Code No: TMS061 Price: 900 Category: Transportation
Summary : This study deals with adaptation of irrigation canals, assets created at considerable costs as navigable waterways and thereby exploring possibilities of creating transportation capacity in a country on the threshold of major economic changes.
Table Of Contents :
- Introduction
- Approach and Methodology
- Irrigation canal
- Design principles in India
- Navigation in canals
- Major canals
- Design of irrigation cum Navigation Canals
- Indira Gandhi, Nehru project and Narmada Canal system
- Annexures Scope of work for Techno-Market Surveys given byTIFAC, List of institutions,
- Questionnaire for canal data, List of Experts, Generating the unit costs of IWT vessels, Simulation study, Brief details of Narmada Navigation study.`
1. Introduction
Transport infrastructure is one of the key elements in the growth of any economy. India has a vast network of irrigation canals. There exists possibility of exploiting these man-made waterways for providing transport capacity – which is being dealt with in this Techno-Market Survey. The Scope of Work outlined by TIFAC, is given in Annexure 1.1.
2. Approach and Methodology
The data collection for the study has been done by extensive interviews and field work with related institutions and experts, reference to research work, expert reports and other relevant literature.
The report evolves cut-off criteria in terms of irrigation canal parameters for determining the navigability or otherwise of canals based o various (i) Technical considerations like suitability of cross sections, side slopes, canal lining, discharges, velocity of flow, cross-drainage structures etc., and the likely impact of forces generated by ships’ motion, and (ii) cost and economics (Chapters 3 – 6).
Conclusions on navigability have been drawn on a number of major canals in India. Indira Nahar and Narmada Canal have been taken-up for more detailed study (Chapter 7).
3. Irrigation Canal: Design Principles in India
A quick review of broad irrigation design principles in India can help gauge the technical inputs required for adaptation for navigation.
The basic inputs to design of an irrigation canal system are agricultural characteristics and demand pattern of water in the command area. Usually the canal alignment follows the ridge line in the command area for ease of flow using gravity on either side.
An irrigation system consists of a hierarchical network of canals, starting with head-works, main canal, branch canals, major and minor distributaries. The water losses in an irrigation system largely accrue from seepage (which is much higher in unlined canals) and evaporation.
The general design steps followed for design of an irrigation canal system in India are:
a. Determine the water demand patter of the command area, and availability of water.
b. Determine the alignment.
c. Based on required discharges and the alignment, determine the cross sectional parameters, bed slope(s) and velocity of flow at various places using continuity equation and fluid flow equations.
d. Factors like characteristics of canal lining and corresponding rugosity coefficient are used along with the above equations to arrive at critical velocity, coefficient.
The final design is an iterative process (Chapter 3). Back
4. Navigation in Canals
The dimensions of the canal like cross section, alignment, lining, discharges, bridges across the canals, lock dimensions, cross drainage structures, and ship dimensions are some of the important factors which determine the navigability of a canal.
The ‘design ship’ is based on accepted designs in this report for ease of analysis and standardization. The ships are therefore classified based on standards of European water ways. The four categories of ships considered are: Class I (300 T), Class II (600 T), Class III (900 T) and Class IV (1350 T). in view of narrower/shallower waterways often encountered in India, a special category of Class I* (100 Y) is also defined.
The cross section of the canal affects the traffic intensity, i.e. the ship speeds and ‘lanes’ of operation. The cross section should have adequate depth and width for steerability and safe passage for design ships at normal speeds.
The ships’ movement causes certain phenomena, resulting in forces on canal sides and bottom. These are:
- Return flow;
- Water level drop;
- Wave generation.
These result in increasing the apparent draft of the vessel, change in the trim of a vessel, and limit the speed of travel. The keel clearance (i.e. the ratio of minimum depth of the fairway to maximum draft of stationary vessel) of the vessel should be 1.3.
The ships’ movement generates two types of waves – primary waves and secondary waves. The amplitude of the waves is a function of speed, hull shape of the ship, and the ‘blockage ratio’ (the ration of wet section of the canal to submerged cross section of the vessel). Waves increase resistance of vessel’s navigation and attack canal banks.
The resistance to the ship’s movement is, within limits, proportional to the square of the ship’s speed, and the propulsive power required is proportional to the cube of the spread.
For safe navigation, the ship requires an effective path width of 1.3 times its beam, since it cannot confine itself to a perfect straight course of on account of wind, cross currents and other forces. The minimum width of a straight channel should be 2.3 times the beam of the vessel for a single lane traffic, and 4.1 times the beam for a double lane traffic respectively. Widths get modified (increase) at curves in the alignment.
