Different snakes are called water snakes. Most are colubrid

Colubrid

A colubrid is a member of the snake family Colubridae. This broad classification of snakes includes about two-thirds of all snake species on earth. The earliest species of the snake family date back to the Oligocene epoch. With 304 genera and 1,938 species, Colubridae is the largest snake family...

s. "Water snake" is also sometimes used as a descriptive term for any snakes that spend a significant time in or near fresh water, such as any species belonging to the family Acrochordidae

Acrochordidae

The Acrochordidae are a monotypic family created for the genus Acrochordus. This is a group of primitive aquatic snakes found in Australia and Indonesia. Currently, 3 species are recognized.-Description:...

. They should not be confused with sea snakes

Sea Snakes

Sea Snakes were a Canadian indie rock band, formed in 2002 and disbanded in 2005. The band consisted of vocalist and guitarist Jimmy McIntyre, guitarist Kristian Galberg, bassist and saxophonist Jeremy Strachan, keyboardist Shaw-Han Liem and drummer Nathan Lawr.Strachan played in the defunct band...

, which live primarily or entirely in marine environments.

Examples of snakes called water snakes include:

• Helicops species, including:
  • Helicops angulatus
    Helicops angulatus
    Helicops angulatus, the brown-banded water snake, is an aquatic snake.-Description:The brown-banded water snake grows to a maximum length of 78 cm ....
    
    
• Liophis
  Liophis
  Liophis is a genus of New World colubrid snakes. They have a wide range of nondescript and local names, among these "water snakes", "mapepires", "corals" or "racers"....
  
  species, including:
  • Liophis cobellus
    Liophis cobellus
    The mangrove snake is a small semi-aquatic snake which is found in the Guianas, eastern Venezuela, and Trinidad and Tobago. It lives in lowland rainforest river floodplains and coastal mangrove swamps where it feeds on frogs, geckos and fish....
    
    
  • Liophis reginae
    Liophis reginae
    Liophis reginae, the High Woods Coral is a snake found in Venezuela and Trinidad and Tobago. It feeds on frogs, frog eggs, tadpoles, fish, small birds and lizards.-Subspecies:The following subspecies can be distinguished:...
    
    
• Enhydris
  Enhydris
  Enhydris is a genus of slightly venomous colubrid snakes. Species include:* sea-leopard snake, Enhydris bocourti * Sind River snake, Enhydris chanardi Murphy & Voris, 2005...
  
  species, including:
  • Enhydris enhydris
    Enhydris enhydris
    The Rainbow Water Snake, Enhydris enhydris, is a species of snake.-Distribution:SE China, Indonesia ;, Bangladesh; Cambodia; C/E India; Laos;...
    
    
  • Enhydris sieboldi
    Enhydris sieboldi
    Siebold's Water Snake is a species of snake found in north-central India, Bangladesh, and western Malaysia.This snake has the upper parts covered in large blotches similar to those of a python but they are distinctive in having their nostrils on the top of the snout to aid their aquatic lifestyle....
    
    
• Xenochrophis
  Xenochrophis
  Xenochrophis is a genus of colubrid snakes found in Asia. They are commonly referred to as Painted Keelbacks.- Species of Xenochrophis :*Xenochrophis asperrimus, Boulenger's Keelback.*Xenochrophis bellula...
  
  species, including:
  • Xenochrophis piscator
    Xenochrophis piscator
    The Chequered Keelback or Asiatic Water Snake is a common species of non-venomous snake found in Asia.-Description:...
    
    – the Asiatic Water Snake or Chequered Keelback
• Hydrodynastes
  Hydrodynastes
  Hydrodynastes is a small genus of colubrid snake in the subfamily Xenodontinae....
  
  species, including:
  • Hydrodynastes gigas – the False Water Snake or Brazilian Smooth Snake