Minto Island Conservation Area Land Management Plan Update

The City of Salem is updating the Minto Island Conservation Area (MICA) Land Management Plan to reflect ongoing restoration efforts, increasing public use, and evolving ecological goals. This update will provide guidance on restoration of native habitats, management of invasive species, and alignment with MICA’s management with regional conservation efforts under the Willamette Wildlife Mitigation Program. Community input is vital, and a draft plan will be available on this webpage for public review and feedback in early December. Please check back the week of December 2nd.

The 307-acre Minto Island Conservation Area (MICA) is located at the northernmost end of Minto-Brown Island Park, nestled between the Willamette River and Willamette Slough. The City of Salem purchased the conservation area in 2013 using funding provided by Bonneville Power Administration and Oregon Department of Fish and Wildlife. This funding was provided for the primary purpose of protecting, restoring, and maintaining the diverse mix of natural habitats found in the MICA.

Prior to its purchase by the City, this piece of land was privately owned, and about 100 acres the property was used for industrial purposes (storage and processing of paper mill waste). Although the industrial site was officially closed in 1985 and subsequently remediated, many parts of the conservation area remain ecologically altered and are in need of restoration to restore floodplain function, reestablish native plant communities, and provide habitat for the many wildlife species that historically inhabited this area.

To this effort, multiple phases of floodplain restoration are planned.

This phase of floodplain restoration in MICA focused on enhancing, restoring, and expanding the riparian floodplain forest and seasonally inundated wetland habitats within 48 acres on the west side of the conservation area adjacent to the Willamette River. This project focused on treating invasive weeds and planting thousands of native plants. The restoration work began in 2019 and will continue through 2029 to reach the desired conditions.

Status: In progress. From 2019-2024 restoration work was conducted under a grant from Meyer Memorial Trust and Bonneville Power Administration. Work under the initial grant restored the West Forest area; however, further work needs to be done on the site to achieve the desired future conditions. In Fall 2024 the City was awarded Oregon Watershed Enhancement Board Restoration Grant to continue work in the Phase 3 area through 2029.

Funding for this project was provided by: Bonneville Power Administration, Meyer Memorial Trust, and the Oregon Watershed Enhancement Board.

This first phase of floodplain restoration was implemented between 2016 to 2020 to address the loss of floodplain forest and scrub habitat due to the park’s historical use for industry and farming. The primary focus of this project was the removal and control of invasive weeds and the planting and establishment of native plants on 103.5 acres of floodplain in the eastern portion of MICA, adjacent to the Willamette Slough. Restoration of this habitat type along the Willamette River will expand the floodplain forest, increase Salem’s tree canopy, and provide important nesting and foraging opportunities for several songbirds listed as threatened or species of concern.

Status: Complete.

Funding for this project was provided by: Oregon Watershed Enhancement Board (OWEB) and Meyer Memorial Trust

Oxbow Slough Habitat Restoration Project

The City of Salem and Willamette Riverkeeper are gearing up for the first year of targeted treatment of an invasive water plant in Oxbow Slough, located in Minto-Brown Island Park. Uruguayan water primrose, also called Ludwigia, has taken over Oxbow Slough, limiting public recreation opportunities and wildlife use of the Slough.

This first round of treatment begins Monday, July 22, 2024 and is expected to run through Friday, August 2, 2024. A follow-up treatment is scheduled during the week of September 3-6, 2024. Willamette Riverkeeper and City of Salem staff will provide outreach in the park during this time. Funding for this project is provided by the Oregon Watershed Enhancement Board and Willamette Riverkeepers.

Signage about the project and restricted uses will be posted at Minto-Brown Park trailheads. Local watercraft rental businesses, the Willamette Queen, and project partners are being notified. Web, media, and social media updates are also scheduled.

Ludwigia forms dense mats in slow-moving backwater channels, oxbow lakes, and sloughs. While this yellow-flowered plant may appear quite pretty, it has the potential to choke entire waterways, severely restricting recreational access, degrading water quality, and creating an environment that is unfriendly to native fish and wildlife.

Up and down the Willamette River, groups have been working to stop the spread of this highly invasive plant. The City of Salem and Willamette Riverkeeper have successfully completed similar work in Willamette Slough from 2020-2024.

The Oxbow Slough Restoration Project is a five-year project that aims to control Ludwigia in the slough through precise contact spraying of an aquatic-approved herbicide sprayed on the plants by state-licensed applicators. In addition, the area surrounding the Slough will be treated for invasive plants. Future work includes planting native plants in and around the Slough. Treatments will continue through the summer of 2028.

