Slovenia was affected by severe floods in 2010, 2012, 2013 and 2014. The region of the Lower Mislinja valley, with which I dealt with in my master thesis, was among them, too. The extent of latest floods from 2012 was the basis where to study the settlement density growth. First I outlined the flood issue in Slovenia. Then the methodology of thesis is presented. Then the settlement growth from 1821 to 2014 is presented. It is based on the Second military charts of the Austro-Hungarian Monarchy from 1821-1836, the Building cadastre (the attribute describing the year in which houses were constructed) and orthophoto maps from Cyclical Aerial Surveying of Slovenia from 1999 to 2014. The land use changings especially areas of buildings from 1985 to 2014 is also presented. These have been collected from spatial planning regulations and acts of municipalities for three different time sections (1985, 1999 or 2004 and 2014). The analysis of spatial planning acts of municipalities was made, where we searched for regulations connected with flood-safety and the safety of potentially flooded areas. The last topic discussed in this work is the flood water height level on buildings flooded in the year 2012. It has been concluded that the spatial planning acts of municipalities pay attention to flooding, but there are troubles realizing them in practice. On the discussed area there is a constant increase in the number of building plot, as well as, number of facilities is growing through time All the facilities having been built in this areas, suffer from immense damage, when flooded. The damage could be avoided by the restriction of building land spread on flood threated terrain.