County officials renew efforts to protect roadside vegetation

Illegal mowing and cultivation are impairing the ability of Iowa's roadside ditches from fulfilling their capabilities as green infrastructure, according to state and county officials.

Encroachment of crops into public rights of way and mowing of ditches before the legally permissible date of July 15 are 'widespread practices' that nullify many of the beneficial functions ditches are designed to perform, said Joy Williams, an agronomist in the Iowa Department of Transportation's Roadside Development Section.

'It's an important issue and a challenge to enforce. We just want to raise public awareness of the benefits of properly functioning, well-vegetated roadside ditches,' said Rob Roman, roadside vegetation manager for the Linn County Secondary Roads Department.

Those benefits, he said, include enhanced wildlife habitat, increased water infiltration, reduced soil erosion, delayed runoff after heavy rains, capture of drifting snow and improved aesthetics.

Iowa Code 314.17 prohibits the mowing of roadside vegetation on public rights of way or medians before July 15. Exceptions include areas near the corporate limits of a city, areas within 200 yards of inhabited dwellings and areas requiring mowing for visibility and safety.

Iowa Code 318.3 prohibits the growing of crops within the right of way.

Williams said the removal of fences along rural property lines, the use of increasingly bigger farm equipment and high grain prices in recent years have encouraged many farmers to plant crops in the public right of way.

Doing so, she said, increases the likelihood of soil erosion along the field edge and hastens runoff into roadside ditches after heavy rains. The spraying of herbicide kills vegetation in the public right of way, which encourages weeds to replace what may have been deliberately planted native grasses and flowers, she said.

Removal of fences, which increasingly are no longer needed to contain livestock, creates 'a gray area' where the line between private farmland and public right of way is blurred, said Rebecca Kauten, manager of the University of Northern Iowa's integrated roadside vegetation management program.

Premature mowing is typically done for aesthetics or to harvest hay, according to Williams. Hay balers first need to secure a permit from the state and approval of the adjacent landowner, she said.

Speeds runoff

The beauty of a roadside ditch is in the eye of the beholder, some of whom favor blooming wildflowers, while others prefer the look of neatly trimmed lawns.

'Some people don't see mowing ditches as an issue. They like neat and tidy and believe that's how things are supposed to look,' Kauten said.

As enforcement often is impractical, roadside vegetation advocates rely on education to convert recreational mowers, pointing out, for example, that well-manicured ditches speed the runoff of water, eliminate cover for ground-nesting birds and other wildlife and shrink plant diversity, which eliminates pollen and nectar sources for many insect species.

The alarming decline in monarch butterfly populations, for example, can be traced in part to the toll taken by herbicide on milkweed, one of the monarch's key food sources, Kauten said.

In the past three years, the state and counties together have planted 1,093 pounds of milkweed seed on 8,102 acres along Iowa's roadsides, Kauten said.

Williams said the Department of Transportation manages 216,300 acres of roadside, of which 52,180 acres have been enhanced with native grasses and wildflowers. Iowa's total roadside area, including county rights of way, is estimated at 750,000 acres.

Because of the general lack of enforcement, the extent of premature mowing and crop encroachment — described as 'common' by both Kauten and Williams — is hard to pinpoint.

Roman said he thinks the planting of crops in ditches has increased dramatically since 1991, when a thorough Linn County inventory found that just 63 of the 8,400 quarter-mile roadside ditch segments had or were suspected to have crops planted in the public road right of way.

In 2013, a conservative estimate of cultivation of crops within those same 8,400 segments would put the number at 800, according to Roman.

Iowa Code 318.12 states that 'A highway authority (typically the state or a county) shall enforce the provisions of this chapter by appropriate civil or criminal proceeding or by both such proceedings.'

But the law is 'pretty vague about how to enforce it,' said Kristi Harshbarger, general counsel for the Iowa State Association of Counties.

'At the county level, enforcement would involve participation of the sheriff, the county attorney and the roads department at a minimum, which would make enforcement time consuming and expensive,' she said.

Most counties accordingly focus on education and prevention rather than enforcement, Harshbarger said.

The issue is critical in terms of water management and water infiltration, according to Roman.

During last June alone, in the eastern one-third of Linn County, road surfaces were damaged by runoff from adjacent properties in 182 locations, requiring 11,000 tons of rock for immediate repairs, he said.

Linn County sends letters to people engaging in questionable practices and conducts face-to-face visits, Roman said.

'We are not out to get anybody, but people have to understand they can't do it. We are not intruding on anyone's property rights. That's public right of way,' he said.

Linn County will again mow crops in the right of way this summer and replant those areas to appropriate plant species, he said.