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Report No. R-90
RESEARCH SUPPORT FOR FORDWAH EASTERN SADIQIA (SOUTH) IRRIGAITON AND DRAINAGE PROJECT
FINAL REPORT
ANALYSIS OF WATER AND SALINITY MANAGEMENT ALTERNATIVES FOR
INCREASING AGRICULTURAL PRODUCTION IN THE FORDWAH EASTERN SADIQIA (SOUTH)
IRRIGAITON AND DRAINAGE PROJECT
Gaylord V. Skogerboe Saeed-ur-Rehman
Muhammad Aslam Albert P. Reichert
June 1999 Pakistan Program
International Water Management Institute Lahore
1
TABLE OF CONTENTS
TABLE OF CONTENTS ................................................................................................................... i
LIST OF TABLES ........................................................................................................................... 111
LIST OF FIGURES ......................................................................................................................... .iv
WOREWORD ..................................................................................................................................... v
ACKNOWLEDGEMENTS ............................................................................................................. vi
1. DESCRIPTION OF PROJECT AREA .................................................................................... 1
2. APPROACH FOR ANALYZING ALTERNATIVE IMPROVEMENTS ............................ 3
3. WATER AND SALINITY MANAGEMENT ALTERNATIVES .......................................... 5
...
3.1. IMPROVED CANAL OPERATIONS ..................... 3.1.1. Decision Support System ........... ..... ................................ 5 3. I . 2. 3.1.3. Dutch Support., ..............................................................................................
Farmers Organizations.. .....................................................
3.2. LINING OF IRRIGATION CHANNELS ....................................................................................... 6 3.2.1. Completed Canal Lini ............................................................ 6 3.2.2. Proposed Canal Lini ............................................................ 6 3.2.3. Lining of Watercourses. ... ................................................ 6
3.3. SUBSURFACE DRAINAGE .................... ..................................................................... 6
3.4. FARMER ACTIVITIES ............................................................................................................. 7 3.4.1. Fractional Skimming Wells. ....................... .................................. 7 3.4.2. Reconstruction of Earthen Watercourses ........................................ 7 3.4.3. Soil Chemical Amendments ....................... ............................................ 7 3.4.4. Improved Surface Irrigation Methods ............................................ 8 3.4.5. Quality of Fertilizers and Biocides ..... ........................................................ 8
4. COST-EFFECTIVENESS ANALYSIS ....................................................................................... 9
4.1. METHODOLOGY .................................................................................................................... 9 4.2. ANALYSIS OF ALTERNATIVES ............................................................................................... 9
4.2. I . Proposed Canal Lining ....................................................................... 9 4.2.2. Subsurface Drainage ............. ....................................................... I I 4.2.3. Fractional Skimming Wells. ................................................... I5 4.2.4. Improved Watercourses .................................................................. 19 4.2.5. Chemical Amendments for Soil Reclamation. ............................................... 24
DISTRIBUTARY COMMAND AREAS ..................................................................................... 24 FESS PROJECT AREA ......................................................................................................... 28
4.3. 4.4.
4.4. I . Improved Canal Operations ....... ................................................... 4.4.2. Cost-effectiveness Options.. . ........................................................
5. INCREASED AGRICULTURAL PRODUCTION ............................................................... 31
5. I . PRESENT SITUATION .................................................................. 3 1 5. I . 1. Current Crop Yields .................. .................................................................... 31
Impact of Waterlogging and Salinity on Crop Yields ................................................. ,34 BASIS OF CROPYIEIB A NALYS IS ....................................................................................... 36
Crop Yield Increase Due To Water Supply.. ............................................................... .36 Crop Yieldincrease Due to Lowering Grounhuater ................................................... 37
5 . 3 . POTENTIAL AGRICUI~TURAL INCREASES ............................................... 39 5.3. I . Lowering Groundwater Levels _ . ............................................................... 39 5.3.2. INCREASED WATER SUPPLY.. ............... .................................................... 40
6 . COMPARISON O F BENEFITS WIT ............................................... 45
6.1. CAPITAL AND O&M COSTS ................................................................... 45 6.2.
6.3. ECONOMIC INDICATORS ........................................................................
6.4. POrENTIAL ADDITIONAL BENEFITS .............................. .................... .49 6.1.1. Farmer Participation ............................. .49
5.1.2. 5.2.
5.2.1. 5.2.2.
ANNUAL BENEFITS AND COSTS ......................................................................
.....................................................
6.4.2. Agricultural Development.. .................................... 6.1.3.
SELECTIONS O F VIABLE ALTERNATIVES ................................................................... 51
7.1. LESSON FROM EXPERIENCE ........................... 5 1 7.1.1. Drainage .................................................... .................................................. 51
7.1.2. Irrigation .................. : ................................................................. 51
7.2. FROM EXTENSIVE TO INTENSIVE AGRICULTURE ... 52 7.3. SUBSURFACE DRAINAGE ................................... .......................... 52 7.4. FARMER-MANAGED ALTERNA I I V E S ....... .............................. 52
7.5. CIVIL WORKS .................................................. ............................ 53 RECOMMENDATIONS FOR PHASE-2 PREPARATION ................................................ 55
Domestic Water and Health.. ........................................................... 7.
...............................
.....................
8.
8. 1. FAKMtKS ORCiANlZATlONS AND DECISION SUPPORT SYSTEM ............................................ 55
8.2. RECONSTRUCTED EARTHEN WATERCOURSES ........................................ 55 8.3. FRACTIONAL SKIMMING WELLS ........................................................................... 55 8.4. LINING HAKRA BRANCH CANAL ........................................................................................ 55
8.5. LINING DISTRIBUTARIES ..................................................................................................... 55 REFERENCES ................................................................................................................................ 57
iv
LIST OF FIGURES
Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5 .
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
Figure 11.
Figure 12.
Figure 13.
Figure 14.
Location Map for the Fordwah Eastern Sadiqia (South) Irrigation and Drainage
Cost-effectiveness Function for Proposed Canal Lining.
Project, as well as Distributary Command Areas. ....................
Water Table Depth Ranges. ......................................................................................... 12
Cost-effectiveness of Subsurface Drainage in FESS .................................................... 13
Schematic Diagrams for Different Skimming Well Designs. ...................................... 16
Cost-effectiveness of Different Fractional Skimming Well Discharges for Operating at 4, 8 or 12 hours per day Throughout the Year. ...............................
Cost-effectiveness Function for Reconstruction of Earthen Watercourses ... 23
Cost-effectiveness Function for Sirajwah, Hakra 3-R Khattan and Hakra 4-R Harun Distributaries ............................................. ........................................ 27
Cost-effectiveness Function for Increasing Cropland Water Supplies in the FESS Project Areas. ............................................................................................................... 30
Cotton Yields at Various Watertable Depths During the Kharif 1996 in the FESS Project Area .................................................................................................................. 33
Wheat Yields at Various Watertable Depths During the Rabi 1996-97 in the FESS Project Area.. ... ....................................................................................... 34
Relative Yields of Major Crops Related to Salinity at Various Watertable Depths. .... 35
Relationship Between Relative Water Supply and Relative Yield for the FESS Project Area. ..................................................................................................... ............. 36
Depth to Watertable and Relative Yield of Wheat for the FESS Project Area. ........... 38
V
FOREWORD
International Irrigation Management Institute (IIMI) has”a contract with the Water and Power Development Authority (WAPDA) for a five-year period ( 1 July 1994 to 30 June 1999), under which it would lend research support for Fordwah Eastern Sadiqia (South) Irrigation and Drainage Project. In addition, this research support was supplemented by other research activities in this project area funded by the Royal Netherlands Embassy, the French Embassy, and llMI Headquarters in Sri Lanka.
Besides providing technical support to various research organizations, there was a major emphasis on providing documentation that would support Phase-2 Preparation of the FESS Project. This FESS Final Report is the last of ten such documents. Three reports have been prepared jointly with other organizations: (a) Mona Reclamation Experimental Project of WAPDA; (b) On-Farm Water Management Directorate of the Punjab Agriculture Department; Punjab and Watercourse Monitoring and Evaluation Directorate of WAPDA.
In selecting viable alternatives for increasing agricultural production, the two major categories are (a) farmer-managed and (b) civil works. Farmers Organization (FOs) and a Decision Support System (DSS) for Improved Canal Operations are required for departing from the present extensive agricultural practices to much more productive intensive agricultural practices, that could adequately feed the growing population of Pakistan.
Gaylor-d V. Skogerboe Consultant Ogden, Utah U.S.A.
vi
ACKNOWLEDGEMENTS
This FESS Final Report was preceded by nine documents that are briefly described in Section 2, Approach for Analyzing Alternative Improvements, of this report. Three of these reports were prepared in collaboration with other government organizations. These highly productive joint efforts are the result of good will and professional assistance of Dr. Akram Kahlown, Project Director, Mona Reclamation Experimental Project, WAPDA. We are also grateful to Mr. Mushtaq Gill, Director General, On-Farm Water Management Directorate, Punjab Agriculture Department; and Mr. M. Sadiq Hassan, Project Director, Watercourse Monitoring and Evaluation Directorate, WAPDA for their candid comments and genuine support.
The authors extend thanks to Mr. Manzoor Hussain and Ms. Shahnaz Akhtar of IWMI for providing excellent secretarial services for the production of this report.
I
1. DESCRIPTION OF THE PROJECT AREA
The first report in this series. Wuterlogging, Salini$and Crop Yield Relutionship, provides a fairly detailed description of the Fordwah Eastern Sadiqia (South) (FESS) project area (Kahlown et al 1998). However. a brief description will be provided to facilitate the presentation in this final report.
The Balloki-Suleimanki (B-S) Link Canal conveys water from the Ravi River to the Sutlej River. which is discharged upstream of Suleimanki Headworks. It consists of a barrage across the Sultlej River and has gates on the left bank that supply two channels; namely Fordwah Canal and Eastern Sadiqia Canal. The length of the Eastern Sadiqia Canal is 255,000 feet (255 RDs) with a discharge capacity of more than 5,000 cusecs (cfs). At the tail of the Eastern Sadiqia Canal is located a trifurcating structure (Jalwala Head): ( I ) on the left side is Hakra Branch Canal (authorized discharge of 2708 cfs); (2) in the middle is Sirajwah Distributary (authorized discharge of 197 cfs); and (3) on the right side is Malik Branch Canal (authorized discharge of 1538 cfs).
A map of the FESS prqject area is shown in Figure 1. The gross command area (GCA) is 1,21,000 hectares (ha) and the culturable command area (CCA) is 105,000 ha. Each of the distributary command areas are identified in Figure 1 because of their importance in the analysis used in this report. The apex of the FESS project area is, however. the Headworks. The Malik Branch Canal serves as a northern boundary and the border with India the eastern boundary with Hakra Branch Canal running parallel to the borders.
2. APPROACH FOR ANALYZING ALTERNATIVE IMPROVEMENTS
Using Dutch funds International Irrigation Management Institute (IIMI) has maintained field stations at Bahawalnagar and Haroonabad since 1994-95. Some research activities have also been funded by the French Government. As a result, IIMI has collected a considerable amount of field data. In addition, some data has also been collected under the FESS Project by research, monitoring and evaluation organizations. Finally, this contract with the Water and Power Development Authority (WAPDA) supported some activities associated with Phase-2 preparation. This final report is intended to provide some guidance towards selecting a solution package for the next phase, without specifying the design details of Phase-2.
