been collected and presented in the comparative format. The CDPU will enable the partner organizations to access individual databases (spreadsheets) submitted by other partner organizations and present comparative analyses carried out from the partners’ spreadsheets. A proposed map of the Central Benchmarking Website is shown in Table 4.

 

Figure 7: Data collection and transmittal framework

 

 

 

 

 

 

 

 

 

Roles and responsibilities for implementation

The implementation of the benchmarking programme will rely on the establishment of a loose network of partner organizations centrally coordinated by the IPTRID Programme and assisted by the World Bank, IWMI and ICID.

IPTRID will have overall responsibility for coordinating and providing support to the benchmarking partner agencies. It will coordinate and assist the development and implementation of data collection by the benchmarking partners and exchange protocols to ensure transportability of results between partners. IPTRID in collaboration with IWMI will also be responsible for establishing and maintaining the Central Database and Processing Unit whose responsibilities have been outlined above. Where necessary, IPTRID will provide benchmarking partners with specialized assistance for implementation of the programme.

The World Bank will provide overall support for the programme through IPTRID and direct assistance to country agencies when appropriate.

IWMI will develop and manage the database on behalf of IPTRID, building on their previous experience with comparative performance assessment of irrigation and drainage systems.

The ICID will provide general support for programme dissemination and advocacy, support to partner organizations and dissemination through a Task Force formed by members of the Working Group on Development and Management of Irrigation Systems, the Working Group on Irrigation and Drainage Performance as well as national committees involved in this programme. In cases where the partner organization requires assistance with communication, exchange and transmittal of data with the CDPU national committees members may be able to assist with this task. ICID National Committee members can also play an important role facilitating the exchange of information and data directly between partner organizations.

Periodic reviews of the programme will be required to ensure that the programme remains flexible and relevant to the benchmarking partners. New performance indicators may need to be added in the future to ensure that emerging issues in irrigation and drainage are reflected in the programme.

 

Selection of benchmarking partners

In principle the decision to join the benchmarking initiative must be taken by the partner organizations themselves. However, benchmarking is a tool of management to improve the performance of service delivery, productivity of agriculture and environmental performance; and as such, certain criteria must be met in order to gain benefits from this activity.

Whilst the criteria for selection of partners in the benchmarking initiative must be flexible, it is desirable in the initial stages of the programme to minimize the spread of physical and managerial characteristics of the participating irrigation schemes. Relevant criteria for the selection of partners are considered to be:

 

 

Institutional and managerial criteria:

 

Physical criteria

 

 

Bibliography

 

ANCID. 2000. 1998/99. Australian Irrigation Water Provider – Benchmarking Report. Victoria, Australia. 68 pages.

ARMCANZ. 1999. The 1997/98 Australian Irrigation Water Provider Benchmarking Report. 51 pages.

Abernethy, C.L. 1990. Indicators and criteria of the performance of irrigation systems. Paper presented at the FAO Regional Workshop on Improved Irrigation System Performance for Sustainable Agriculture, Bangkok, Thailand, 22-26 October.

Bottrall, A.F. 1981. Comparative study of the management and organization of irrigation projects. World Bank Staff Working Paper No. 458, World Bank, Washington D.C.

Bos, M.G., Murray-rust, D.H., Merrey, D.J., Johnson, H.G. and Snellen, W.B. 1994. Methodologies for assessing performance of irrigation and drainage management. Irrigation and Drainage Systems, Vol. 7, Kluwer Academic Publishers, The Netherlands.

Bos, M.G. and Nugteren, J. 1990. On irrigation efficiencies. 4th edition. ILRI Publication 19, International Institute for land Reclamation and Improvement, Wageningen.

Bos, M.G. 1997. Performance assessment for irrigation and drainage. Irrigation and Drainage Systems, Vol.11, Kluwer Academic Publishers, The Netherlands.

Burt, C.M. and Styles, S.W. Modern water control and management practices: Impact on performance. Water Report 19, FAO/IPTRID/World Bank, published by Food and Agriculture Organization, Rome.

Dastane, N. D. 1974. Effective rainfall in irrigated agriculture. FAO Irrigation and Drainage Paper. 61 pp, Rome. Food and Agriculture Organization, United Nations.

LWRRDC. 1998. Report of the national programme for irrigation R&D benchmarking project. Land & Water Resources Research & Development Corporation, Canberra, Australia.

