A state agency apologized Tuesday for what it called a misunderstanding about proposed fines that farmers could face if they don't comply with the state's buffer law.

The Minnesota Board of Water and Soil Resources oversees implementation of the law, which requires farmers to have vegetated buffers along cropland that borders ditches, streams, rivers and lakes.

The current law allows counties and watershed districts to impose a penalty of $500 per parcel for landowners who don't establish buffers of sufficient width to protect the waterways from runoff and pollution. On April 2, the board proposed an amendment that would add a second penalty option and allow higher fines for noncompliance, based on total linear feet of waterway along a parcel.

The proposal provoked a storm of protest from farmers, who said the fines could reach tens of thousands of dollars for some operations and called the idea regulatory overreach.

"These regulations are costly and unnecessary," Jamie Beyer, vice president of the Minnesota Soybean Growers Association, said in a news release. "To burden small farmers when farm income is down an average of 50 percent since 2013 shows this administration clearly does not understand farmers or rural Minnesota."

Republican chairmen of the Legislature's agriculture committees also criticized the proposal as ludicrous and heavy-handed.

Gov. Mark Dayton weighed in with a letter to the board, saying that he was "surprised and disturbed" to learn about the proposed penalty option. He called the fines unreasonable, and said they came as a shock to him and to Minnesota farmers.

Fines should be used only as a last resort, Dayton said, and he urged the board to swiftly reconsider the proposal.

The board apologized in a statement for what it called a "communication misunderstanding." The draft proposal was meant only to provide one of several options for county officials and watershed districts to achieve compliance, it said.

More than 98 percent of farmers with land that borders public waters are in compliance, the board said. No public ditch landowners are affected by the law yet because their deadline is not until Nov. 1.

No administrative penalties have been issued yet as part of the buffer law, the board said, and even if that happens in the future, the fines will be forgiven if landowners bring their land into compliance.

A board committee is scheduled to consider public comments on the proposed penalty later this month.

"If the additional option doesn't have broad support from landowners or local governments, we expect the board will not adopt it," the statement said.