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P. van Hofwegen, Senior Lecturer Irrigation Management, International Institute for Infrastructural, Hydraulic and Environmental Engineering, Delft, The Netherlands, A. B, El Gueddari, Director, and Mimoune Chibani, Chef de Service de gestion des réseaux d'irrigation et du drainage, Office Regional de mise en valeur agricole de la Moulouya, Berkane, Morocco |
SUMMARY
Efficient water use at farm level requires flexibility in irrigation scheduling. The possibility for flexible scheduling practices is largely determined by policy choices on water delivery and distribution. These are a result of the irrigation environment, the objectives of the managing agency and, sometimes, the service agreement between farmers and the managing agency. In agency managed systems, policy choices are made concerning cropping arrangements, water allocation, cost recovery and management (farmer participation). These policies eventually result in physical infrastructure (canals and flow control systems) and procedures on its operation and maintenance. The possibilities for flexible irrigation scheduling are constrained by: (i) the willingness and capability of the farmers to adopt flexible scheduling and, if necessary, to pay for the more demanding service; (ii) the capability of the irrigation infrastructure to deliver water accordingly; and (iii) the capability of the irrigation service to realize this flexible water delivery in a reliable way. This article describes the above-mentioned policy constraints and possibilities for water-saving irrigation scheduling in the Triffa scheme in Morocco. Here flexible scheduling is constrained by the need for volume-based payment of irrigation fees and the need to distribute the limited amount of water in an equitable but productive way. Improvement towards a more flexible delivery will require a more automated flow control system, reduced duration of irrigation cycles, on-farm storage, and conjunctive use of groundwater in times of water scarcity. However, this will result in more complicated delivery procedures, especially in scarcity situations, leading to a higher level of staffing or automation. Introduction of water-saving scheduling must therefore be done in a conducive environment where policy choices support the flexible water delivery required.
Irrigation scheduling is the planning of water deliveries to the crops by the irrigator. To plan for an effective and efficient use of water, the irrigator requires information on the actual irrigation requirements and the time and amount of water available in terms of flow size, duration and interval. Ideally, irrigators should have direct access to water so they can react adequately to changes in the moisture situation, to optimize their irrigation schedules and synchronize them with other on- and off-farm activities. This is, however, not the case in most gravity irrigation schemes because the often limited amount of available water has to be shared with other irrigators. It usually becomes the task of irrigation authorities to distribute the limited amount of water in an equitable and efficient way, in order to achieve the national goals as far bas possible and to satisfy the needs of the users. However, the rules and regulations required for distributing water and their implementation restrict the flexibility of water delivery to the users and hence the potential for flexible irrigation scheduling.
Adoption of new technologies developed to support improved irrigation scheduling depends on a reliable water delivery from a network of canals and structures with physical limitations (capacity, response times) and managed by institutions with organizational limitations (procedures, manpower and finance). Having the know-how, introduction of flexible and water saving irrigation scheduling basically requires:
· farmers willing, able and capable to apply flexible scheduling to save water;· an irrigation infrastructure (canals and flow control system) capable of flexible water delivery;
· an irrigation service, able and capable to provide in a flexible way, an adequate, reliable and timely supply of the amount needed for optimum crop production (or optimum productivity of water!).
FIGURE 1 - Location of the Triffa scheme
The ability and capability of the irrigation service is determined by the environment in which irrigation is taking place, the resources (water, land, finance) at its disposal and the policy choices (ultimately translated into operation rules and regulations) made for the development and management of the irrigation scheme. The infrastructure in general and the flow control system in particular have been developed on the basis of an original set of policy choices. Changing policies to increase flexibility of water delivery will place additional requirements (and costs!) on the flow control system. Moreover, the rules of the game the farmers and operators were accustomed to will change, especially if the costs have to be recovered. The willingness of farmers to adapt water-saving irrigation scheduling will very much depend on their established way of dealing with irrigation, their willingness and capability to invest in a better on-farm infrastructure, to pay higher fees for this more demanding service; and the socio-economic benefits they can derive from its application.
This article describes the above-mentioned policy constraints and possibilities for water-saving irrigation scheduling in the Triffa scheme in Morocco from the perspective of the managing agency: the 'Office regional de mise en valeur agricole de la Moulouya' (ORMVAM). After a description of the scheme and its irrigation environment, the policy choices with the consequences and constraints for flexible water delivery will be explained and some possibilities for improved scheduling will be presented.