A report on Waterlogging, Salinity and Crop Yield Relationships, was published with the collaboration of Mona Reclamation Experimental Project (MREP) of WAPDA (Kahlown et a1 1998). It presents functions for cotton, wheat, rice and sugarcane in the FESS project area. These relationships can be used to quantify increased agricultural production, resulting from improvements (e.g. canal lining or subsurface drainage). This study also revealed the impact of salinity and sodicity on croplands, quite a useful contribution for predicting increases or decreases in crop yields.
A report was prepared by Aslam et al ( I 999) on Soil Salinity-Sodicity and Land Use Suitability in the FESS area. The various degrees of salinity and sodicity have been identified for each distributary command area as support to the remaining studies.
There has been considerable controversy regarding the ponding method or the inflow-outflow method for measuring channel losses (seepage plus leakage) in irrigation channels. A separate argument is presented by Skogerboe et a1 (1 999) in the report, Inflow-Outflow Channel Losses and Canal Lining Cost-effectiveness in FESS. An assessment of the water savings resulting from the FESS Canal lining program has been completed. In addition, the cost-effectiveness function for the completed canal lining is presented.
A study on Spatial and Temporal Assessment of Groundwater Recharge in FESS (Ejaz and Ahmed, 1999) was essential before preparing this report. This study utilized the data collected by the SCARPS Monitoring Organization (SMO) of WAPDA for the modal network of groundwater observation wells in the FESS project. The groundwater recharge assessment was accomplished for each distributary command area to be used in preparing water balances and in evaluating the needs for subsurface drainage.
A very unique approach has been reported on Water Performance Indicators Using Satellite Irnageryfor FESS (Alexandrids et al 1999). This approach is based on very recent studies by IIMI addressing the variability in actual evapotranspiration (ETact) across the Indus Basin Irrigation System. Four satellite images were used to evaluate ETact variability across FESS and for each distributary command area as to adequacy, reliability and equity. These results will also be very helpful in preparing water balances.
Another required study prior to undertaking this report was Water Supply and Water Balances for FESS (Khan et al 1999). The llMl Bahawalnagar field station staff have monitored the distributary head regulators along Hakra Branch Canal for one-and-a-half years using Dutch funds. In addition, there are a number of IlMl studies on watercourse outlets, including the Kharif 1998 Joint Research Dissemination Program on the bed-and-furrow irrigation method for cotton production with the On- Farm Water Management OFWM Directorate, MREP and IlMl (Alberts and Kalwij 1999; Kalwij et
4
al 1999). Many of the studies described above come together in preparing a water balance for each distributary command area, as well as the FESS project.
The water balance for the FESS command area will be used for this report i'n conjunction with a cost-effectiveness function for each water and salinity management alternative described below in Section 3 . This function will be unique for the FESS command area.
5
3. WATER AND SALINITY MANAGEMENT ALTERNATIVES
3.1. IMPROVED CANAL OPERATIONS
As already shown by Khan et al (1999), there is a tremendous amount of daily discharge variability at the distributary head regulators along Hakra Branch Canal. Much of this variability is due to the distributary rotation schedules and inadequate communication facilities for gate operators. However, an essential prerequisite for improved canal operations is that the farmers have organized into a Water Users Federation (WUF) at each distributary command area, including the establishment of a Water Users Association (WUA) for each watercourse served by the distributary. The Royal Netherlands Embassy is planning to fund such an endeavor for Hakra Branch Canal in the near future.
3.1.1. Decision Support System
The implementing agency for a Decision Support System (DSS) would be the Punjab Irrigation and Drainage Authority (PIDA). The intent is to improve the accuracy of the hydraulic data being collected and rapid transmission of this data using improved communications facilities. Improvement in hydraulic operations would then reduce discharge variability in the system enabling farmers to irrigate their fields more effectively.
Field discharge calibrations are required for the headworks of each branch canal, cross-regulators, as well as distributary and minor head regulators. These channel losses have to be measured using the inflow-outflow method for each reach over the range of operating discharges. Finally, time lags have to be evaluated for each reach.
The communications network would include a base radio station where the Sub-divisional Officer (SDO) would be located, one at the Division Level and another at the Circle Headquarters in Bahawalnagar, along with Suleimanki Headworks. At the headworks at Malik and Hakra Branch Canals, including all cross-regulators. there will be a facility far communicating with the concerned SDO.
The combination of better hydraulic data and an improved communications network will be linked with an Irrigation Management Information System (IMIS). This will strengthen interactions between PIDA and the Farmers Organizations (FOs).
3.1.2. Farmers Organizations
The On-Farm Water Management (OFWM) Directorate has been organizing the farmers served by Sirajwah Distributary under the FESS Project. At the same time, l l M I has been organizing the farmers on Hakra 4-R Distributary using Dutch funds. Both distributaries have a CCA of about 18,000 ha (45,000 acres).
At this point in time, the major emphasis of these WUFs is to achieve equity in water distribution to each watercourse WUA. For this purpose, many farmer leaders (132) have received training in water measurement, for which they were very enthusiastic (Zainan et al 1998). This training provided transparency about the present situation regarding water distribution to watercourses. The farmer leaders are committed to achieving equity.
By organizing every distributary along Hakra Branch Canal, and having an organizational arrangement similar to an Area Water Board (AWB), should be highly effective for improving canal
6
operations. This organization should preferably have a representative from PlDA and the Punjab Agriculture Department (PAD).
3.1.3. Dutch Support
The Royal Netherlands Embassy may fund a three-year program focused on DSS and FOs for Hakra Branch Canal. PlDA would be responsible for DSS with the objective of achieving equitable water distribution to all at the distributaries served by Hakra Branch Canal. OFWM would be responsible for organizing each watercourse into a WUA and each distributary into a WUF. Each WUF would establish a DSS for establishing equitable water distribution to all watercourses. Instead of an AWB, there would be a Joint Committee on Water Allocation, with representatives from FOs, PIDA, OFWM and others, whereas IIMl would provide technical assistance.
3.2. LINING OF IRRIGATION C H A N N E L S
3.2.1. Completed Canal Lining
Considerable lining of distributaries and minors using geomembranes has been completed under the FESS Project. Both Bodla et al (1998) and Skogerboe et al (1999) have assessed the water savings resulting from this lining. In addition, a cost-effectiveness function for this lining has been prepared (Skogerboe et al 1999, Figure 6).
3.2.2. Proposed Canal Lining
The remaining distributaries to be lined in future are: ( I ) Sirajwah Distributary from RD 0 - 67+700 (tail); (2) Hakra 3-R Distributary in various reaches having a total length of 92,770 feet; and (3) Hakra 4-R Distributary from RD 0 - 72+150. Malik Branch Canal could also be lined from head to tail (RD 0 - 1 16+900), as well as Hakra Branch Canal in two reaches, from RD 0 - 90 and RD 90 - 165. A cost-effectiveness function has been developed (Skogerboe et al 1999, Figure 7).
3.2.3. Lining of Watercourses
The watercourse conveyance losses are generally quite high (Lashari et al 1999), commonly amounting to more than 30 percent of the watercourse inflows measured at the mogha. These losses were recognized in the 1970’s and resulted in the creation of provincial On-Farm Water Management (OFWM) Directorates by July 1976 when a USAID-funded program was launched to reconstruct earthen watercourses. By the mid-I990’s, the lining had increased to 30 percent of the watercourse length. Watercourse lining still remains a viable alternative, along with reconstruction of earthen watercourses (see Section 3.4.2).
3.3. SUBSURFACE DRAINAGE
The FESS Irrigation and Drainage Project is actually a drainage project, but using irrigation technologies and practices to minimize subsurface drainage requirements because of higher costs than irrigation itself. Thus, FESS Phase- 1 was designed to explore various technologies for alleviating drainage problems. Later on, it was envisioned that FESS Phase-? would focus on employing subsurface drainage to correct the remaining drainage requirements. Thus. there has always been an expectation that subsurface drainage would be a major component of FESS Phase-7.
7
3.4. FARMER ACTIVITIES
There are a number of water and salinity management alternatives for increasing agricultural production that can be accomplished by farmers, WUAs and WUFs. The greatest requirement for supporting these activities would be technical assistance.
3.4.1. Fractional Skimming Wells
The term “fractional” is often used to imply a fraction of one-cusec (e.g. 0.3 cusec or any other number less than one). Fractional skimming wells are particularly expedient for pumping shallow groundwater of reasonable salinity (used for domestic or irrigation purposes) that overlies more saline groundwater at deeper depths. As the pump discharge rate is increased, there is a greater likelihood of upcoming that will bring the deeper saline groundwater upward into the well. Sometimes, there is a need to reduce the pump discharge to only 6 Ips (0.2 cusec) to avoid this potential problem.
The FESS area is underlain by an impervious layer that ranges in depth from roughly 3-1 1 meters, with an average of about 6-m depth. The water above this layer is of reasonably good quality, while the underlying water is fairly saline. Thus, fractional skimming wells would be ideal for capturing some of the better quality groundwater.
The local population generally uses canal water for domestic purposes. Unfortunately, this water largely comes from the 9-S Link Canal, with intercepts a considerable amount of industrial as well as biological waste. This, fractional skimming wells would provide a much better domestic water supply. Installing a fractional skimming well would also provide highly significant health benefits.
Fractional skimming wells can also be suitable for irrigation. Under the National Drainage Program (NDP), the Water Resources Research Institute (WRRI) of the National Agriculture Research Centre, MREP and IIMI have undertaken a research project, titled Roof Zone Salinify Managenienf Using Fractional Skimming Wells with Pressurized Irrigation. The initial testing is being done at MREP with the results to be applied in the FESS area.
3.4.2. Reconstruction of Earthen Watercourses
At the time of implementing the On-Farm Water Management Development Projects in the four provinces during July 1976, the major focus was on organizing the farmers of a watercourse command area to reconstruct their earthen watercourse in order to reduce conveyance losses. However, the program allowed for only ten percent of the watercourse to be lined with bricks-and- mortar. The preference was village areas, for social and health reasons, but generally the lining was done at the head of the watercourse in order to secure the support of head reach farmers. Eventually, the program became totally focussed on watercourse lining; organizing farmers and reconstructing earthen watercourses became defunct.
In a water-scarce environment like FESS, the technology for reconstructing earthen watercourses should be of considerable value. Certainly, this is a technology, which should be evaluated. The W A S would be the implementers with the OFWM Directorate providing technical assistance.
3.4.3. Soil Chemical Amendments
The Soil Salinity Studies by MREP in the FESS area clearly shows that there is considerable irrigated cropland affected by salinity and sodicity (Kahlown et al 1998). Leaching of salts from the
8
root zone will reclaim lowering of water table on these lands. However, some of these irrigated soils are also sodic. Therefore besides lowering the water table, chemical amendments such as gypsum will also have to be applied by farmers.
