If you’ve ever biked or walked through Portland’s Skidmore/Old Town Historic District, you’ve likely had a bit of a bumpy ride or wobbly stroll. That’s because many of the streets there are paved with old basalt cobblestones called “Belgian Blocks.” Charming reminders of Portland’s early history, what’s left of these stone pavers pose a challenge for people with mobility limitations and/or those who may be using a wheelchair or walker.
Although historic Belgian Blocks have been repurposed throughout the City since the 1970s (especially in parks and historic districts), in recent years accessibility requirements have complicated the design and approval of their redeployment. City ordinances require that the historic blocks be salvaged and stockpiled for reuse whenever they are unearthed in construction projects. And while a significant number of blocks have been recovered and are ready for deployment, their reuse has dwindled in recent years.
Finding new uses for Belgian Blocks
As part of its historic resources program, the Bureau of Planning and Sustainability recently commissioned a technical report regarding the use and redeployment of the City’s collection of salvaged Belgian Block cobblestones. Authored by Peter Meijer Architect (PMA), the Belgian Block Report provides policy and technical solutions that respond to modern accessibility standards and consider how to deploy the stockpiled Belgian Blocks more readily.
The study follows a grant award from the Kinsman Foundation, which funded a pilot project to clean and redeploy a small number of Belgian Blocks for reuse on the landings of the new Earl Blumenauer Bridge. The grant award recognized the blocks as historical and cultural resources that reflect the region’s natural history and provide an adaptive reuse alternative to common paving materials with high embodied carbon, such as concrete.
Key Findings
The initial findings from PMA’s draft report were discussed at a Historic Landmarks Commission briefing on June 28; the final report was published September 3.
The report focused on ways in which the blocks can be reused to meet accessibility requirements, including ways to modify the physical characteristics of the blocks while meeting historic standards of appropriateness. Among the findings, the report recommends the City:
- Update local ordinances to allow more diverse options for deploying Belgian Blocks, including as landscape features, streetcar track demarcations, and in accessible plaza areas.
- Prepare design details showing ADA compliance details and opportunities for reuse as decorative streetscape elements.
- Allow modification of the block surfaces to increase slip resistance and resolve textural variations.
The report includes technical background, case studies from other North American cities, and more recommendations to be considered by City staff, the Historic Landmarks Commission, and designers considering utilization of the blocks.
About the Belgian Blocks
Portland’s first streets were laid out in the mid-19th century, with some of those earliest streets following the alignments of trails used by indigenous peoples. These simple dirt roads turned to barely navigable mud in the wet Northwest winters and hard, dusty ruts in the summer. Early attempts at more durable solutions included wooden blocks (Nicolson paving) and packed crushed stone (Macadam). However, these materials proved especially problematic on the busy warehouse-lined streets near the waterfront, where frequent spring floods would wash away lighter materials.
By the early 1880s, the City had turned to the ancient technology of stone paving, specifically basalt blocks, for street paving. The primary sources for Portland’s Belgian Blocks were basalt quarries along the lower Columbia River. The majority of Portland’s stone pavers were sourced from a group of basalt quarries located two miles north of Ridgefield, Wash., near the mouth of the Lewis River. The old quarries are now part of the Basalt Cobblestone Quarries Historic District located within the Ridgefield National Wildlife Refuge.
Approximately 30 miles of Portland’s streets were paved in Belgian Blocks by the early 1900s, but the pavers proved to be a noisy, slippery surface that became uneven as block corners and edges wore down and chipped from impacts. Portland’s basalt paved streets remained in active use well into 20th century, but over time the blocks were removed and simply paved over. A few sections with original Belgian Block paving continue to be maintained, including portions of NW Irving and Marshall Streets in the Pearl District.
By the mid-1970s, the Portland City Council recognized that the remaining Belgian Blocks were a significant historic resource worthy of preservation, salvage and reuse. In 1976, City Council passed an ordinance requiring the blocks be cleaned and stored for possible future deployment whenever roadwork resulted in the removal of 150 or more blocks. City Council tasked the Historic Landmarks Commission with the responsibility of reviewing deployment proposals against two criteria: The blocks be 1) reused in areas of the city where they were previously used; and 2) used in large paving areas, primarily in public pedestrian spaces.
Early projects made use of the City’s stockpile: Belgian Blocks were deployed in Ankeny Plaza, Cathedral Park, Laurelhurst Park, Lewis and Clark College, and along the MAX Blue Line downtown. Although redeployment of the blocks was commonplace in the 1970s and ‘80s, the passage of modern regulations—specifically those included in the Americans With Disabilities Act (ADA)—resulted in uncertainty about where and how historic pavers can be used while ensuring safe and accessible pathways.
Next steps
With the publication of the report, BPS staff will coordinate with other bureaus and the Historic Landmarks Commission to begin the process of revising the City’s ordinances governing use of the blocks and developing technical details for design teams interested in reusing the blocks. Completion of the pilot redeployment project funded by the Kinsman Foundation is expected to coincide with the construction of the Earl Blumenauer Bridge landings, anticipated to be finished in 2022.