Resumen
This paper is a Colombian case study that calculates the total water footprint (blue, green, and grey) for heavy crude production (11.5 average API gravity) occurring in three fields, located in the Magdalena watershed. In this case study, the highest direct blue footprint registers 0.19 m3/barrel and is heavily influenced by cyclic steam stimulation practices. This value could be reduced if the water coming out of the production well was to be cleaned with highly advanced wastewater treatment technologies. The highest grey water footprint, at 0.06 m3/barrel, is minimal and could be reduced with conventional wastewater treatment technologies and rigorous maintenance procedures. The green water footprint is negligible and cannot be reduced for legal reasons. The indirect blue water footprint is also considerable at 0.19?0.22 m3/barrel and could be reduced if electricity was produced onsite instead of purchased. In addition, the paper identifies methodological flaws in the Colombian National Water Study (2014), which wrongly calculated the direct blue water footprint, leading to a 5 to 32-fold sub-estimation. It also ignored the grey, with important implications for water resource policy and management. To rectify the situation, future National Surveys should follow the procedure published here.