3.4.4. Improved Surface Irrigation Methods
In 1994, IIMI began a research program on improved surface irrigation methods and practices. The hndamental applied field research has been done at the Hasilpur Field Station at the tail at Fordwah Branch Canal in Chishtian Sub-division. The research has focused on both the traditional basin irrigation and bed-and-furrow irrigation, along with furrow irrigation. A new aspect has been the basin-with corrugations, which can be easily adopted by farmers.
For Kharif 1996, the bed-and-furrow irrigation method was transferred to MREP for use in the FESS area on cotton production. MREP succeeded in this irrigation method. MREP, OFWM, IlMI and Agricultural Extension designed a Joint Research Dissemination Program i n January 1998. This program was implemented during Kharif 1998 with the Water Users Organizations at Bahadarwah Minor (Alberts and Kalwij, 1999). These farmer organizations were very effective in selecting sites for disseminating this technology, including the collective of rental fees (Rs. 100 for the tractor and Rs. 50 for the bed shaper).
Some of the major benefits of the bed-and-furrows irrigation method are: ( I ) more bed-and furrow fields can be irrigated during a warabandi than basin fields because of rapid advance; (2) during heavy rainfall periods, water does not remain on fields, but can be drained by furrows; and (3) if' the soil becomes crusted early in the season, instead of sowing again, water can be supplied to fiirrows, so that the combination of lateral infiltration and capillary rise will suffer the soil and allow plant emergence.
3.4.5.
There is an increasing problem regarding the qualiiy of fertilizers and biocides (herbicides, pesticides, etc.). There have been numerous cases when fertilizers purchased from the market were tested in the laboratory, they were found to have zero nutrient value. Meanwhile, biocidcs are frequently found to be adulterated and are worthless. Since the government is unable to regulate these chemicals, the only feasible solution for the farmers is to develop mechanisms for testing the quality of fertilizers and biocides. Linkages can also be developed between farmers and the private sector. The WUFS are the logical choice for undertaking such an effort. If all the distributaries along a canal are organized, this endeavor is more likely to succeed.
Quality of Fertilizers and Biocides
9
Ranking
4. COST-EFFECTIVENESS ANALYSIS
Channel Lining Costs (MRs) Water Savings (ha-m/yr)
4.1. METHODOLOGY
Reach Accumulated
The methodology for undertaking a cost-effectiveness analysis was reported by Walker et al ( 1979) for optimizing salinity control alternatives for the Grand Valley located in the Upper Colorado River Basin in the Western U.S.A. In this case, capital costs were used and the measure of effectiveness was reduced by tons of salt-load returning to the Colorado River from the irrigated croplands. The reduced salt load was directly related to the amounts of reduced canal seepage, as well as reduced deep percolation losses from irrigated croplands.
Reach Accumulated
When lining an entire canal, different reaches vary both in lining costs and the amount of reduced seepage. Consequently, the cost-effectiveness (cost divided by effectiveness) varies among reaches, usually substantially. The most cost-effective reach would have the lowest value of cost- effectiveness. The reaches would be ranked from most cost-effective (ranking of I ) , second most cost-effective (ranking of 2), to ranking all the reaches (e.g. see Skogerboe et al 1999, Figure 6) .
1.
2.
3.
The same process can be followed for other alternative technologies, followed by a comparison. The first comparison would likely be done for each sub-area (e.g. each secondary canal command area). The second comparison would be undertaken at a higher level (e.g. a canal command area). These levels of comparison will be illustrated in the following section using the FESS project area.
Malik Branch Canal 1070 1070 7564 7564
Hakra Branch RD 90-165 875 1945 5632 13196
Hakra 4-R Distributary 269 2214 1510 I4706
4.2. ANALYSIS OF ALIEI1NATIVES
4.
4.2.1. Proposed Canal Lining
Skogerboe et al (1999) have explored the costs and water savings that would result from geomembrane lining of three distributaries, along with Malik and Hakra Branch Canals, in the FESS project area. The cost-effectiveness data is listed in Table I , which is plotted in Figure 2.
Hakra 3-R Distributary 345 2559 1870 16576
Table 1. Lining costs and water savings for reaches of proposed canal lining in accordance with cost-effectiveness ranking.
5.
6.
Hakra Br. RD 0-90 1330 3889 6839 234 15
Siraj wah Distributary 249 4138 575 23990
10
0 4.000 8.m 1zm 16.000 20.000 24.000 28.000
Water Savings inhbmlyear
Figure 2. Cost-effectiveness Function for Proposed Canal Lining.
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DTW (m)
4.2.2. Subsurface Drainage
To assess the cost-effectiveness of subsurface drainage 'in FESS, antecedent water table levels and drain spacing needs to be determined. The FESS area was divided into 16 sub-units based on distributary command areas (Figure 1). Some adjacent areas irrigated by direct outlets were lumped together for the purpose of the analysis (e.g. Malik Direct Outlet Area), and partial distributary command areas were considered where the entire command area did not fall within FESS.
Designation
Water table levels were monitored over the course of four years via a piezometer field that blanked the study area, and monthly levels were averaged and tabulated. The average high water table depths throughout the project area were considered within the ranges listed in Table 2. The spatial distribution of these ranges are depicted in Figure 3.
<0.5 A l - 0.5-0.75 A2
0.075-1 .O A3 1 .O- 1.25 A4
>1.5
The depth to water table throughout the FESS area fluctuates during the year due to seasonal precipitation and irrigation peaks and troughs. It was, therefore, decided that a transient state approach should be used in determining drain spacing. The United States Bureau of Reclamation (USBR) Drain-Spacing Method was selected. In the USBR method, both the depths to the drain and the spacing between drains are independent variables. There is no unique solution, but rather a unique drain spacing for each drain depth, given the existing soil properties and recharge patterns, that results in desired water table. A range of incremented depths to drain, therefore, was considered, and corresponding drain spacing of each depth was determined.
A6
The depth to an impermeable layer, along with soil permeability and specific yield, were estimated from soil survey maps. Contours representing the depth to an impervious layer were interpolated at 5-foot intervals from the 20-foot contours available from the soil survey, and a weighted-average for each of the 16 sub-areas was determined. A weighted-average soil permeability (and by inference, specific yield) was computed for each of the 16 sub-areas. All weighted averages were exclusive of areas in which subsurface drainage is either infeasible or unnecessary - primarily areas of standing water and dune-lands.
Due to variability in water delivery in the project area, it was decided that relatively shallow water table of not less than 1.5 meters beneath the soil surface was optimal. The water table depth, therefore, was set at 1.5 meters at the midpoint between drains in the month in which it is, on average, at its highest point.
Initial drain spacing was assumed, the drawdown calculated and net recharge estimated in monthly time steps throughout the year for each sub-area. The drain spacing was then adjusted in such a way that the water table would be in dynamic equilibrium - i.e., the drainage and recharge were balanced so that the mean water table depth remained constant from year-to-year. This process was repeated for a half dozen drain depths between 1.7m and 2.0 m.
Figure 3. Water Table Depth Ranges.
. ^
Sub-Area Hakra I-L Hakra 1-R
Drain Depth (m) Drain Spacing (m) Discharge Ilps/ha) I .8 208 0.027 I .8 226 0.053
Hakra 2-R Hakra 3-R Hakra 4-R
1.8 176 0.040 1.75 230 0.027 1.8 223 0.026
Bhaku Shah I 1.92 I 171 I 0.033 Bhukan I 1.8 I 215 I 0.035
Hakra 5-R I 1.8 I 181 R.B. Hakra 6-R I 1.8 I 207
0.022 0.023
Sirajwah I 1.75 I 203 [ 0.034 Hakra D.O. A. 1 1 1.8 I 182 I 0.018
Girdhariawala I 2.0 I 191 L.B. Murad 1 1.75 I 244
0.046 0.024
The cost-effectiveness function for subsurface drainage in the FESS project area is shown in Figure 4, with the date listed in Table 4. The column listing the cost-effectiveness in Table 4 is of particular importance. The complete analysis regarding the cost effectiveness of sub-surface drainage, including each distributary command area, is contained in Annex D.
Hakra D.0.A 2 Hakra D.O. A.3 Malik D.0.A
1 JlI.1) I
1.8 177 0.04 1 1.8 217 0.024 1.8 216 0.034
Figure 4. Cost-effectiveness of Subsurface Drainage in FESS.
14
Areas to be drained Investment Water Cost- Accumulated Accumulated (M Rs) Volume effectiveness Investment Water Volume
Removed (MRS/ha-m) (MRs) Removed
15
2338 2357 2740 300 1 3024 3024 3066 3135 3212 3290 329 1 3301
Areas to be drained
52957 53171 57303 60030 60256 60256 60673 61336 62073 62733 62744 62827
I Bhaku Shah A3 I L.B. Murad A4
I Hakra DOA-3 A4 Malik DOA A4 I-L A4 R.B. 6-R A4 Sirajwah A4
Hakra DOA-2 A4
Bhaku Shah A4 L.B. Murad A5
5-R A4
2-R A4
3-R A5
I 1-LA5 I R.B. 6 A5
48.9 18.7 383.8 261.1 22.1 0.0 42.8 68.3 77.3 77.8 1.3 10.0 40.6 15.6 258.6 150.3 1.3 37.4 33.6 15.8 37.0 39.4 32.2
654 I 0 0747 214 I 0.0874 4132 I 0.0929
0.0957 0.098 1 0.0988
417 I 0.1026 663 I 0.1030
0.1049 0.1 178
11 I 0.1204 82 I 0.1211
0.1246 0.2622
928 I 0.2786 523 I 0.2872
E 0.3079 109 I 0.3091 50 I 0.3146 105 I 0.3533 109 I 0.3632 86 I 0.3737
Accumulated Accumulated Investment Water Volume
Removed
63153 63212 64141 64664 64668 64790
3839 I 64899 3854 I 64949 389 1 I65054 3931 165162 3963 I65249
4.2.3. Fractional Skimming Wells
The Fordwah Eastern Sadiqia (South) (FESS) Irrigation and Drainage Project area is generally underlain with an impervious layer around 6m depth, but varies throughout the project area. Substantial areas are having grouqdwater tables at 0.5, 1.0 and 1.5 m depths. The quality of groundwater above the impervious layer is relatively fresh (WAPDA, 1988). In such hydro- geological conditions, fractional skimming wells can be installed effectively for domestic. irrigation and drainage purposes.
There may be several designs of fractional skimming wells. However, the adoption of any design in the field will depend mainly upon the cost of water pumped and the purpose of installation (i.e., domestic, irrigation and/or drainage). Besides these economical and technical factors, social aspects should also be given full consideration, such as existing traditions, indigenous drilling methods and the impact on local employment.
Figure 5 gives some designs for different skimming well configurations that can be adopted for domestic, irrigation or drainage purposes in the FESS area. The design parameters and assumptions made for designing different skimming well options, along with the selection of small capacity pumps and motors against different discharges and well designs are presented in Annex E.
16
In selecting the designs, specific considerations have been given to the availability of technical know-how at the project area, the existing traditions, and the availability of construction material. The design is based on the design of private tubewells presently being used by farmers in the villages of the project area. The mild steel casing pipes, coir string strainers, galvanized iron pipes, small capacity pumps (reciprocating, centrifugal, and jet types), and the electric motors are all manufactured locally in Pakistan. The wells are only 6m deep, and therefore, can be installed without much difficulty.
