Water snakes are fascinating creatures that inhabit freshwater environments across the world.
These remarkable reptiles can be found swimming in lakes, ponds, rivers, and marshes where they hunt for their favorite meals.
Unlike many people believe, most types of water snakes are non-venomous and pose little threat to humans, though they may still deliver a painful bite if threatened or handled improperly.
These aquatic serpents play important roles in their ecosystems, helping to control populations of fish, frogs, tadpoles, and crayfish.
With their sleek bodies adapted for swimming, water snakes can be identified by their unique coloration patterns and behaviors.
Many species, such as the brown water snake, are commonly found in specific regions like the southeastern Coastal Plain of Alabama.
When encountering these creatures in their natural habitat, it’s crucial to distinguish between harmless water snakes and the venomous water moccasin, also known as cottonmouth.
Learning to identify the different species can help outdoor enthusiasts stay safe while appreciating these important members of our aquatic ecosystems.
Northern Water Snake

The Northern Water Snake (Nerodia sipedon) is one of the most common water snakes in the United States.
This non-venomous reptile is often mistaken for dangerous water moccasins or cottonmouths due to its appearance.
These snakes have heavy bodies and can reach lengths of 2-4.5 feet.
Their coloration varies widely, appearing in shades of gray, reddish, brown, or black.
Young snakes typically have more distinct patterns with dark crossbands that fade as they age.
Northern Water Snakes can be identified by their keeled scales, which give them a rough appearance.
When threatened, they will not hesitate to strike and can deliver a painful bite.
These reptiles are frequently seen basking on rocks, logs, or branches near water bodies.
They’re excellent swimmers, moving with their heads raised above the water surface.
Habitat & Range:
- Lakes and ponds
- Rivers and streams
- Swamps and marshes
- Reservoirs
Northern Water Snakes are found throughout much of the eastern United States, including Virginia and other eastern states. They prefer freshwater habitats with ample cover and food.
When handled, they often release a foul-smelling musk as a defense mechanism.
They’re also known to defecate on their captors—another reason to admire them from a distance!
Mating occurs in spring, with females giving birth to live young (10-40 babies) in late summer rather than laying eggs.
These snakes primarily eat fish and amphibians, playing an important role in their ecosystems.
Southern Water Snake
The Southern Watersnake (Nerodia fasciata) is a common aquatic snake found throughout the southeastern United States. This non-venomous species is often mistaken for dangerous water moccasins due to their similar appearance and habitats.
Southern Watersnakes are thick-bodied reptiles that can grow up to 5 feet in length, though most are typically smaller. They have keeled scales that give them a rough appearance and helpful traction in water.
These snakes come in three recognized subspecies:
- Broad-banded watersnake (N. f. confluens)
- Banded watersnake (N. f. fasciata)
- Florida watersnake (N. f. pictiventris)
Their coloration typically features dark crossbands or blotches on a brownish or reddish background. The belly has distinctive square or triangular blotches, which helps distinguish them from the Northern Watersnake, which has reddish half-moon markings.
Southern Watersnakes spend much of their time in or near water bodies like ponds, lakes, streams, and swamps. They are excellent swimmers and can stay submerged for extended periods.
Their diet consists primarily of aquatic prey such as fish, frogs, salamanders, and crayfish. They hunt by ambushing prey in shallow water or along shorelines.
When threatened, these snakes may flatten their bodies, release a foul-smelling musk, and strike repeatedly. Though non-venomous, their bite can be painful and potentially cause infection.
Conservation efforts focus on habitat preservation and public education to reduce unnecessary killing of these beneficial snakes that are often confused with venomous species.
Brown Water Snake
The Brown Water Snake (Nerodia taxispilota) is a large, non-venomous snake found primarily in the southeastern United States. Adults typically measure between 30-60 inches in length, with some exceptional specimens reaching nearly 70 inches.
These snakes have distinctive physical characteristics that help with identification. They possess stout bodies with light tan or brown coloration and darker brown squarish blotches running down their backs.
