A preliminary screening framework for retention pond siting in flat terrains using resistivity–depth compatibility

ABSTRACT

Retention ponds are widely implemented as a low-impact development strategy; however, site selection in flat areas remains challenging because natural depressions are often absent and locations are frequently chosen based on land availability rather than subsurface suitability. Comprehensive geotechnical investigations are often time-consuming and costly at early planning stages. This study presents a preliminary feasibility screening approach for retention pond site selection based on subsurface resistivity interpretation and excavation depth compatibility. In this study, because the proposed retention ponds function primarily as water storage facilities rather than infiltration systems, clay-rich subsurface conditions are considered favourable. Electrical resistivity surveys using a Wenner–Schlumberger array were conducted to generate two-dimensional resistivity models, which were interpreted in terms of lithology and permeability within the planned excavation depth. An ordinal scoring scheme was applied to evaluate clay-rich layer dominance, depth compatibility, and the presence of permeable materials, allowing sites to be classified as feasible, conditionally feasible, or not feasible. The proposed approach was applied to five candidate sites in a flat urban setting. The results indicate that resistivity-based screening provides a practical and cost-efficient tool for early-stage retention pond site selection in flat terrains.