OK I don't remember any of the actors all I remember was there was this body of water a swamp/lake/quarry/etc. and people in town were scared and thought there was a creature in it. At the end of the film it turns out to be a big piece of machinery sunk at the bottom. I have no idea how that movie popped into my head today but trying to figure out the name is driving me crazy. Any help is appreciated. Thanks.