The goal is to reduce the plant’s population to such a degree that additional herbicide treatment will not be necessary once the project is complete. Planting of native plants will provide shading to the shoreline and reduce habitat for sun-loving invasive species like Ludwigia. In the future, any new or remaining Ludwigia will be controlled by hand-pulling.

Recreational users are advised to steer clear of the Slough while treatment is in progress and for 24 hours after treatment to limit potential exposure to the herbicides and to ensure maximum treatment effect. Treated plants will show signs of a blue-green dye, which is mixed with the herbicide so that applicators can see where it has been applied and reduce the amount of herbicide needed for control efforts.

Funding for this project was provided to Willamette Riverkeeper by the Oregon Watershed Enhancement Board.

More about Ludwigia

Oxbow Slough was identified by the Willamette Aquatic Invasive Network as having a large source population of Ludwigia. Ludwigia spreads long distances through plant fragments and by seeds. During high water events the plant is most likely to move downstream with the flow of the river and establish new populations at other riverside and off-channel habitats.  Due to its location, treating Ludwigia in Oxbow Slough will help reduce its downstream spread.

Invasive aquatic plants and animals can also be dispersed by watercraft so it is important to clean, drain, and dry your boat before transferring it to another waterbody.

Additional information about restoration efforts in the Minto-Brown Island Park Conservation Area can be found online at Restoring the Willamette River.

Creeping water primrose, also called Ludwigia, is an invasive aquatic plant that had started choking out the Willamette Slough in recent years. The species impacts water quality, wildlife habitat, and recreational opportunities. Recreationists who enjoyed paddling and fishing in the slough found it increasingly difficult to do so due to the dense growth of this fast-spreading aquatic weed. The dense mats of Ludwigia were impeding water movement, blocking growth of native aquatic and riparian plants, reducing dissolved oxygen, which is essential for survival of aquatic organisms. Ludwigia also reduced the amount of habitat available for fish and wildlife that previously lived, reproduced, or stopped over in the slough, including native freshwater turtles, amphibians, waterbirds, fish, and other wildlife.

In 2019, Willamette Riverkeeper was awarded three years of funding (extended for a fourth year) to restore the Willamette Slough in partnership with the City of Salem. The project, which officially started in 2020, consisted of treatment of the Ludwigia throughout the slough using an aquatic-approved herbicide applied by a state-licensed contractor. The goal is to control the spread of this highly invasive plant within the Willamette Slough and reduce its spread to downstream locations in the Willamette River. In the fourth and final year of the grant funded project, native riparian vegetation was planted along the edges of the slough and native aquatic plants reintroduced in select locations.

This restoration effort complements the City of Salem's other restoration efforts occurring at Minto Island Conservation Area, as well as the efforts of Willamette Riverkeeper and the Willamette Aquatic Invasive Network within the greater Willamette River Watershed.

The project completed the fourth of four years of treatment for aquatic weeds. 2023/24 treatments included the planting of more than 12,000 new willows and other plants along the banks of the slough.

Status: In progress. Ongoing efforts are occurring via paddle and pull events planned for the summer of 2024 with Willamette Riverkeeper and Elderberry Wisdom Farms.

Funding for this project is provided by: Meyer Memorial Trust and Bonneville Power Administration

We are grateful for the support of the following organizations who helped to make this project possible: City of Keizer, Glenn Gibson Watershed Council, Marion Soil and Water Conservation District, North Santiam Watershed Council, Oregon Department of Fish and Wildlife, Oregon State Parks, Salem Audubon Society, Salem Environmental Education, and Willamette Riverkeeper.

Up until recently, portions of Pringle Creek right above its confluence with the Willamette River were obstructed and hidden under layers of concrete from the former Boise Cascade Paper Mill. This project removed the concrete remnants and returned the creek channel to a more natural condition. Site improvements included a new channel that includes a more natural fishway that replaced an old fish ladder, boulders and large natural wood structures that provide stream roughness and habitat refuge, and native Oregon trees and shrubs planted on both sides of the creek to shade the creek and help keep it cool. All these design elements provide better habitat for fish and other aquatic animals that live in the creek.

Status: Monitoring and Maintenance. We are still working to establish native vegetation on the banks and riparian area and prevent invasive species from taking over before native plant cover is established.

Funding: South Waterfront Urban Renewal Area and City of Salem stormwater utility funds.