The Cape Restionaceae species, an endemic of the Fynbos Biome, is threatened by urbanization, alien plant invasion, agricultural expansion, and groundwater extraction. This is further worsened by the semi-arid conditions and hydrological variability factors, which influences species niche dynamics. Therefore, it is important to assess and monitor the Restionaceae species for preservation of their endemism and richness. This study models the hydrological niche and distribution changes of Restionaceae species at the New Years Peak (NYP) at microclimate level for biodiversity conservation. MaxEnt modelling and GIS analytical approaches were applied at various stages in niche modelling process as follows: (i) microclimatic input raster layers’ generation, (ii) ecological modelling and hydrological niche manipulation, and (iii) spatial distributional change mapping. The hydrological niches of the Restionaceae were effectively examined under the recent climate and compared with RCP2.6 and RCP8.5 future climate scenarios as the microscale environmental inputs. The results showed that most of the studied Restionaceae species positioned themselves along a hydrological gradient. Each species tolerated a range of hydrological conditions, which formed their hydrological niche. Changing climate would cause both positive and negative species range shifts. The study assists in plant species conservation and future climate change impact analysis on endangered plant species.