Research Insights
We have categorized our concerns into several critical topics. Each topic reflects a specific area of concern identified by neighbors and experts.
Updated 7/26/26
Environmental Impact
The Tualatin River basin includes North Rock Creek and Beaverton Creek that run through Noble Woods Park. This area is a migration path, foraging region, and spawning ground for salmonid species including the threatened steelhead. There are several species of freshwater mussels that are threatened by human-caused habitat degradation including sedimentation due to bank erosion and contamination from runoff. This wetland and forest area includes bottomland riparian forest which is a priority habitat in the Oregon Conservation Strategy. Steelhead and Pacific lamprey rely on shaded riparian forests, particularly during winter during flood events. Flooding is a regular occurrence in Noble Woods during winter.
The Willamette Watershed Council’s strategy for the Tualatin River basin includes preventing stormwater runoff and maintaining stream canopy cover. These focus areas have been in place since DEQ designated this region as water quality limited due to low dissolved oxygen concentrations. Roadway runoff can contribute to low dissolved oxygen concentrations. Removal of 267 established trees around the newly constructed road will reduce shade and increase water temperatures in summer months increasing the likelihood of algal blooms.
The City of Hillsboro set a goal for this project to place the Storm Management Facility (SMF/ water quality detention pond) outside of the flood plan to collect and treat runoff from the newly constructed road. It was stated in an FAQ released by the City of Hillsboro from 2021, “the majority of the area beneath the bridge falls within an established floodplain which has numerous challenges if a Storm Management Facility (SMF) is located there. Ideally, the SMF and system would be located outside of the floodplain where the impact to habitat would be minimal.“ Measurements from the recently released design maps on the Washington County website of the detention facility compared to the FEMA flood plain maps shows that a portion of the SMF extends approximately 65 ft into the floodplain.
The Washington County NPDES General Permit 1200-C form submitted by Russell Knoebel, the Capital Projects Manager, on 06-03-2026 notes that construction of this project will require “dewatering”. There is potential for significant harm to the habitat and water quality in Beaverton Creek as a result of this process. Drying out the riverbed will cause loss of aquatic life and critical habitat for threatened species. Pumping water back into riverways and wetlands during dewatering can add sediment into waterways, clog the gills of fish, destroy larvae, alter water temperature and salinity, and increase nutrient load.
Summary of Requests:
DEQ require a study to be done to confirm that Total Maximum Daily Loads (TMDLs) of discharge into the waterways not captured by the SMF during yearly winter flooding events will not exceed the established limits of the Clean Water Act.
DEQ require a highly detailed, multi-phase Stormwater Pollution Prevention Plan (SWPPP). Washington County must demonstrate how they will isolate Rock Creek and Beaverton Creek from runoff during bridge construction and bank realignment as well as during regular winter flooding events once the project is complete.
DEQ to mandate advanced controls, to keep turbidity from escaping the site into the waterways.
DEQ require all heavy grading and river bed work to stop during significant rain events to prevent sediment from washing directly into the river system.
During construction, DEQ require daily, independent turbidity and temperature monitoring upstream and downstream of the construction zone, and results be shared publicly on the Washington County Century Blvd Extension Project website.
DEQ require that Washington County provide documentation justifying that this project still meets the CE classification allowing for no Environmental Impact Study (EIS) or Environmental Assessment (EA) to have been done.
Public Safety
We are deeply concerned about road safety around Washington County and the CBEP does nothing to address safety concerns along this new commuter route. There are numerous routes that are designed to encourage speeding creating unsafe conditions for pedestrians and bicyclists. This project, in particular, creates a new 4 way intersection at the already dangerous 3 way intersection of Main St. & Century Blvd. The increased traffic in an area known for speeding and traffic fatalities will only make it a more dangerous intersection. There is nothing in the CBEP plan to address safety at this intersection such as a protected bike lane, protected pedestrian crossings, or a reduced speed limit along Main St.