The minimum bend radius is also governed by the length of the ship. At the bends, a distance of at 5 times the length of the ship should be clear to provide an unhindered view to the pilot of the ship.
Movement under a bridge needs special parameters described above, in addition to vertical clearances of at least 0.2 meters at the highest water levels. Bridge piers need be provided with protection in he form of protective dolphins and/or fenders.
The bottom and sides of navigation canals are affected by ship induced hydraulic forces. The canals need to be suitably lined to protect from washing away of the subsoil (Chapter 4).
5. Major Canals
Most of the irrigation cum navigation canals in India were constructed over 100 years back, and designed mainly for country craft movement. These are mostly located in Orissa, Andhra Pradesh, Tamilnadu and Kerala. Some of these are Taldanda Canal, Kendrapara Canal, Eluru Canal, Commamur Canal, Buckingham Canal, Kakinada Canal, West Coast Canal, Champakara Canal, etc. DVC Canal in West Bengal is of relatively recent origin, Hijli Tidal Canal (Orissa), Sone Canal (Bihar) are some other canals.
The larger potential waterways, however, exist in the form of networks of irrigation canals like Ganga Canal, Sarda Shayak Canal, Indria Gandhi Nahar (Rajasthan Canal), Narmada Canal etc. (Chapter 5). Back
6. Design of Irrigation cum Navigation Canals
An irrigation cum navigation canal would have to satisfy basic requirements of both irrigation and navigation uses of the waterway 0 giving priority to irrigation as per the Water Resources Policy of the Government of India.
- The navigability criteria are based on
- The transport capacity
- The length of the transport linkage
- The transport demand.
The first two are functions of physical characteristics and dimensions of the canal. The third is determined by the traffic potential of the hinterland.
The transport capacity of a canal is defined as the number of ships that can be passed in each direction in a unit time multiplied by the carrying capacity.
The ‘canal lane’ is defined as “the rectangular cross sectional area formed by the lane width and the minimum water depth which would permit safe movement of a vessel of particular class.”
A simulation exercise on ships’ operational parameters has been carried out for the design vessels discussed earlier.
On the basis of this, two Navigability Criteria are recommended:
Navigability Criteria I- An existing irrigation canal, its cross-sectional parameters should be at least equal to that required for the Narrow Section for the Class I vessels i.e. the channel bottom width of 17.5 m and top-width of 22.5 m with water depth of 3.12 m. In case the requisite minimum canal width is available but the canal water depth is less than 3.12 m, it could still be considered for navigation of the Class I vessel with loading restrictions. At the minimum loaded draught of 1.2 m (requiring a minimum water depth of 1.6 m), it would have a carrying capacity of 150 T.
Even if canal cross section is very wide and deep, it still does not provide for a viable transport link unless is also has a reasonable navigable length. For this, a break-even distance based on representative cost of competing modes is looked at.
Navigability Criteria II – The canal should also have a navigable length of at least 60 km.
Based on these criteria, 18 canal stretched from those listed in Chapter 5 (vide table 5.4, last row) are found to be candidates for possible adaptation for navigation, and three others with reservations.
7. Indira Gandhi Nehar Project & Narmada Canal System
- Indira Gandhi Nehar Project
- The construction of Indira Gandhi Nehar Project is taken up in two stages:
- Stage I - 204 km feeder from Harike Barrage and 189 km long main canal.
- Stage II - Further 256 km of main canal and 5112 km long distribution system.
It is found based on the navigability criteria developed earlier, that the main canal including the feeder canal could provide navigation with Class II vessels (600 T). in the tail-end section of last 152 km, due to blockage ratio constraints, the navigation restriction would have to be imposed by way of allowing only unladen vessel to overtake a laden vessel with caution. The upper 497 km would have unrestricted navigation, with laden vessel overtaking another laden vessel with caution. Though the upper 393 km reach can support navigation of 1350 T vessels, these are not recommended on the bass of standardization and overall economics.
The Class II vessels would therefore be the design vessels for sizing up various facilities along the canal like the Locks, bridge clearances, bend radii, minimum water depth etc. it would have a turnaround time of 280 hrs (operational time), make 20 round-trips in a year, and have a throughput potential of 15.24 Million T-Km per year, or equivalently an annual transport capacity of 11740 T each way.
Hydraulic structures across the main canal do not have provision for navigation. In order to pride navigation even during periods of no discharge, 22 locks would be required with a water level drop of 3 m for 649 km long main canal, to provide a minimum navigable depth of 3.25 m.
