The board of directors of a rural fire protection district, with other state and federal agencies, may evaluate the need for firebreaks and ensure that unprotected acreage enrolled in the conservation reserve program is dissected into approximately one-hundred-sixty-acre [64.75-hectare] containment areas for fire control. In developing plans for firebreaks, the board shall make the best possible use of existing natural and artificial barriers, such as lakes, streams, wetlands with water, ponds, clean tilled cropland, gravel pits, and roads. For purposes of this section, a firebreak means a strip of fire-retarding vegetation, no less than thirty feet [9.14 meters] nor more than fifty feet [45.72 meters] wide.