THE IRRIGATION ENVIRONMENT OF THE TRIFFA SCHEME
The Triffa scheme (36 160 ha) is located on the right bank of the Moulouya River and is one of four schemes (with Zebra, Garet and Bou Areg) in the Moulouya basin in the north-east of Morocco.
The climate is semi-arid Mediterranean with a low and irregular average annual rainfall of 300 mm varying between 150 mm and 450 mm. Rainfall is concentrated in the months of December, January and April.
The water availability for irrigation is highly dependent on the runoff in the Moulouya catchment area. Surface water comes mainly from the Moulouya River with an average annual runoff of 800 Mm3. The discharges are regulated by the Mohammed V reservoir with at present a live storage capacity of 470 Mm3 and the Mechraa Homadi barrage with a live capacity of 42 Mm3. There is water scarcity during the frequent prolonged droughts.
At Moulay Ali, downstream of the Mechraa Homadi barrage, a pumping station has been constructed for additional supply with a capacity of 4 m3/s. It enables an additional average annual volume of 100 Mm3 to be pumped up some 95 metres from the Moulouya River into the Triffa main canal.
The Triffa plain is blessed with groundwater of good quality and sufficient quantity. It is used in times of scarcity for supplementary irrigation.
Irrigation network
Water for the Triffa scheme is diverted from the right intake of the Mechraa Homadi barrage. From the intake, the water crosses a mountain ridge via a tunnel some 10 km long. The intake and the tunnel are within the jurisdiction of the department of Public Works. The authority of ORMVAM starts at the outlet of the tunnel. From the right main canal, Berkane and the adjacent communities are provided with 500 l/s water for sanitation and drinking water.
The lined main canal has a total length of 155 km. The secondary and tertiary canals are elevated semi-circular concrete canals. Higher areas are served by eight pumping stations.
Water levels in the main canal are regulated by a mixture of control structures: duckbill weirs, mixed control Neyrpic gates, AVIO downstream control gates and AMIL upstream control gates. The turnouts to the secondary canals in the main canal are Neyrpic baffle distributors. The lower level turnouts (prises) are Neyrpic baffles with the water level regulated by duckbill weirs. Water distribution between the farmers downstream of the prises is through on-off gates in distribution boxes.
The irrigation methods used are mainly gravity surface systems (35 032 ha) consisting of basins in orchards and the 'Rupta' system: a traditional system where small basins are made and crops are planted on the sides of these basins. In some places, farmers have started with micro or drip irrigation for their tree crops (200 ha). The present scarcity of water has increased farmer interest in this technique. In a small area (828 ha), use is made of moveable sprinkler installations.
System management
ORMVAM was established by Royal Decree in 1966 as a public establishment with financial autonomy under the supervision of the Ministry of Agriculture. ORMVAM is responsible for:
· development of infrastructure in its area of jurisdiction (350 000 ha);· management of the irrigation and drainage networks;
· intensification of productivity by training of farmers and strengthening professional organizations.
This includes the design, construction, operation and maintenance of the irrigation networks, supervision of farming operations for industrial crops, and assistance in the establishment and monitoring of agricultural cooperatives. ORMVAM integrates all the production services required by farmers under one management structure.
ORMVAM has its own budget. Separate budgets are allocated for investment (BdE: Budget d'Equipement) and operations (BdF: Budget de Fonctionnement). Water charges are collected by ORMVAM to cover the operations budget. Shortages on the operation and maintenance (O&M) budget occur because the price of water does not balance the O&M cost. Prices are fixed by the national government. To cover deficits, additional funds are allocated from the Ministry of Finance in the form of subsidies.
POLICY CHOICES
Policy objectives
Irrigated agriculture has a high priority in Morocco, both to meet the needs of its rapidly growing population and to expand exports of commodities and processed agricultural products. The objectives of the agricultural policy of Morocco are in line with its economic development policies (Ait Kadi, 1988). They are:
· to improve self-sufficiency by a better cover of the primary food requirements like wheat, sugar, oils, dairy products and meat;· to improve the trade balance by developing exports of agricultural products, especially fruits and vegetables;
· to improve the living conditions of the rural population by increasing revenues, generating rural employment and reducting the social gap;
· to utilize agricultural products to develop the agro-industry.
The development and management of the schemes within these national objectives is directed towards optimal overall productivity of the scarce water available.