Ground Surface
Groundwater Table
Draw Down
Pump and Motor
Impervious Clay Layer
(a) Single-trainer
1 Om apart
(b) Two-strainers skimming well pattern
Pipe
- 15m apart
(c) Three-strainers skimming well pattern
Figure 5. Schematic diagrams for different skimming well designs.
17
The cost of pumped water is probably the most important consideration in selecting any of the skimming well designs. The detail of capital costs, operational costs, and the costs of effective groundwater removal for different skimming wells are given in Annex E. The capital cost for a 15 liter per second capacity well is 25, 50 and 55 percent higher than 12, 9 and 6 liter per second capacity wells, respectively.
Figure 6 shows the cost-effectiveness curves for skimming wells operating at 4, 8 and 12 hours per day for the whole year. Table 5 shows the cost-effectiveness of fractional skimming well designs operating at 4, 8 or 12 hours per day. These costs have been developed on the basis of using diesel motors for the pumps. At places where electricity is available, diesel motors may not be used. The use of electric motors for the pumps would reduce the operational costs by 40 percent, provided there is a government subsidy on electricity charges. Otherwise, electricity is becoming more expensive than diesel nowadays.
Table 5. Cost-effectiveness of different fractional skimming-well designs for operating at 4, 8 or 12 hours per day.
6 I 0.0186 I 0.0832 [ 3.15 I 22.08 I 0.005906
0
- 0
N 0
W 0
P 0
ul 0
Q\ 0
-4 0
Annual Capital Cost (MRs) P 0 0 0
+ i4 i4 ul 0 ul 0 0 0 0 0 0 0 0 0
81
19
No. Bricks @SO01 m3
4.2.4. Improved Watercourses
4.2.4.1 Lining
Tertiary irrigation conveyance systems in the Indus Basin lose 30 to 50 percent of their flow. There is a need to reduce losses, thereby improving the efficiency of the tertiary conveyance system (watercourses), which carries the irrigation water from the secondary canals to the fields. There are two types of watercourse improvements; namely, lining and reconstruction of earthen watercourses. The cost-effectiveness analysis plays an important role in selecting a particular improvement technique by evaluating the water savings against the investment made on the improvement technique.
Bricks Cost (Rs.) @Rs . 13001 1000
Watercourse lining is a high cost improvement technique, which can achieve high delivery efficiency. Generally, as the effectiveness of a canal-lining program in reducing losses increases, its cost also increases. In the present study, a cost-effectiveness analysis was performed for brick and mortar lining of watercourses typical in the lndus Basin Irrigation System. In this analysis, a typical watercourse of 4000 meters (m) length was considered, which has an inflow of 3 cfs and loss rate of 40 percent of the inflow at the watercourse head. The total length of a watercourse was divided into ten reaches of 400 m each. For each reach of watercourse, the total volume of masonry works, quantities and costs of materials (bricks, cement, sand), costs of labor and masons, and total lining cost using prices and rates of 1999 were estimated and provided in Tables 6 and 7.
Table 6. Cost Estimates for Brick and Mortar Lining of Watercourse Typical in the Indus Basin.
Reach Length to be lined (m)
Total Volume of Masonry Works on3)*
Materials and Costs
Cement bags No. @ 1.8731 m3
cost of Cement
Rs. 240/bag
60236
(Rs.) @
Volume of Sand (m3> @0.26 m3/ m3
Sand Cost (@ Rs. 2501 m3
Total Material Cost (Rs)
400 134 67000 I 87100 25 I 35 8710 156046
17225 308598 800
1200
265
3 96
496
742
119123
178080
69
103 25750 461230
1600 527 987 236897 137 34255 613702
1232 295784 171 42770 766254 2000
2400
658
789 1478 354671 205 51285 9 18806
2800 920 1723 413558 239 59800 1 07 1358
3200 1051 1969 472446 273 683 15 122391 1
3600 1182 2214 53 1333 307 76830 1376463
4000 1313 2459 590220 34 1 85345 1529015
* Lined section dimensions: depth 0.52m; bottom width 0.06m (width between two walls) floor thickness 0.07m; floor width 1.26m and wall thickness 0.23 m. Animal wallow volume 3.2 m3.
20
Reach Length to be lined (m)
400 800
1200
1600
Table 7. Cost Estimates for Brick and Mortar Lining of Watercourse Typical in lndus Basin.
Labour and Masons Costs
Renovation c o s t of Animal Total Labour Cost (Rs) @ Construction of Wallow and Masons 0.5 indim, @ Lined Section Cost (Rs) Costs (Rs) Rs. lO0iind (@ Rs. 100/in 20000 40000 1000 6 1000 2 17046
40000 80000 I000 121000 429598
60000 120000 I000 181000 642230
80000 , I60000 1000 24 1000 854702
Total Lining Cost** (Rs)
2000
2400
2800
~ ~~~~~~
100000 1 200000 1000 30 1000 I067254
240000 1000 36 I000 1279806 120000
280000 , 1000 42 1000 1492358 140000
1 3200 160000 I
3600 ~ 180000
320000 1 1000 1 481000 1 170491 I I
360000 I 1000 I 541000 I I917463
Table 8 presents the values of expected annual water savings for each reach against lining cost of that reach. This table also shows the cost-effectiveness of each reach, which was determined by dividing lining cost (Million Rupees, MRs) by water savings (ha-iniyr) i n each reach. The water savings were deteriiiined based on the assumptions that lining will reduce the loss rate (cfs,'m of reach length) by 90 percent and water will be conveyed i n the watercourse for 42 weeks pel- year (294 days). Table 8 also shoms the ranking by the most cost-effective reach being 1. Essentially. the cost-effectiveness can be assumed as having a constant value o f 0 027.
14000 I 200000 1400000 i 1000
Table 8. Cost-effectiveness of Brick and Mortar Lining of Watercourses.
60 1000 \2130015
21
The cost-effectiveness function reveals a linear relationship between the cost of lining and water savings. As the annual water savings increase, the cost of lining also increases, which is generally true. For example, if a water savings of 450 ha-idyr'are required, about 12 Million Rupees (MRs) would be invested on lining o f watercourses (450ha-m/yr x 0.027 MRs/ha.m/yr = MRs 12.15). On the other hand, 16 ha-m/yr water savings would require about 0.43 MRs to be spent on lining. This way, the cost-effectiveness function will help decision makers in deciding how much should be invested on lining to achieve the target water savings annually, or conversely, how much water savings will be achieved by spending a pre-decided amount of money to be spent on lining.
4.2.4.2 Reconstruction of Earthen Watercourses
Earthen renovation of watercourses involves complete destruction of old watercourse banks and reconstruction to specifications based upon hydraulic design and the installation of permanent structures at junctions and major outlets. This technique falls between the cleaning and repair program and lining in both costs and water saving potential. Even if farmers supply manual labor, the program still requires significantly more time to complete than the cleaning and repair program because o f more extensive earth work, the installation of structures and the need for trained personnel to carry out the design work and oversee the construction.
If much of the losses in watercourses are avoidable (i.e., leakage and excess seepage), earthen renovation will be a good investment in terms of program costs and water savings. Earthen renovation should save all of the losses, which cleaning and repair can save, plus additional losses associated with porous vegetation covered banks and uneven, irregular channels. Rebuilding banks will eliminate excess seepage resulting from insect and animal burrows. Good compaction of rebuilt banks can significantly reduce bank porosity and permeability and discourage renewed activity of these pests. The thicker and higher banks reduce possibilities of bank washouts and overtopping. Permanent structures can reduce outlet leakage and washouts. Measurement of conveyance losses in renovated channels will determine the actual benefits. I n Pakistan. about 50 percent of the watercourses were saved with earthen renovation. Though earthen renovation of watercourses wi II retain their improvement longer than those. which are only cleaned, and repaired, many of the benefits are still temporary, and continual maintenance is'critical to maintaining the increased water supply.
For cost-effectiveness analysis of earthen improvements, the same watercourse was used as was discussed under the lining improvement technique. The costs of materials, labor, masons and total earthen improvement cost using prices and rates o f 1999 were estimated, which are given in Table 9. The annual water savings and earthen renovation costs are presented in Table 10, which also reveals the cost-effectiveness and ranking, by the most cost-effective reaches. The water savings were determined assuming that earthen improvement would reduce loss rate by 50 percent and that watercourse will be operational for 294 days per year. The accumulated water savings and costs of reconstruction of earthen watercourses are provided in Table I I . A cost-effective function for reconstruction of earthen watercourses was developed using accumulated costs and water savings, which is presented in Figure 7.
22
Table 9. Cost Estimates for Earthen Improvement of Watercourse Typical in the Indus Basin.
Reach Length (m)
Total Mat. Cost (Rs)* Reconstruction 1 Nakkas & I Total Labour and
Labour and Masons Costs
400
800 I 54266.63 1 16000 1 12000 I 28,000
Cost (Rs.) @ Culverts Masons Cost 0.2 mdm, @ Cost (Rs) (Rs.) Rs. 100/md
54266.63 8000 12000 20,000
1200
1600
2000 1 54266.63 I40000 1 12000 I 52,000
- ~~
54266.63 24000 12000 36,000
54266.63 32000 12000 44,000
2400
2800
3200 1 54266.63 I 64000 1 12000 I 76,000
54266.63 48000 12000 . 60,000
54266.63 56000 12000 68,000
3600
4000
Total Reconstruction Cost (Rs.)**
~
54266.63 72000 12000 84,000
54266.63 80000 12000 92,000
74266.63 I
3600
4000
90266.63
1.08 0.54 314 ’ 39 0.138 0.004 2
1.20 0.60 350 43 0.146 0.003 1 I
98266.63 I
122266.63
* based on 40 n a k b s and 5 culverts for which bricks, cement and sand costs are Rs. 30,290, 20,947.63 and 3029, respectively. The sum of these costs given total materials cost.
Total Reconstruction Cost = Total Material Cost + Total Labour and Masons Cost. **
23
Table 1 1. Accumulated Water Savings and Reconstruction Costs
1 2 1
a 0 8
I 1
i B O 4
0 2
0
R m c o n s I r u ~ t . d length 2400 m
R e c o n s t r u c l e d length 2 8 0 0 m
R e c o n s t r u c t e d length 3200 m
R e C o n s l w C I e d length 3600 m
R e c o n s t r u c t e d length 4000 m
0 50 100 150 200 2 5 0
w.1~1 S a v l n i l In ha-mlyr
Figure 7. Cost-Effectiveness function for Reconstruction of Earthen Watercourses.
Clearly, as the water savings increase with earthen improvement, costs also increase. To save 43 ha- m per year of water, 0.146 MRs need to be spent on earthen improvement of watercourses. For 237 ha-m per year water savings, there would be need of 1.1 MRs for earthen improvement. This way, the cost-effectiveness function is a good tool to help decision-makers in deciding about earthen improvement of watercourses (how much investment should be made in order to achieve target water savings in ha-m per year or for the given amount of money, how much water savings will be achieved).
