Annexing Higher Ground and Preparing Receiving Areas in Hamilton, Washington

Executive Summary

In 2019, after decades of repetitive flooding, the town of Hamilton in Skagit County, Washington partnered with Forterra, a local land conservancy nonprofit, to annex a 48-acre parcel of land located outside of the town’s 100-year floodplain. Annexing this land will provide Hamilton with a higher, drier ground area where town residents could voluntarily relocate to new homes. Forterra is developing plans for the annexed parcel to build affordable, environmentally conscious homes for Hamilton residents. Hamilton provides an example for other municipalities and local governments either in a pre- or post-disaster context for revitalizing a community challenged by frequent flooding through adaptation actions. As done in Hamilton, local governments may consider possibilities for providing relocation options to residents within a floodplain, including by annexing new land, particularly where sufficient higher ground land within existing municipal boundaries is not available. Annexation can allow local governments to maintain local communities, tax bases, and economies.



Hamilton is a historic mining and logging town located in Skagit County, Washington, within the floodplains of the Skagit River. The town was established in 1872 and is home to approximately 300 residents in 2021. 

Hamilton has a long history of flooding. On average, the town floods twice each year, and the town experiences a significant flood every three to four years. Property owners in Hamilton have received more flood insurance payments from the National Flood Insurance Program than anywhere else in the state. Specifically, to date, the National Flood Insurance Program has paid $4 million in claims to Hamilton residents. In 1979 and 1980, a small number of residents accepted a government-funded buyout. Two other buyout attempts failed in the 1990s and in 2003, largely because of the lack of housing options to which Hamilton residents could afford to relocate.


Managed Retreat Examples

Frequent flooding in Hamilton has impacted property values and the number of residents living in the town. In 2017, when confronted with a small tax base and limited funding availability, the then-mayor of Hamilton contacted Washington-based land conservancy and development group, Forterra. The mayor asked Forterra to fund the purchase of a 48-acre parcel of farmland outside of the floodplain that could serve as Hamilton’s new town center. Forterra agreed and purchased the property. 

In July 2019, the Hamilton Town Council voted in favor of annexing the Forterra-purchased property to permit future development outside of Hamilton’s existing municipal boundary and the Skagit River’s floodplain. The town needed to annex the property to run the town’s utilities to this area and develop the land for residential use. Forterra and the Town of Hamilton plan to develop the parcel with environmentally friendly, affordable homes. Reducing repetitive losses from flood-prone areas and helping Hamilton’s residents relocate out of harm’s way has been a priority for the Hamilton Public Development Authority since 2007. The efforts in Hamilton to expand the Town's Urban Growth Boundary, annex the higher ground parcel, and build a sustainable, affordable housing stock on the parcel are explored below in more detail. 

Planning and Zoning: Expanding Hamilton's Urban Growth Boundary

In 2007, the Hamilton Public Development Authority recognized the need for flood mitigation solutions in Hamilton. Accordingly, the development authority established the Skagit County Floodway Mitigation & Hamilton Relocation Program. The program, organized under the development authority, is focused on facilitating Hamilton’s relocation vision. The program can enable Hamilton to enter into public-private partnerships to purchase higher ground land, help residents relocate out of the floodplain to the higher land, and return the floodplain properties to their natural state.

An integral program goal was accomplished in 2008 by when the town and county expanded Hamilton’s “Urban Growth Area”2 and simultaneously approved the Hamilton Relocation Subarea Plan. The Skagit Board of County Commissioners approved Hamilton’s plan to expand its Urban Growth Area by 107 acres as part of its efforts to relocate the town outside of the Skagit River floodplain. The 48-acre parcel land, which was officially annexed in 2019, lies within the Urban Growth Area.


After identifying a suitable parcel of higher ground land that was available for purchase, the former mayor of Hamilton worked with Forterra to annex the parcel. The 48-acre parcel is located less than a mile to the north of the current Downtown Hamilton area and at a higher elevation outside of the 100-year floodplain. Forterra purchased the parcel, with some funding from the town as well, and applied to the Hamilton Town Council to request the land’s annexation. The Town Council approved the annexation in July 2019.

