Water and Urban Land‐Use Planning in Cali, Colombia

Abstract

A multiobjective urban land‐use/water‐resource model, appropriate for use at the strategic planning level in less‐developed countries (LDCs), is described and applied to Cali, Colombia. Objectives are to minimize service costs and biochemical oxygen demand (BOD) loadings and maximize service levels while accommodating population growth. Vector optimization based on generating techniques allocates new residents to potential urban‐expansion zones while simultaneously determining the optimal mix of various water‐supply and sanitation systems. Potential flood impacts are then simulated and the results used to constrain development in critical areas. Further flood control and reduction of nonpointsource pollution via detention basins are examined. Postoptimality analysis shows solutions to be quite sensitive to estimated water consumption and preset density limits. Deficiencies due to the optimization‐simulation linkage and the runoff modeling assumptions are discussed and their significance for such modeling in LDC settings is appraised.