Malano, H. & Hofwegen, P.V. 1999. Management of Irrigation and Drainage Systems: A Service Approach. IHE Monograph 3. A. A. Balkema. The Netherlands. 149 pages.

Molden, D. 1997. Accounting for water use and productivity. SWIM Paper 1, International Irrigation Management Institute, Colombo.

Molden, D.J. and Gates, T.K. 1990. Performance measures for evaluation of irrigation water delivery systems. Journal of Irrigation and Drainage Engineering, ASCE, Vol. 116 (6).

Molden, D.J., Sakthivadivel, R., Perry, C.J., de Fraiture, C. & Kloezen, W. 1998. Indicators for comparing performance of irrigated agricultural systems. Research report 20, International Water Management Institute, Colombo.

 

 

Murray-Rust, D.H. & Snellen, W.B. 1993. Irrigation system performance assessment and diagnosis. Joint IIMI/ILRI/IHEE Publication, International Irrigation Management Institute, Colombo, Sri Lanka.

Oad, R. & McCornick, P.G. 1989. Methodology for assessing the performance of irrigated agriculture. ICID Bulletin Vol.38, No. 1, International Commission on Irrigation and Drainage, New Delhi, India.

Rao, P.S. 1993. Review of selected literature on indicators of irrigation performance. IIMI Research Paper No.13, International Irrigation Management Institute, Colombo.

Sakthivadivel, R., de Fraiture, C., Molden, D.J., Perry, C. & Kloezen, W. Indicators of land and water productivity in irrigated agriculture. Water Resources Development, Vol. 15, No.1 and 2.

Smith, M. 1990. Introduction to irrigation system performance: Comparative analysis of case studies. Paper presented at the FAO Regional Workshop on Improved Irrigation System Performance for Sustainable Agriculture, Bangkok, Thailand, 22-26 October.

Small, L.E. & Svendsen, M. 1992. A framework for assessing irrigation performance. IFPRI Working Papers on Irrigation Performance No.1, International Food Policy Research Institute, Washington, D.C., August.

Wolters, W. & Bos, M.G. 1990. Irrigation performance assessment and irrigation efficiency. 1989 Annual Report, International Institute for Land Reclamation and Improvement, Wageningen.

Zhi, Mao. 1989. Identification of causes of poor performance of a typical large-sized irrigation scheme in South China. ODI/IIMI Irrigation management Network Paper 89/1b, Overseas Development Institute, London.

 

 

 

 

 

 

 

 

APPENDICES

 

 

 

 

 

 

Appendix A1 Performance indicators

IPTRID-BM-Guidelines-Appendices Rev1.doc

mab 30.4.2001

 

 

 

 

 

 

 

APPENDICES

 

 

 

 

 

 

Appendix A1 Performance indicators

 

SERVICE DELIVERY PERFORMANCE

 

(a) System operation

Indicator

Definition

Data specifications

Total annual volume of irrigation water delivery (m3/year)

Total volume of water delivered to water users over the year or season. Water users in this context describe the recipients of irrigation service, these may include single irrigators or groups or irrigators organized into water user groups.

Measured at the interface between the irrigation agency and water users.

 

Annual irrigation water delivery per unit command area (m3/ha)

Total annual volume of irrigation water inflow

Total command area serviced by the system

Total annual volume of irrigation water inflow:

Total annual volume of water diverted or pumped for irrigation (not including diversion of internal drainage).

 

Total command area serviced by the system:

The command area is the nominal or design area provided with irrigation infrastructure that can be irrigated.

 

Annual irrigation water delivery per unit irrigated area (m3/ha)

Total annual volume of irrigation water inflow

Total annual irrigated crop area

Total annual volume of irrigation water inflow:

Total annual volume of water diverted or pumped for irrigation (not including diversion of internal drainage).

 

Total annual irrigated crop area:

The total irrigated area cropped during the year.

 

 

Main system water delivery efficiency

Total annual volume of irrigation water delivery

Total annual volume of irrigation water inflow

Total annual volume of irrigation water delivery:

Total volume of water delivered to water users over the year or season. Water users in this context describe the recipients of irrigation service, these may include single irrigators or groups or irrigators organized into water user groups.

Total annual volume of irrigation water inflow:

Total annual volume of water diverted or pumped for irrigation (not including diversion of internal drainage).

