<b>Source data for the article </b><b>“</b><b>Water beetles (</b><b><i>Coleoptera</i></b><b>) of the south‑eastern Altai (Siberia), steppe–tundra Pleistocene refugia</b><b>”</b>

Samples of aquatic beetles were collected in 2023 in the Republic of Altai (Russia) in two areas: the upper Chuya River basin (13–20 July; 13–23 August) and the Ukok Plateau (22 July–11 August), using sweeping with an aquatic net. Files included: "waterbodies.csv" contains the characteristics of water bodies id – waterbody IDlat – latitudelon – longitudetype – type, including origin (F, floodplain (inundated), including oxbows; MD, moraine‑dammed; TK, thermokarst; l, lake; p, pond; pl, pool; m, mire)sp_num – species richness in each water body; elevation – altitude, m a.s.l.; area – surface area, km²; tds – mineralisation, ppm; landscape – landscape type (alpine level, dwarf‑birch tundra, mesic woodland, steppe)cluster – water‑body cluster number in the association analysis. "species.csv" is a species–samples matrix species – species binomial Latin namecluster – species cluster number in the association analysis V1–V42 – waterbody IDs corresponding to the same IDs in the waterbodies.csv file