To evaluate and reflect thesustainability of services in the region, an overall sectorsustainability assessment was done taking into account fourmain dimensions: access to services, quality of services,efficiency of services, and financing of services. Each ofthese dimensions is measured through three simple andobjective indicators. For each indicator, best practicevalues are established by looking at the best performers inthe region, and the countries closest to those bestperformers are deemed to have a more mature sector. A morecomplete description of the methodology to assess sectorsustainability is included in the annex of the state of thesector regional report from the Danube Water Program. Theoutcomes of this assessment for the Croatia water sector aredisplayed in Figure 9, which also shows average and bestpractices in the Danube region. The Croatian sectorsustainability score is 72, which is above the Danubeaverage sustainability of 64. The assessment shows that onaverage, the country performs well in terms of access topiped water and flush toilets, continuity of service,nonrevenue water and customer satisfaction. The maindeficiencies of the Croatia water sector identified throughthe sector sustainability assessment are the wastewatertreatment coverage and the operating cost ratio. The mainchallenges are: financing compliance with the Europeanenvironmental acquis; ensuring affordability of futuretariffs; implementing successfully the aggregation reform;and strengthening regulation in the water sector.