The transport potential of this corridor is estimated to be of the order of 6000 T/Hr. the corresponding annual transport potential in each direction works out to about 21.8 billion Tkm., or annual transport capacity of 22.7 million tonnes each way over the entire stretch. Speed restrictions are estimated to reduce the transport capacity by about 15-20%.
Modifications in structures can be effected in three phases. Phases I should coincide with the completion of the Command Area Works while the Phase II & III would be dependent on the utilization of the transport capacity created and the performance of the existing canal lining.
The total modification costs for phase I, II and III are estimated to be of the order of Rs. 226 million, Rs. 620 million and Rs. 2087 million respectively.
Traffic level to break-even with annual costs is estimate at about Rs. 84.37 Million T-Km., or equivalent to 130000 T of originating traffic on the waterway or 65000 T of traffic in both upstream and downstream direction annually, or equivalent to transport of 186 T of cargo in both directions everyday for 350 days operations in a year. Back
Navigation in Narmada Canal
The Narmada Main Canal flows North from Sardar Sarovar dam with 460 Km. in Gujarat and 74 km. in Rajasthan. There are 35 branches off taking from the Main Canal, the longest being Saurashtra Branch with design discharge of 267 cumec. The Main Canal has 118 principal structures, comprising regulators, siphons, aqueducts, super passages etc. There are 8 railway bridges and 23 main road bridges crossing the alignment.
The main canal can be divided into 3 reaches based on its cross-sectional parameters. The first reach from the Head regulator to the Sabarmati Escape – 230 km long having a minimum bottom width of 58.6 m and water depth of 7.3 m. this cross-section is adequate for providing a 2 lane Normal Section for even vessels larger than Class IV (1350 T carrying capacity with Beam = 9.5 m and loaded drought of 2.8 m.).
In the Second reach from 230 km to 437 km upto last cross regulator near the Rajasthan boarder, the minimum cross-section dimension reduced to the bottom width of 10.8 and a full supply depth of 5.55 m. these dimensions are just width of 10.8 m and a full supply depth of 5.55 m. These dimensions are just about adequate for having a restricted double lane movement using a Narrow section of Class II vessels (600 T carrying with Beam = 6.6 m and loaded drought of 2.5 m).
In the last reach from the Godrisa cross regulator to the Cross-regulator at the Chitwana distributary about 22 kms before the tall end of the canal in Barmer district of Rajasthan i.e. from Km 437 to km 512 (75 km), the canal has been designed suing parameters of a mehboob section (refer chapter 3).* The minimum depth of water in this reach is 4.0 m. with this water depth the channel would have a minimum width of (4.47 x 4.0 – 2x2x1.3 =) 12.68 m which would be just adequate for single lane movement of a class I vessel (Class I vessel operated at a reduced draught of 1.3 m giving carrying capacity of 150 T i.e. 2xB =2x5.1 = 10.2 m).
The unit fleet costs of Class I vessel are lowest for the first reach of 230 km. or in case navigation takes place on both the Reach I and Reach II. For the last Reach of 75km, it would be only possible to use the modified Class I vessel operating at reduced draught with carrying capacity of 150 T.
The investments required for modifications to the Reach I, Reach II and Reach III are Rs. 1006 million, Rs. 1337 million, and Rs. 431 million respectively.
Based on these costs, the break even traffic works out to 5.4 lakh tonnes in ach direction annually, or 1554 tonnes daily in each direction.
* Mehboob section has side slopes of 1 vertical : 2 horizontal with the bottom in form of a circular arc of radius equal to full supply depth.
Conclusions, Recommendations and Plan of Action
Vast investments are already made I the field of irrigation canals, where technological status of India compares favourably with that if any other country. India has limited natural waterways which are exploitable for navigation. Successful modern navigation in man-made waterways (which present their own problems and techniques/ technologies to deal with them) is virtually absent.
Several large irrigation canal projects that have been completed in the country in the last few decades have not included inland navigation in their developmental plans. As a result, the opportunity of providing a cheap and reliable transport system at a marginal extra cost to the large areas served by these canals could have been missed out.
In certain cases it may perhaps be too late to make such modifications are required for providing navigation facilities on these canals. Yet in some others which have been constructed or are under construction/at planning stage, it may be quite viable to incorporate navigation.
The present study deals with adapting a highly developed expertise of irrigation canals to relatively less developed sector of navigation in canals in India.
