Roadside Vegetation Management
Benton County works with a weed cooperative and property owners to control noxious weeds on roadways with a combination of mowing and herbicide application. Mowing is used to keep grasses and brush away from driving surfaces and provide a clear line of sight for vehicle traffic. Environmentally safe products are applied to roadsides in order to reduce overgrowth and minimize weeds and invasive species.
Mowing: Benton County mows roadsides in the Spring and Fall as weather permits. Due to wildfire considerations, this program is suspended for most of the summer. Spring mowing consists of 1-2 passes of the mower (head width 3-6'). At reduced site distance locations, multiple passes may be required. The focus is on keeping grasses cut short before the summer growing season. Fall/Winter mowing are multiple passes and focus on brush removal and overhanging limbs. Special Management Areas can be mowed only during certain times of the year (usually starting September 1st through March 1st).
Broadleaf Application: Benton County applies a broad based foliar-active herbicide to eliminate noxious weeds (as defined by the Oregon Dept of Agriculture) and undesirable vegetation between the road shoulder and edge of right-of-way. Application is made using a truck with a boom sprayer unit,, hand/backpack or small tank mix unit. Our objective is to control the spread of State listed noxious weeds and preserve sight distance requirements.
Application of herbicides cease 25' prior to crossing over a listed stream to protect water resources and sensitive fish species. Herbicides are used in accordance with EPA labels, including weather criteria and disposal of empty containers. No herbicides will be applied in front of schools or designated bus stop waiting areas when persons are present, driveways, or permitted no-spray areas, as long as the permit is current and the right-of-way is maintained per agreement on the permit.
Hand spraying herbicide is utilized within 25' of bridges if 1) removal of the vegetation is critical to the function of the structure, 2) rain is not forecast in the timeframe outlined in the herbicide label and 3) an aquatic approved herbicide is used. Any application on or over waterways will be with an aquatic approved herbicide only. Application occurs between May and October 15.
Herbicide Use on Shoulders: Benton County applies foliar-active and/or soil residual herbicides to eliminate undesirable vegetation within the defined road shoulders. Application is made using a truck with a boom sprayer unit. The objective in maintaining shoulders free of vegetation are five-fold: 1) to preserve the sub-structure of the road base, thus extending the life of the road surface, 2) allow water to shed from the paved surface of the road reducing potential for hydroplaning; 3) create a fire barrier between the road and adjacent vegetation; 4) provide a vehicle recovery area, and 5) maintain sight distance.