Proposed Dates of Use: October 18-20, 2023
Street Address/Site Name: Davis Wetlands, 45400 Country Road 28H
Detailed Location of Application Site: Road tops, edges, and areas where runoff is unlikely to occur.
Posting and Notification: A notice of 72 hours will be given before the application. No applications will be in the vicinity of playgrounds, schools or picnic areas. Additionally, this area will be locked down restricting the use of pedestrian traffic.
Pesticide Product:
Product (W/ active ingredients): Round up Custom – Glyphosate, N-(phosphonomethyl) glycine 53.8%
EPA Reg #: 524-343
Pesticide Type: Herbicides
City Use Type: Tier 1 limited use, most restrictive. Primary use on levee and pond road tops and edges.
Target Pests: Pepper weed, short-pod mustard, black mustard, Italian thistle, yellow star thistle, milk thistle, fluellin and other annual weeds.
Justification for Use: This herbicide use is justified due to the need for safe access to these critical infrastructure facilities year–round. Public Works Utilities & Operations staff need to be able to safely access stations, roads and facilities throughout the year to perform maintenance and react to changing conditions during the rainy season. Similarly, keeping vegetation controlled on the road tops is important to allow safe public access to the Wetlands. The chemical identified here will provide effective control of the broad range of vegetation that is found in and around the listed sites. All applications will be applied where runoff into bodies of water or drains will be unlikely.
Pepper weed is of particular concern because there is no reliable way to control it without herbicide. Mechanical cultivation or hand hoeing are not options because the plant can reproduce from vegetative material and these methods will actually increase the infestation. The plant can cause damage to stations and road tops because it’s large, tuberous roots can undermine pipes, foundations and other facilities. There is no reliable way to kill these weeds using non-chemical methods at the scale they exist on the sites.
Explanation of IPM Methods Used: Staff will only use herbicide in the areas identified above. All other acreage included in water management areas is maintained without pesticides. Areas that can be mowed or trimmed will receive those treatments, as needed to keep access clear and fire risk low. Crews will do hand trimming, and pruning in areas that mowing is not accessible by tractors.
Strategies to Prevent Future Applications: Effective, well-timed control will decrease pesticide usage over time because less seed and reproductive material will be present in the soil. However, the need for access to secure public safety may affect this trend, depending on conditions such as rainfall amounts, timing and ground temperature. We propose to reduce our use in the following ways:
- Practice responsible vehicle access during wet months to prevent road damage and the need for repair work that is a vector for invasive species.
- Clean and maintain all equipment before and after use to prevent the transfer of seeds and plant materials between sites and/or into sensitive areas.
- Continue to use hand and power tools to keep control of the weeds as much as possible.
More information on the IPM Program, including the current Policies and Procedures guidance, can be found on the City's webpage: Integrated Pest Management