There are 4 neighborhood schools that will be impacted by CBEP: Century High School, Brown Middle School, Imlay Elementary, and Ladd Acres Elementary. Students walking to school cross Century at numerous intersections and crosswalks. Adding traffic from busy commuters hoping to speed through our neighborhood in the morning will make it much less safe for kids to walk, bike, or scooter to school. The new speed limit along Century will be 35 mph which will increase the risk of deadly accidents with bicyclists and pedestrians. The busiest intersections for students are Francis & Century, Lois & Century, and 2 painted crosswalks by Century High School. This project will not add enhanced pedestrian crossings at these crosswalks. The road extension cutting through the woods at Lois St will encourage drivers to go faster through this area since they will now be able to go straight instead of stop and turn to continue on Century. How many families will have to give up letting their kids walk to school due to the lack of a safe route?
The CBEP does not create a lighted intersection at Borwick St. & Century Blvd but will have a lighted pedestrian crosswalk. Borwick already lacks sidewalks on both sides of the road from Century to 66th Ct. This project will not extend sidewalks down Borwick St which has been requested by residents many times over the years. This is indicative of the county not taking into account the needs of the neighorhood during the planning process. Getting to Noble Woods along Borwick is already unsafe due to the lack of sidewalks and shoulder to walk on. Every morning, neighbors head along this route to walk their dogs or go for a run and risk getting hit by drivers. Particularly in the winter months, it is very dangerous to be walking in the road along Borwick to Noble Woods but there is no other option when there is no sidewalk or shoulder available.
Traffic studies justifying this project have not been made public. In a recently shared report on the Washington County CBEP page, a document responding to citzen's concerns with the noise study utlized a traffic model created by Washington County. This is not public information and would be useful to understand how increased traffic in the future will continue to create unsafe road for pedestrians & bicyclists across the city of Hillsboro. We have heard that the road design is not the reason for traffic fatalities, but rather reckless drivers. However, drivers will see a wide open 5 lane road like Main St like an airport runway and accelerate well over the speedlimit wihtout realizing it. Protected bike lanes, lower speed limits, bollards at crosswalks, and medians with trees that create the perception of a narrower road are proven design imrpovements that encourage drivers to slow down and be aware of their surroundings.
Noise Study Analysis
Washinton County conducted a noise study, one of the few studies they did do in prepartion for this road expansion. The entire region was designated as Activity Category C which requires that the noise stay below 66dB. the study measured noise in excess of this limit in the neighborhoods just north of Main & Century. Within the wetlands of Noble Woods park, noise is projected to exceed 58dB which can still disturb wildlife. In response to public concerns with how the study was conducted, a document was published to the Washington County CBEP page responding to the questions raised. From this, we have new qeustions we have asked for answers to including:
Apparently, no environmental impact statement (EIS) or Environmental Assessment (EA) was needed for this project. From reviewing the agreement between the Federal Highway Administration (FWHA) and ODOT, this project qualifies as a Section 4(f) area due to it including trails, a river, and wildlife/waterfowl refuge that are publicly owned. Can you please share the Individual Section 4(f) Evaluation that was submitted for this project as required by the U.S. Deptartment of Transportation Act?
Given that this project constitutes a Type 1 Project and has resulted in significant public comment in opposition concerning the environmental impacts, we assume the County consulted with FWHA OR Division to confirm that this project can use the Categorical Exclusions (CE) classification. Can you provide documentation justifying that this project still meets the CE classification allowing for no EIS or EA?
We have also requested the Washington County traffic modeling study that is referenced in this document.
Transportation Capacity
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From what we've found, a traffic study has never been done in the planning of the Century Blvd Extension Project. Why this matters:
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(Details to come)
Poor Planning and Lack of Public Engagement
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Was there a traffic study done?
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Is there evidence that this helps alleviate traffic along Cornelius Pass & Brookwood
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Is there evidence that driving through the new extension is a viable alternative to Corn Pass or Brookwood (Orenco Station & the Max light on Century is new and often spot of high traffic in the morning)
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Incomplete plan at Century & Ariel
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Lack of consideration for new developments that should have caused reason to pause and reassess the needs of the community (Century HS opened in 1998, Orenco Max stop opened in XXX, Orenco Station development began in XXX, South Hillsboro development began in XXX)
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Century Blvd is not a major feeder for residential areas in South Hillsboro