Cropping policies and water rights
The national objectives are translated into cropping and water delivery policies at ORMVAM (Hofwegen, 1994). There is no arranged cropping pattern. Farmers are free to select their crop. Twice a year an inventory (recensement) is made of the actual cropping plans per farmer. These are registered and will serve as a basis for future water allocation. The only regulatory mechanism in the cropping pattern is the priority for irrigation given to crops in the event of water scarcity. Access to irrigation in the event of scarcity is directly related to the type of crop cultivated. Tree crops (especially citrus) have first priority as they represent farmers' long-term investments and contribute to the foreign exchange generation objective. Second in line are the industrial crops to ensure input for the agro-industry, followed by fodder crops for cattle and dairy. Last on the list are cereals and vegetables as they can be purchased on the international market. As tree crops are relatively safe, farmers have increased their area under citrus. Consequently ORMVAM has decided to restrict the irrigation to the citrus area by recognizing only a maximum of one-third of the farmers' holding as cultivated with tree crops.
Announcement of not irrigating certain crops will be made prior to the irrigation and cropping season. Especially under scarcity conditions, farmers will have to plan their crops carefully. Those with access to groundwater are encouraged to use it by allocating to them only half of their surface water share.
Service agreement
There is a direct service link between the farmers and ORMVAM via the water masters (aiguadiers). There is no water users' association acting as an intermediary between farmers and ORMVAM. Farmers interests are defended in the elected Chamber of Agriculture (Chambre d'Agriculture) which is a member of the Governing Council of ORMVAM and the Regional Technical Coordination Committee (CTR). There is no real contract concerning water delivery between the ORMVAM and the farmers. However, farmers can make use of the irrigation services (ORMVAM, 1994) only if:
· they are official state-registered landowners, tenants or representatives in the event of co-ownership within the command area of the scheme;· they purchase land in accordance with the official regulations (code des investissements agricoles).
At this point, they obtain a statement (Deposition) allowing the farmer to benefit from the irrigation services by taking part in the irrigation cycles (Tour d'eau). This document constitutes an agreement which obliges the farmer to pay the service charges for a period of at least three years. For irrigation matters, ORMVAM only recognizes one single mediator with a mandate from the co-owners, in the case of subdivision of an ownership of less than five hectares. This procedure gives more responsibilities to the farmers and limits the number of mediators dealing with the system operators.
Cost recovery policy
In principle, farmers pay charges for investment costs in newly developed areas (flat rate per hectare) and for operation and maintenance costs. To stimulate efficient water use, the farmers are charged for irrigation services on the basis of volume of water delivered at their turnout. The water charges should in principle cover 10% investment amortization, 100% operational cost (Budget de fonctionnement), 100% maintenance cost and 40% plant renewal (Budget d'équipement). In practice, however, this distribution key cannot be applied as the price of water does not cover its cost. The present level of charges is DH 0.17/m3 for gravity irrigation. Extra charges for energy consumption are determined at a level of DH 0.13/m3 for the lift irrigation and DH 0.19/m3 for pressure irrigation (sprinkler)1.
1
1 DH = $US 0.09.
Water delivery policy
The structural water scarcity situation has resulted in: (i) a supply oriented water distribution system; and (ii) the payment for irrigation services based on volume of water supplied. This requires knowledge of the actual volume delivered to each consumer.
Each farmer with a land title will receive a predetermined volume of water per irrigation cycle with a duration of 10-14 days (Tour d'eau), usually in one but sometimes in two or more deliveries. Water is released at a fixed rate (20 or 30 l/s) through an ORMVAM managed turnout (prise) to a number of farmers who take the flow in turn one at a time and for a duration according to the schedule as agreed with the aiguadier. The volumes to be delivered are based on a list with the number of irrigations and the unit water requirements per crop in cubic meter per hectare per month. These are converted in duration of delivery (in hours) of the fixed unit irrigation rate. This volume depends on the crop, the time of year and the storage level in the reservoir.
Depending on the water availability and requirements, the management of ORMVAM decides on the implementation of an irrigation cycle, its duration and the volumes per hectare for the various crops to be applied. The starting dates of these tour d'eau are based on the need for irrigation so they are not fixed. This means that for each cycle, the delivery of water to individual farmers is fixed in terms of time and discharge. If water is sufficiently available, the cycles can be predicted quite accurately.
In scarcity situations, water-saving procedures consist of reducing the volumes to be delivered, reducing of the number of irrigations and, ultimately excluding low priority crops from irrigation, considering the severeness of the drought and the inflow and water availability in the reservoir. These decisions are taken prior to each cycle in coordination with the Regional Technical Committee.
