ADVANCES IN THE SUSTAINABLE MANAGEMENT OF THE YAQUI RIVER RESERVOIRS SYSTEM OCTOBER 20, 2003

ACTUAL WATER RESOURCES PROBLEM

PRECIPITATION IN YAQUI RIVER UPPER BASIN (mm) ( ) YEARS PRECIPITATION (mm)

DEVIATION FROM AVERAGE PRECIPITATION (mm) ( ) DEVIATION FROM MEDIAN PRECIPITATION (mm) YEARS

DROUGHT INDEX USING “SPI” METHOD ( ) DROUGHT

HISTORICAL RESERVOIR INFLOW AND OUTFLOW IN YAQUI BASIN (MCM). ( ) MEDIAN 2842 ANNUAL RESERVOIR INFLOW (MCM ) MEDIAN 3085

DEVIATION FROM MEDIAN RESERVOIR INFLOW (MCM ) YEARS DEVIATION FROM MEDIAN RESERVOIR INFLOW (MCM) ( ) DROUGHT MEDIAN 2842

HISTORICAL RESERVOIR MANAGEMENT ( INFLOW vs OUTFLOW) IN YAQUI BASIN (MCM) ( ) -2,905.0 MCM 10,622.0 MCM 5,401.8 MCM

STORAGE VOLUME OF WATER IN YAQUI RESERVOIR SYSTEM, OCTOBER 1 ST ( MCM) ( ) YEARS (3,084 (MCM) 74 % FROM AVERAGE 4189 MCM 1105

YAQUI RIVER RESERVOIR MANAGEMENT (VOLUME OF STORED WATER AT THE END OF THE MONTH IN MCM) DEAD STORAGE MONTHS

AVAILABLE VOLUME OF WATER FOR THE AGRICULTURAL YEAR (OCTOBER 1 ST, 2003). IRRIGATION DISTRICT 041 SURFACE WATER (MCM) GROUNDWATER (MCM) TOTAL (MCM) TOTAL

CAUSES NATURALANTHROPOGENIC DROUGHT CONDITIONSEXCESSIVE SURFACE WATER WITHDRAWAL (SOCIAL AND ECONOMIC PRESSURE) CLIMATE CHANGES ???????BUILDING SMALL RESERVOIRS IN THE BASIN. GROUNDWATER POLLUTION THERE IS NOT LONG-TERM PLANNING FOR WATER RESOURCES

SUSTAINABILITY CRITERIA The World Commission on Environment and Development (Bruntland, WECD, 1987) defines sustainability as: “Development that meets the needs of the present without compromising the ability of the future generations to meet their own needs”.

SHORT-TERM MODEL (FIRST YEAR, 2002) OBJECTIVE FUNCTION (MAXIMIZE PROFITS) RESERVOIR STORAGE CONSTRAINTS RELEASES CONSTRAINTS CONTINUITY CONSTRAINTS IRRIGATION CONSTRAINTS MARKETING CONSTRAINTS

SUSTAINABLE WATER RESOURCES MANAGEMENT MODEL. MODELING SUSTAINABILITY IN THE YAQUI BASIN REQUIRES SPECIFYING THE RELATIONS BETWEEN WATER USES IN THE PRESENT AND THEIR LONG-TERM CONSEQUENCES,

LONG-TERM MODEL (SECOND YEAR, 2003) RISK CRITERIA a).- Reliability b).- Vulnerability c).- Reversibility EQUITY CRITERIA

EQUITY CRITERION EQUITY CRITERION IS USED IN THE MODEL TO: 1.- ENSURE THAT WATER USE BENEFITS ARE NON- DECREASING IN ALL YEARS. 2.- ENSURE THAT PEOPLE AT DIFFERENT YEARS HAVE EQUITABLE ACCESS TO WATER SUPPLY FOR AGRICULTURAL DEVELOPMENT AND M&I USE.

LONG-TERM OBJECTIVE FUNCTION WHERE S s = Sustainability indicator of the Yaqui Reservoir system s = System index

DATA AND ASSUMPTIONS THE PLANNING HORIZON MODELED IS 15 YEARS, FROM 1993 TO FROM 1993 TO 2003 REAL DATA WAS USED. THE SAME CROP PATTERN WAS USED DURING THE PLANNING HORIZON, WHERE THE MAJOR CROPS ARE WHEAT, MAIZE, OILSEEDS, COTTON, SOYBEANS, ALFALFA AND FRUITS. CROP YIELD, CROP PRICE, AND CROP COSTS WERE USED TO ESTIMATE ECONOMIC BENEFITS. THE SAME TOTAL IRRIGATION DISTRICT EFFICIENCY WAS USED DURING THE PLANNING HORIZON. REAL DATA FROM THE AQUIFER WAS USED. REAL RESERVOIRS INFLOW WAS USED THE FIRST 10 YEARS, USING DRY SCENARIOS FOR THE NEXT 5 YEARS. FIVE DIFFERENT LEVELS OF OPERATION (MINIMUM) ARE USED; 900, 2000, 2500, 2800 AND THE REAL SCENARIO.

PRELIMINARY RESULTS

STORAGE VOLUME AT OCTOBER 1 ST MINIMUM OPERATION LEVELS (JUNE)

AVAILABLE VOLUME OF SURFACE WATER IN YAQUI VALLEY, OCTOBER 1 ST (10 3 CUBIC METERS) MINIMUM OPERATION LEVELS (JUNE)

AREA PLANTED WITH DIFFERENT CROPS IN YAQUI VALLEY MINIMUM OPERATION LEVELS (JUNE)

SUSTAINABILITY INDEX FOR DIFFERENT RESERVOIRS MANAGEMENT LEVELS. LEVEL INDEX NO RESTR. REAL AREA RELIABILITY VOLUME RELIABILITY AREA VULNERABILITY VOLUME VULNERABILITY AREA REVERSIBILITY VOLUME REVERSIBILITY EQUITY

m m 3

TOTAL AGRICULTURAL NET ECONOMIC BENEFITS UNDER DIFFERENT RESERVOIRS MANAGEMENT LEVELS OPERATION LEVELAGRICULTURAL NET ECONOMIC BENEFITS 2000$ 6,975,825, $ 6,618,929, $ 6,231,750,966 NO RESTRICTIONS$ 5,855,594,116 REAL$7,215,496,858** **Source: SAGARPA

PROGRAM FOR THE YEAR 2004 INCLUDE IN THE LONG-TERM MODEL THE NEXT SUSTAINABLE INDICES: 1.- HYDRAULIC INFRASTRUCTURE SUSTAINABILITY. 2.- ENVIRONMENTAL SUSTAINABILITY ( SOIL AND WATER QUALITY). 3.- ECONOMIC SUSTAINABILITY. TO DEVELOP SUSTAINABLE RESERVOIR OPERATION RULES. INCLUDE THE STOCHASTICITY OF THE RANDOM VARIABLES USING MONTECARLO SIMULATION. TO DEVELOP A LONG-TERM DROUGHT PLAN.

MUCHAS GRACIAS