 

 

 

 

Annual relative water supply

 

 

Total annual volume of total water supply

Total annual volume of crop water demand

Total annual volume of total water supply:

Total volume of surface diversions into the scheme and net groundwater abstraction for irrigation, plus total rainfall, excluding any recirculating internal drainage water within the scheme.

Total annual volume of crop water demand:

Total annual volume of water used by the crop to meet evapotranspiration demand. For rice, percolation losses must be included.

 

 

 

Annual relative irrigation supply

 

 

Total annual volume of irrigation water inflow

Total annual volume of crop irrigation demand

Total annual volume of irrigation water inflow:

Total annual volume of water diverted or pumped for irrigation (not including diversion of internal drainage).

Total annual volume of crop irrigation demand:

Total annual volume of irrigation water required by the crop less effective rainfall. For paddy rice, percolation losses must be included.

 

Water delivery capacity

 

 

Canal capacity to deliver water at system head

Peak irrigation water consumptive demand

Canal capacity to deliver water at system head:

Actual discharge capacity of main canal at diversion point.

Peak irrigation water consumptive demand:

The peak crop irrigation water requirement for a monthly period expressed as a flow rate at the head of the irrigation system.

 

Security of entitlement supply

 

Irrigation water entitlement and probability of meeting entitlement

System water entitlement:

The bulk volume or bulk discharge of water to which the scheme is entitled per annum.

Security of supply:

The frequency with which the irrigation organization is capable of supplying the established system water entitlements

 

 

(b) Financial indicators

Indicator

Definition

Data specifications

 

 

Cost recovery ratio

 

 

Gross revenue collected

Total MOM cost

Gross revenue collected:

Total revenues collected from payment of services by water users.

 

Total MOM cost:

Total management, operation and maintenance cost of providing the irrigation and drainage service excluding capital expenditure and depreciation/renewals.

 

 

Maintenance cost to revenue ratio

 

 

Maintenance cost

Gross revenue collected

Maintenance cost:

Total expenditure on system maintenance

Gross revenue collected:

Total revenues collected from payment of services by water users.

 

 

 

Total MOM cost per unit area (US$/ha)

 

Total MOM cost

Total command area serviced by the system

Total MOM cost:

Total management, operation and maintenance cost of providing the irrigation and drainage service excluding capital expenditure and depreciation/renewals.

 

Total command area serviced by the system:

The command area is the nominal or design area provided with irrigation infrastructure that can be irrigated.

 

Total cost per person employed on water delivery (US$/person)

 

 

Total cost of personnel engaged in I&D service

Total number of personnel engaged in I&D service

Total cost of personal engaged in I&D service:

Total cost of personnel employed in the provision of the irrigation and drainage service.

 

Total number of personnel engaged in I&D service:

Total number of personnel employed in the provision of the irrigation and drainage service.

 

Revenue collection performance

 

Gross revenue collected

Gross revenue invoiced

Gross revenue collected:.

Total revenues collected from payment of services by water users.

 

Gross revenue invoiced:

Total revenue due for collection from water users for provision of irrigation and drainage services.

 

Staffing numbers per unit area (Persons/ha)

 

Total number of personnel engaged in I&D service

Total command area serviced by the system

Total number of personnel engaged in I&D service:

Total number of personnel employed in the provision of the irrigation and drainage service.

Total command area serviced by the system:

The command area is the nominal or design area provided with irrigation infrastructure that can be irrigated.

 

Average revenue per cubic metre of irrigation water supplied (US$/m3)

 

Gross revenue collected

Total annual volume of irrigation water delivery

Gross revenue collected:

Total revenues collected from payment of services by water users.

 

Total annual volume of irrigation water delivery:

Total volume of water delivered to water users over the year or season. Water users in this context describe the recipients of irrigation service, these may include single irrigators or groups or irrigators organized into water user groups.

 

 

 

PRODUCTIVE EFFICIENCY

 

Agricultural productivity and economics

Indicator

Definition

Data specifications

 

Total gross annual agricultural production (tonnes)

 

Total annual tonnage of agricultural production by crop type.

 

 

 

Total annual value of agricultural production (US$)

 

Total annual value of agricultural production received by producers.

