What is conjunctive use of surface water and groundwater?

Conjunctive use is coordinated management of surface water and groundwater to maximize water availability and reliability. Surface water (variable but large) used during wet periods; groundwater (stable but limited yield) supplements during dry periods. Methods include: aquifer storage and recovery (ASR), recharge basins, streambed infiltration, and managed aquifer recharge. Benefits include drought resilience, peak demand management, reduced infrastructure costs, and water quality blending. Requires understanding of aquifer properties and surface-groundwater interactions.