Brown Water Snakes are often misidentified as venomous cottonmouths or water moccasins due to their similar habitats and somewhat similar appearance. This mistaken identity can lead to unnecessary fear and sometimes harm to these beneficial reptiles.
Common Names:
- Water-pilot
- False moccasin
- Great water snake
- Pied water snake
- Southern water snake
- Water rattle
These snakes are excellent swimmers and spend much of their time in or near water bodies. They can often be spotted basking on branches that hang over water, ready to drop in if disturbed.
Their diet consists primarily of fish and amphibians, making them important members of aquatic ecosystems. Unlike the yellow-bellied water snake, which has a bright yellow or cream underside, the Brown Water Snake typically has a paler belly with dark markings.
When threatened, Brown Water Snakes may flatten their heads and bodies to appear larger. They might also release a foul-smelling musk and may bite if handled, though they are not venomous.
Diamondback Water Snake
The Diamondback Water Snake (Nerodia rhombifer) is a large, heavy-bodied non-venomous water snake found in the United States. It is often mistaken for venomous snakes like cottonmouths or rattlesnakes, which unfortunately leads to many being killed out of fear.
This snake gets its name from the distinctive diamond-shaped light markings along its back. These patterns help it blend into its aquatic environment while hunting.
Adult Diamondback Water Snakes typically grow to impressive sizes, measuring between 2½ to 5 feet in length. They are among the largest water snakes in their range, with the Northern Diamond-backed Watersnake being the largest watersnake in Missouri.
Behavior and Temperament:
- Highly aggressive when threatened
- Will bite repeatedly if handled
- Not venomous, but bites can be painful
- More common than venomous water snakes in their habitat
Despite their intimidating appearance and defensive behavior, Diamondback Water Snakes pose no serious threat to humans. They prefer to flee rather than confront people, but will defend themselves vigorously if cornered.
These snakes play an important role in aquatic ecosystems by controlling fish and amphibian populations. They’re excellent swimmers and can often be spotted basking on branches over water, ready to dive in when disturbed.
Plain-bellied Water Snake
The Plain-bellied Water Snake (Nerodia erythrogaster) is a common semi-aquatic, non-venomous snake found in various water habitats. Despite its harmless nature, many people mistake it for venomous species due to its appearance.
This snake has several regional names including Yellow-bellied Watersnake and Red-bellied Watersnake. Some locals mistakenly call it copper-bellied moccasin or red-bellied black snake.
Physical Characteristics:
- Solid-colored back (typically brown, gray, or reddish)
- Distinctive plain belly (yellow, orange, or red)
- Lacks the banded pattern seen in other water snakes
- Adults typically reach 24-40 inches in length
The Plain-bellied Water Snake was previously divided into multiple subspecies. Taxonomy changes have affected how scientists classify these snakes, though some regional variations still exist.
Unlike the Banded Watersnake (N. fasciata), which has complete bands covering its entire body, the Plain-bellied Water Snake has a more uniform coloration on its back.
These snakes primarily eat fish and amphibians, hunting in freshwater environments like ponds, lakes, streams, and wetlands. They’re excellent swimmers and can stay submerged for extended periods.
When threatened, Plain-bellied Water Snakes may flatten their bodies and strike defensively. They might also release a foul-smelling musk. While intimidating, they pose no significant danger to humans and serve important ecological roles as predators.
Green Water Snake
The Green Water Snake refers to several different species in the water snake family. The Mississippi Green Watersnake is a medium-sized snake with a heavy body and dark coloration.
This semi-aquatic reptile was once common in southeastern Missouri but has become less prevalent over time. Green water snakes differ from other North American water snakes through distinct physical characteristics.
The Florida Green Watersnake (Nerodia floridana) was previously considered a subspecies but has been elevated to full species status. These snakes typically inhabit freshwater environments like ponds, lakes, and slow-moving streams.