 

 

 

 

Output per unit serviced area (US$/ha)

 

 

Total annual value of agricultural production

Total command area serviced by the system

Total annual value of agricultural production:

Total annual value of agricultural production received by producers.

Total command area serviced by the system:

The command area is the nominal or design area provided with irrigation infrastructure that can be irrigated.

 

 

 

 

Output per unit irrigated area (US$/ha)

 

 

Total annual value of agricultural production

Total annual irrigated crop area

Total annual value of agricultural production:

Total annual value of agricultural production received by producers.

 

Total annual irrigated crop area:

The total irrigated area cropped during the year.

 

 

 

 

Output per unit irrigation supply (US$/m3)

 

 

Total annual value of agricultural production

Total annual volume of irrigation water inflow

Total annual value of agricultural production:.

Total annual value of agricultural production received by producers.

Total annual volume of irrigation water inflow:

Total annual volume of water diverted or pumped for irrigation (not including diversion of internal drainage).

 

 

 

 

Output per unit water consumed (US$/m3)

 

 

Total annual value of agricultural production

Total annual volume of water consumed by the crops

 

 

Total annual value of agricultural production:

Total annual value of agricultural production received by producers.

 

Total annual volume of water consumed by the crops:

Total volume of water consumed by the crop to meet evapotranspiration demand. For rice crops this excludes deep percolation losses.

 

ENVIRONMENTAL PERFORMANCE

Indicator

Definition

Data specifications

 

Water quality: Salinity (mmhos/cm).

 

Salinity (electrical conductivity) of the irrigation supply and drainage water.

 

 

Water quality: Biological (mg/litre)

 

Biological load of the irrigation supply and drainage water expressed as Biochemical Oxygen Demand (BOD)

 

 

Water quality: Chemical (mg/litre).

 

Chemical load of the irrigation supply and drainage water expressed as Chemical Oxygen Demand (COD).

 

 

Average depth to watertable (m)

 

Average annual depth of watertable calculated from watertable observations over the irrigation area.

 

 

 

Change in watertable depth over time (m)

 

Change in watertable depth over the last five years.

 

 

 

Salt balance (tonnes)

 

Differences in the volume of incoming salt and outgoing salt.

 

.

 

 

 

 

 

 

 

Appendix A2

Protocols for data collection and processing

 

1

Data item No.1

Total annual volume of irrigation water delivery

Definition

Total volume of water delivered to water users over the year or season. Water users in this context describe the recipients of irrigation service, these may include single irrigators or groups or irrigators organized into water user groups.

Measurement

specifications

Location:

Measurement should occur at the point of interface between the irrigation provider and the water user(s).

Frequency:

The magnitude and frequency of fluctuation in discharge will determine the desired frequency of measurement. Discharge should be monitored at least twice daily to ensure sufficient accuracy. The best accuracy can be obtained from continuous monitoring of discharge by electronic monitoring devices.

Processing

Daily average discharges must be converted into daily delivery volume using the actual delivery time. The total volume of water delivered is the aggregate result of daily volume of supply.

Units

Expressed in cubic metres (m3)

 

 

 

 

Data item No.2

Total annual volume of irrigation water inflow

Definition

Total annual volume of water diverted or pumped for irrigation (not including diversion of internal drainage).

Measurement

specifications

Location:

Inflow will be measured at the diversion point in case of gravity diversions or at the pump delivery of groundwater or river pumps. In situations where there are additional inflows and/or diversions for any purpose other than irrigation, e.g. urban supply, industrial supply, etc. a mass balance of the net inflow for irrigation must be carried out. Inflows from drainage recovery must be deducted from the inflow amount whereas catchment inflows must be included as irrigation diversions.

Frequency:

The magnitude and frequency of fluctuation in discharge will determine the desired frequency of measurement. Discharge should normally be monitored at least twice daily to ensure sufficient accuracy. The best accuracy can be obtained from continuous monitoring of discharge by electronic monitoring devices.

Processing

Daily average discharges must be converted into daily delivery using the actual delivery time.

The total volume of water delivered is the aggregate result of daily volume of supply converted into daily volume.

Units

Expressed in cubic metres (m3).

 

 

 

Data item No.3

Total command area serviced by the system

Definition

The command area is the nominal or design area provided with irrigation infrastructure that can be irrigated.

