COVID-19 Notice – City facilities and playgrounds are closed until further notice in an effort to mitigate the spread of COVID-19 in our community. Dog parks, tennis courts, and select park amenities are open.
Get the latest coronavirus updates on our COVID-19 webpage.
Para actualizaciones sobre el coronavirus en español, visite a nuestra página de noticias.

Restoration at Jackson Bottom Wetlands Preserve

Press Enter to show all options, press Tab go to next option

Oak Island Marsh Restoration Project

Photo of Jackson Bottom WetlandsThe City of Hillsboro Parks and Recreation, with help from strategic partners, is restoring 270 acres of degraded wetland habitat in the 635-acre Jackson Bottom Wetlands Preserve. The Oak Island Marsh Restoration project will create a resilient habitat filled with diverse, native plants and animals that will help protect our local watershed.

What is a Wetland?

Wetlands are areas covered with water for all or part of the year. Sometimes called marshes, swamps or bogs, wetlands can be found within floodplains along rivers and streams. These sensitive areas protect water quality, shelter wildlife and provide recreation and education opportunities.

They are also fragile. Decades of mismanagement have damaged the world’s wetlands causing more severe flooding, degrading water quality and endangering native plants and animals. Some statistics state that the US has lost 50% of our wetlands since the 1700s. Preserving and restoring wetlands will strengthen ecosystems, help protect our water and connect our community through recreation and education.

Jackson Bottom History

Jackson Bottom has a varied—and sometimes unfortunate—history of use. Native people hunted the diverse, migratory waterfowl that passed through and gathered edible plants especially the highly-prized common camas bulbs and wapato tubers. Early European settlers homesteaded on the dry uplands.

Since then the area had been through a lot. It was cleared, ditched and drained for agricultural purposes. Reed canary grass was introduced for cattle grazing.  The land was used as a dumping ground for construction debris, cannery waste and sewage water. From 1935 to the early 1970s it was an experimental “sewer farm,” employing over 200 people at one point. Eventually farming ceased and the highly-invasive reed canary grass took over.

Starting in the 1970s, concerned citizen groups like Friends of Jackson Bottom have worked to restore and improve the degraded floodplain by constructing wetlands and planting native plants. Today the City of Hillsboro Parks & Recreation Department manages Jackson Bottom Wetlands to protect wildlife and is overseeing on-going restoration projects.

Restoration: Why it’s Important

This restoration will bring crucial benefits to Jackson Bottom Wetlands, the City of Hillsboro and the entire Tualatin River watershed. The 80-mile long Tualatin is Washington County’s only river. Slow moving, it drains from more than 700 square miles of forest, agriculture and urban areas before joining with the Willamette. The Tualatin is used for irrigation, recreation and even drinking water for nearly 400,000 local homes and businesses. Restoring Jackson Bottom Wetlands will help protect this important water source.

The Oak Island Marsh Restoration project encompasses five degraded wetland areas and over 80 acres of abandoned fields. Each of the five areas will require a different restoration approach. When finished, these restored habitats will encourage biodiversity, improve water quality and provide wildlife-dependent recreation (hiking, bird watching, photography) and education opportunities.


Because of their degraded states, the wetlands within the Oak Island Marsh project support a variety of invasive plants and animals including reed canary grass, nutria, bullfrogs and common carp, which outcompete and crowd out native species.  Some areas within the Oak Island Marsh project are 100% reed canary grass.

To encourage biodiversity, invasive plants will be removed and aggressively replanted with a mix of native woody and herbaceous wetland species. This restoration approach will produce a thick cover of woody vegetation and herbaceous plants to keep invasive species from re-establishing. The new plants will also provide critical wildlife habitat, improve water quality and increase biodiversity.

The restoration will make Jackson Bottom less welcoming to invasive species like nutria, carp and bullfrogs and more attractive to native amphibians, mammals and birds. Designated an Important Bird Area by National Audubon Society, Jackson Bottom is already home to over 150 different migratory and resident bird species including a pair of nesting bald eagles and ospreys.

Water Quality

Dense and diverse native vegetation does more than suppress invasive plants and support native wildlife. It also acts as a filter, cleaning and cooling water before it drains into the Tualatin River. When complete, the biologically diverse environments created by the Oak Island Marsh Restoration project will improve water quality for both people and wildlife throughout Washington County.

Recreation and Education

Jackson Bottom Wetlands Preserve welcomes about 30,000 visitors a year including 6,500 children who come for classes and camps. The Oak Island Marsh Restoration project will provide these visitors and students with an accessible, high-quality, living example of wetlands ecology. Specially designed education/viewing stations will be strategically placed to allow the best views while protecting sensitive wildlife habitats. Trails within the restoration project will be upgraded and stabilized, including the North-South Trail.

Restoration at Jackson Bottom Wetlands

Community Involvement

There will be many opportunities to get involved in the Oak Island Marsh Restoration project. The project will require about 1500 volunteers to give 4,000 hours of their time. Volunteer opportunities will include chipping trails, planting native species, collecting seeds or building bat and bird boxes. There will be two major volunteer planting events held at Jackson Bottom each year that will be managed by Friend of Trees. Visit the Friends of Trees website for planting dates.

Jackson Bottom also has a robust Citizen Science program. These volunteers collect and report bird monitoring data. Continued bird monitoring will track the success of the restoration project.


The City of Hillsboro has partnered with local, regional and national organizations to gain funding and support for this restoration project. These partners share the City’s dedication to preserving nature and strengthening community. Below is a list of major partners for this project:

  • Metro
    A $335,000 Nature in Neighborhoods capital grant, funded by Metro’s natural areas bond measure approved by voters in 2006, was awarded to this project in 2015. These funds will be used for wetland construction and restoration, trail signage and wildlife viewing areas. 
  • Clean Water Services
    Clean Water Services (CWS) is the water resources management utility for more than 542,000 residents in urban Washington County, Oregon. CWS operates four wastewater treatment facilities, constructs and maintains flood management and water quality projects, and manages flow into the Tualatin River to improve water quality and protect fish habitat. CWS owns a portion of the preserve and is contributing significant funds towards the construction, restoration and protection of the wetland habitats.
  • Ducks Unlimited
    Ducks Unlimited has years of experience constructing high functioning, cost-efficient wetlands. Since 1937, Ducks Unlimited has completed more than 20,000 restoration projects in North America, conserving more than 12 million acres of valuable wildlife habitat. As part of a NAWCA (North American Wetlands Conservation Act) grant Ducks Unlimited is contributing almost $200,000 to the construction of this project.
  • Oregon Watershed Enhancement Board
    A $92,000 restoration grant, funded by OWEB, was awarded to the project in 2017. These funds will be used for wetlands restoration including purchasing native plants for the site. 


Free viewers are required for some of the attached documents.
They can be downloaded by clicking on the icons below.

Acrobat Reader Download Acrobat Reader Flash Player Download Flash Player Windows Media Player Download Windows Media Player Microsoft Silverlight Download Microsoft Silverlight Word Viewer Download Word Viewer Excel Viewer Download Excel Viewer PowerPoint Viewer Download PowerPoint Viewer