Vernal pools are shallow wooded wetlands that fill with water in the spring and fall, then dry out in the summer. They may simply look like a large muddy puddle, but in reality these small depressions are filled with life and benefit local water quality.

• Water Resource Benefits

By capturing water from snowmelt and heavy rains, vernal pools reduce the amount of runoff – and the contaminants it carries – reaching nearby surface waters and developed lands. This lowers flooding risks, improves water quality, and contributes to groundwater recharge as the trapped water slowly infiltrates through the soil.

• Aquatic Invertebrates and Amphibians

Vernal pools rarely contain fish because their water levels fluctuate dramatically. This provides a safe haven for many invertebrate and amphibian species that would otherwise be heavily predated upon. Many depend on vernal pools during their egg and larval stages, leaving for nearby aquatic and terrestrial habitats once fully developed. Others spend their entire life within or near the wetland's depression.

• Birds, Reptiles, and Mammals

Due to their abundance of amphibians and invertebrates, vernal pools supplement the food and water needs of wildlife such as waterfowl, songbirds, turtles, snakes, bats, and even bears. These benefits stem beyond the vernal pool itself when many of the invertebrates transition from aquatic larvae to terrestrial adults, serving as forage for insectivore species.

Explore and Protect

Vernal pools are highly sensitive to changes in vegetation cover, climate, and local topography. Because they are nearly invisible for much of the summer, they can be easily missed and destroyed if the land is modified; even an unintentional pass through these depressions during an ATV ride can strongly impact their function. 

Seasonal wetlands like vernal pools are regulated under the Minnesota Wetland Conservation Act (WCA). You can prevent impacts to vernal pools on your property by marking their boundaries when visible in the spring and avoiding disturbance throughout the year. This is also a great time to explore the abundance of wildlife in and around these wetlands – an especially popular adventure for children.

Additional Resources

"Spring-to-Life Ponds": an Illustrated Learning Guide, produced by the MNDNR

MN Frog ID and Calls and Common Vernal Pool Invertebrates, produced by the MPCA and University of Wisconsin

Locating and Protecting Vernal Pools, produced by the MN Land Trust 

As spring snowmelt and rainwater rushes down your street and into the nearest stormwater drain, you may contemplate its ultimate fate and journey along the way.

In a natural landscape, much of this water would evaporate or soak into the ground – destined to support vegetation or join the groundwater below – while the remainder would move downward along the surface to nearby wetlands, lakes, and streams. In developed landscapes, impermeable surfaces such as roofs and pavement prevent water from soaking into the ground while manmade drainage networks rapidly channel it to local waterways.

Anoka County contains many interconnected lakes, wetlands, streams, and rivers that receive and transport stormwater. Unfortunately, many of these have experienced increased pollution, erosion, and flooding as a result. Management practices such as rain gardens, bio-swales, and storm ponds have been established throughout the county to intercept stormwater pipes and ditches, decreasing the pollutant load and total amount of runoff entering our surface waters.

Ultimately, all of Anoka County drains into the Mississippi River – either directly from the land near its banks, or indirectly through its many tributaries (such as Coon, Cedar, and Rice Creeks, and the Sunrise, Rum, and St. Croix Rivers). The path that stormwater takes to these major rivers is unique to each neighborhood, city, and watershed; the figures below show examples of stormwater drainage scenarios common in Anoka County. 

Current subzero temperatures can make warmer months seem far away, but winter is a great time to begin planning for spring and summer conservation projects at your home. Whether you want to create an oasis for pollinators and other native wildlife or install features that improve local water quality, there are many great informational resources to help you get started.

Create a native vegetation planting plan and control invasive species

Establishing areas of diverse native vegetation and managing invasive plant species produces multiple environmental benefits, including the provision of food and habitat resources for native wildlife and the improvement of local soil and water health, particularly for areas adjacent to rivers, lakes, and wetlands. Sourcing native plants and landscaping services from local experts is the best way to ensure your efforts maximize ecological benefits in your area. 

• ACD native tree, shrub, and seed sale: https://www.anokaswcd.org/tree-sale-order-forms/instructions.html
• MNDNR lists of native plant suppliers and landscapers: https://www.dnr.state.mn.us/gardens/nativeplants/suppliers.html
• Native plant lists and planting tips: https://extension.umn.edu/find-plants/native-plants
• Invasive plant identification and management: https://www.dnr.state.mn.us/invasives/terrestrialplants/index.html

 Address lawn care needs sustainably

The ways in which we mow, irrigate, and chemically treat our yards can lead to unintended impacts in nearby aquatic and terrestrial ecosystems. This year, consider developing a lawn care regime that strategically targets nutrient and pesticide needs and reduces the need for irrigation.

• MPCA lawn and garden care tips for a healthy environment: https://www.pca.state.mn.us/living-green/yard-and-garden
• Achieving a sustainable lawn: https://doitgreen.org/topics/gardening/achieving-sustainable-lawn/
• Pollinator-friendly pest control: https://xerces.org/sites/default/files/2019-09/19-034_01_Protecting%20Pollinators%20at%20Home_web.pdf

Participate in community surveys and attend educational events

Winter is a great time to explore environmental topics that pique your interest and inspire you to become involved in backyard conservation efforts. Many of Minnesota's environmental and conservation organizations provide free or low-cost educational opportunities such as webinars and workshops. You can also become involved in natural resource surveys such as those for wildlife, weather, and water quality, which greatly improve our understanding of conservation needs across the state. 

• MNDNR Natural Resources Education Opportunities: https://www.dnr.state.mn.us/education/index.html
• University of Minnesota Extension courses and events: https://extension.umn.edu/courses-and-events?search=&end_date=&start_date=&subject%5B676%5D=676&page=1
• MN Zoo backyard science and conservation opportunities: https://mnzoo.org/educator-corner/conservation-citizen-science/
• MPCA citizen science: https://www.pca.state.mn.us/water/citizen-water-monitoring