Could this be Sleep Dealer (2008)?

The near future. Like tomorrow. In a world marked by closed borders, corporate warriors, and a global computer network, three strangers risk their lives to connect, break through the barriers of technology, and unseal their fates.

This synopsis mentions the water and the drones.

Memo (Luis Fernando Peña), a young Mexican, lives on a milpa in Santa Ana, Oaxaca with his family. Once, a river flowed through the milpa, which his father owns. But a few years ago, the Del Rio Water Company built a dam upstream. Now, residents of Santa Ana must pay $1/gallon to enter the facility and collect water.

In his spare time, Memo tinkers with discarded radio parts and builds an antenna to pick up voices from far away. One night, he overhears a transmission between Rudy (Jacob Vargas), a drone gunship operator, and his compatriots. His signal is detected, and tracked down to his family's shack in Santa Ana. Live on TV the next day, Rudy carries out a mission to neutralize an "aqua-terrorist intercept". As Memo and family watch on their TV, they soon realize that the target is the antenna on top of their shack. They run back to the shack, only to see it obliterated by a hovering drone gunship. As Memo's father crawls out of the building, Rudy gets confirmation that he is a known "aqua-terrorist", and Rudy fires a rocket at him, blowing him to bits.

This is Sleep Dealer (2008).

The near future. Like tomorrow. In a world marked by closed borders, corporate warriors, and a global computer network, three strangers risk their lives to connect, break through the barriers of technology, and unseal their fates.

This synopsis mentions the water and the drones.

Memo (Luis Fernando Peña), a young Mexican, lives on a milpa in Santa Ana, Oaxaca with his family. Once, a river flowed through the milpa, which his father owns. But a few years ago, the Del Rio Water Company built a dam upstream. Now, residents of Santa Ana must pay $1/gallon to enter the facility and collect water.

In his spare time, Memo tinkers with discarded radio parts and builds an antenna to pick up voices from far away. One night, he overhears a transmission between Rudy (Jacob Vargas), a drone gunship operator, and his compatriots. His signal is detected, and tracked down to his family's shack in Santa Ana. Live on TV the next day, Rudy carries out a mission to neutralize an "aqua-terrorist intercept". As Memo and family watch on their TV, they soon realize that the target is the antenna on top of their shack. They run back to the shack, only to see it obliterated by a hovering drone gunship. As Memo's father crawls out of the building, Rudy gets confirmation that he is a known "aqua-terrorist", and Rudy fires a rocket at him, blowing him to bits.