Notice of Intent to Spray - Wildhorse Agricultural Buffer, South Fork Preserve, Mace Ranch Park, Woodbridge, Willowbank 10, Putah Creek Parkway, Cannery Hedgerow, Uplands, Parks Corporation Yard
Proposed Dates of Use: As conditions and time permit the week of December 11-15, 2023
Street Address/Site Name: Wildhorse Agricultural Buffer, South Fork Preserve, Mace Ranch Park, Woodbridge, Willowbank 10, Putah Creek Parkway, Cannery Hedgerow, Uplands, Parks Corporation Yard
Detailed Location of Application Site: Throughout each site, exact location depends on location of unwanted vegetation. Site-specific postings will include details on exact location at time of application.
Posting and Notification: Site notifications will be posted at least 48 hours before application via the pesticide application electronic notification system and at site entrances, remaining 24 hours after.
Target Pests: Woody vegetation that poses an obstruction to trails, interferes with visibility or prevents safe access for maintenance and emergencies.
Justification for Use: This herbicide use is justified due to the need to conduct fire-fuel abatement in Open Space areas, and for safe, year-round public access to the sites. Dense woody vegetation in close proximity to roads and paths poses a threat to users because it block visibility and can physically block the lanes. City operations staff is also experiencing increased call for fire abatement in all areas of town. Open Space staff also needs to safely access these areas throughout the year to perform maintenance and react to changing conditions during the rainy season.
Just cutting back most species of trees and shrubs (the current management program) does not kill the vegetation. Instead, this management technique causes multi-stemmed regrowth that becomes even thicker and more difficult to manage. Herbicide stump-cut treatments are necessary to kill the unwanted vegetation and prevent regrowth, thus reducing the need for additional vegetation management going forward.
Explanation of IPM Methods Used: Staff will only use cut stump herbicide application in the areas identified above. All other acreage included in stormwater management areas is maintained using all IPM techniques, always with a priority on least chemical use. Access roads, channels and slopes that can be mowed, trimmed or grazed will receive those treatments, as needed, to keep access clear and fire risk low.
The use of mechanical removal of cut stumps (ex. using heavy equipment to dig up root masses) was analyzed and eliminated from consideration due to multiple problems. The primary challenge is that excavating root masses would potentially damage near-by desirable vegetation. Further, resulting disturbed soil will promote new weed growth and possibly impact stormwater quality via sediment transport.
Strategies to Prevent Future Applications: Well-timed stump-cut application will kill the specific, unwanted tree or shrub immediately and eliminate the need for future management. Once large, unwanted woody vegetation is removed, staff can prevent the establishment of new woody vegetation through mowing and hand removal while still small.
Additional comments: Fire and Open Space staff have extensive experience with fuel/ vegetation management. This justification will allow staff to continue to meet their mandate for public health and safety, with limited overall reliance on chemical pesticides. It’s important to note that staff will coordinate vegetation management efforts with the Environmental Resources Division to ensure water quality and habitat value are preserved. Thinning dense areas of vegetation can help protect habitat value by reducing fuels that could lead to intense fire and resulting full loss of habitat.
More information on the IPM Program, including the current Policies and Procedures guidance, can be found on the City's webpage: Integrated Pest Management