24
Comparing lining with earthen improvement, it can be seen that for 47 ha-m per year water savings, 1.28 MRs need to be spent on lining, whereas for earthen improvement, 43 ha-m per year of water savings could be made by spending MRs 0.146. Similarly, spending 5.5 MRs on watercourse lining could make 200 ha-m per year of water savings, whereas in the case of earthen improvement, the same water savings could be achieved by investing only 0.8 MRs. This comparison reflects that reconstruction of earthen watercourses is more cost-effective as compared to watercourse lining, but continual maintenance is vital to sustain water savings in earthen improved watercourses.
4.2.5.
Based on the results reported by Kahlown et al (1998), a soil salinity and sodicity survey was undertaken in the FESS Project area as reported by Aslam et al (1999). The results for each distributary command area are listed in Annex F. Four root zone soil classifications were used: ( I ) non sodic; (2) slightly sodic; (3) moderately sodic; and (4) strongly sodic. If the watertable was lowered to 1.5 m, it was established that 23 percent of the moderately sodic and strongly sodic croplands could benefit from the application of chemical amendments, such as gypsum.
Chemical Amendments for Soil Reclamation
Hahra 5-R Bagsar Distributary has 45.4 percent of the gross command area as moderately and strongly sodic, while the Right Bank command area of Hakra 6-R Mainan Distributary has 34.6 percent. In contrast, three command areas have less than one percent of their gross command areas as moderately to strongly sodic: (1) Girdhariwala Distributary; (2) Hakra 2-R Dunga Distributary; and (3) left bank of Murad Distributary in the FESS Project area.
Deleting the Right Bank command area of Hakra 6-R Maman Distributary, the total command area for applying chemical amendments is 2,335 ha. Applying 6.5 tons gypsum per ha at a cost of Rs. 800 per ton, the total cost of gypsum would be M Rs. 12.142.
4.3. DISTRIBUTARY COMMAND AREAS
Distributary command areas can be used to illustrate the choice of technological improvements. For this purpose, the command areas of Sirajwah, Hakra 3-R Khattan and Hakra 4-R Harun will be used. To begin, a comparison will be done for proposed canal lining (Table 1) and subsurface drainage (Table 4). Each alternative can be ranked from tnost to least cost-effective as listed in Table 13, 13 and 14. The cost-effectiveness functions are shown in Figure 8 where subsurface drainage is more cost-effective than canal lining, except for the A5 category, which lowers the watertable from a depth of 1.25 m to 1 S O m.
A comparison of fractional skimming wells (Table 5) with subsurface drainage (Table 4) clearly shows that skimming wells are much more Cost-effective. Also, the higher discharge rates are much more cost-effective than the lower discharges. However, the lower discharge rates are much better for assuring lower salinity levels in the pumped water. Thus, the 6 Ips skimming wells in Table 5 are strongly recommended. For this comparison the maximum number of tubewells will be one per square (25 acres) and the preferred operation will be 8 hours per day. The volume of water to be pumped will correspond with the volume of water removed by subsurface drainage (Table 4). The comparison in Table 15 shows that subsurface drainage is roughly one hundred times costlier than fractional skimming wells (84 for Sirajwah, 106 for Hakra 3-R and 97 for Hakra 4-R).
4 Sub-Dr A4 77 737 0.105 747 15044
5
6
I I I I Savings I Effectiveness I Investment I Water Savings 1
-~ ~
Sub-Dr A5 16 50 0.315 763 15095
C. Lining 249 575 0.433 1 1012 I 15670
Rank Alternative Investment Water Cost- Accumulated Accumulated
I
2
Table 14. Cost-effectiveness ranking for proposed canal lining and subsurface drainage in the Hakra 4-R Distributary command area
(M Rs) (ha-m) (M Rs/ha-m) (M Rs) (ha-ni)
Sub-DrA 1 14 506 0.028 14 506
Sub-DrA2 42 1057 0.040 56 I563
Rank I Alternative I Investment I Water I Cost- I Accumulated I Accumulated
3
4
I I I Savings 1 Effectiveness I Investment I Watcr Savings
Sub-DrA3 181 3244 0.056 237 4807
Sub-DrA4 384 4132 0.093 . 62 1 8938
5 6
C. Lining 345 1870 0.184 966 10808
Sub-DrA5 259 928 0.279 1224 1 I737
~~
I Sub-Dr A 1
(M Rs) (ha-m) (M Rs/ha-m) (M Rs) (ha-m)
1 31 0.029 1 31
2
3
4
5
6
Sub-Dr A2 53 1291 0.04 I 54 1322
Sub-Dr A3 226 3930 0.057 280 5252
Sub-DrA4 261 2727 0.096 54 1 7979
C. Lining 269 1510 0.178 810 9489
Sub-Dr A5 150 523 0.287 960 10013
26
Table 15. Cost-effectiveness comparison of fractional (6 Ips) skimming wells with subsurface
Distributary Water Removed (ha-m)
S iraj wah 15,088
Hakra 3-R 9,867
Hakra 4-R 8,502
Number of Cost- cost of Wells effectiveness Wells (MRs)
(MRs/ha- m/Yd
1,779* 0.005 100 9.07
1,564 0.005268 8.24
1,348 0.005268 7.10
Cost of Sub- surface drainage
763.0
879.4
6910.0 I
-
I
1400
1
1200
1000
800
600
400
200 0
&su
rfac
e d
mg
e A
5
Ca
na
l li
ni
ub
smfa
ce d
rair
ag
e A
4
Su
bs
da
ce
dra
ira
ge
A3
Su
bs
da
ce
dra
ira
ge
A2
pu
bsu
rfac
e dr
aina
ge A
1
0 20
00
4000
60
00
8000
10
000
1200
0 14
000
1600
0
Wat
er V
olum
e R
emov
ed (
ha-m
)
--- -
Sira
jwah
- - H
akra
3-R
H
akra
4-R
1
I I
1
Figu
re 8
. C
ost-e
ffec
tiven
ess
Func
tions
for S
irajw
ah, H
akra
3-R
Kha
ttan
and
Hak
ra 4
-R H
arun
Dis
tribu
tarie
s
4.4. FESS PROJECI’ AREA
4.4.1. Improved Canal Operations
Khan et al (1999) clearly shows the higher degree of discharge variability that occurs at distributary head regulators and watercourse outlets. The technology for improving canal operations is not difficult; in fact, the appropriate technologies should be Standard Operating Procedures (SOP), but unfortunately, this is not the situation.
To improve canal operations implementation of an effective decision support system (DSS) is required. However, there are vested interests that prefer highly unreliable canal water deliveries. Consequently, improving upon the present situation of unreliability and inequity cannot be achieved by technology alone. Farmers organizations are an absolute prerequisite.
For a canal or a branch canal, every distributary must be organized into a Water Users Federation (WUF), including a Water Users Association (WUA) for each watercourse. As an absolute prerequisite for implementing a Decision Support System (DSS) it would improve canal operations by significantly reducing discharge variability and providing reliable and equitable water deliveries.
4.4.1 .l. Farmers Organizations
WUFs can only continue to exist over time if they are capable of achieving equitable water distribution to watercourse outlets. One of the primary functions of a WUA is to assure that they receive their equitable share of water delivered to the WUF. Thus, a major performance indicator for a WUF is the degree of equity achieved.
The evolution of a solid irrigation partnership between the farmers organizations and irrigation personnel should become the bedrock of sustainable participatory irrigation management. Service transactions and fee payment will need to be fully legalized and regularized. Support services to farmers, especially in the experimental and transitional phases, are needed to enhance farmers’ O&M capab’ilities along with rehabilitating dysfunctional irrigation hardware. Communicative skills among the groups need to be developed. Relations of dominance and dependency need to be replaced by a cooperative mode based on a greater autonomy for FOs. Many farmers communicated that they seek to be freed from illegal demands of rent-seeking behavior. Resources need to be channeled into system maintenance and operation rather than private consumption. The stress and pressures of disorganized irrigation management need to be replaced by reliability of canal water deliveries (Zaman and Starkloff, 1999).
To include farmers organization in the cost-effectiveness analysis, the basic assumption is that equitable water distribution to watercourses will be achieved. Based on the studies reported by Khan et al (1999) for the FESS project area, equity would result in 11,231 ha-miyr being provided to water-short watercourses and with a like amount being taken from water-rich watercourses. In the proposal to the Royal Netherlands Embassy, the total funding allocated to organizing WUFs along Hakra Branch Canal is 169 MRs. Thus the cost-effectiveness is 0.0 150 (MRs 169t I 1,23 I ha-miyr).
4.4.1.2. Decision Support System
For the purpose of the cost-effectiveness analysis, the fundamental assumption is that the canal water supply will be equitably distributed among distributaries. For the FESS project area, the studies by Khan et al (1999) show that an additional 6,701 ha-miyr would be provided to water- short distributaries, with water-rich distributaries being reduced by 9.975 ha-m/yr and the difference of 3,274 ha-m/yr (9975-6701) being allocated to distributaries along Hakra Branch Canal
29
Rank
1
2
3
4
5
6
downstream of FESS. The funds allocated to DSS in the proposal to the Royal Netherlands Embassy are MRs 138. Thus, the overall cost-effectiveness for DSS is 0.0206 (MRs 13896701 ha- m/yr).
Alternatives Increased Capital Cost- Cumulative Cumulati Water Costs effectiveness water ve Costs Supply (ha- MRS MRslha- Supply ha- M Rs mlyr) mlyr m/yr
Reconstructed Earthen 65,249 196 0.0030 65,249 196 Watercourses
Farmers Organizations 11,231 169 0.0 150 76,480 365
Decision Support System 6,701 138 0.0206 83,181 503
Lining Malik Branch Canal 7,564 1,070 0.1415 90,745 1,573
Lining Hakra Branch Canal 12,47 1 2,205 0.1768 103,2 I6 3,778
Lining Distributaries (Hakra 3,380 614 0.1817 106,596 4,392 3-R and 4-R)
4.4.2. Cost-effectiveness Options
Now, a cost-effectiveness analysis will be undertaken focused on increased water supply. Fractional skimming wells, improved watercourses, farmers organizations, decision support system and canal lining will be employed for the FESS project area. The ranking of these alternatives are listed in Table 16, which are plotted in Figure 9.
30
0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 m 0 In 0 m 0 0 m m 0 -r m m N N 7
m 7
0 0 0 0 -r 7
0 0 0 0 N -
0 0 0 0 0 7
0 0 0 0 00
0 0 0 0 (D
0 0 0 0 -r
0 0 0 0 N
0
5. INCREASED AGRICULTURAL PRODUCTION
Cropping year
1988-89
5.1. PRESENT SITUATION
One of the major objectives of the FESS project was to improve the socio-economic conditions of the rural community through providing drainage and reclamation measures to enhance irrigation water supplies mainly through canal lining and drainage facilities. It was expected that significant changes would occur in the cropping pattern and cropping intensities after the implementation of various components of the FESS Irrigation and Drainage Project.
Yield in Kg/ha - Cotton Sugarcane Rice Wheat 1044 23493 1048 I669
Another expectation was that those crops which were grown in salt tolerant soil conditions, which can also survive under high watertable conditions, will be replaced by less tolerant and high value crops; as a result, intensive agricultural activities would take place instead of the current extensive agricultural practices. Similarly, with better irrigation supplies, equity of water distribution could help in partly replacing the low delta crops by high delta crops. These changes in cropping pattern, cropping intensities and yields constitutes a major objective of this project.