For every cycle, the water master (aiguadier) prepares the FTE form (FTE = feuille de tour d'eau) for his area of jurisdiction. This form indicates the start and end of delivery to each farmer. After the delivery the farmers have to sign a note of acceptance of their share of water (Feuille de Control) which lists the date, time, duration, discharge of delivery and the total volume delivered. Based on this note, the level of payments will be determined by the tariffication bureau of ORMVAM. The accorded volumes consumed per land title are input in the computer and every six months the invoices are prepared and sent.
CONSTRAINTS AND POSSIBILITIES FOR IMPROVED SCHEDULING
The possibility for flexible water delivery required for water-saving irrigation scheduling in the Triffa scheme is constrained by several policy choices:
· The policy choice to have the scarce amount of water distributed by ORMVAM in an equitable, efficient and effective (= productive) way. This requires farmers to follow the ORMVAM schedules, which have been prepared in different degrees of participation depending on the water availability.· The policy choice on payment of water use based on volume. This has resulted in a water delivery policy of supplying predetermined volumes to individual users rotating fixed discharges for a predetermined duration between small groups of farmers. Deviating from this system will introduce considerable additional operational activities such as water distribution and discharge measurement (to farm level), consultation and administration at system level as well as with and between farmers. New working rules and accountability systems would have to be established and might not necessarily leading to a more effective and efficient overall use of water.
· The policy choice to have a gravity scheme has resulted in a mixed upstream flow control system in the main canal and an upstream control system in the laterals. Offtakes are all manually operated. More flexible delivery to the farmers might result in a more efficient use of water at farm level but will probably increase operational losses in the main system considerably. Adjustment of the flow control system is necessary.
· The present level of the irrigation fees does not enable increased staffing levels for more flexible delivery. Increased fees present a problem for the competitiveness of the produce on local and international markets.
Limited flexibility in hardware (flow control system) and software (staff, procedures, payment) limits the flexibility of water delivery to the users. An improved and more flexible delivery would mean a considerable increase in capital and operational costs. It is unlikely that under the present circumstances, where water rates are determined by the government and do not fully cover the cost for system management, farmers will be prepared to pay more for this additional service.
To stimulate water-saving irrigation practices, flexibility of irrigation scheduling and consequently a reliable and flexible water delivery are necessary. Under the present circumstances various measures are being taken by ORMVAM, as well as by some farmers:
· increase flexibility of the main canal flow control system (automation) to allow a more reliable delivery to (groups of) farmers;· a reduction of the duration and interval of the irrigation cycles enables a more flexible scheduling, especially for shallow-rooted crops (presently practised for vegetables);
· on-farm storage to reduce the dependence of the farmer(s) on the timing of deliveries (a necessity for farmers changing to drip irrigation);
· development of the use of groundwater in conjunction with surface water. Flexibility in scheduling can be obtained by combining the rigid delivery from ORMVAM with flexible additions from the groundwater. (Whether this can still be categorized under 'water-saving irrigation scheduling' very much depends on the price and cost of surface and groundwater. This requires further investigation.)
CONCLUSIONS
Introduction of water-saving irrigation scheduling must be done in a conducive environment where the policy choices support the required flexibility in water delivery. Flexible and effective scheduling at the field level does not automatically result in a more efficient overall water use. Infrastructure and operating costs are major constraining factors. In the Triffa scheme, flexible scheduling is constrained by the policy choices concerning volume-based payment of service charges, and the need to distribute the limited amount of water in an equitable but productive way. Flexible and reliable delivery will generally require a fairly automated flow control system. However, in the Triffa case, flexible delivery will also result in more complicated scheduling procedures within the established policy framework. This will lead to either higher levels of staffing or automation of the allocation, monitoring and processing. Given the policy constraints, flexibility in irrigation scheduling in the Triffa scheme can be improved by: (i) a more flexible delivery from the main canal by increasing the level of automation in flow control; (ii) automation of allocation procedures, data collection and processing; (iii) on-farm storage reservoirs; and/or (iv) conjunctive use with groundwater as an additional source.
REFERENCES
Ait Kadi. 1988. Major features of Moroccan large scale irrigation projects. ODI/IIMI Irrigation Network Paper 88/Id.
Hofwegen, P. van. 1994. Use and Utilities of Performance Parameters in the Triffa Scheme of ORMVA Moulouya. IIMI-IHE-ILRI Collaborative Research Programme on Irrigation Performance, IHE-Delft.
ORMVAM. 1994. Politique de livraison d'eau a usage agricole. Berkane.
