INTEGRATED MANAGEMENT OF LANDBASED ACTIVITIES IN THE SÃO FRANCISCO BASIN PROJECT ANA/GEF/UNEP/OAS Subproject 4.3 - Quantification and Assesment of the Efficiency of Water Usage by Agriculture in the São Francisco River Basin Executive Summary of the Final Report QUANTIFICATION AND ASSESSMENT OF THE EFFICIENCY OF WATER USAGE BY AGRICULTURE IN THE SÃO FRANCISCO RIVER BASIN UNIVERSIDADE FEDERAL DE VIÇOSA Departamento de Engenharia Agrícola Viçosa – MG INTEGRATED MANAGEMENT OF LANDBASED ACTIVITIES IN THE SÃO FRANCISCO BASIN PROJECT ANA/GEF/UNEP/OAS Subproject 4.3 - Quantification and Assesment of the Efficiency of Water Usage by Agriculture in the São Francisco River Basin Executive Summary of the Final Report QUANTIFICATION AND ASSESSMENT OF THE EFFICIENCY OF WATER USAGE BY AGRICULTURE IN THE SÃO FRANCISCO RIVER BASIN Technical Coordination Coordenador: Márcio Mota Ramos Coordenador Adjunto: Fernando Falco Pruski Suely de Fátima Ramos Silveira - UFV Demetrius David da Silva - UFV Lineu Neiva Rodrigues – OEA Consultants Wallisson da Silva Freitas Sérgio Oswaldo de Carvalho Avellar Alessandro de Freitas Teixeira Gessionei da Silva Santana Rafael de Almeida Ribeiro Nori Paulo Griebeler January 2003 QUANTIFICATION AND ASSESSMENT OF THE EFFICIENCY OF WATER USAGE BY AGRICULTURE IN THE SÃO FRANCISCO RIVER BASIN EXECUTIVE SUMMARY INTRODUCTION In the elaboration of the “Integrated Management of Land Based Activities in the São Francisco River Basin Project - GEF/ANA/OAS/UNEP, also known as the GEF São Francisco Project, irrigation was identified as responsible for the consumption of approximately 70% of the water diverted from the São Francisco, which could be affecting the availability of the resource. Even though the irrigated area in the Basin is still small, corresponding to less than 10% of the irrigable area, they are concentrated in regional poles. Besides this, there are evidences that irrigated agriculture in the Basin presents a really low efficiency. These facts led to the inclusion of Activity 4.3 (Quantification and Assessment of the Efficiency of Water Usage by Agriculture in the São Francisco River Basin) in the São Francisco Project. The Activity was implemented with donation funds provided by the Global Environmental Facility – GEF and was implemented by the United Nations Programme for the Environment – UNEP. The international executive agency was the General Secretariat of the Organization of American States – OAS and the original national executor was the Water Resource Secretariat of the Ministry of the Environment – SRH / MMA, until May of 2001, when the responsibility was transferred to the National Water Agency – ANA. The Federal University of Viçosa (UFV), through its Agricultural Engineering Department, was responsible for the coordination of the Activity, whose objectives were quantifying the availability of water in the Basin, characterizing the use of water by agriculture and assessing irrigation efficiency. The fulfilling of these objectives will provide subsidies for the optimization of the use of the water resources and, consequently, augmentation of the availability. Thus, the work is subdivided into chapters corresponding to a description of the Basin’s general characteristics, to an analysis of its hydrologic regime and to the use of water by irrigation. 1. GENERAL CHARACTERISTICS OF THE SÃO FRANCISCO BASIN The São Francisco Basin (Figure 1) is located between the 7º and 21º S latitudes and the 35º and 47º40’ W longitudes, spreading over the States of Minas Gerais, Bahia, Goiás, Pernambuco, Sergipe and Alagoas, besides the federal District. From its origin, in the Sierra da Canastra, to its mouth in the Atlantic Ocean, the River travels around 2,700 km, draining a 639,219 km2 area, in which there are 503 Municipalities, with a 1999 population of 15,545,866 inhabitants (CODEVASF, 2002b). The Basin is traditionally divided into four sub regions: the Upper São Francisco (from its origin to the City of Pirapora); the Middle São Francisco (from Pirapora to the City of Remanso); the i Middle-Lower São Francisco (from Remanso to Paulo Afonso) and the Lower São Francisco (from there to its mouth). Figure 1. São Francisco Basin (from http://www.sfrancisco.bio.br/mapbacia.htm) ii In the mouth of the River, the long term mean discharge is presented in the literature with values varying from 2,850 (ANA, 2002b) to 3,360 m3/s (ANA, 2002a; ANEEL, 2002a). The tributaries with permanent flows originate, predominantly, in the cerrados of Minas Gerais (Upper and Middle São Francisco) and in the Western part of Bahia, thanks to the higher precipitation depths in the Region and to the great permeability and thickness of the local soils. Around 85% of the water in the River is originated in the cerrados and 72% comes from the State of Minas Gerais. Water demands for the various uses in the basin are around 224 m³/s. From this total, 28 m³/s (12.5%) are for urban supply, 160 m³/s (71.4%) for irrigation, 7 m³/s (3.1%) for animal consumption and 29 m³/s (13%) for industrial