Iowa is home to approximately 66 natural lakes, often called "glacial lakes," primarily located in the northern part of the state. Beyond these natural formations, Iowa also features hundreds of artificial lakes, reservoirs, and impoundments, significantly increasing the total number of water bodies considered "lakes" by many residents and visitors. The exact count of "lakes" can vary depending on how one defines a lake, especially when distinguishing between larger reservoirs and smaller impoundments.
Understanding Iowa’s Lake Landscape
The distinction between natural and artificial lakes is crucial when discussing Iowa’s water bodies. The state’s geological history largely dictates the presence of its natural lakes, while human engineering has shaped the landscape with numerous man-made water features.
Natural Lakes: Glacial Gifts
Iowa’s natural lakes are predominantly found in the northwest and north-central regions, a legacy of the last glacial period. These "kettle lakes" were formed when melting glaciers left behind large blocks of ice that created depressions in the land. When these ice blocks melted, they filled with water, forming the lakes we see today.
The most famous of these are the Iowa Great Lakes: Spirit Lake, West Okoboji Lake, and East Okoboji Lake. This complex is a major recreational hub, drawing visitors from across the Midwest. Other significant natural lakes include Clear Lake, Storm Lake, and Big Spirit Lake.
Artificial Lakes: Engineered for Purpose
The vast majority of Iowa’s "lakes" are artificial, created for a variety of purposes including flood control, municipal water supply, recreation, and power generation. These impoundments are formed by damming rivers and streams. They range in size from vast reservoirs covering thousands of acres to smaller community ponds.
Major artificial lakes play a critical role in Iowa’s infrastructure and recreational offerings. Examples include Saylorville Lake and Lake Red Rock on the Des Moines River, Lake Macbride, Lake Rathbun, and Coralville Lake. These lakes are vital for managing water resources and providing extensive outdoor activities.
The Geological Story Behind Iowa’s Lakes
Iowa’s relatively flat to gently rolling topography is a result of repeated glaciations. While glaciers left behind fertile soil, they also scoured the land, creating the conditions for natural lake formation primarily in the younger glacial drift plains of the Des Moines Lobe. This geological history explains why natural lakes are concentrated in specific areas rather than spread uniformly across the state.
The absence of natural lakes in southern Iowa, for instance, is due to older glacial advances that had more time to erode and fill in depressions. Here, almost all significant water bodies are artificial, created to meet the region’s water and recreational needs.
Iowa’s Lakes: A Hub for Recreation and Economy
Iowa’s lakes, both natural and artificial, are cornerstones of the state’s outdoor recreation and tourism economy. They offer diverse opportunities for residents and visitors alike.
Popular Activities:
- Boating: From sailboats on the Okobojis to powerboats on Saylorville, boating is a prime activity.
- Fishing: Anglers target species like walleye, bass, crappie, and catfish. The Iowa Department of Natural Resources (DNR) actively manages fish populations.
- Swimming: Designated swimming beaches are popular during warmer months.
- Paddling: Kayaking, canoeing, and stand-up paddleboarding are growing in popularity on many lakes.
- Camping and Hiking: Many lakes are surrounded by state parks or recreation areas offering camping, hiking, and wildlife viewing.
The Iowa Great Lakes region, in particular, is a significant economic driver, attracting hundreds of thousands of tourists annually. Resorts, restaurants, and various businesses thrive on the influx of visitors seeking lakeside experiences.
Practical Tips for Enjoying Iowa’s Lakes
Exploring Iowa’s lakes is a rewarding experience. Here are some tips to make the most of your visit:
- Check DNR Resources: The Iowa DNR website (www.iowadnr.gov) is an invaluable resource for lake information, including fishing reports, water levels, park amenities, and regulations.
- Plan Ahead: Especially for popular destinations like the Iowa Great Lakes, book accommodations and campsites well in advance, particularly during peak summer months.
- Know Your Lake: Some lakes are better suited for specific activities. For example, larger reservoirs like Saylorville are excellent for powerboating, while smaller lakes might be ideal for quiet paddling.
- Visit State Parks: Many of Iowa’s lakes are within or adjacent to state parks, offering well-maintained facilities and diverse activities.
Safety and Legal Considerations on Iowa’s Waterways
Safety is paramount when enjoying Iowa’s lakes. Adhering to regulations and exercising caution ensures a pleasant and secure experience.
- Boating Regulations: All boaters must follow Iowa’s boating laws, including having proper safety equipment (life jackets for all occupants), observing speed limits, and understanding navigation rules. Boating under the influence is strictly prohibited.
- Fishing Licenses: A valid Iowa fishing license is required for anyone 16 years or older to fish in public waters. Licenses can be purchased online or from authorized vendors.
- Water Quality: The DNR monitors water quality at public beaches. Always check for advisories regarding bacteria levels or harmful algal blooms before swimming.
- Ice Safety: During winter, ice fishing and skating are popular, but never venture onto ice unless you are certain it is thick enough (minimum 4 inches for foot travel, 5-7 inches for snowmobiles/ATVs). Always check local conditions.
- Respect Wildlife: Iowa’s lakes are home to diverse wildlife. Observe animals from a distance and avoid disturbing their natural habitats.
Frequently Asked Questions About Iowa’s Lakes
Q: What is the largest natural lake in Iowa?
A: Spirit Lake is the largest natural lake in Iowa by surface area, covering approximately 5,660 acres. West Okoboji Lake is the deepest, reaching depths of 136 feet.
Q: Are there any natural lakes in southern Iowa?
A: No, southern Iowa primarily features artificial lakes and reservoirs. The geological history of the region did not lead to the formation of natural glacial lakes.
Q: What is the difference between a lake and a reservoir in Iowa?
A: In Iowa, a "lake" often refers to a natural body of water, typically formed by glacial activity. A "reservoir" is an artificial lake created by damming a river or stream, primarily for flood control, water supply, or recreation.
Q: Can you swim in all Iowa lakes?
A: Not all lakes have designated swimming areas, and water quality can vary. Always check with the Iowa DNR or local park authorities for current swimming conditions and advisories before entering the water.
Conclusion
Iowa is home to a distinct blend of approximately 66 natural glacial lakes and hundreds of artificial lakes and reservoirs. While the natural lakes are concentrated in the state’s northern reaches, man-made impoundments are spread throughout, serving vital roles in flood control, water supply, and recreation. Together, these diverse waterways offer Iowans and visitors abundant opportunities for outdoor enjoyment, making them invaluable assets to the state’s natural beauty and economy.
