Beware of These 10 Water Snakes in Texas

Written by Lev Baker
Updated: July 14, 2023
© Patrick K. Campbell/
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Deep in the heart of Texas lies a hidden danger that lurks beneath the surface of its beautiful waters: water snakes. It’s essential to understand that not all creatures in the Lone Star State are friendly. Those who encounter these water snakes should exercise caution, as they represent a possible danger. Keep reading as we’ll look closer at these water snakes in Texas and explore why it’s essential to beware of them.

This is our list of the top 10 water snakes that you’ll probably see in Texas.

Where Can You Find Water Snakes in Texas?

Water snakes thrive in the aquatic wonderlands of Texas, where they gracefully navigate its myriad of lakes, rivers, and wetlands. Often drawn to the lush vegetation of marshes, swamps, and rice fields, these versatile reptiles are masters of freshwater and brackish habitats. 

A significant population of water snakes lives in areas such as Toledo Bend Reservoir, Inks Lake, Lake Texoma, Sam Rayburn Reservoir, and the mysterious Caddo Lake. These popular destinations lure adventurers for fishing, swimming, and boating, making it essential to remain vigilant of our serpentine neighbors. 

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By respecting the presence of these slithery creatures, we can coexist in harmony with these fascinating water snakes in the mesmerizing underwater realms of Texas. 

1. Western Cottonmouth (Agkistrodon piscivorus leucostoma)

The western cottonmouth is the only venomous water snake species in Texas. It comes in different hues, such as dark brown, olive brown, olive green, or nearly all black. They have wide dark bands, which can be more distinct in some cottonmouths than others. These snakes can reach lengths of 30 to 42 inches.

Their diet comprises small water birds, fish, snakes, frogs, carrion, and small mammals. Their ability to bite underwater helps them to eat fish, which is an integral part of their diet.

Western cottonmouths are semi-aquatic, thriving both in and out of the water — they are great swimmers, too! Moreover, they also thrive in wooded areas in East Texas, aside from their common habitats in lakes, salt marshes, and rivers.

Western cottonmouths usually avoid humans and rarely bite unless provoked. Nevertheless, it is crucial to stay away from them as their venom can cause severe tissue damage. On average, around 2-4 people in the United States get bitten by cottonmouths each year. Symptoms from a western cottonmouth can include severe pain, rapid swelling, discoloration of the skin, and difficulty breathing. 

Western cottonmouth snake isolated
Western Cottonmouth (Agkistrodon piscivorus leucostoma).

©Ryan M. Bolton/

2. Southern Water Snake (Nerodia fasciata)

Found primarily in the eastern and western regions of Texas, the southern water snake is predominantly aquatic and tends to consume fish and amphibians. Interestingly, these reptiles are fond of basking in the sun! Southern water snakes typically hunt during nighttime or following substantial rain when capturing frogs is more accessible.

One characteristic trait of the southern water snake is a dark stripe running from the eye to the corner of the mouth. However, their overall coloration can vary. The snake’s primary hue may be gray, beige, deep olive, or black. The underside typically displays a white or near-white shade.

Adult southern water snakes generally measure between 22 and 42 inches in length, with the longest on record reaching 62.5 inches. Their natural habitats include lakes, rivers, ponds, and marshes.

Although southern water snakes pose no significant threat to humans or domestic animals, they can bite in self-defense. Almost all bites occur when the snake is deliberately provoked.

During the winter months, these snakes hibernate under rocks or logs or within burrows. However, in times of severe drought, they may leave their usual habitat in search of a more suitable aquatic environment.

Southern Water Snake (Nerodia fasciata).

©Deborah Ferrin/

3. Green Water Snake (Nerodia cyclopion)

In Texas, the green water snake is one of the few aquatic snakes that occasionally resides in brackish water. However, its primary habitat remains lakes, marshes, and swamps.

Fully grown green water snakes are typically around 30 to 55 inches long and possess a robust body structure. They come in various colors, including green, brown, and orange, with no distinctive patterns except for dark spots. These snakes have sizeable heads with tiny scales positioned between their eyes and upper lip.

Their diet primarily consists of freshwater fish and amphibians. Unlike constrictors, they do not coil around their prey. Instead, they capture it with their jaws and swallow it alive.

Despite being non-venomous, the green water snake has effective defense mechanisms when threatened. They tend to bite repeatedly and secrete a potent musk from their vent, which is their excretory opening.

