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Example Mitigation for Adverse Effects
When a project on federal land, or funded, licensed, or permitted by a federal agency, negatively impacts a historic property, Section 106 of the National Historic Preservation Act of 1966 requires that the agency agree to complete preservation-minded projects to “mitigate” the impact.  These projects are mutually agreed to between the agency, the Oregon SHPO, and other parties in a Memorandum of Agreement (MOA), a binding legal document. Mitigation cannot, and is not intended to, fully compensate for damage to or the loss of irreplaceable historic buildings and places. Instead, mitigation is an opportunity for a federal agency to preserve and document the past for the public’s education and appreciation.
Good mitigation is project-specific, taking into account the current and future impact(s) of the project, and the needs of the local community. Projects may include documenting historic resources before they are demolished; creating websites, displays, and brochures; holding public education events; or any number of other activities. MOAs may only require that the agency complete a single activity, or if the impacts are great, that several related efforts be completed. Examples of mitigation products and the MOAs that created them are provided below.


Documenting historic resources with reports, photos, maps, and drawings is the most common type of mitigation, and is frequently completed as part of a larger mitigation project.
Oregon SHPO Documentation
Depending on the project impact, agencies may complete Oregon SHPO Documentation, which requires a physical description, history, maps, and photos, among other items. This level of documentation takes the least time and effort to complete.
US Forest Service
Mapleton Ranger Station
Mapleton, Lane Co.
In preparation to sell the Mapleton Ranger Station, the US Forest Service documented the buildings and wrote a history of the site. The report also includes current and historic photos, maps, and drawings. As part of the agreement between SHPO and the Forest Service, this document was distributed to the University of Oregon, Allied Arts and Architecture Library, and the Oregon Historical Society.

Eugene Water and Electric Board (EWEB)
Standby Steam Plant
Eugene, Lane Co.
Part of a larger National Register-eligible maintenance complex, EWEB documented the Standby Steam Plant before the building was demolished to allow the site to be redeveloped. While focused on the Steam Plant, the document discusses the history of EWEB and the buildings the Plant was associated with. Clear photos and detailed maps and appendixes complete the document. 
Historic American Building Survey (HABS), Historic American Engineering Record (HAER),
and Historic American Landscape Survey (HALS)
In some cases more thorough documentation may be required if the historic property is particularly historically important.  HABS, HAER, and HALS are National Park Service documentation standards, and require a complete description and history of the resource, photos, and in some cases scale drawings. Completed documentation is archived by the Library of Congress and available online.
National Register of Historic Places Nominations
In cases where a building, structure, site, object, or district may be impacted, but will not be demolished, it may be appropriate to the property in the National Register of Historic Places. The nomination document records the property and its history, and the designation allows the owner to take advantage of state and federal grant and tax programs. In some communities, provides local protections. Please see the National Register page for more information
Oregon Department of Transportation​
Willamette River Bridges National Register Nomination
Portland, Multnomah Co.
After the completion of a project that negatively impacted the National Register-eligible Morrison Bridge in Portland, ODOT agreed to study the many historic bridges spanning the Willamette River in the Portland metro area and list the Broadway, Burnside, Hawthorne, and Morrison Bridges in the National Register of Historic Places using a Multiple Property Document (MPD). An MPD provides a general history for a type of historic resource and outlines under what circumstances a specific property may be listed. The MPD and a sample nomination are included below.


Brochures, Displays, Interpretive Panels, and Websites

A key goal of mitigation is to educate the public about historic resources. Brochures, exhibits, interpretive panels, and websites are effective ways of achieving this goal


Brochures - Sorry, no examples available


Port of Portland
Museum-Quality Display
Portland, Multnomah Co.
The Port of Portland created this interesting display featuring a historic grain scale as mitigation for the demolition of Pier 1, a  grain elevator determined eligible for listing in the National Register for its association with Portland's industrial history. The museum-quality exhibit is prominently placed at the agency's main office lobby where it may be viewed by the public.

Jackson County
Interpretive Park
Jackson County
In 2010 the Gold Ray Dam was removed, allowing the Rogue River to flow freely for the first time in over 100 years since the dam was built. The dam's construction was unique, relying on rope-driven turbines to produce electricity. While the dam could not be preserved, Jackson County salvaged key parts of the powerhouse for incorporation into an outdoor interpretive exhibit and retained a portion of the dam in the river.  Located in a County park adjacent to the dam's former location, the exhibit is regularly visited by the public.

--> Gold Ray Dam Interpretive Park [pdf]​

Interpretive Panels
City of Albany
Albany Canal Interpretive Panels
Albany, Benton Co.
The City of Albany owns and manages the Albany Canal, which runs through the city, supplying drinking water, irrigating local farms, and generating electricity. When a seismic retrofit diminished the Pump Station's historic appearance, the City mitigated the impact by creating interpretive panels describing the history of the canal and its importance to the community. The panels are installed at key locations along the canal, accessible to the public.


Portland General Electric
Clackamas River Hydroelectric Project
Estacada, Clackamas County

The River Mill Dam is listed in the National Register of Historic Places; however, the conditions of the federal license to operate the dam required PGE to install equipment to allow for fish passage. While necessary, the additional equipment altered the historic appearance of the dam. To compensate for this loss, PGE installed interpretive panels in a nearby park overlooking the site.

--> Clackamas River Panels [pdf]​

US Forest Service
Mapleton Ranger Station
Mapleton, Lane Co.
In preparation to sell the Mapleton Ranger Station, the US Forest Service in cooperation with Oregon State University digitized 5,000 digital images from the late 1880s to the present that reflect changing forest management practices, landscapes, and people over the course of Siuslaw National Forest history.


Management Documents

Mitigation can include creating management plans for the continued use and maintenance of a historic resource. These plans allow for continued changes to the resource, but establish guidelines for ensuring that the historic appearance is maintained. In many cases, these documents can be written to allow an agency to complete work without project-by-project consultation with the SHPO. Generally, these documents are most appropriate for agencies and businesses responsible for managing large historic districts or campuses.
Portland General Electric
Confederated Tribes of the Warm Springs
Pelton Round Butte Hydroelectric Project
Madras Vicinity, Jefferson Co.
As part of its ongoing management of the Pelton Round Butte Hydroelectric Project, an eligible but not listed, National Register Historic District, PGE and the CTWS created a Manual for Built Resources. The document identifies the Project's important historic properties and includes guidelines for their management to ensure that these resources continue to provide power for PGE's customers while retaining their historic character.