Physical Characteristics:
- Medium to large size
- Heavy-bodied appearance
- Dark coloration (despite the “green” name)
- Non-venomous
It’s important to note that Green Water Snakes are often misidentified. In Africa, the Green Water Snake is frequently mistaken for the dangerous Green Mamba, similar to how the harmless Natal Green Snake is misidentified.
Water snakes can appear intimidating due to their size and defensive behaviors when threatened. They may flatten their bodies and strike, but remember they are non-venomous and primarily feed on aquatic prey like fish and amphibians.
When encountering these snakes in the wild, it’s best to observe from a distance. Respecting their space ensures safety for both humans and these important members of aquatic ecosystems.
Concho Water Snake
The Concho water snake is a small non-venomous reptile that can grow up to 3 feet in length. Its most distinctive feature is the large dark reddish-brown bands that cover its body.
This snake species is quite rare and has a very limited habitat range. It can only be found in a few restricted areas of Central Texas, specifically in the Colorado and Concho river basins.
Physical Characteristics:
- Length: Up to 3 feet
- Color: Dark reddish-brown bands
- Classification: Non-venomous colubrid
The Concho water snake is mostly aquatic in nature, spending much of its time in or near water. It belongs to the genus Nerodia, which includes nine species of water snakes known for their aquatic behavior.
Conservation efforts are important for this species. The Concho water snake is considered endangered due to its restricted habitat. Human development and changes to river systems have threatened its natural environment.
Swimmers and hikers in Central Texas should be able to identify this snake. While non-venomous, it’s best to observe from a distance and not disturb these rare creatures in their natural habitat.
Brazos Water Snake
The Brazos Water Snake (Nerodia harteri) is a unique species that lives only in Texas. This mostly aquatic, nonvenomous snake belongs to the Colubridae family.
Unlike many other water snakes, the Brazos Water Snake has a very limited habitat. It is endemic to the upper Brazos River drainage in north-central Texas, making it a truly local species.
This snake is relatively small compared to other water snakes. It has distinctive features that help people identify it in the wild.
How to Identify a Brazos Water Snake:
- Rounded head (not triangular)
- Round pupils (not vertical like venomous snakes)
- Distinctive pattern along its body
- Smaller size than many other water snakes
The Brazos Water Snake can be confused with the venomous cottonmouth. However, you can tell them apart by looking at the shape of the head. The cottonmouth has a more triangular head, while the Brazos Water Snake’s head is rounded.
These friendly residents of Texas rivers primarily eat fish. Their diet and habitat make them an important part of the river ecosystem.
Conservation efforts are crucial for this species. Their limited range makes them vulnerable to habitat changes and water management decisions.
If you spot one while near the Brazos River, remember to observe from a distance. While nonvenomous, all wild animals deserve respect and space.
Salt Marsh Snake
The Saltmarsh Snake (Nerodia clarkii) is a non-venomous water snake that has adapted to live in coastal environments. It is also known by several other names including Saltmarsh Watersnake, Atlantic Saltmarsh Watersnake, Gulf Saltmarsh Watersnake, and Mangrove Saltmarsh Snake.
These snakes primarily inhabit coastal wetlands with brackish water. Their preferred habitats include saltmarshes, mangrove swamps, and mud flats, though they occasionally venture into freshwater areas.
Unlike some marine reptiles, the Gulf Salt Marsh Snake doesn’t have salt glands to help process salt. This means they must be careful not to drink saltwater, which would be harmful to them.
Salt Marsh Snakes can be identified by their distinctive markings. Many specimens have dark stripes running down part or all of their body length, which helps distinguish them from the Southern Watersnake.
There are several subspecies of Salt Marsh Snakes found across the Gulf Coast and Atlantic coastal regions, including:
- Atlantic Saltmarsh Snake
- Gulf Saltmarsh Snake
- Mangrove Saltmarsh Snake
When encountering these snakes, it’s important to remember they are non-venomous. However, like many water snakes, they may bite if threatened or handled. It’s best to observe them from a distance in their natural habitat.
Their diet typically consists of small fish and crustaceans found in their coastal environments, making them well-adapted predators in these specialized ecosystems.