purposes (ANA, 2002b). The São Francisco, with annual potential water storage of 64.4 billion m3 (2,042 m3/s), is responsible for 69% of the total surface reserves and 73% of the firm availability in Northeastern Brazil. The surface storage capacity in the Northeast is 85.1 billion, with 50.9 billion stored within the Basin, in the reservoirs of Sobradinho (34.1 billion), Itaparica (11.8 billion), Xingó (3.8 billion) and Moxotó (1.2 billion). Três Marias, outside of the Northeast, but within the São Francisco Basin, stores additional 19.3 billion m3 (CODEVASF, 2002b). Until the end of 2000, the Company for the Development of the São Francisco and Parnaíba Rivers (CODEVASF) had already built 270 dams with a total storage capacity of 1.4 billion m3. According to the Brazilian Hydroelectric Power Information System, of the Brazilian Hydropower Systems and Electrical Plants Planning Coordination Group, the São Francisco Basin has a potential power generation in the order of 26,346 MW. Until November of 1997, 9,290 MW were already installed and operating, what persists until now. At the time, plants with 1,000 MW capacity were under construction. The São Francisco Basin, with 64 million hectares, has 25.6 million hectares (40%) of agriculturable land. In the Upper and Middle São Francisco, where rainfalls are more abundant and regular, rainfed agriculture predominates. In the Middle-Lower, the activity is limited, as the area rests on the Semi-Arid Region. The downstream part of the Middle is also within the semi- Arid, being subject to the same restrictions (Vale do São Francisco, 2002c). Of the agriculturable land, 3 million hectares are irrigable, but only 300.000 hectares (10%) are presently being irrigated (Vale do São Francisco, 2002b). According to Lima and Miranda (2001), from 1970 to 1990, irrigated area in the São Francisco presented a 286% growth, which corresponds to 8,620 ha/year, while the economic development growth was 266%. Only in the 1980-1990 period, irrigated area in the Basin reached 61%. Governmental involvement in the São Francisco Basin is significant, being represented mostly by CODEVASF, whose basic mission is to promote regional development, through irrigated agriculture. The major part of the Basin presents ideal climatic conditions for irrigation, combining elevated temperatures and sunlight with relatively low humidity. Nevertheless, water deficit is high, given the small amount of precipitation and irregular distribution of rainfalls. The Region has a great diversity of climates, going from humid, in the Southern and Western parts, to semi-arid, in the Juazeiro/Petrolina area. Annual mean precipitation depths vary from 400 to 1,600 mm. iii From 1970 to 2000, irrigated areas in the Semi-Arid underwent significant changes, particularly with respect to the used crops. Irrigation projects in the Basin, both public and private, still lack adequate planning and, even after their implementation, they have not been subject to a proper management. The water resources sustainability indexes estimated by studies under way area cause of concern, with respect to the availability of water for multiple uses. Some areas, such as Northern Minas Gerais, Rio Verde Grande Basin and the Salitre River Basin, in the State of Bahia, are already considered critical, regarding the demand/availability ratio. According to CODEVASF (2002c), in 1994, the multipurpose demands in the Basin were 9.1 billion cubic meters: 6.4 billion (70.3%) corresponding to ecologic demand (non-consumptive) and 2.7 billion (29.7%) to consumptive uses. Even though the São Francisco Basin has presented a significant growth in agricultural activities, the results were not immediate for the regional economy. That was due to a decentralized commercialization of the products, still with inadequate quality and standards, and to the lack of air transportation to allow the conveyance to the distribution and consumption centers. Today, regional centers such as Juazeiro-Petrolina, Pirapora, Janaúba-Jaíba, and Barreiras, have stood out both in the production and commercialization of their products, and the installation of agroindustries has resulted in added value to the products, in the own Region. Some of these centers are more noticeable in the Basin, due to their geographical location, existing infrastructure and also by their level of production. Chart 1 presents water demands in the São Francisco Basin and indicates that irrigation is responsible for 74.1% of the consumptive use. The present development of the São Francisco Basin is, in part, due to the implementation of public and private irrigation projects, which changed and continue to change the regional economy. This change, however, occurred in a relatively short period, for approximately 20 years, which was not enough to allow immediate learning and adoption of adequate irrigation management techniques, nor of preventive and corrective maintenance of the equipment. Chart 1. Water demands in the São Francisco Basin, by type and use, in 1994.