Fifteen years ago, Daniel Schaaf was on target to put himself out of business. He was doing landscape work and installing rocks along shorelines in Wisconsin and Minnesota at a time when the "rip rap" method of controlling erosion was falling out of favor.

One day, a manager at the Minnesota Department of Natural Resources challenged Schaaf to come up with a more environmentally friendly way to stabilize eroding lake and riverbanks.

With no background in engineering, Schaaf did just that, devising a system now marketed under the name of ShoreSox. The patented approach uses 6-foot wide strips of burlap mesh that are stuffed with inexpensive organic material, such as corn husks or tree mulch. The fabric gets folded in half to form a tube (or sock) and is staked into the ground several feet back from the fragile shoreline.

Deep-rooted native aquatic plants can then be planted directly atop the fabric, which further binds the organic material to the shoreline and helps filter the nitrates and phosphates from runoff that promotes toxic algae blooms. The fabric itself eventually disintegrates, Schaaf said.

"It's simple to install, cost-efficient and instantly stops erosion and promotes revegetation," said Schaaf, the energetic and earnest CEO of the Minnetonka-based company.

Schaaf spent 13 years perfecting the method before taking it to market two years ago. He started out with small demonstration projects on lakes and waterways around the Twin Cities and property he owns in western Wisconsin, working with private homeowners, cities, counties and watershed districts to split the cost.

Winter's freeze-thaw cycle challenged him to design a system that could handle the shifting earth yet strong enough to contain the waterlogged fill, which can weigh 500 pounds when saturated.

While the industry's biggest player, India-based Geotextiles, uses shredded coconut hulls, Schaaf experimented with locally sourced materials. In the Midwest, he worked with farmers to source bales of hay or corn husks. In Florida, he stuffed the ShoreSox with pine needles, mulch from invasive Melaleuca trees or the muck dredged from the canals that were being fortified with the system.

This approach allows Schaaf to avoid the expense of warehousing or shipping tons of heavy organic filler. The fabric, which Schaaf also patented, is shipped directly from his manufacturer, Volm Co., a family-owned business in Antigo, Wis.

ShoreSox requires no heavy equipment — usually just a wheelbarrow and hammer — but it is labor intensive, costing $40 to $70 per linear foot installed. The ShoreSox product has been used in wide-ranging applications by municipalities, parks, golf courses and housing developments in Florida, Texas, New York and Canada. FEMA used it to help rebuild a flooded wetland in Indiana.

Last year, the city of Eden Prairie set up a pilot project with ShoreSox around a stormwater filtration pond that was taking over a resident's yard after several years of storms and flooding.

The city kicked in about $4,000 for labor and wood chips, and the Riley-Purgatory-Bluff Creek Watershed District contributed another $3,000. The homeowner paid for black dirt, native plants and an extension beyond the 50 feet that ShoreSox contributed.

It's early, but Rick Wahlen, Eden Prairie's manager of utility operations, said ShoreSox has "great potential," given the number of streams that threaten private properties along bluffs.

"The product, if it proves itself out, could be a great fix," Wahlen said. "It could also work out well for watershed districts and community projects. … All it takes is a Saturday afternoon with a couple dozen volunteers. The cost of material is cheap."

Schaaf, 60, formed the business with his wife, Denise, who died unexpectedly six years ago. The couple funded the operation using their own cash and credit cards. Lake and Wetland Management Inc., an environmental resource management company based in Boynton Beach, Fla., that helped Schaaf launch the product and expand its uses, has a 20 percent stake in ShoreSox and exclusive rights to sell it in Florida. With patents, royalties and licensing agreements, ShoreSox has been "self-sufficient" for the past two years, said Schaaf, whose oldest daughter Sage is vice president and in line to someday take over the company.

After more than a decade of research, Schaaf believes ShoreSox is on the cusp of major growth. So far, there's not a lot of competition. Besides Geotextiles, the industry's other major player is Wisconsin-based American Excelsior.

ShoreSox recently landed its biggest project yet, a $250,000 project with the University of Alabama to restore a mile of crumbling cliff around sacred Indian burial mounds.

With Gov. Mark Dayton pushing farmers to comply with buffer zones, Schaaf says ShoreSox can be installed without sacrificing cash crops.

"With this little company, we have an environmentally friendly product that in the end helps clean up the water," he said. "It's a win-win."