A land of 10,000 lakes for sure. But how about springs?

The Land of 10,000 Lakes also may be the Land of 15,000 Springs. Or many more.

Minnesota stands to gain that distinction as the Department of Natural Resources works to build an online inventory of the state's estimated 15,000 to 22,000 springs.

A spring is a natural flow of water from an aquifer — an underground layer of rock — to the earth's surface, in the definition of DNR research analyst Greg Brick, who began work last year on the spring inventory project. Springs are critical resources even if they go overlooked compared to the state's beloved lakes, rivers, streams and wetlands.

Among their benefits, springs give life to cold-water trout streams and create and support special habitats. Many lakes and streams depend on springs, which also can offer evidence of groundwater impairment and help defend against invasive species. Too, their documentation is used by businesses and agencies for project planning. Like lakes and other bodies of water, springs can inspire a connection to nature and add to a sense of place — and discovering a spring can give rise to a sense of wonder.

"This is just a whole other category that has the same kind of water-human connection," DNR hydrogeologist Paul Putzier said. "There's a spiritual connection for people, there's a cultural connection for people."

Indeed, Brick said he was overjoyed when he and DNR hydrogeologist Rachel Brunstad in January found a relatively large spring near the "ghost town" (his words) of Golden Gate in Brown County near the Minnesota River. Finding the spring, flowing at a rate of 50 gallons a minute, confirmed a field report that state geologist Newton Horace Winchell had made in 1888 of a spring near the village of Golden Gate, which vanished after railroads bypassed it.

"We had to go out there and field-verify this old data," Brick said. "That was exciting. It's kind of fun detective work."

Now citizen scientists and those who enjoy the outdoors can contribute as well, submitting spring locations they discover through the DNR's new Minnesota Spring Inventory reporting application. The agency will add verified citizen reports to the Minnesota Spring Inventory map on its website.

The statewide spring inventory began with Brick, later joined by Brunstad, gathering legacy data such as Winchell's report on Golden Gate from a variety of state agencies. The search included Brick's discovery in DNR Fisheries files of a long-forgotten 5-by-2 linen map of the North Shore that aquatic biologist Thaddeus Surber drafted on durable linen in 1922. Brick used paper maps from the U.S. Geological Survey to plot spring locations when he produced the first systematic map of springs in Minneapolis and St. Paul in 1993, identifying seven belts of springs in the Mississippi River gorge.

Today, Brick and Brunstad use global positioning system data to record spring locations accurately. They combine that with a surveying method called LIDAR (light detection and ranging), which uses laser pulses from the air and other data to produce high-resolution landscape maps, when planning their field campaigns in search of springs. Unlike aerial photography, LIDAR penetrates leaf cover, giving it an advantage, Brunstad said, in spotting features that offer clues to where springs may be.

The field work focuses on public lands, state parks, forests and scientific and natural areas along the North Shore and the Mississippi, St. Croix and Minnesota rivers because of their accessibility, Putzier said. The DNR is sending postcards to some 4,000 private landowners asking them to notify it of springs on their river valley property or to use the app to report them. The Minnesota Environment and Natural Resources Trust Fund is paying for the spring inventory project, as recommended by the Legislative-Citizen Commission on Minnesota Resources (LCCMR).

"One of the reasons we have the citizen app is because we have thousands and thousands of people who like to get out, hunters, anglers and others," Putzier said. "We want to say if you see stuff, get it to us. This is an important element for us to expand our reach."

Spring into action

Those interested in joining the search can download the app, which works on Android, iOS and Windows operating systems. It is available on the DNR website. Users can enter the date of their find, specify its GPS coordinates or an address, and upload a photo. They also can specify the spring type, whether the origin is a cave, a stream bank, lakeshore or another source, with photos of each type included in the app to help make the identification.

Winter is the prime season for spring hunting because springs leave telltale "meltspots" in the snow and fewer leaves obscure the view. The lack of mosquitoes also is a decided advantage when standing still to enter data on a tablet. "I remember going out last summer and it was just brutal," said Brick, the research analyst. "Your hands are just gray because there's so many mosquitoes on them."

When looking for springs, don't expect to find something like a fountain bubbling up from a pool in a public square or a Florida-style tourist attraction complete with a mermaid show, Brick advised. A more likely find may be a spring flowing at a rate of a gallon per minute or, like a garden hose, three to five gallons a minute.

"A lot of times it's just a wet spot on the ground, more like a seep than a true spring," Brunstad said. "They wouldn't necessarily consider that a spring, but to us that is."

Todd Nelson is a freelance writer from Woodbury. Reach him at todd_nelson@mac.com.