Measurement

specifications

This area is usually derived from the design drawings for the irrigation system. Over time areas may go out of production due to a variety of factors, including construction of houses, buildings, drainage channels, etc. Adjustments should be made to the command area to allow for this reduction in irrigable area.

Processing

The command areas for each tertiary unit are measured and aggregated up for the whole system.

Units

Expressed in hectares (ha).

 

 

 

Data item No.4

Total annual irrigated crop area

Definition

The total irrigated area cropped during the year.

Measurement

specifications

This value is the result of the total area nominally commanded by the system multiplied by a cropping intensity factor to take into account the actual intensity of land utilization during the year.

Processing

The area cultivated in each cropping season is the aggregate of the areas planted to each individual crop. The annual irrigated area is the aggregate value of the each season’s cropped area. These data are usually collected by the irrigation and drainage organization for operation and accounting purpose and/or by other related agencies that compile production statistics.

Units

Expressed in hectares (ha).

Example

For instance, if the area commanded by the irrigation system is 10,000 ha and the areas cultivated during the year are: wet season 8,000 ha, and dry season 6,000 ha, the total area irrigated by the system is 14,000 ha. The cropping intensity is 1.4.

 

 

 

Data item No.5

Total annual volume of total water supply

Definition

Total volume of surface diversions into the scheme and net groundwater abstraction for irrigation, plus total rainfall, excluding any recirculating internal drainage water within the scheme.

Measurement

specifications

Location:

Inflow will be measured at the diversion point in case of gravity diversions or at the pump delivery of groundwater or river pumps. In situations where there are additional inflows and/or diversions for any purpose other than irrigation, e.g. urban supply, industrial supply, etc. a mass balance of the net inflow for irrigation must be carried out. Inflows from drainage recovery must be deducted from the inflow amount whereas catchment inflows must be included as irrigation diversions.

Frequency:

The magnitude and frequency of fluctuation in discharge will determine the desired frequency of measurement. Discharge should normally be monitored at least twice daily to ensure sufficient accuracy. The best accuracy can be obtained from continuous monitoring of discharge by electronic monitoring devices

Rainfall should be measured daily and then aggregated monthly and annually

Processing

Rainfall should be converted to volume by multiplying by the irrigated area.

Units

Expressed in cubic metres (m3)

 

 

 

 

 

Data item No.6

Total annual volume of crop water demand

Definition

Total annual volume of water used by the crop to meet evapotranspiration demand. For rice, percolation losses must be included.

Measurement

specifications

Location:

Crop evapotranspiration will be calculated using the FAO CROPWAT model for the net area planted to each crop in the irrigated command area.

Frequency:

The preferred Etc calculation period is daily. In situations where daily data are not available the shortest possible interval is to be used. The calculation of Etc will include the entire growing season from planting to harvest.

Processing

The total annual volume of water consumed by all crops grown in the system is the weighted sum of the water consumed by individual crops as follows:

Where:

Vetc = Total volume of water consumed by crops (m3)

Etci = Evapotranspiration from crop i, from planting to harvest (m3)

Ai = Area planted to crop i.

 

For rice crops the average percolation rate will be multiplied by the crop area and growth period to obtain the total percolation volume.

Units

Expressed in cubic metres (m3)

 

 

 

 

 

 

Data item No.7

Total annual volume of crop irrigation demand

Definition

Total annual volume of irrigation water required by the crop less effective rainfall. For paddy rice, percolation losses must be included.

Measurement

specifications

Location:

Crop evapotranspiration will be calculated using the FAO CROPWAT model for the net area planted to each crop in the irrigated command area. Estimation of effective rainfall may prove to be difficult in some circumstances. There are a variety of methods included in CROPWAT for estimating effective rainfall (Dastane, 1974). The use of the USDA-SCS model is recommended.

Frequency:

The preferred Etc calculation period is daily. In situations where daily data are not available the shortest possible interval is to be used. The calculation of Etc will include the entire growing season from planting to harvest.

Processing

The total annual volume of water consumed by all crops grown in the system is the weighted sum of the water consumed by individual crops as follows:

VETNet = ?(Etci - Re)Ai

where:

VETNet = Total volume of water consumed by crops less effective rainfall (m3)

i = Crop type

Etci = Evapotranspiration from crop i from planting to harvest (m3)

Re = Effective rainfall over crop area from planting to harvest (m3)

Ai = Area planted to crop i. (ha)

 

For rice crops the average percolation rate will be multiplied by the crop area and growth period to obtain the total percolation volume.

