As a storm approaches a southern Louisiana bayou community called the "Bathtub" (a community cut off from the rest of the world by a levee), six-year-old Hushpuppy and her ailing, hot-tempered father Wink are optimistic about their life and their future. The children in school are being taught by Miss Bathsheba about nature and the release of prehistoric creatures called "Aurochs" from the melting ice caps. At home, Hushpuppy fends for herself while her father is missing. When he returns, he is wearing a hospital gown and bracelet. They argue, and when Hushpuppy returns to her house, she deliberately sets it on fire. A chase ensues between the two, and she ends up getting slapped by Wink. When she retaliates by punching him in the chest, Wink collapses. Hushpuppy, realizing the damage she has caused, runs for help only to find her father missing when she returns.
Meanwhile, in the Arctic, the frozen Aurochs in an ice shelf start drifting into the ocean.
Many of the Bathtub residents start fleeing due to the threat of an approaching storm. Wink reappears, staggering along the side of the road; he finds Hushpuppy and takes her home to start barricading before the storm hits. In an effort to make his daughter feel better, Wink attempts to scare off the storm by firing a rifle at the clouds. The next day, the two tour the devastation and connect with surviving residents.
The Bathtub residents celebrate and make plans to rebuild their community, but the environment is damaged because of the salt water brought in by the storm surge to fresh waters. Wink hatches a plan to drain the water away by destroying the levee. He and a small group of friends plant dynamite and blow a hole in the wall using an alligator gar, and the water recedes. Authorities arrive and enforce a mandatory evacuation order, removing the residents of the Bathtub to an emergency shelter. Wink receives surgery, but it is too late to restore his health. At the first opportunity, the evacuees leave and escape back to their homes.
Aware of her fatherâs condition, Hushpuppy searches for her absent mother. She and her friends swim to a boat, which takes them to a floating bar, known as the Elysian Fields. Hushpuppy meets a cook who may be her mother, though the woman doesn't recognize her. The cook says that the girl can stay with her if she wants, but Hushpuppy says that she's got to go home. Hushpuppy and her friends return home where she confronts the Aurochs. As the Aurochs leave, Hushpuppy returns home. She says her last goodbyes to the dying Wink, listening to his last heartbeat. She sets his funeral pyre ablaze, standing together with the remaining residents of the Bathtub.

Question: Why is the environment damaged after the storm?
Answer: From the salt water. 
Alternative answer: Salt water contaminates the fresh water.