Repeatedly occurring droughts in the Czech Republic in previous years have heightened the need to answer questions concerning the provision of drinking water in small municipalities in the context of their development. The goal of the research was to assess what mutual relationships exist between insufficient drinking water supply and the socio-economic level of municipalities with less than 2000 inhabitants. The basis of the study is formed by data collected via a questionnaire survey of the mayors of 2110 municipalities. For the purposes of the analysis, the Drinking Water Supply Threat Index (DWSTI) composite indicator was established. Subsequently, the effect of selected factors on DWSTI was determined via correlation and regression analysis, and results were compared for two size groups of municipalities indicate water supply problems. The digging of new wells for individual needs is seen to be the most significant signal of problems. The absence of water supply infrastructure results in a heightening of the socio-economic deprivation of small municipalities, as it limits new building and becomes a limitation to their development. A solution is possible based on regional or trans-regional financial and managerial support of development together with an active approach on the part of municipalities.