A/HRC/45/10 charges may have a retrogressive effect on the enjoyment of rights, particularly when the tariffs are high, leading people to avoid using services and putting a strain on public health.51 Another relevant area is the sustainability of services and facilities, in other words the continuity and improvement of services and facilities over time. 52 The privatization of water and sanitation services raises concerns related to sustainability since often private companies refrain from investing in the expansion, improvement or maintenance of infrastructure, especially when their contracts are due to be terminated imminently. E. Justification for non-compliance 60. In certain situations, there may be a justification for the action or inaction of States that amounts to retrogression or a failure to progressively realize rights. There is a strong presumption that retrogressive measures in relation to the human rights to water and sanitation are prohibited under the International Covenant on Economic, Social and Cultural Rights, except when States can show that retrogression was unavoidable despite having utilized all available resources. 53 When States refer to resource constraints as an explanation for the retrogressive steps taken, the Committee on Economic, Social and Cultural Rights considers such explanations on a country-by-country basis in light of certain objective criteria. 54 These justifications, however, should be understood with the caveat that States have made every effort to improve the way they execute their budget, spending all the allocated funding in a timely and effective manner. 55 61. It should also be understood, however, that the “maximum of available resources” does not constitute default grounds for all permissible justifications. Even when resources are very limited, States must still show that they have utilized those resources to give effect to rights to the extent possible. In particular, this principle does not alter the immediacy of the obligation and, therefore, even when States face a resource shortage, they must meet their minimum core obligations. In short, there is flexibility for States to determine the levels of resources they can make available to realize economic, social and cultural rights, and how to prioritize the allocation of those resources to different rights. Guideline: transparency and accountability 62. To avoid misusing or exploiting the principle of the maximum of available resources as a justification for States’ failure to implement their obligations, safeguards must be put in place to ensure that States are indeed using the maximum of their available resources. Several dimensions of maximum of available resources, particularly, maximum allocation and spending, should be accompanied by measures to uphold transparency. In Colombia, for example, the national System of Investments in Drinking Water and Basic Sanitation monitors the spending of financial resources in the sector, especially those resources that are transferred to local governments and with a special component to monitor the particular conditions of rural areas.56 VI. Monitoring 63. States have an obligation to monitor their compliance with and implementation of human rights and to devise national plans that set out such monitoring processes, which should be reviewed regularly to ensure that they meet the needs of the population. 57 Several methodologies have been adopted to assess and monitor compliance with the obligation to progressively realize human rights. 51 52 53 54 55 56 57 16 A/HRC/30/39, paras. 29–31. A/70/203, para. 36. Committee on Economic, Social and Cultural Rights, general comment No. 15, para. 19. E/C.12/2007/1, para. 10. Committee on Economic, Social and Cultural Right, general comment No. 3, para. 10, and general comment No. 15, para. 41. Submission from Colombia. Committee on Economic, Social and Cultural Rights, general comment No. 15, para. 37 (f).