1. The best time to examine navigability in an irrigation canal is at the design stage. This fact is well recognized. There have been attempts in some recent projects where navigation possibilities in irrigation projects have been examined. It was found, sometimes, that either the navigational possibility was examined solely by irrigation engineers involved in the design of the project, or the final judgment lay with them.*
It needs to be recognized that Navigation is a specialized field by itself, and in terms of expertise, as well a final users, distinct from irrigation. This is imperative for exploiting the expertise Assets being created in our resource starved economy.
* During data collection for the IG Canal system, it was to our notice that a formal advertisement was inserted in March 1989 for conducting a feasibility study for enabling navigation on the canal. However, the details/ conclusions study are not available.
While the Water Resources Policy of the Government gives a precedence to irrigation over navigation, given an irrigation project framework, navigation possibilities need to be finally decided upon by experts with comparable representation from both the disciplines.
Clear guidelines need to be prepared for effecting the above. Being an interministerial issue, Planning Commission is well placed to coordinate. Back
Organizations:
- Planning Commission (Coordinator)
- Ministry of Water Resources;
- Ministry of Surface Transport;
- Inland Waterways Authority of India;
- Central Water Commission
2. Indira Gandhi Nehar is one of the most ambitious projects recently taken up, expected to open a vast economic hinterland. A comprehensive study should be taken up for examining navigation possibilities, with findings of Chapter 7 being treated as a starting point.
Organizations:
- Ministry of Water Resources;
- Ministry of Surface Transport;
- Inland Waterways Authority of India;
- Central Water Commission
- Consultancy organizations with relevant expertise.
3. The earlier studies on Narmada canal system were limited to the stretch up to Sabarmati. Partly this seems to be necessitated due to large barge size (over 2000 T) required for coal transportation. The great volume of such a cargo, and size of these vessels seem to have posed major technical problems with uneconomical solutions. As per the findings in Chapter 7, this needs to be re-examined for operations at a lower levels, which are more cost effective, using Class I or Class II vessels.
Organizations:
- Ministry of Water Resources;
- Ministry of Surface Transport;
- Inland Waterways Authority of India;
- Central Water Commission
- Narmada Planning Group/irrigation Department, Government of Gujarat;
- Consultancy organizations with relevant expertise.
4. Based on the navigability criteria developed in Chapter 6,18 canal stretches provide potential for adaptation for Navigation (vide last row of Table 5.4). These should be taken up for detailed examination.
Organizations:
- Ministry of Water Resources;
- Ministry of Surface Transport;
- Inland Waterways Authority of India;
- Central Water Commission
- Consultancy organizations with relevant expertise.
5. Country boats ply in certain regions of the country like Bihar, Uttar Pradesh, West Bengal (especially Sunderbans), Kerala, Andhra Pradesh etc. This is a local low investment expertise historically developed. Though often not in a position to offer direct competition to alternative modes of transport, they cater for a specific class of users. The canals falling in these regions should be examined for use by country craft too, which are technically less demanding on the restricted waterways. .
Organizations:
- Ministry of Water Resources;
- Ministry of Surface Transport;
- Inland Waterways Authority of India;
- Central Water Commission
- Irrigation departments of concerned states;
- Consultancy organizations with relevant expertise.
6. Broad standardization should be effected by developing a range of ‘modules’ for use in designing and examining navigation in restricted waterways. An illustrative list of modules is:
i. infrastructure like jetties, and shore based facilities;
ii. vessels;
iii. navigation aids;
iv. road and rail bridge clearances and related structures;
v. locks for various level differences and vessel sizes: etc.
For each module, suitability, typical design ranges, economics and suppliers (wherever applicable) should be worked out, and updated at regular intervals. These modules may need modification from case to case basis, but would provide valuable starting point for experts as well policy makers.
Organizations:
- Ministry of Surface Transport;
- Inland Waterways Authority of India;
- Central Water Commission
- Consultancy organizations with relevant expertise.
7. Country craft have evolved over a period of time with the local economy, using largely local skills and materials along India’s natural and man-made waterways. No database, policy frame or standards exist regarding their operation in India. There use in mechanized/unmechanized form would be of considerable interest from the point of view in navigation in irrigation canals. Comprehensive studies need to be undertaken in this regard.
Organizations:
- State Governments (Especially Assam, UP, Bihar, West Bengal, Kerala, Andhra Pradesh)
- Ministry of Surface Transport;
- Inland Waterways Authority of India;
- Central Water Commission
- Consultancy organizations with relevant expertise.
