Using geomembranes to improve the storage efficiency of runoff catchment ponds in the community of El Rincon, in Queretaro, Mexico: A benefit-cost analysis

This study presents a benefit-cost analysis of using geomembrane liners to improve the water storage efficiency of four runoff catchment ponds for one case study in Querétaro, Mexico. The lining technique is intended to help increase irrigation capacity (agricultural production) by eliminating the infiltration loss of stored pond water. The study uses rainfall, evaporation, and animal consumption data to calculate rainfall runoff (potential catchment) and each source of stored water loss from the four ponds. After determining that rainfall runoff is sufficient to fill the ponds on an annual basis, the study calculates project-generated water savings by comparing rates of runoff accumulation and evaporation loss for the critical dry season carry-over. The value of this water is calculated by predicting its yield-enhancing effect on two crops: irrigated (“punta de riego”) corn and cempasuchil. A net present value and benefit-cost ratio is calculated for each of the four ponds to determine the project's cost-effectiveness.; This study concludes that for the ponds and crops studied, the installation of geomembranes is not a cost-effective means of increasing agricultural production. However, Geomembranes should not be fully discounted as a potential water management tool for the site without further study as to their cost-effectiveness and overall feasibility.