Blood Lake: Attack of the Killer Lampreys (2014)

Fish and Wildlife employee Michael and his family relocate to a small town after Michael is hired to resolve the problem of the thinning fish population.  It turns out there are lampreys in the water and they're killing all the fish. No one is overly concerned since they figure they can keep them out of the water by using the shut off in the dam near the beach.

To their surprise the lampreys start hoping over the dam and going through an opening they thought was secured.  Michael and his co-workers figure out that the lampreys have gotten into the towns water system. They beg the Mayor to shut it down and tell people to stay away from bodies of water. But the Mayor doesn't want word to get out because it would inconvenience people and they should be able to enjoy the beach.

Too bad the Mayor didn't realize these are mutant lampreys who enjoy eating people, and don't seem to need water to get to where they're going.  Perhaps if he'd heeded the warning of the experts, he wouldn't have died a terrible toilet lamprey death.  Truly disgusting.

This is exactly what you'd expect from The Asylum.  Not very good CGI, plenty of nonsensical actions by the characters, and a better title than a movie.