Israeli academics say smart water irrigation systems can be hijacked by nefarious threat actors who could cause a mass water crisis by forcing these systems to consume more water than usual. Such attacks, they say, could lead to the emptying of local emergency water reservoirs, and even to water utility companies shutting down water supply in extreme cases. The biggest danger, he argues, is from nation-state actors, who could use DDoS-for-hire botnets to attack smart irrigation systems on the same network as the irrigation system.
Source: https://www.bleepingcomputer.com/news/security/flaws-in-smart-irrigation-systems-expose-water-utilities-to-botnet-grade-attacks/