1993-94
1994-95
The benefits of the project would be measured in terms of increased agricultural production brought about by the implementation of the irrigation and drainage facilities provided to the farming areas. The increased production will be measured by looking at the change in the cropping pattern, cropping intensities and crop yields.
942 32362 1639 1773
575 31415 I893 1801 -
5.1.1. Current Crop Yields
5.1.1.1. Yearly Crop Yields in the project area
The crop yields depend upon a number of factors, some of them being: ( I ) appropriate amounts of crop inputs; (2) improved cultural practices; (3) control of waterlogging and salinity, (4) fertility management of the soils; ( 5 ) efficient water use of the irrigation water; and (6) timely irrigation of crops. The increases in the crop yields of the four major crops are potentially higher in the project area than the data given in Table 17. The data indicates that cotton yields are continuously decreasing except in 1996 and 1997. The cotton yields were better in the baseline year as compared to the recent years.
1996-97
Sugarcane yields show an increasing trend for the 1993 and 1994 crops, but in 1995 and 1996, the yields have again gone down substantially. This trend shows the aggravating situation in the project area. Similarly, rice yields were better in 1988 and 1989, but afterwards, rice shows a decrease in per hectare yield. Wheat is the single crop that showed a consistent increase, but the yields are not comparable with other areas of the Punjab.
725 .26098 1297 1819
Table 17. Average yield of the major crops in the FESS project area.
I 1995-96 1 609 I 29 I76 I 1566 I 1819 I
32
5.1.1.2 Crop Yield by Type of Tenure
T a b l e ' l 8 shows the average yields in the three major crops in the FESS project area on a yearly basis by type of tenure. The data on the cotton crop indicates that tenant cultivators obtained better yields from 1993-94 to 1995-96, except in 1996-97. where owner and owner cum tenant cultivators have achieved better cotton yields. In the case of sugarcane, owner cum tenant cultivators have achieved better yields as compared to the other two categories of cultivators followed by owner cultivators and lastly the tenants. The data pertaining to the wheat crop shows that owner cultivators obtained better yields followed by owner cum tenants, with tenant farmers again on the lowest in these three categories.
Table 18. Yield ofmajor crops by type of tenure during cropping years of 1993-94 and 1996-97
Type of Tenure
Owner Cultivator
Owner-cum Tenant
Tenant
Cropping Year
1993-94
1994-95
1995-96
1996-97
1993-94 1994-95 1995-96
1996-97
1993-94
1994-95
1995-96
1996-97
Cotton 960
568
62 1
669
820 527 573
670
1 I23
675
678
602
Yield in kgtha
30352
30590
28899
24053
3 542 7 33346
26683
28258
3 1668 30043
33 127
23802
SU, oarcane Wheat 1873
1917
1902
1872
1718
1718 I752
1701
1650
1713
I802
1739
5.1.1.3. Crop Yields by Watertable Depth
The results of the various agro-economic surveys conducted by the WMED show interesting results for various watertable depths which can be seen in Table 19. This data provides information about three consecutive years of 1994-95, 1995-96 and 1996-97. For the cotton crops, higher per hectare yields were achieved with the watertable depth of 1-2 m and then within the range o f 2-3 in,
followed by < I m range of watertable depth. The sugarcane crop also shows the trend that better yields were reported by farmers having a watertable depth of 2-3 i n , except in the )car 1994-95, when better yields were obtained at a watertable depth of 1-2 m, followed by < I in depth to watertable. In the case of wheat, the best yields were obtained with 2-3 m depth.to watertable, in the range of 1-2 m. while the lowest yields were obtained at a watertable depth of <Im.
Figure 10 shows cotton yields obtained by the farmers in the FESS project area, which depicts that for most cases, yields were lower than 10 maunds per acre and these were obtained within 0- I .5 ni watertable depth. The trend line indicates an increasing yield trend with greater watertable depths, where cotton yields were higher at > 1.5 m watertable depth. Most importantly, Figure 10 illustrates the tremendous variability in cotton yields. where watertable depth explains very little of this variability.
Table 19. Average yield of major crops by watertable depth in the FESS project area.
Note. Crop yield estimations for the cropping year 1994-95 were done on the basis of three watertable depth categories i.e.. 0.5-0.7 in, 0.7- 1.5 m. and 1.5-2.3 m. respectively.
Figure 1 1 indicates the yields of wheat at various watertable depths during the Kabi 1996-97 cropping season. Farmers achieved yield less than 30 maunds per acre between 0.50-1.5 in watertable depth. The trend line indicates that yields were higher at >1.5 watertable depths in the project area. Again, watertable depth explains very little of the wheat yield variability. This would imply that careful f ie ld experiments are I-cqiiired to clearly show hm\. crop yields vary with watertable depth.
2750
2500
2250
2000
1750 f
2
5 1250
M
5 1500 .- x
- - 6 1000
750
500
250
0 - 0.00 0.20 0.40 0.60 0.80 I .oo 1.20 1.40 1 .hll
\Vatertable Depth (111)
Figure 10. Cotton yields at various watertable depths during the Kharif 1996 in the FESS project area.
34
5000
4500
4000
3500
- $ 3000 3 .Y 2500
0
x *
f 2000
1500
500
0 0.00 0.20 0.40 0.60 0.80 1.00 1.20 1.40 1.60
Watertable depth (m)
Figure 1 1 . Wheat yields at various watertable depths during the Rabi 1996-97 in the FESS project area.
5.1.2. Impact of Waterlogging and Salinity on Crop Yields
Recent research in the Fordwah Eastern Sadiqia Irrigation and Drainage Project i n Southern Punjab (Kahlown et al, 1998) has separated the impact of waterlogging and salinity on the yields of wheat, cotton, rice and sugarcane, which are the four major crops of this area that covers about 85 percent of the cultivated area. The research results showed the effect of sodicity on reducing the yield potential of these four major crops of the project area, which is the area between the U.S. Salinitary Laboratory results reported by Maas and Hoffinan (1977) and the relationship for the 2-3 m watertable depth shown for each major crop in Figure 12. The area between the watertable depths of < I and 2-3 m results from the lack of sub-surface drainage. These results demonstrate the importance that must be given to waterlogging, salinity and sodicity to achieve sustainable crop yield increases in the FESS project area.
4 .In
, ."
100
90
80
70
60
50
40
30
20
10
n
"I
01
23
45
67
8S
10
11
12
S
oil
Saiin
ity (
dS
Irn
)
I m
Ra
ng
e 0-1
m
0
Ra
ng
e 1
-2 m
-U
SS
LJ
(r\
Rir
p
110
100
90
80
70
60
50
40
30
20
10
0
So
il S
ali
nit
y (
dS
lin
) 1 I R
an
g-
0-1
rn
0
Ran
g.
1-2m A
Ran
g- 2-3m -
US
SL
1
(h\
Wh
eat
0
1 2
3 4
5 6 7 8 9
10 11 12 1
3 1
4 1
5 16 1
7 1
8 1
9 20
So
il S
alin
ity (
dS
lrn
)
I I R
an
ge
0-1
rn
0
Ran
ge 1-2 rn
A
Ra
ng
e 2
-3 1
11 -
US
a
Id\
Sii
aa
rrs
np
Figu
re 1
2.
Rel
ativ
e Y
ield
s of
Maj
or C
rops
Rel
ated
to S
alin
ity a
t Var
ious
Wat
erta
ble
Dep
ths.
W
v,
36
5.2. BASIS OF CROP YIELD ANALYSIS
5.2.1.
In this analysis, the principle of diminishing returns has been used which indicates that at some point in the production process, it is no longer feasible to apply additional amounts of some particular input. This point is where the highest possible total output from the farm business is realized, beyond which the total output declines, which is called the point of maximum output. All applications prior to the point tend to increase the output, but at a decreasing rate. After a certain stage and at the point of maximum output, the application of any input results in no increase in the total output. Therefore, the additional application should be avoided. The point of highest possible product, as determined by the principle of diminishing marginal return is not a fixed point.
Crop Yield Increases Due To Water Supply
The general shape of the yield versus water supply for a few selected crops was composited to provide the curvilinear relationship shown in Figure 13. Afterwards, the total output declines. Using this principle, a polynomial equation was written to develop a relationship between relative water supply and relative yield. The curve and fitted equation can be seen in Figure 13.
" 0 5 10 15 20 25 30 35 40 45 50 55 M 65 70 75 80 85 90 95 1W 105 110 115 120 125 130 135 140
Relative Water Supply (%)
Figure 13. Relationship between relative water supply and relative yield for the FESS Project area.
For the calculation of increased agricultural production due to increased water supply, the method of calculations can be described as follows:
37
From the Relative Water Supply-Relative Yield Curve, the present water supply was identified against the present yield for each of the four major crops of wheat, cotton, rice and sugarcane; By using the water supply for each crop in Step 1 and multiplying with the potential water supply for a particular crop, an assessment was made for current water supply for a particular crop; To assess the additional water supply due to improved technology measures for various alternatives like fractional skimming wells, reconstructed earthen watercourses and lined watercourses, etc., increased water supply was calculated on a seasonal basis for the whole FESS project area; Additional water supply to be available in future for a particular crop was obtained by multiplying the cropped area with increased water supply; then by adding the present water supply and water supply in the future, the relative water supply (YO) was determined from the Relative Water Supply-Relative Yield Curve; By using the Relative Water Supply-Relative Yield Curve, future yield was determined and by deducting present yield from the future yield, the increased yield was obtained; Increased agricultural production due to increased water supply was obtained by multiplying the increased yield with the percentage of the cropped area of the wheat, cotton, rice, sugarcane and culturable command area of the FESS project minus the chemically amended area; and The value of increased agricultural production has been calculated by using the current prices of the four major crops.
5.2.2.
For relating the watertable depth with yields for the four major crops, relative yields for each crop were calculated by dividing the Actual Yield by the Yield Potential (Kahlown et al 1998).
Crop Yield Increased Due to Lowering Groundwater
Where
actual yield for a crop (kg/ha) y,,, = potential yield or yield potential (kg/ha); and yre.1 = relative yield (%)
- - yac t
The yields and respective watertable depths were arranged i n two separate columns. To make a logarithmic transformation, the logs of both columns were taken. Then, a linear fit was made of the log values by doing a best-fit line. All calculations were carried out with the help of the following log function.
[In(?)] In Yield = EXP
38
Where
log of Yield log of Depth to Watertable slope
- In Yield - In DTW - m
- - -
0
0.5
h
E v
f 1
P ti - I! d 1.5 a d
2
2.5 0 10 20 30 40 so 60 70 80 90 100
Relative Yield (YO)
Figure 14 shows the relationship between watertable depth and relative yield for the wheat crop in the FESS project area.
Figure 14. Depth to Watertable and Relative Yield of Wheat for the FESS Project Area.
