The results obtained through the geophysical survey carried in this phase allowed to clarify several aspects of great interest, first of all providing a clear answer with respect to the continuity between the aquifer of the Cuenca de Esquipulas (Guatemala), and the aquifer present in of the Rio Lempa Valley downstream of Esquipulas, in Honduras and El Salvador.
What had been so far referred to as the Trifinio Transboundary Aquifer appeared at the end of this phase to be a string of two close but separate aquifers that followed the Rio Lempa valley floor. Strong geological evidence was gathered for the lack of continuity between the aquifer of the Cuenca de Esquipulas in Guatemala, and the valley aquifer of Ocotepeque in Honduras, the connecting element being represented by the Rio Lempa itself, contributing both to the discharge and the recharge of the aquifers.
The fact that two distinct groundwater bodies are present in the subsurface of the Upper Rio Lempa Valley has already been communicated to the main stakeholders, but a wider dissemination of this information is foreseen in the upcoming months. In particular, a Regional seminar will take place in July in Guatemala with this objective.
With additional short surveys on geological reconnaissance and re-interpretation of the hydro-geochemical data on surface and groundwater, the “Characterisation Phase” will be completed.
A sustainable development strategy for the Trifinio Aquifer Complex calls for the adoption of conjunctive surface and groundwater management approaches for the Upper Rio Lempa valley, including both segments of the Trifinio Aquifer Complex.