Since the green water snake is not a protected species in Texas, individuals with hunting licenses are allowed to capture them legally.

green snake eating prey
Green Water Snake (Nerodia cyclopion).


4. Plain-Bellied Water Snake (Nerodia erythrogaster)

The plain-bellied water snake is a widely distributed species across the southeastern United States. In Texas, they are among the most common water snakes.

Growing up to around 30 to 48 inches long, adult plain-bellied water snakes are robust, with a uniform greenish-gray or reddish-brown appearance on their backs. Their neck, belly, and lip scales are typically a consistent shade of yellow or reddish-orange, with no discernible markings.

These snakes are mainly aquatic, feeding primarily on freshwater fish and amphibians. Therefore, they prefer living near permanent water sources like ponds, lakes, or streams.

What sets the plain-bellied water snake apart from other water snakes is its tendency to travel away from water when feeling threatened or during extremely hot weather. As a result, they can often be seen basking on the banks of water bodies.

No other water snake loves the summer like a plain-bellied water snake. On exceptionally hot days, they will remain active both day and night.

Plain-bellied water snake (Nerodia erythrogaster)
Plain-Bellied Water Snake (Nerodia erythrogaster).

©Danny Ye/

5. Brazos Water Snake (Nerodia harteri)

The Brazos water snake is an indigenous species to Central Texas, specifically found in the Brazos River System, and is at risk of becoming endangered. These particular snakes inhabit rocky regions along the riverbanks. 

Their coloration is a combination of green and brown or gray and brown, with distinct dark dorsal spots forming a checkerboard pattern along their bodies. These water snakes have a pink or orange-colored underside, while their necks are typically cream or yellow in color. Their length ranges from 16 to 32 inches.

The Brazos water snake is a diurnal predator that depends on rocky habitats for shelter and protection while hunting for prey. They usually prey on small fish but occasionally also on salamanders, frogs, and crayfish.

Brazos water snakes are non-venomous, lack dangerous fangs, and are not constrictors. Despite their reputation, these snakes do not exhibit aggression towards humans. Instead, they have a docile demeanor, though they may bite defensively when provoked, much like other reptiles.

Dice snake (Natrix tessellata)
Brazos Water Snake (Nerodia harteri).

© Macat

6. Diamondback Water Snake (Nerodia rhombifer)

The diamondback water snake is a nonvenomous species that commonly lives in the aquatic regions of Texas. 

Its back bears a diamond-shaped pattern consisting of dark bars and lighter colors running along its sides. Its underside is marked by yellow or light brown with dark blotches. However, the snake’s identification can be challenging as it is often covered in algae or silt.

These snakes feed on various aquatic creatures like fish, frogs, and toads, and they even prey on young turtles. Typically, they prefer a solitary lifestyle and spend most of their lives in solitude. Only during hibernation do they sometimes share their dens with other snakes.

Due to their sharp teeth that grip slippery fish, the diamondback water snake’s bite can be quite painful. However, their defensive behavior is often misinterpreted as aggression. This leads to confusion with the venomous cottonmouth, which shares their habitat in some areas.

Diamondback Water Snake (Nerodia rhombifer).

©Tucker Heptinstall/

7. Texas Indigo Snake (Drymarchon melanurus erebennus)

The Texas indigo snake is a snake native to Texas and nearby Mexico. It is predominantly black with a shiny almost-blue iridescent hue to its smooth scales. Its underside is often salmon pink. This large snake can grow up to 72 inches in length.

This snake species thrives near bodies of water, particularly dry grasslands near ponds. They are diurnal and tend to hide actively. They consume various prey, including frogs, eggs, birds, mammals, lizards, turtles, and even other snakes. Many farmers in southern Texas consider them helpful due to their aggressive attacks on rattlesnakes.

While the Texas indigo snake is not typically aggressive toward humans, it may bite or release a foul-smelling musk if handled or provoked. It is considered a threatened species in Texas, primarily due to habitat loss from human development.

Texas indigo snakes are large-bodied, very long snakes with a base color of iridescent black scales and brown speckles.
Texas Indigo Snake (Drymarchon melanurus erebennus).

©Joe Farah/

8. Texas Garter Snake (Thamnophis sirtalis annectens)

The Texas garter snake is a native reptile found primarily in central Texas, with smaller populations in Kansas and South Dakota. This snake has a very distinct appearance.

