Fanno Creek Trail Crossing at Scholls Ferry Road

The Frequency of Flooding has Increased

Flooding of Fanno Creek Trail near Scholls Ferry Road has occurred for some time. In the past, we heard that it was inconvenient, but that the impacts were manageable as the flooding typically occurred in the middle of the rainy season and was somewhat predictable.

The Simple Solution Doesn't Work Long Term

People frequently asked why the trail could not simply be raised underneath the roadway bridge so that it would flood less often. While raising the trail is being considered as a short-term solution, it is not an ideal long-term solution. This is because it does not meet trail standards for overhead clearance and could create additional safety issues. In addition, the downstream beaver activity shows no signs of slowing down, so there is no guarantee that even a raised trail would never flood in the future.

The Impacts of Flooding are No Longer Manageable

Some folks have told us they think it is neat to observe the beaver activity in the area, but we mostly heard that people are getting frustrated and concerned about how often the trail floods and can stay flooded over time. When the trail is flooded, trail users are forced to go through the water, backtrack to a different route, or find their way up to the street level of Scholls Ferry Road.

A Safe and Convenient Crossing of Scholls Ferry Road is Needed

Trail users who choose to travel up to Scholls Ferry Road have to travel out of their way to the next closest intersections that have traffic signals and crosswalks (SW Conestoga Drive to the southwest, or SW Nimbus Avenue to the northeast). Some trail users are choosing to dart across Scholls Ferry Road mid-block at unmarked and unsignalized crossing locations.

It was made clear that the community no longer feels the current flooding impacts are manageable, and that a permanent solution is needed to lessen the impacts of the flooding while also allowing the safe crossing of Scholls Ferry Road.

Five Partner Agencies Collaborated on a Study of At-Grade Crossing Options

It became apparent that an “at-grade” crossing of Scholls Ferry Road (one that crosses at street level, instead of going under or over it) would be the only viable long-term solution. An engineering study was completed to compare different route options for safety, usability and convenience, feasibility, impact, and cost.

The routes studied included going through adjacent residential and commercial developments, along Scholls Ferry Road, adding trail bridges to cross Fanno Creek, and adding or modifying traffic signals at intersections along Scholls Ferry Road.

A Mid-block Pedestrian Signal East of SW Springwood Drive Ranked Highest

After looking at all of the identified routes, one route clearly ranked the highest based on the study criteria; installing an at-grade, mid-block pedestrian signal roughly 350 feet east of SW Springwood Drive (slightly west of the existing roadway bridge over Fanno Creek), while also keeping the existing undercrossing.

• During periods when the undercrossing is flooded, trail users would cross Scholls Ferry Road at the proposed pedestrian signal.
• At times when the undercrossing is dry, trail users could cross underneath the roadway at the current location.
• The trails on the north and south sides of Scholls Ferry Road that connect to Fanno Creek Trail would be reconstructed to provide accessibility for all trail users, provide more direct access from Scholls Ferry Road to Fanno Creek Trail, and to reduce how far trail users must travel out of their way to safely cross the road.
• The existing sidewalks used for this route on Scholls Ferry Road would be widened to support two-way bike/pedestrian traffic.

Rendering of Proposed Scholls Ferry Road at-Grade Crossing (looking east)

We Also Learned that We Can Provide More Information

In addition to any long-term solution to the trail flooding at Scholls Ferry Road, we can do a better job providing trail users with information about available detour routes and when the trail is flooded, before they encounter the flooded trail. One accomplishment:

• Tigard and Tualatin Hills Park and & Recreation District installed signs along the trail showing available detour routes for when the trail is flooded.

The Project Team Will Work to Fund Crossing Improvements

This crossing study only identifies what the crossing would consist of and where it would occur — it is not actual design engineering that can be used to construct the crossing. Additionally, no funding is currently available for the design and construction of the mid-block crossing. If the feedback we get from this virtual open house is in support of the identified crossing, the project team will pursue funding opportunities, which might include regional, state, or federal funds as they become available. In our experience, completing this type of study is critical to showing grant providers that the project has been thoroughly planned, increasing the likelihood of the project being awarded grant funding.

The Trail Under the Bridge will be Raised Slightly

While raising the trail under the roadway bridge is not a viable standalone long-term solution, it is worth continued consideration until the at-grade crossing is constructed. Clean Water Services is working on this and is currently securing the permits needed to do this work. Depending on when the permitting phase is complete, work will be dependent on weather. While it is Clean Water Services’ hope to get this constructed before the rainy season, it may have to wait. Some key aspects of this work include:

• Raising the trail approximately 10 inches, which analysis shows should significantly increase the number of days that the undercrossing remains dry.
• To address concerns about reducing overhead clearance and warning signs will be added to both sides of the undercrossing to alert trail users to the lower overhead clearance.

A Portion of the Trail will be Relocated

Tigard and Clean Water Services are partnering to relocate a portion of Fanno Creek Trail north of Ironwood Loop in Englewood Park. Crews will construct a new asphalt trail segment in approximately the same location as a dirt path trail users have worn into a grassy area to get around the area of the trail that sometimes floods. Once the new trail segment is constructed, the existing trail segment will be removed and restored with native plants.

Monitoring will Continue

Tigard and Tualatin Hills Park & Recreation District will continue to clear debris and sediment that accumulates on the trail after flooding. In addition, Clean Water Services will continue to monitor beaver dam activity and flow devices that aim to reduce the flooding impacts resulting from the dams.

Fanno Creek Trail is a regional trail that extends from Tualatin to Portland, passing through Tigard, Beaverton, and unincorporated Washington County. The vision dates back to 1975; a 15-mile walking and biking trail from the Willamette River in Southwest Portland to Fanno Creek’s confluence with the Tualatin River in Tualatin. It is a paved, multi-use pathway for walkers, runners, bicyclists and nature enthusiasts of all ages.

Given its geographic location, Fanno Creek Trail must cross numerous roadways, including Scholls Ferry Road (between Nimbus Avenue and Springwood Drive, approximately 0.5 miles west of OR-217 and the Washington Square Mall), which is a 4-lane arterial roadway at the Fanno Creek Trail crossing location. Fanno Creek Trail runs parallel to, and on the west side of, Fanno Creek in the vicinity of Scholls Ferry Road. The trail currently crosses Scholls Ferry Road by going beneath the roadway bridge that spans Fanno Creek.

The Fanno Creek floodplain is relatively wide in this area. It allows for storage of stormwater runoff that helps reduce downstream flooding. The regional community at-large has consistently expressed that access to nature is a top desirable trail amenity, which this proximity to Fanno Creek provides. However, the trail’s close proximity to Fanno Creek in this location has resulted in the trail being flooded at times, which has become more frequent over the years. Much of this trail flooding is attributable to beavers building dams downstream of Scholls Ferry Road.

Five different agencies have varying jurisdictional oversight responsibilities where Fanno Creek Trail crosses Scholls Ferry Road, which is a Washington County jurisdictional roadway. North of Scholls Ferry Road is within Beaverton city limits and the trail is maintained by Tualatin Hills Park & Recreation District. South of Scholls Ferry Road is within Tigard city limits and the trail is maintained by Tigard. Clean Water Services has regulatory authority over Fanno Creek and its surrounding natural areas.