Fifty-foot grass buffer strips would be required along nearly all Minnesota waters, including streams, rivers and ditches, to reduce soil erosion, improve water quality and create wildlife habitat, under a landmark bill introduced this week in the Legislature.

The bill is the brainchild of Gov. Mark Dayton, who called for a new buffer requirement after learning last fall at a Pheasant Summit that the state's current buffer laws were sporadically enforced.

Under the bill, local soil and water conservation districts would implement the requirements, but enforcement would fall to the Department of Natural Resources (DNR).

"This is very significant," said Tom Landwehr, DNR commissioner. "Buffers are not the silver bullet; they're not going to fix everything. But buffers will improve water quality." And provide aquatic and wildlife habitat.

Environmental and sportsmen's groups hailed the bill, but the agricultural community expressed opposition.

"It's an important step that we think Minnesota needs to take," said Joe Duggan, a Pheasants Forever vice president. "We're hoping a lot of the buffers can be managed for wildlife."

But Thom Petersen, government relations director for the Minnesota Farmers Union, said his group won't support the bill, as written. He said there are too many unanswered questions.

"Buffers are important — we support buffers — but we want to do it right," he said. "The 50-foot, one-size-fits-all approach isn't widely supported. For some farmers, that's a lot of land [to take out of production.] You're asking people to give up their land. But we're willing to keep working on it."

Petersen also said his group, which represents about 14,000 farm families, is concerned about the fast timeline required under the bill: The DNR must prepare maps of perennial waters — including those that flow during the majority of the growing season — by April 1, 2016, and buffers would have to be in place by Sept. 1, 2016.

The Minnesota Farm Bureau, which represents about 20,000 farm families, also opposes the bill.

The bill extends the requirement for buffers to waterways that weren't covered in the past, said Whitney Clark, executive director of Friends of the Mississippi River. "That's the real strength of this bill," he said. "I think we'll see a significant impact to [stream] bank stability and water quality. It won't solve all our agricultural water problems. But it's a good step."

And a bold one, he said.

"This will have a lot of habitat benefits, not just for game species, but nongame species, including pollinators."

Steve Morse, executive director of the Minnesota Environmental Partnership, called the bill "a major conservation advancement."

Under the bill, the buffers would be required adjacent to all "perennial waters" that have a "bed and bank." That would include most ditches. But landowners still could utilize that land.

"They can hay or graze it," Landwehr said, "and it doesn't provide public access.

"It will certainly require them to change the way they do business. But we have a buffet of programs that landowners can enroll in that will compensate them for any loss of tillable land."

One is the federal Conservation Reserve Program continuous sign-up.

"It pays landowners on an annual basis, and will pay for some of the establishment costs [for the buffers]," Landwehr said.

Most lakeshore homesites with lawns wouldn't be affected, Landwehr said, noting exemptions in the bill. Recreation sites, such as beaches, marinas or water accesses, or areas with roads, buildings or other structures and lands within sewered areas covered by city water discharge permit also are exempted.

Soil and Water conservation districts would be required to implement the buffer requirement, or delegate that responsibility to another local unit of government, such as a county. The bill says the DNR or Board of Water and Soil Resources must provide "sufficient funds" for the conservation districts to implement the law. But funding sources aren't mentioned in the bill.

The DNR could fine violators and require them to take corrective action. The DNR also could withhold funding to soil and water conservation districts for failing to implement the law.

Supporters say they are cautiously optimistic the bill can find bipartisan support. Chief author in the House is Rep. Paul Torkelson, R-Hanska, who was ill Tuesday and unavailable for comment. In the Senate, Sen. John Marty, DFL-Roseville, is chief author.

"All the environmental groups and sportsmens' groups and public really support it," said Marty. "I think there's a decent chance.''

Just last week, the Minnesota Pollution Control Agency issued a report saying many of the lakes and streams in southwest Minnesota are unsafe for both people and fish to swim in. Nitrate pollution from farmland is a major problem. And of 93 streams the study examined, only three were able to fully support aquatic life, and only one was safe for aquatic recreation.

Doug Smith • doug.smith@startribune.com