The hydrogeological regime covering a section passing from Anamaduwa to the Kalpitiya peninsula in northwest Sri Lanka was examined to understand the groundwater flow across the metamorphic and sedimentary rock terrains. The study was conducted as a hydrogeological survey based on a structured questionnaire (n = 82) on the consumption, water level fluctuation, and water supply, supplemented by field examination of shallow dug (n = 20) and tube wells (n = 62). In Kalpitiya the average water level fluctuation was 3.44 m (vary from 2.95 to 6.39 m) while it was 6.27 m (vary from 2.25 to 8.52 m) in the Anamaduwa-Puttalam area. The drinking water supply in Kalpitiya was 24 hours per day irrespective of the dry or wet climate. However, in the Anamaduwa-Puttalam area, it was 14 hours during the dry period while it may extend up to 21 hours during the wet period. The average daily per capita domestic water consumption in the Kalpitiya area was 72.4 L while in the Anamaduwa-Puttalam area, it was 81.5 L. The EC of groundwater in the Anamaduwa-Puttalam area varies from 0.479 to 35.42 dS/m (average 3.336 dS/m) whereas the TDS varies from 319 to 23360 mg/L (average 2190 mg/L). However, in Kalpitiya peninsula EC varies from 0.339 to 5.980 dS/m (average 1.457 dS/m) whereas the TDS varies from 223 to 3847 mg/L (average 962 mg/L). Barring of groundwater flow through faulted basins in Andigama-Anamaduwa area and near the unconformity between Wanni complex and limestone belt are hydro-geologically responsible for the higher EC (>2.500 dS/m) and TDS (>2000 mg/L). Seawater intrusions along with sandy aquifers in the Kalpitiya peninsula are responsible for the EC/ TDS variations. Moreover, Kalpitiya indicates better prospects compared to landward areas. The outcome highlighted future water sector challenges in support of achieving the Sustainable Development Goal (SDG) target 6 in the study area.

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