Units

Expressed in cubic metres (m3).

 

 

 

 

Data item No.8

Canal capacity to deliver water at system head

Definition

Actual discharge capacity of main canal at diversion point.

Measurement

specifications

Location:

Discharge capacity must be determined at the system head assuming canal freeboard according to canal design specifications.

If not yet available, it can be determined using any accepted flow measuring technique including: flow metering, measuring flumes and control sections.

Frequency

Needs to be determined annually at the start of the irrigation season.

Processing

 

Units

Expressed in cubic metres per second (m3/s))

 

 

 

 

Data item No.9

Peak irrigation water consumptive demand

Definition

The peak crop irrigation water requirement for a monthly period expressed as a flow rate at the head of the irrigation system.

Measurement

specifications

Location:

The calculation is based on the maximum monthly crop water requirement in the system. The field, distribution and main system conveyance efficiency must be used to index this value to the head of the system. For paddy rice the peak requirement may occur during the land preparation stage.

Frequency:

Calculated each season.

Processing

The maximum monthly crop water requirement should be available from the calculation of crop water requirements for the entire system. The main system delivery efficiency must be calculated according to the definition provided in Appendix A1.

Units

Expressed in cubic metres per second (m3/s).

 

 

 

 

Data item No.10

System water entitlement

Definition

The bulk volume or bulk discharge of water to which the scheme is entitled per annum.

Measurement

specifications

The bulk water entitlement may be defined in terms of an average volume entitlement or discharge entitlement or as a variable quantity related to the availability of water resources each year. A volume entitlement is more common in regulated systems whereas a discharge entitlement is more common in run-of-the-river systems. If a security level is attached to this value, this must be entered in the security of supply cell in the data spreadsheet.

Units

Expressed in m3 (volume) or m3/s (discharge).

 

 

 

 

 

 

Data item No.11

Security of supply

Definition

The frequency with which the irrigation organization is capable of supplying the established system water entitlements.

Measurement

specifications

Location:

Water entitlements will be specified at the delivery point. For individual water users this is the total amount of water available to the farm or per unit area. For user groups this is the amount of water available at the point where the user group becomes responsible for distribution of water. In situations where only a bulk entitlement is defined at the system inlet, this can be converted into user entitlement by using the appropriate main system water delivery efficiency.

Frequency:

This entitlement is usually only specified once, but in some localities it is specified annually.

Processing

Two quantities are required to specify the security of supply: (a) The volume of water entitlement and (b) the associated level of exceedence probability.

Units

Percentage of years that the water right can be guaranteed to be available.

 

 

 

 

Data item No.12

Gross revenue collected

Definition

Total revenues collected from payment of services by water users.

Measurement

specifications

This item includes all the revenues (cash and in-kind) received by the irrigation or drainage service provider as payment for water supply and disposal, and other services using the agency’s infrastructure. Where drainage charges are levied separately these must be included in the calculation.

Processing

A single annual value is required for this item. Where services are charged on a different basis, e.g. seasonal, bi-annually, etc. the partial figures must be aggregated annually according to the financial calendar of the organization.

Payment made in kind must be converted into monetary terms, either using local market prices for the in-kind commodity, or at rates stipulated in the service agreement.

Units

Expressed in United States dollars (US$). The exchange rate and date must be shown when converting from the local currency.

 

 

 

 

 

Data item No.13

Total MOM cost

Definition

Total management, operation and maintenance cost of providing the irrigation and drainage service excluding capital expenditure and depreciation/renewals.

Measurement

specifications

This item includes all costs involved in the provision of the irrigation and drainage service. Typically these include:

    • Bulk water fee

    • Staff cost

    • Operation cost (e.g. electricity for operation of plant and equipment and water supply)

    • Maintenance cost

    • Overheads (include administrative expenses, insurances, taxes, etc.)

Processing

A single annual value is required for this item. All costs items must be aggregated annually according to the financial calendar of the organization.

Units

Expressed in United States dollars (US$). The exchange rate and date must be shown when converting from the local currency.

 

 

 

 

 

Data item No.14

Maintenance cost

Definition

Total expenditure on system maintenance

Measurement

specifications

This item includes all the costs associated with maintenance of the irrigation and drainage infrastructure either carried out by the organization or by external contractors. It should not include major repairs or rehabilitation work.

