A/HRC/30/39 60. While being easier and cheaper to administer, they have the drawback of not always being able to differentiate between people living in poverty, who may be able to pay a small amount, and people living in extreme poverty, who cannot afford to pay more than a nominal sum or anything at all. In many instances, it may be useful to utilize a mixture of mechanisms. For example, a comparison of schemes of subsidies in Chile (based on household means) and in Colombia (based on categories of socio-economic status and socio-geographic context) suggests that means-tested subsidies are more effective at identifying poor households than geographically targeted schemes. 36 For example, it may be beneficial to provide subsidies automatically in low-income areas, but to permit people outside such areas to apply for subsidies on the basis of their low income. Moreover, where an income supplement is provided, households that are not connected to a network, including those living in rural areas, could also be eligible. E. Social protection floors 61. A broader mechanism for achieving access to water and sanitation services for people living in poverty is to put in place “social protection floors”. These are nationally defined basic social security guarantees that ensure access to essential services, including water and sanitation, as well as providing basic income security to those in need. 37 Human Rights Council resolution 28/12 of 9 April 2015 acknowledged “that social protection floors may facilitate the enjoyment of human rights… safe drinking water and sanitation, in accordance with the human rights obligations of States” and encouraged “States to put in place social protection floors as part of comprehensive social protection systems” (A/HRC/RES/28/12, paras. 6 and 8). Social protection floors can be particularly relevant for achieving gender equality and protecting marginalized or disadvantaged individuals and groups. At the national level, for instance, Cambodia has made support for sanitation and water in times of emergency and crisis a key intervention under the National Social Protection Strategy for the Poor and Vulnerable. 38 In Mexico, the federal budget for social spending, which contributes to building a social protection floor, includes water supply and sewerage.39 F. Ensuring affordability through tariff schemes 62. Other types of mechanisms to ensure the affordability of services can be built into tariff schemes. Different tariff systems have different potentials but also limitations to ensure the affordability of services. These are generally only relevant to those connected to piped water and sewerage systems. 1. Flat rate 63. Flat rates are commonly used where meters are not installed, where a charge based on a certain volume of water used or sewage discharged would be impossible to implement. Some countries use property taxes as the basis for charging unrelated to consumption. Differentiated flat rates could be used that rise or fall depending on such criteria as 36 37 38 39 16 Andrés Gómez-Lobo and Dante Contreras, “Water subsidy policies: a comparison of the Chilean and Colombian schemes”, The World Bank Economic Review, vol. 17, No. 3 (2003), pp. 391-407. International Labour Organization (ILO), “Social Protection Floors Recommendation” recommendation No. 202, 2012. UNDP and ILO, Sharing Innovative Experiences, Successful Social Protection Floor Experiences (2011), p. 125. Ibid., p. 299.