Mariposa Creek Parkway Phase 1 and Phase 2 Restoration Project

Mariposa Creek Parkway Phase 1 and Phase 2 Restoration Project

The Mariposa Creek Parkway Riparian Restoration Project (Project) will be implemented by Mariposa County in conjunction with the Southern Sierra Miwuk Nation (SSMN) and the Sierra Foothill Conservancy (SFC). The Project proposes the removal of invasive species within approximately 4.05-acres of riparian habitat, planting native trees, planting native plants within areas where invasives are removed, installing temporary irrigation and plant protection measures, and installation of signage. Mariposa Creek Parkway Master Plan (adopted in 2020) identifies several opportunities for the Parkway to serve as a cornerstone of natural resilience and cultural heritage for the community. One of the priority opportunities identified is the implementation of a riparian restoration project that would enhance such an invaluable resource for both wildlife and people. Implementation of the Project will aid in achieving the goals of the Mariposa Creek Parkway Master Plan by reconnecting the local Tribe and traditional ecological knowledge (TEK) practices to this landscape, removing invasive plant species, reestablishing intact native habitat, and providing greater access opportunities for the public. The Project site is currently dominated by invasive Himalayan blackberry (HBB) (Rubus armeniacus) and Tree of Heaven (TOH) (Ailanthus altissima). The Project is required to control 95% of Target Species Cover removal techniques will be completed manually, mechanically, and chemically where applicable. The Project will utilize shovels, spades, rakes, McLeods, pole saws, hedge trimmers, chain saws, post hole diggers, and a masticator. The methods will involve mechanical cutting, hand pulling, digging/grubbing, spot spray chemical treatments, broadcast herbicide application, and prescribed burning. Prescribed fire is used to alter, maintain, or restore vegetative communities, achieve desired resource conditions, and protect life, property, and values that would be degraded or destroyed by wildfire. The Project will implement an integrated environmental restoration strategy, blending traditional ecological knowledge with scientific expertise to apply prescribed burning techniques for the control and removal of Target Species. Burning operations will be timed to occur in the fall and/or winter, when high-moisture conditions are conductive to low-intensity prescribed fire, and specific weather patterns (including wind speed/direction, temperature, and humidity) will be closely monitored before determining a specific day to conduct burning activities. Professional fire personnel, including the Mariposa County and Tuolumne Rancheria Fire Departments, as well as CALFIRE, will be on-site to coordinate both site preparation and prescribed burning activities, and to respond rapidly to potentially hazardous fire conditions. Planting the Project area with native vegetation will provide habitat for wildlife species -and erosion control, while encouraging the re-infestation of invasive plant species such as the HBB and TOH. Priority for revegetation will be given in areas where HBB and TOH have been treated. Establishment of native plants in these areas will be an important component of the Project's invasive species control strategy, as the established native plants will reduce available sunlight and nutrients to invasive plants. Revegetation of the Project area will be transformed from a majority population of invasive non-native Target Species to a multilayered riparian corridor consisting of native trees, shrubs, and herbaceous species. The diversity and percent cover (abundance) of native species within the Project area are expected to more than double. Revegetation will occur in the winter of 2025/2026 which is the optimum time for stock container plant acquisition, natural watering over the wet season and root establishment prior to spring and summer reproductive stages. Native seed mixes used for post-fire revegetation., erosion control, and the re-establishment of local species will be approved by California Department of Fish and Wildlife (CDFW) prior to use. Cultivated native species will be selected from the Project's developed plant palette in consultation with project partners. The Project has been designed to be compliant with the Mariposa Creek Parkway Habitat Restoration and Management Plan including preconstruction surveys for nesting birds, bats, and northwestern pond turtles. Additionally, the Project will implement erosion control and Best Management Practices (BMPs) to reduce the potential for sediment or pollutants at the Project site. Measures will include the following: -Erosion control measures will be placed between Waters of the U.S., and the outer edge of the staging areas, within an area identified with highly visible markers (e.g., construction fencing, flagging, silt barriers) prior to commencement of construction activities. Such identification and erosion control measures will be properly maintained until construction is completed and the soils have been-stabilized -Fiber rolls used for erosion control will be certified by the California Department of Food and Agriculture as weed free. -Seed mixtures applied for erosion control will not contain California Invasive Plant Council (Cal-IPC) designated invasive species (Cal-IPC 2024) and will be composed of native species appropriate for the site. -Trash generated onsite will be promptly and properly removed from the site. - Any fueling in the upland portion of the Study Area will use appropriate secondary containment techniques to prevent spills. - A qualified biologist will conduct a mandatory Worker Environmental Awareness Program for all contractors, work crews, and any onsite personnel on the potential for special-status species to occur on the Project site. The training will provide an overview of habitat and characteristics of the species, the need to avoid certain areas, and the possible penalties for noncompliance. CDFW has jurisdiction over the bed and bank of natural drainages according to Section 1602 of the California Fish and Game Code. Activities that may modify such waters through the diversion or obstruction of their natural flow, change or use any material from their bed or bank, or the deposition of debris require a Notification of Streambed Alteration. Therefore, the Project is preparing a Notification of Streambed Alteration

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