To calculate the increased agricultural production due to lowering of groundwater, the following method was adopted:
The average monthly areas under various depths to watertable categories (i.e. 0.25, 0.625, 1.125 and 1.375) were considered as the initial watertable for the study area;
By using the Relative Yield -Depth to Watertable Curve, the present yield for each watertable category was determined for all of the four major crops;
Using the same Relative Yield - Depth to Watertable Curve, the yield at 1.5 m depth to watertable was calculated for all of the four major crops;
Increase in the yield for four major crops was determined by taking the diffetence of yields obtained in Steps 3 and 2;
39
The percentage of area in each depth to watertable category was taken by using the figures obtained from Step 1 ;
Agricultural production was calculated for each watertable category by using the percentage of area (Step S), multiplying by the culturable command area of the FESS project minus the chemically amended area, then multiplying by the percentage of the wheat, cotton, rice and sugarcane cropped areas;
Total increase in agricultural production has been calculated by taking the sum of the production increases in each watertable category; and
The increased agricultural production by lowering the groundwater has been valued on the basis of current prices of the four major crops.
5.3. POTENTIAL AGRICULTURAL INCREASES
5.3.1. Lowering Groundwater Levels
In the project area, on average, existing yields are very low. The averagg wheat yield is only 61% of the potential yield (3,600 kg/ha), cotton yield is only 29 percent of the potential yield of 2,500 kg/ha. Whereas the rice yield is only 43% of the potential yield of 3,000 kg/ha and sugarcane yields are only 50 percent of the potential yield of 52, 000 kg/ha for the FESS project area. Therefore, there is a great scope for achieving about 90 percent of the potential yields in the project area.
Table 20 depicts that for the alternatives of fractional skimming wells, reconstructed earthen watercourses, and lined watercourses accomplish the same objective of lowering watertable to 1.5 m, so the increased agricultural production is identical for each alternative. For each alternative, 65,249 ha-m/year of water will be available due to lowering groundwater, which will result in increased agricultural production by 9,226,665 kg of wheat,' 5,038,578 kg of cotton, 2 1,482,592 kg of rice and 1,127,929 kg of sugarcane. The production increases for wheat will generate 55.36 million rupees, for cotton 100.77, for rice 214.83 and for sugarcane 0.85 million rupees for each of the three alternatives, which totals about M Rs 372.
For the subsurface drainage alternative, 63,153 ha-miyear water will be removed and as a result crop production will increase. Wheat production will increase by 8,930,276 kg, cotton by 4,876,723 kg, rice by 20,792,505 kg and sugarcane by 1,09 1,696 kg and there will be an increase in revenue by 53.58, 97.53, 207.93 and 0.82 million rupees, respectively. due to the lowering of groundwater, which totals about M Rs 360.
Similarly, for the last three alternatives of lining distributaries, lining Malik Branch Canal and lining Hakra Branch Canal, will reduce water losses by controlling seepage from the canals resulting in lowering the depth to watertable. This effect will enhance crop production and will produce several million rupees of increased production. For the case of lining Hakra 3-R and Hakra 4-R, wheat production will increase by 7,982,306 kg, cotton by 12,966,076 kg, rice by 280,275 kg and sugarcane by 3,4222,954 kg. The additional income from this increased agricultural production will provide 47.89, 259.32, 2.80 and 2.57 million rupees in the case of wheat. cotton, rice and sugarcane, respectively, which totals about M R 313.
40
Lining of Malik Branch Canal will result in an additional 15,425,930 kg of wheat, 19,855,5 14 kg of cotton, 589,297 kg of rice and 7,533,660 kg of sugarcane with values to 92.56, 397.1 1, 5.89 and 5.65 million rupees for these four major crops, respectively, which totals to about M Rs 501.
The alternative of lining Hakra Branch Canal will enlist an increase of 22,330,869 kg of wheat, 25,041,944 kg of cotton, 898, 319 kg of rice and 12,063,343 kg of sugarcane which will amount to 133.99, 500.84, 8.98, and 9.05 million rupees for wheat, cotton, rice and sugarcane, respectively, which totals to about M Rs 653.
5.3.2. INCREASED WATER SUPPLY
The first three alternatives given in Table 20 of fractional skimming wells, reconstructed earthen watercourses, and lined watercourses will provide an increased water supply each by 65,249 ha- m/year, so the increased agriciiltural production will be identical for each alternative. Due to this increased water supply, additional crop produce for wheat will be 71,742.815 kg, for cotton 20,590,903 kg, for rice 553,364 kg and 6,845, 908 kg of wheat by generating an additional value of 430.46, 41 1.82, 5.53 and 5.13 million rupees, respectively, for each alternative, which totals about M. Rs 853.
The alternative of Farmer Organizations will be helpful in increasing the additional water supply due to better management of the system, providing 1 1 , 23 1 ha-m/year water. This additional water will increase the production of wheat by 14,348,563 kg, cotton by 3,406,014 kg, rice by 93,425 kg and sugarcane by 1,438,747 kg and the value of this additional production will be 86.09, 68.12, 0.93, and 1.08 million rupees, respectively, which totals to about M Rs 156.
The Decision Support System alternative provides an additional water supply of 6, 70 1 ha-m/year due to better decisions by the irrigation system managers. Due to this water availability, wheat production will increase by 8,569,961 kg, cotton by 2,012,645 kg, rice by 57,492 kg and sugarcane by 877,478 kg. The value of crop production will be of 5 1.42, 40.25, 0.57 and 0.66 million rupees for wheat, cotton, rice and sugarcane, respectively, whi'ch totals to about M Rs 93.
The Chemical Amendments will be applied to 2,335 ha of moderately to strongly saline-sodic soils resulting in the production of additional wheat by 6,371,048 kg, cotton by 2,538,145 kg, rice by 4,546,245 kg and sugarcane by 91,408,245 kg. The value of this additional production would be 38.23, 50.76, 45.46, and 68.56 million rupees, respectively, which total to about M Rs 203.
The lining of Hakra 3-R and Hakra 4-R Distributaries will provide 3,380 ha-m/year water which will be used to produce about 4,358,437 kg of wheat, 1,006,322 kg of cotton, 28,746 kg of rice and 426,881 kg of sugarcane. The value of this production is 26.15, 20.13, 0.29 and 0.32 million rupees, respectively, which total to about M Rs 47.
The lining of Malik Branch Canal would provide an additional 7,564 ha-m/year of water, which may be used to produce 9,696,299 kg of wheat, 2,283,578 kg of cotton, 64,679 kg of rice and 988,151 kg of sugarcane. This will generate revenue equal to 58.18. 45.67, 0.65 and 0.74 million rupees for wheat, cotton, rice and sugarcane, respectively, which total to about M Rs 105.
Lining of Hakra Branch Canal will provide 12,471 ha-m/year of additional water, from which 38,246,5 1 I kg of wheat, 28,835,005 kg of cotton. 1,006,l 17 kg of rice and 13.668,099 kg of sugarcane can be produced. The increased crop production from this alternative will be of 95.49, 75.86, 1.08 and 1.20 million rupees from wheat, cotton, rice and sugarcane, respectively, which total to about M Rs 174.
Alte
rnat
ices
I Lo
wer
ing
I In
crea
sed
I I
Incr
ease
d A
gric
ultu
ral P
rodu
ctio
n (k
ilogr
ams)
V
alue
of
Due
to
Low
erin
g G
roun
dwat
er
I I
Frac
tiona
l Ski
mm
ing
Wel
ls
65,2
49
65.2
49
Whe
at
9.22
6,66
5 7
I ,74
23 15
80
,969
.480
48
5.82
Cot
ton
5,03
8,57
8 20
.590
,903
25
,629
,481
5
12.5
9
Ric
e 2 1
,482
,592
5 5
3,36
4 22
.035
.956
22
0.36
I Sug
arca
ne
I 1,
127,
929
I 6.
845,
908
7,97
3,83
7 I
5.98
Rec
onst
ruct
ed E
arth
en W
ater
cour
ses
65,2
49
65.2
49
Whe
at
9,22
6,66
5 71
.742
31 5
80,9
69,4
80
485.
82
Cot
ton
5,03
8,57
8 20
,590
,903
25
,629
,48
1 51
2.59
Ric
e 2 1
,482
,592
55
3.36
4 22
.035
.956
22
0.36
I I
Line
d W
ntei
cour
ses
I Sug
arca
ne
I 1,
127,
929
I 6.84
5,908-r-
7,97
3.83
7 I
5.98
65,2
49
65.2
49
Whc
at
9.22
6,66
5 71
.742
,815
80
,969
,480
48
5.82
Cot
ton
5,03
8,57
8 20
.590
.903
25
,629
.48
1 51
2.59
Ric
e 2 1
,482
,592
55
3.36
4 22
.035
.956
22
0.36
Tota
l 12
24.7
5
Farm
ers
Org
aniz
atio
ns
1 1,2
3 1
\‘hea
t 14
,348
,563
14
,348
,563
86
.09
Cot
ton
3,40
6,01
4 3,
406.
01 4
68.1
2
I I
I Sup
arca
ne
I 1,
127.
929
I 6.
845,
908
I 7,
973,
837
I 5.
98
Tota
l 12
24.7
5
I I
I [<ic
e I
I 93
,425
I 93
,425
I 0.
93
I I
I Sug
arca
ne
I I
1.43
8,74
7 I
1,43
8.74
7 I
I .08
To
tal
156.
22
Tab
le 2
0.
Incr
ease
d ag
ricu
ltura
l pr
oduc
tion
from
wat
er a
nd s
alin
ity
man
agem
ent a
ltern
ativ
es.
Dec
isio
n Su
ppor
t Sys
tem
6,701
Whe
at
Cot
ton
Ric
e
Suga
rcan
e
Lini
ng D
istri
buta
ries
8,569,961
8,569,96 1
5 I .42
2,O 12,645
2,O 12,645
40.25
57,492
57,492
0.57
0.66
877,478
877,478
3,380
* -
Che
mic
al A
men
dmen
ts
(Hak
ra 3
-R &
Hak
ra 4
-R)
Whe
at
6,371,048
38.23
Cot
ton
2,538,145
50.76
Ric
e 4,546,245
45.46
Suga
rcan
e 91.408.245
68.56
Subs
urfa
ce D
rain
age
I Sug
arca
ne I
3,422,954 1
426,881
~ 3,849,835 I
2.89
63,153
Whe
at
8,930,276
930,276
53.58
Cot
ton
4,876,723
4,876,723
97.53
Ric
e 20.792305
20,792,505
. 207.93
Suga
rcan
e I ,09 1,696
1,091,696
0.82
Whe
at
I I
Cot
ton
Ric
e
P
t3
~~
~ ~~
7,982,306
4,358,437
12.340.744
74.04
12,966,076
1,006,322
13,972,399
279.45
280,275
28,746
309.022
3.09
Lini
ng M
alik
Bra
nch
Can
al
(RD
0 - 1
16+900)
7,564
7,564
Whe
at
15,425,930
9,696,299
25,122,228
150.73
Cot
ton
I9,855,5 I4
2,283,578
22,139,091
442.78
6.54
Ric
e 589,297
64,679
653,976
Tabl
e 20
. (C
ompl
ete)
Suga
rcan
e 7.
533,
660
988.
15 I
8,52
1.81
I 6.
