Kedah Menteri Besar Muhammad Sanusi Md Nor's plan to control the flow of Sungai Muda which he claimed may leave Penang with "muddy waters" could backfire, warns an environmental group.

The Global Environment Centre (GEC) said instead of water running dry at the lower end of Sungai Muda, seawater could start flowing inwards, threatening agricultural crops in both Kedah and Penang.

Sungai Muda's source begins in...