Processing

A single annual value is required for this item. All maintenance costs items must be aggregated annually according to the financial calendar of the organization.

Units

Expressed in United States dollars (US$). The exchange rate and date must be shown when converting from the local currency.

 

 

 

 

Data item No.15

Total cost of personnel engaged in I&D service

Definition

Total cost of personnel employed in the provision of the irrigation and drainage service.

Measurement

specifications

This item includes the cost of all personnel employed by the organization including contractors and contract employees engaged in the administration, management and operation.

Processing

A single annual value is required for this item. All personnel cost items must be aggregated annually according to the financial calendar of the organization.

Units

Expressed in United States dollars (US$). The exchange rate and date must be shown when converting from the local currency.

 

 

 

 

Data item No.16

Total number of personnel engaged in I&D service

Definition

Total number of personnel employed in the provision of the irrigation and drainage service.

Measurement

specifications

This item includes all personnel employed by the service provider including contractors and contract employees engaged in the management, operation and maintenance. It must be expressed in Equivalent Full Time (EFT) units.

Processing

A single annual value is required for this item. All personnel must be aggregated annually according to the financial calendar of the organization and expressed in EFT units.

Units

Expressed in Equivalent Full Time units. The time of part-time or seasonally employed personnel should be converted to the equivalent full time employment based on the proportion of full time worked.

Example

Full time weekly hours: 38 hours EFT = 1.0

Employee working 19 hrs part-time per week EFT = 0.5

 

 

 

 

Data item No.17

Gross revenue invoiced

Definition

Total revenue due for collection from water users for provision of irrigation and drainage services.

Measurement

specifications

This item includes all fees levied (cash and in-kind) by the service provider in payment for water supply and other services provided by the irrigation and drainage infrastructure. Where drainage charges are levied separately these must be included in the calculation.

Processing

A single annual value is required for this item. Where services are charged on a different basis, e.g. seasonal, bi-annually, etc. the partial figures must be aggregated annually according to the financial calendar of the organization.

Payment to be made in kind must be converted into monetary terms, either using local market prices for the in-kind commodity, or at rates stipulated in the service agreement.

Units

Expressed in United States dollars (US$). The exchange rate and date must be shown when converting from the local currency.

 

 

 

 

Data item No.18

Gross annual agricultural production

Definition

Total annual tonnage of agricultural production by crop type.

Measurement

specifications

Total tonnage of utilizable production obtained from each crop.

Processing

Records normally compiled by the irrigation and drainage organization or related agricultural organizations are adequate for this purpose.

Units

Expressed in metric tonnes (t).

 

 

 

 

 

 

Data item No.19

Total annual value of agricultural production

Definition

Total annual value of agricultural production received by producers.

Measurement

specifications

The total value of agricultural production received by producers is determined at local (domestic) market prices. For international comparison this value will be converted into a common measure as described below.

Processing

The total gross value of production is calculated as follows:

Where:

Yi= yield of crop i,

Ai= Area planted to crop i,

Pi= local price of crop I,

MU = currency exchange rate (USUS$/unit local currency)

Units

Expressed in United States dollars (US$). The exchange rate and date must be shown when converting from the local currency.

 

 

 

 

Data item No.20

Total annual volume of water consumed by the crops

Definition

Total volume of water consumed by the crop to meet evapotranspiration demand. For rice crops this excludes deep percolation losses.

Measurement

specifications

Location:

Crop evapotranspiration will be calculated using the FAO CROPWAT model for the net area planted to each crop in the irrigated command area.

Frequency:

The preferred Etc calculation period is daily. In situations where daily data are not available the shortest possible interval is to be used. The calculation of Etc will include the entire growing season from planting to harvest.

Processing

The total annual volume of water consumed by all crops grown in the system is the weighted sum of the water consumed by individual crops as follows:

Where:

VETc = Total volume of water consumed by crops (m3)

Etci = Evapotranspiration from crop i, from planting to harvest (m3)

Ai = Area planted to crop i.

Units

Expressed in cubic metres (m3)

 

 

 

 

Data item No.21

Water quality: Salinity

Definition

Salinity (electrical conductivity) of the irrigation supply and drainage water.