Building a Sustainable, Affordable Housing Stock

Notably, Forterra is the land purchaser of the annexed area, as well as the developer and planner for the site. Forterra plans to build a "green," environmentally friendly development. The development will be primarily residential but will likely have some commercial spaces as well.4 Forterra intends to include sustainable features into the design of the homes.5 Specifically, the residential area will include an advanced wastewater and sewage treatment system, the area will have ample green space, and the homes will be "triple net zero." Triple-net-zero homes are homes that create as much energy and water as they use and that capture more carbon than was released in producing and transporting the building materials.

Forterra plans to make the first phase of the new housing stock available to current Hamilton residents interested in moving outside of the floodplain. The homes sold to current Hamilton residents will be available for purchase at a lower cost via grants to lower the upfront costs of a down payment and through access to 40-year fixed rate mortgages to facilitate lower monthly mortgage payments for residents.6 Any homes in the development not sold to current Hamilton residents will be sold at market rate to non-Hamilton residents. This will help subsidize the affordability of homes for Hamilton residents relocating there.



This endeavor was primarily funded by Forterra. Forterra contributed $575,000 to buy the land, while the town of Hamilton contributed $75,000.7 In total, Forterra intends to spend $1 million to develop a higher, drier community in Hamilton.8 


Next Steps

With the annexation complete, Forterra is now engaged in the process of planning the new Hamilton development. In February 2021, Forterra approved a master plan for the development of the 48 acres of annexed land.

As a precursor to relocating to this new area of the town, homeowners in Hamilton will also need to seek buyouts from the government (e.g., Federal Emergency Management Agency, Washington state) or nongovernmental entities (e.g., conservation groups) in order to ensure that relocation is an economically feasible option for residents.9 At this time, it does not appear that the town or Forterra have conducted any buyouts related to this parcel of land. If homes are bought out, the homes will be razed, infrastructure will be decommissioned, and the lots will be returned to riparian habitat. Hamilton homeowners could then use their buyout funds to purchase a subsidized home in the new annexed area or anywhere else. Accepting a buyout and relocating to the new development is completely voluntary.

The process for developing a higher, drier Hamilton has faced some challenges. In November 2019, the town elected a new mayor who ran on a platform of opposing the relocation project. Questions concerning housing affordability on the annexed parcel have decreased local support for the project.10 


Considerations and Lessons Learned

The early efforts in Hamilton to expand the town's boundaries present a model for how local governments can proactively modify boundaries and local zoning requirements to facilitate future relocation efforts. By proactively expanding the Urban Growth Area and approving the Hamilton Subarea Plan in 2008, Hamilton and Skagit County facilitated the eventual annexation of the new land "receiving" area in 2019. Local governments seeking to take similar proactive actions must allocate appropriate resources and support local programs capable of facilitating long-term managed retreat strategies. Hamilton's model of phased planning and zoning actions could be adopted by other jurisdictions interested in facilitating managed retreat actions and, particularly, annexation. 

Relatedly, the efforts in Hamilton to annex land and facilitate relocation present a model for how local governments can use proactive managed retreat strategies to rebuild out of harm’s way. Hamilton offers an example of how annexing land can help to better prepare communities for the impacts of flood events, improve the sustainability of the built environment, and maintain local communities, tax bases, and economies. By annexing new land, Hamilton utilized an acquisition tool that will enable it to make higher ground investments in “receiving” areas. While municipalities can seek to identify receiving areas within their current jurisdiction, local governments can also consider the potential for annexation, especially where space outside of the floodplain is limited and a large number of residents will need new affordable housing options after voluntarily participating in buyout programs.

The efforts in Hamilton also highlight the value of public-private partnerships. Hamilton offers an example of how municipalities and local governments can leverage limited dollars for managed retreat purposes. Local governments with limited means for achieving managed retreat can consider more traditional funding sources, such as government grants, but should similarly note the value of partnering with private organizations like land trusts. 

In addition, the efforts highlight the importance of community engagement in any managed retreat process. It appears that residents of Hamilton have varying levels of interest in the town’s ongoing relocation efforts—largely due to concerns over a lack of affordable housing in the annexed development and other perceptions surrounding the circumstances of the development (e.g., residents fear they will be forced out of their homes). Local governments should be aware of the importance of engaging with the community—to increase support for a relocation plan and address community concerns—when initiating relocation efforts. In addition to engaging the community, local governments should recognize the value of building trust within the community and providing a meaningful engagement forum to provide information to the public, address any misinformation, and answer questions so that residents can make informed choices regarding their futures in the face of flooding. 

Publication Date: June 2021

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