Abstract:
This research conducted to deep groundwater aquifer mapping for fresh water supply in sub
district Reteh Indragiri Hilir Regency of Riau Province. There are nine of Villages have been
measured using Schlumberger configuration geoelectric method. The result of the research there
are four formation layers in that region. The result also correlated with regional geology formation
map which formation rock is consisting of the alluvium of upper Minas and Palembang
formations. The result of geoelectric measurement from top to bottom layers, the first layer has
resistivity average < 100 Ωm with 7.5m – 15m average thickness, interpreted as peat moss and soil
contain water brackish. The second layer has resistivity average 90 to 150 Ωm with 50m to 130m
average of thickness, interpreted as unconsolidated sandstones and clay, this layer consist of free
aquifer saturated groundwater which is intruded water surface. The third layer has resistivity
250Ωm with 50m to 120 m average of thickness, interpreted as compact and consolidated
sandstones which are contain fresh groundwater supplay. Finally the fourth layer has resistivity >>
4000Ωm interpreted as hard rock (bedrock), compact and impermeable. From nine villages
conducted geoelectric measurement possibility there are any aquifer and fresh groundwater supply,
but do not have artesis source, this match to local geology which is formation are stream terrace
and alluvial