Measurement

specifications

Location:

The salinity of irrigation inflow will be measured at the diversion point in the case of gravity diversions or at the pump delivery of groundwater or river pumps. In situations where there are additional inflows these should be monitored separately.

The salinity of drainage water will be measured at the point where drainage flows leave the irrigation scheme or just before entering a receiving body of water, e.g. river, lake, etc.

Frequency:

The magnitude and frequency of fluctuation in discharge will determine the desired frequency of measurement. Weekly or monthly readings are typically used.

Processing

A single value of the parameters is necessary each year. Weekly or monthly readings must be converted into weighted average according to the volume of irrigation supply water or drainage water occurring during the measuring period.

Units

Expressed in micro mhos per centimetre (mmhos/cm).

 

 

 

 

Data item No.22

Water quality: Biological

Definition

Biological load of the irrigation supply and drainage water expressed as Biochemical Oxygen Demand (BOD)

Measurement

specifications

Location:

The biological load of the irrigation inflow will be measured at the diversion point in the case of gravity diversions or at the pump delivery of groundwater or river pumps. In situations where there are additional inflows these should be monitored separately.

The biological load of drainage water will be measured at the point where drainage flows leave the irrigation scheme or just before entering a receiving body of water, e.g. river, lake, etc.

Frequency:

The magnitude and frequency of fluctuation in discharge will determine the desired frequency of measurement. Weekly or monthly readings are typically used.

Processing

A single value of the parameters is necessary each year. Weekly or monthly readings must be converted into weighted average according to the volume of supply water or drainage water occurred during the measuring period.

Units

Expressed in milligrams per litre (mg/litre).

 

 

 

Data item No.23

Water quality: Chemical load

Definition

Chemical load of the irrigation supply and drainage water expressed as Chemical Oxygen Demand (COD).

Measurement

specifications

Location:

The chemical load of the irrigation inflow will be measured at the diversion point in the case of gravity diversions or at the pump delivery of groundwater or river pumps. In situations where there are additional inflows these should be monitored separately.

The chemical load of drainage water will be measured at the point where drainage flows leave the irrigation scheme or just before entering a receiving body of water, e.g. river, lake, etc.

Frequency:

The magnitude and frequency of fluctuation in discharge will determine the desired frequency of measurement. Weekly or monthly readings are typically used.

Processing

A single value of the parameters is necessary each year. Weekly or monthly readings must be converted into weighted average according to the volume of supply water or drainage water occurred during the measuring period.

Units

Expressed in milligrams per litre (mg/litre).

 

 

 

Data item No.24

Average depth to watertable

Definition

Average annual depth of watertable calculated from watertable observations over the irrigation area.

Measurement

specifications

Location:

Watertable depth must be monitored by a network of piezometers distributed over the commanded area in sufficient density to enable the delineation of contour lines of watertable depth. The installation of piezometers must follow the standard guidelines described in FAO Irrigation and Drainage Paper No.38 Drainage Design Factors.

Frequency:

Watertable levels are typically monitored on a monthly basis.

Processing

Individual readings will be average over the 12-month period to produce a single value required for this item.

Units

Expressed in metres (m).

 

 

 

 

Data item No.25

Change in watertable depth over time

Definition

Change in watertable depth over the last five years.

Measurement

specifications

The calculation of this item is based on the measurement of depth to watertable.

Processing

Change in watertable depth is calculated as the difference between watertable depth over a five-year period.

Units

Expressed in metres (m).

 

 

 

 

Data item No.26

Salt balance

Definition

Differences in the volume of incoming salt and outgoing salt.

Measurement

specifications

Incoming salt: Total amount of salt entering the irrigation area through the water supply system. The salinity of irrigation inflow will be measured at the diversion point in the case of gravity diversions or at the pump delivery of groundwater or river pumps. In situations where there are additional inflows these should be monitored separately.

Outgoing salt: The total amount of salt that leaves the irrigation area through the irrigation supply and drainage system. The salinity of drainage water will be measured at the point where drainage flows leave the irrigation scheme or just before entering a receiving body of water, e.g. river, lake, etc. Additional salt outgoings may occur where irrigation water leaves the system through outfalls or is diverted for other uses.

Processing

The annual incoming and outgoing amounts of salt will be the aggregate of the individual readings collected for each individual period. This may vary in length according to water quality practices although daily readings are preferred.

Units

Expressed in metric tonnes (t).