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4 Types of Water Snakes in Iowa (With Pictures)

Iowa is well known for its corn fields and its prairies, but this state is also home to a slew of different bodies of water, including both man-made and natural lakes. It’s these aquatic habitats that make great homes for water snakes, and Iowa has a few different species of water snakes living within its borders.

Collage of water snakes in iowa

4 Water Snakes In Iowa

The 4 true water snakes in Iowa are the Diamond-Backed Water Snake, Copperbelly Water Snake, Northern Water Snake, and Plain-Bellied Water Snake.

While Iowa is home to some venomous snakes, these 4 water species pose no risk to humans. Even though they aren’t considered dangerous, you should still keep your distance as they can become aggressive and may bite if they feel you’re a threat.

1. Diamond-Backed Water Snake

Diamondback Water Snake
Diamondback Water Snake | k.draper | Flickr | CC BY-ND 2.0

Scientific Name: Nerodia rhombifer

The diamond-backed water snake is a threatened species, and the state of Iowa has actually made it illegal to collect or kill this snake. This non-venomous water snake is harmless to humans and can reach lengths of between 30 to 48 inches long.

They have a grayish, brownish, or greenish colored body with a chain-like pattern on their backs. Their belly is cream or yellow in color with half-moon shapes.

Diamond-backed water snakes have only been documented in the southeastern part of the state, but it is extremely common in just about any other state east and south of Iowa. This water snake is active throughout the months of April and October, inhabiting various bodies of water, including rivers, ponds, backwaters, sloughs, and oxbows.

Diamond-backed water snakes breed in the spring, and can produce up to 60 live young at one time. These carnivores consume a wide array of aquatic creatures, including fish, toads, frogs, and salamanders. They will also prey on crayfish, insects, and other small mammals that they come across.

2. Copperbelly Water Snake

Copperbelly water snake
Copperbelly water snake | image by Peter Paplanus via Flickr | CC BY 2.0

Scientific Name: Nerodia erythrogaster neglecta

The copperbelly water snake is an endangered species that is found in wetlands where there is mature timber. It is the loss of their habitat due to agricultural development that has made this species endangered. They are found in the southern portion of Iowa, and not nearly as wide spread as some of the other water snakes.

This water snake measures 30 to 48 inches long with a gray to light colored body and dark bands close to its head. These bands become more of a blotched pattern as it goes down its body and towards its tail. Juvenile copperbelly water snakes have a light colored belly that will change to orange as they age.

The copperbelly water snake’s diet consists of amphibians, such as frogs and tadpoles, but it can also consume fish, crayfish, insects, and even small mammals. Even though they can appear scary, these snakes are not venomous, nor are they overly aggressive. They typically only bite when provoked or when they feel threatened.

3. Northern Water Snake

Northern water snake basking
Northern water snake basking | image by via Flickr | CC BY 2.0
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Scientific Name: Nerodia sipedon

The northern water snake is found throughout Iowa, except for the northwest corner of the state. They are native to the state and inhabit various aquatic areas, such as rivers, lakes, ponds, marshes, streams, and reservoirs.

They can measure between 24 to 42 inches long and have a large round head. Their bodies are black to reddish brown in color and are covered in a blotch-like pattern. Their bellies are lighter in color, usually yellow or pink, and with half moon shapes in hues of orangish brown.

Northern water snakes are not venomous, nor are they aggressive. That doesn’t mean, however, that they won’t bite you if you threaten or aggravate them. While the bite isn’t deadly, it is painful and the saliva of this snake is an anti-coagulant, which makes clotting difficult.

This can make it difficult to stop the bleeding at the bite wound. Because of this, it’s best to keep your distance from any and all water snakes. This will help ensure you and the snake stays safe.

4. Plain-Bellied Water Snake

Plain-bellied water snake
Plain-bellied water snake | image by Northeast Coastal & Barrier Network via Flickr | CC-SA 2.0

Scientific Name: Nerodia erythrogaster

Once known as the yellow-bellied water snake, the plain-bellied water snake is not nearly as common in Iowa as the other species on our list, but that doesn’t mean they haven’t been spotted before. There have only been two populations of the yellow-bellied water snake found in Iowa, and those were at the very bottom corner of the state.

The yellow-bellied water snake has a brown body free from any markings or patterns. Its belly is yellowish orange in color, and it can grow 30 to 48 inches long.

Like other species of water snake, the yellow-bellied water snake thrives in aquatic areas, consuming the creatures in and around its home. Its main food source is fish, but it will also prey on amphibians, such as frogs and salamanders, and even insects and crayfish.