This document presents a virtual grid-based dynamic routes adjustment (VGDRA) scheme for wireless sensor networks with a mobile sink. The scheme aims to minimize the energy consumed when sensor nodes adjust their routes to the sink's new location. It divides the sensor field into a virtual grid with cell headers. When the sink moves, only the cell headers participate in rerouting to the new location, reducing the communication cost compared to all nodes adjusting routes. The VGDRA scheme maintains nearly optimal routes to the mobile sink while minimizing the cost of route reconstruction as the sink moves.