39
Lini
ng H
akra
Bra
nch
Can
al
(RD
0 - 1
65) * C
hem
ical
Am
endm
ents
will
be
appl
ied
to 2
, 335
ha
of m
oder
atel
y to
stro
ngly
sal
ine-
sodi
c so
ils (s
ee A
nnex
F).
12,4
7 1
12,4
71
Whe
at
22,3
30,8
69
15.9
15.6
42
38,2
46,5
1 I
229.
48
Cot
ton
25,0
4 1,
944
3,79
3.06
1 28
,835
,005
57
6.70
Ric
e 89
8,3 1
9 10
7.79
8 1,
006.
1 17
10
.06
Suga
rcan
e 12
,063
,343
1,
604.
757
13,6
68.0
99
10.2
5
P
W
45
6. COMPARISON OF BENEFITS WITH COSTS
6.1. CAPITAL AND O&M COSTS
In Section 4, the capital costs for each water and salinity management alternative was used in the various cost-effectiveness analyses. In Section 5 , the agricultural production increases for each alternative were calculated on an annual basis. Thus, in order to compare these agricultural benefits with costs, the capital costs must be annualized, or capital costs plus operation and maintenance (O&M) costs over the expected life of each alternative is preferred.
Table 21 lists the capital costs and expected life for each alternative. The O&M costs over the expected life was done using a highly effective maintenance program, which is rarely the case in Pakistan, but is considered necessary to sustain the calculated agricultural production increases. For reconstructed earthen watercourses, the water savings over five years was assumed as 100, 80, 60, 40 and 20 percent, while the estimated annual maintenance cost was assumed as 2, 5, 8, 10 and 12 percent of capital costs over the five-year expected life. The annual operating costs for a 6 Ips skimming well operating eight hours per day throughout the year is Rs. 29,2000, which amounts to MRs 2,7 I7 for 10,340 wells over nine years (the first year of operating costs is included with the capital cost). For lined watercourses, the first year of maintenance was assumed as one percent of capital cost, which was increased by one-fourth of one percent each year, which becomes seven percent in the twenty-fifth year. For subsurface drainage, the total maintenance costs over a fifty-year life expectancy was assumed as two-thirds of capital costs. For farmers organizations, the annual O&M costs were assumed as RS. 150/ha/yr, while Rs 125/ha/yr were used for a decision support system. For chemical amendments, gypsum applications were assumed once every three years. For the canal lining alternatives using geomembrane, geotextile and concrete cover, the estimated maintenance costs over 50 years was assumed as half of the capital costs.
The last column in Table 21 shows the long-term annual costs over the expected life of each alternative. The lowest annualized cost is for chemical amendments at 4.0 M Rs/yr. The annualized costs for farmers organizations (19.3 M Rs/yr) and decision.support system (15.9 M Rs/yr) are a very reasonable p.ackage (see potential additional benefits in Section 6.4). Reconstructed earthen watercourses (53.7 M Rs/yr) has a fairly high-annualized cost because of the short five-year life expectancy. Canal lining varies from 18.4 -66.1 M Rs/yr, which is fairly reasonable to somewhat high in annualized costs. Lined watercourses have a high-annualized cost (142.6 M Rs/yr), but fractional skimming wells are more than double (306 M Rs/yr). These 6 Ips skimming wells operating eight hours per day throughout the year have a fairly low capital cost (343 M Rs, which includes the first year of operating costs), but very high operating costs (Rs 29,200 per year for each skimming well).
6.2. ANNUAL BENEFITS AND COSTS
The comparison of annual benefits and costs for each alternative is shown in Table 22. The annual benefits are the agricultural production increases listed in Table 20, while the annual costs are obtained from the last column in Table 21. The ratio of benefits divided by costs is listed as the Benefit-Cost Ratio in the last column of Table 22.
The highest benefit-cost ratio (50.7) is for Chemical Amendments, followed by reconstructed earthen watercourses (22.8), lining distributary (19.6) and lining Malik Branch Canal ( 1 8.9). The lowest benefit-cost ratios are for subsurface drainage (3.2) and fractional skimming wells (4.0). The intermediate benefit-cost ratios are for lining Hakra Branch Canal (1 2 . 9 , lined watercourses (8.6), farmers organizations (8.1) and a decision support system (5.8).
46
Table 2 I . Total capital and O&M costs for water and salinity management alternatives.
Alternatives Capital costs
Reconstructed Earthen
196
(6,070 km) Fractional Skimming Wells
~~
343
0&M Costs for Expected Life, M Rs
Expectec Life, Yr
Total Capital and O&M Costs, for Exp.Life M Rs
268.52
3,060
Long-Term Annual Costs, Expected Life M Rslyr
53.7
306.0
l M R s 5 72.52
I Watercourses I
10 2,7 17
I Lined I 1,782 25 1,782 3.564
I Watercourses I I(3,345 km) I I Subsurface 13,342 50 2.228 5.570 Drainage
(AI-A4)
Chemical 12.1 Amendments
Farmers 169
12.1 4.0 I 3
50 788 957 19.3 I 1 Organizations I I Decision I138 50 656 794
I Svstem I Lining 614 Distributaries (Hakra 3-R &
, Hakra 4-R) 'Lining Malik 1,070 Br. Canal
50
50
307
535
92 1
1,605 32.1 I
I(RD 0 - 116+900) I I Linino h Hakra 12,205 50 1,102 3.307 66.1 I I Br. Canal I I
I(RD 0 -165) I
47
Table 22. Comparison of benefits with costs for water and salinity management alternatives.
Alternatives Long-Term Annual Increased Agricultural Benefits-Cost Ratio, Costs, Over exp. Life, M Production, M Rs/yr
Rs/yr Dimensionless Reconstructed Earthen 53.7 1225 22.8 Watercourses (6.070 km) Fractional Skimming 306.0 1225 4 0 I Wells (1 0,340)
Lined Watercourses 142.6 1225 8.6 (3,345 km)
Subsurface Drainage 11 1.4 3 60
I
I
I 3.2 t (A I -A4)
Chemical 4.0 203 50.7 Amendments Farmers Organizations 19.3 156 8.1
~
Decision Support 15.9 93 5.8 I ~~~
System Lining Distributaries 18.4 360 19.6 (Hakra 3-R & Hakra 1 4-R)
Lining Malik Br. 32.1 606 18.9 Canal (RD 0 - 116+900)
Lining Hakra. Br. 66.1 826 12.5 I Canal (RD 0 -165)
6.3. ECONOMIC INDICATORS
Table 23 has been prepared in order to compare the water and salinity management alternatives in terms of capital costs, annualized capital plus O&M costs denoted as long-term annual costs, benefit-cost ratio and cost-effectiveness. The last two columns in Table 23 are cost-effectiveness for capital costs (as used in Section 4) and annual costs (capital costs plus O&M costs over the life expectancy of the alternative, with the sum divided by the life expectancy).
For a civil works program-4 the alternatives have been ranked in Table 24 according to ascending capital costs. As the capital costs increase, the benefit-cost ratio decrease, except for lined watercourses that is lowest, which is unique for the FESS project area. Under the civil works alternatives, there are two sub-sets: (1) lined watercourses and subsurface drainage for lowering the watertable to 1.5 rn below the ground surface; and (2) lining of distributaries and branch canals. For the first sub-set, both the capital costs and benefit-cost ratio can be compared, which favors lined watercourses over subsurface drainage. For the second sub-set on canal lining, only the benefit-cost ratio should be compared, which favors geomembrane (plus geotextile and concrete cover) fining of
48
Alternatives
Reconstructed Earthen Watercourses (6.070
Hakra 3-R and Hakra 4R Distributaries, followed by lining of Malik Branch Canal, then Hakra Branch Canal from RD 0 165.
Capital Long-Term Benefits-Cost Cost Effectiveness costs, Annual Ratio, Capital Annual Costs M Rs Costs, Over Costs M M Rsiha-miyr
exp. Life, Dimensionless Rs/ha- M Rslyr miyr
196 53.7 22.8 0.0030 0.00082
For farmer-managed alternatives, the most important economic indicators are long-term annual costs and the benefit-cost ratio. These alternatives are listed in ascending annualized costs in Table 25. The benefit-cost ratios are, however, low for a decision support system (5.8). And for farmers organizations (8. I ) , the long-term annual costs are quite reasonable considering that farmers are paying the O&M costs for Hakra Branch Canal and all of the distributaries off-taking from this canal. Reconstructed earthen watercourses have a very high benefit-cost ratio (22.8), which would then make the use of Chemical Amendme'nts feasible because of lowering the watertable. Fractional skimming wells have a low benefit-cost ratio (4.0), as well as very high annual operating costs.
Fractional Skimming Wells (1 0,340)
Lined Watercourses (3,345 km)
Table 23. Comparison of economic indicators for water and salinity management alternatives.
343 306.0 4.0 0.0053 0.00469
1,782 142.6 8.6 0.0273 0.002 I8
Chemical Amendments Farmers Organizations
Decision Support Svstem
12.1 4.0 50.7
169 19.3 8.1 0.01 50 0.001 72
138 15.9 5.8 0.0206 0.00237
Subsurface Drainage 1 3,342 1 1 1 1.4 1 . 3.2 I 1 (A 1 -A4)
Lining Distributaries (Hakra 3-R & Hakra
Lining Malik Br. Canal (RD 0 - Il6+900) Lining Hakra. Br. Canal (RD 0 - 165)
4-R)
614 18.4 19.6 0.1817 0.00544
1,070 32.1 18.9 0.1415 0.00424
2,205 66.1 12.5 0.1768 0.00530
Alternative
Lining Distributaries (Hakra 3-R & Hakra 4-R)
Capital Costs Benefit-Cost Ratio M Rslyr dimensionless
614 19.6
Table 25. Comparison of economic indicators for farmer-managed alternatives.
Lining Malik Br. Canal (RD 0 - 1 16+900)
Lined Watercourses (3,346 km)
Lining Hakra Br. Canal (RD 0 - 165) Subsurface Drainage (A I - A4)
1,070 18.9
1782 8.6
2205 12.5 3342 3.2
Alternative
1 Farmers Organizations I 19.3 I 8. I I
Capital Costs Benefit-Cost Ratio M Rslyr dimensionless
Chemical Amendments
Decision Support System
4.0 50.7
15.9 5.8
6.4. POTENTIAL ADDITIONAL BENEFITS
Watercourses (6.070 km)
6.4.1. Farmer Participation
Many of the water and salinity management alternatives require strong participation by farmers. Individual farmers would be involved with installing fractional skimming wells and applying Chemical Amendments, like gypsum, to soils that are moderately to strongly saline-sodic. Farmers organized at the watercourse level into water users associations (WUAs) would implement the reconstruction of their earthen watercourses. The most important role of farmers is improved canal operations, where organized farmers are a prerequisite to implementing a decision support system for reducing discharge variability and providing more reliable and equitable water deliveries to each water users federation (WUF) that is responsible for a distributary command area.
53.7 22.8
What is even more important than organizing a WUF, including WUAs, is to organize every distributary along a branch canal or canal. Then, a representative from each V4T can serve on an Area Water Board (AWB) for a canal command, or a similar organization for a branch canal. These roles for farmers are crucial for improving system performance.
Fractional Skimming Wells (l0,340( 306.0 4.0