Featuring a greenish-black dorsum, the Texas garter snake displays a vivid orange or red central stripe and yellowish lateral stripes that span through the second to fourth rows of dorsal scales above the ventral plates. They can reach up to 28 inches in length.

As carnivorous creatures, Texas garter snakes primarily consume frogs and toads, but their diet may also include small birds, fish, and rodents.

These snakes are not typically found in large groups due to their scarcity. They favor environments close to permanent water sources but can also adapt to various habitats. Nevertheless, they tend to remain near water, often inhabiting damp soil or areas close to streams.

In terms of their ecological role, Texas garter snakes aid humans by managing pest populations and also act as a food source for predators such as raccoons, hawks, herons, foxes, and other snakes.

Generally, these snakes display a passive nature, although younger individuals might exhibit defensive behavior when threatened. When handled, they may thrash about in an attempt to escape and emit a malodorous musk from their cloaca, or vent.

Texas Garter Snake (Thamnophis sirtalis annectens).

©Dawson / CC BY-SA 2.5 – License

9. Common Water Snake (Nerodia sipedon)

The common water snake is a species prevalent in several central and eastern states in the United States, including Texas It surprisingly counts over 15 different names, including “northern water snake” and “black water snake.”

Usually, common water snakes measure between 24 and 55 inches and possess a dark coloration that can be brown, tan, or grayish Young and damp specimens tend to exhibit more vibrant colors Their backs and sides feature a pattern of square blotches that alternate, and sometimes combine to create bands.

Active during both day and night, common water snakes may limit their feeding to daylight hours if water temperatures drop at night Their diet mainly comprises fish, though they also consume frogs, toads, salamanders, insects, crayfish, and occasionally mice and shrews.

These snakes inhabit various freshwater wetlands that offer adequate cover and food You can often spot them resting near the water’s edge on the shoreline They bask on stream banks and dive into the water when disturbed. 

The common water snake has the ability to defend itself when threatened or captured, and its bite can cause discomfort to humans, especially when it comes from larger specimens.

Common watersnake
Common Water Snake (Nerodia sipedon).

©Jay Ondreicka/

10. Concho Water Snake (Nerodia paucimaculata)

The Concho water snake is a species of snake that is exclusive to the west-central Texas and Concho river systems Due to their limited range, these snakes are at risk of becoming endangered.

Characterized by four rows of dark brown spots alternating with lighter-colored patches, the Concho water snake has a distinctive checkerboard pattern on its gray, brown, or reddish-brown back This non-venomous snake shares many similarities with other aquatic snakes You can spot it near permanent bodies of water, such as ponds or fast-flowing rivers.

Although active during the day, these snakes tend to inhabit rocky areas near the water, such as cliffs or shorelines Their diet consists mostly of smaller fish, and they may fall victim to trot lines, which can be deadly for them.

The greatest threat to Concho water snake populations is habitat loss and degradation Without immediate action to address this issue, these unique creatures could soon become extinct.

Rio Conchos
The Concho water snake is a species exclusive to the west-central Texas and Concho river systems.

©Levi bernardo / CC BY-SA 3.0 – License

Summary of 10 Water Snakes in Texas

NumberWater SnakeFun Fact
1Western CottonmouthThis venomous snake’s mouth is white on the inside
2Southern Water SnakeThey bask all day and hunt at night
3Green Water SnakeThis snake may be nonvenomous – but it will bite repeatedly and emit a fowl-smelling musk in self-defense
4Plain-Bellied Water SnakeDuring the hot summer months – this snake stays active day and night
5Brazos Water SnakeThese docile snakes can only be found in Texas
6Diamondback Water SnakeOften confused with the cottonmouth – this nonvenous snake still has a painful bite
7Texas Indigo SnakeFarmers like this snake because it attacks rattlesnakes
8Texas Garter SnakeThe vivid orange-red stripe down its back makes this snake stand out
9Common Water SnakeAlthough they usually slip into the water when seen – this water snake will defend itself if threatened
10Concho Water SnakeExclusive to the west-central Texas and Concho River systems

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About the Author

I have been a freelance writer for the past 2 years. My two biggest loves in the world are music and animals. I have even gone on to start my own personal blog called Frontman Philosophy. I have a huge love of animals and I love building my knowledge of animals through research. I love sea creatures in particular, my favorite being the octopus because of their intelligence, and I mean, come on, what's not to love! I have a rescue boxer named Dante who is the friendliest pup a man could ask for.

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