title: Financial feasibility of end-user designed rainwater harvesting and greywater reuse systems for high water use households.
abstract: Water availability pressures, competing end-uses and sewers at capacity are all drivers for change in urban water management. Rainwater harvesting (RWH) and greywater reuse (GWR) systems constitute alternatives to reduce drinking water usage and in the case of RWH, reduce roof runoff entering sewers. Despite the increasing popularity of installations in commercial buildings, RWH and GWR technologies at a household scale have proved less popular, across a range of global contexts. For systems designed from the top-down, this is often due to the lack of a favourable cost-benefit (where subsidies are unavailable), though few studies have focused on performing full capital and operational financial assessments, particularly in high water consumption households. Using a bottom-up design approach, based on a questionnaire survey with 35 households in a residential complex in Bucaramanga, Colombia, this article considers the initial financial feasibility of three RWH and GWR system configurations proposed for high water using households (equivalent to >203 L per capita per day). A full capital and operational financial assessment was performed at a more detailed level for the most viable design using historic rainfall data. For the selected configuration ('Alt 2'), the estimated potable water saving was 44% (equivalent to 131 m3/year) with a rate of return on investment of 6.5% and an estimated payback period of 23 years. As an initial end-user-driven design exercise, these results are promising and constitute a starting point for facilitating such approaches to urban water management at the household scale.
authors.affiliation: Grupo de Investigación en Recursos Hídricos y Saneamiento Ambiental (GPH), Escuela de Ingeniería Civil, Facultad de Ingenierías Físico-Mecánicas, Universidad Industrial de Santander, Carrera 27 Calle 9, Bucaramanga, Colombia.
authors.forename: Edgar Ricardo
authors.initials: ER
authors.lastname: Oviedo-Ocaña
authors.affiliation: Grupo de Investigación en Recursos Hídricos y Saneamiento Ambiental (GPH), Escuela de Ingeniería Civil, Facultad de Ingenierías Físico-Mecánicas, Universidad Industrial de Santander, Carrera 27 Calle 9, Bucaramanga, Colombia.
authors.forename: Isabel
authors.initials: I
authors.lastname: Dominguez
authors.affiliation: Centre for Water Systems, College of Engineering, Mathematics and Physical Sciences, University of Exeter, Kay Building, North Park Road, Exeter, EX4 4QF, UK. sarah.ward@exeter.ac.uk.
authors.forename: Sarah
authors.identifier: http://orcid.org/0000-0002-1432-4204
authors.initials: S
authors.lastname: Ward
authors.affiliation: Grupo de Investigación en Recursos Hídricos y Saneamiento Ambiental (GPH), Escuela de Ingeniería Civil, Facultad de Ingenierías Físico-Mecánicas, Universidad Industrial de Santander, Carrera 27 Calle 9, Bucaramanga, Colombia.
authors.forename: Miryam Lizeth
authors.initials: ML
authors.lastname: Rivera-Sanchez
authors.affiliation: Grupo de Investigación en Recursos Hídricos y Saneamiento Ambiental (GPH), Escuela de Ingeniería Civil, Facultad de Ingenierías Físico-Mecánicas, Universidad Industrial de Santander, Carrera 27 Calle 9, Bucaramanga, Colombia.
authors.forename: Julian Mauricio
authors.initials: JM
authors.lastname: Zaraza-Peña
mesh_terms: D003105:Colombia; D000074067:Conservation of Water Resources / Q000191:economics* / Q000379:methods*; D060766:Drinking Water; D006798:Housing; D011891:Rain; D062065:Wastewater; D014881:Water Supply / Q000191:economics
chemical_list: D060766:Drinking Water; D062065:Wastewater
keywords: Alternative water supply systems; Colombia; End-user; Financial feasibility; Greywater reuse; Rainwater harvesting