Feedback Regarding Loop Road Closure


On June 24, Tillamook County Public Works Director, Liane Welch, presented several proposed solutions regarding the closed Cape Meares Loop Road at the Tillamook County Board of Commissioners meeting.

The Board of Commissioners is requesting feedback from both individuals and from the Cape Meares Community Association regarding the various proposals that were shared.  The feedback should be provided beyond our three county commissioners. Resources are needed for the project at the federal level so senators and representatives should be contacted to let them know of our needs.

This message will provide a summary of the information that was presented at last week’s meeting as well as a link to the survey that will enable you to provide feedback that will then be communicated to the Board of Commissioners and beyond. Parts of the meeting summary were copied from the PowerPoint document that was made available by Ms. Welch.

The public meeting was recorded and will be played back on Channel 4 (Public Service Channel) in future days.  The meeting was approximately 90 minutes.  No viewing schedule was announced for the meeting.

The Loop Road is more than a communication link between Cape Meares and Oceanside.  It is also the major link to the Cape Meares Lighthouse and the Wildlife Refuge.  Because of serving the Lighthouse and refuge it is possible to pursue a request for federal dollars to pay for 100% of a suitable solution.  The road closure provided for $250,000 to be used to study the closure and propose solutions.  Ms. Welch assembled a team of experts that included civil engineers and others with expertise related to roads in active slide areas like the one near our community.

Currently residents of Cape Meares are limited to only Bayocean Road as an evacuation route.

Landslide Features

a2 All of the engineers involved in the project had spent considerable time in the past months walking the area around the slide and taking many measurements to understand more about the movement of the slide.  The picture above illustrates two areas in pink that are particularly active.  The one is a well known and understood area that has been active and moving and various speeds for decades.  The other smaller area is near the location of the old Cape Meares water tank.  All of the areas that are of a shaded color are in a slide zone but the movement in the various sections is much slower than in the pink areas.  The area in light gray is considered to be more stable land with no sign that there will be significant movement in the immediate future.

Geotechnical Explorations


In 2007, surveyors for Tillamook County installed a number of GPS instruments along the center line of the Loop Road in the area of the slide.  This turned out to be a very wise move because it has provided an abundant amount of data related to the most active area of the slide.  In the past seven years the center line of the current roadbed has moved between 13 and 14 feet toward the Pacific Ocean.

The slide area surrounding the Loop Road is approximately 3,000 feet wide and 4,000 feet  long.

A number of boring holes were drilled into the soil to a depth between 80 and 130 feet.  Movement, albeit less than on the surface, was measurable at a depth of 110 feet.  This means that the slide is very deep.

Measurements of the slide moving date all the way back to the late 1890s when it was reported that there was approximately 230 feet of movement.  Since that time of first measurements the slide action has varied with an uptick of the movement in the last seven years and definitely associated with the amount of precipitation the area receives.

The slide area affecting the road is not just below where the roadbed currently is located.  It extends to the top of the mountain to the south.

Possible Alternatives



The project team offered eight possible ways to deal with the slide.  Add one more if the choice is to do nothing and keep the road closed.  The first of the choices mentioned was referred to as a “Deep Patch.”  The option is not really what the name suggests.  This option involved having layers of fabric placed below the roadbed in an effort to stabilize the slide.  The proposed cost for this option is $2.42 million.  This option was not viewed as a permanent solution to the slide problem; it was regarded as a band-aid. Ms. Welch indicated that this was such a temporary solution that Tillamook Country would reject this option if the federal government recommends it.

Horizontal Drains


The second of the options offered was to install a series of horizontal drains surrounding the location of the current roadbed and also to have drains further down the slope and closer to the Pacific Ocean.  The purpose of these drains would be to divert the water more quickly so that it did not seep down into the soil which promotes the slide action.  The proposed cost for this option is $14.5 million.  The view was this option would likely slow down the speed of the slide but it would not necessarily stop it.

Install Buttresses


The third suggestion shared by the project team was to build giant buttresses in key locations in the slide area.  The primary purpose for these earthen dams would be to stop the action of the slide in its tracks.  This option is only a theory, however.  The engineers expressed some concern about what would happen on the ocean side of the buttresses.  There was a very large unknown related to a possible impact on the Cape Meares community of such an option.  Proposed cost for this solution is $16.9 million.

Roadway Alternatives


There were a total of six roadway alternatives that were shared.  All involved the creation of a by-pass road that would be around the slide and to the south.  All of the choices would have to go through private land so the purchase of lands or the exchange of lands would be involved for all of the choices.  Each of the choices had pros and cons associated with it related to safety, proposed highway speed, distance, and cost.  Options 1A, 1B, and 1C and Option 2 would exit near the location of the rock quarry.  Option 3 would join the current Loop Road north of Oceanside near the entrance to the water treatment plant in Oceanside.  The map above illustrates the five options.  Estimated cost for each of the options are shown below.It’s fairly obvious that the cost for options 2 and 3 is such that neither is likely.

    • Proposed cost for Route 1A–$17.1 million
    • Proposed cost for Route 1B–$18.2 million
    • Proposed cost for Route 1C–$15.2 million
    • Proposed cost for Route 2–$51.7 million
    • Proposed cost for Route 3–$54.1 million

Risk Matrix


The matrix shown above is difficult to read.  The exhibit is critical because it shows a rating of low, medium or high risk for each of four categories.  Those categories are (1) Traveling Public Safety, (2) Longevity of the Solution, (3) Constructability Concerns, and (4) Potential for Community Isolation.

The clear choice in terms of this rating scale was the proposed 1B solution where the ratings were “Low Risk” across all of the categories.  Not surprisingly this is also the option that was recommended by Ms. Welch and the rest of her team.


The Tillamook County Commissioners all seemed to be very supportive of the option recommended by the project team, but if the Federal government is going to be paying for the total cost of the project they will have a very large role in selecting the option they think is best.  Here’s where Ms. Welch and the county commissioners need our help.

Residents of Cape Meares and Oceanside are the primary benefactors of a new slide.  The total number of residents for the two communities is not large so it is going to be necessary to come up with arguments other than the needs of the residents in the Cape Meares and Oceanside communities.

A survey has been created to seek feedback from local residents about the proposed options.  There are several questions that will require your response to multiple-choice options.  There is also an open-ended questions where you can offer comments that will then be shared with the Tillamook County commissioners as well as other governmental representatives.  Please click on the link below to access the survey and offer your input. Please complete the survey by no later than Sunday, July 6.

Click link to complete survey.

You may also wish to contact the county commissioners directly.  Same is true for others in government that may help us direct the decision makers to select the option that the project team has recommended since the federal government will be paying for the repair.  On the survey you will find mailing addresses and e-mail addresses for elected officials who may also be weighing in on the solution for the Cape Meares Loop Road.

Residents of Cape Meares are invited to the Oceanside Neighborhood Association meeting on August 2 at 10 AM where Ms. Welch will be available to answer questions regarding the proposed solutions to the Loop Road.  You can also provide public comments at that meeting.