FAQs - North Cooper Mountain Area Planning

If you need to contact Washington County about the North Cooper Mountain planning effort, you can email the Long Range Planning section at lutplan@co.washington.or.us or call us directly at 503-846-3519.

Where is the North Cooper Mountain Planning Area located?

North Cooper Mountain is generally bounded by SW Grabhorn Road to the west, SW Gassner Road to the north, SW 185th Avenue and Cooper Mountain Nature Park to the east, and SW Stonecreek Drive to the south.

Why is the North Cooper Mountain Area undergoing planning efforts now?

In 2002, Metro added approximately 510 acres of the northwest portion of Cooper Mountain to the regional Urban Growth Boundary (UGB). In 2011, the 544-acre South Cooper Mountain area and the 1,232-acre Cooper Mountain Urban Reserve were added to the UGB. The Urban and Rural Reserves inter-governmental agreement (IGA) between Metro and Washington County required the City of Beaverton and Washington County to plan these three areas concurrently when developing future land use and transportation options in the Cooper Mountain area.

Areas brought in to the UGB are intended for future urban development. Concept and community plans for newly-added areas are required by Metro prior to development.


What is already there?

The area is roughly 510 acres, with 230 existing homes and approximately 91 acres of undeveloped land.

Existing development is served by septic tanks. There are approximately 225 existing septic tanks in North Cooper Mountain.

About 88 acres of North Cooper Mountain are within the Cooper Mountain Nature Park, which is owned by Metro and is a permanent open space.

The land currently has a land use designation of Future Development-20 Acre District (FD-20), an urban 'holding zone' for lands inside the UGB not yet annexed by a city.


What is the difference between concept planning and community planning?

A concept plan is a "big picture" look at land use and transportation planning for an area. Examples of elements typically included in a concept plan are the potential location of services, such as schools and parks, identifying areas best suited for employment and residential land use designation, and identifying locations and types of suggested transportation improvements.
A community plan is a more detailed planning effort that closely evaluates zoning possibilities, housing density, and more specific recommendations for transportation and service options. Each of these plans are required by Metro in new urban areas so that future development is efficiently coordinated with surrounding areas and infrastructure needs can be addressed.


What is the Cooper Mountain Concept Plan?

The City of Beaverton completed the Draft Concept Plan for the Cooper Mountain area in 2014.

The Concept Plan area includes two subareas inside the UGB–North Cooper Mountain and the South Cooper Mountain Annexation Area–and a subarea between these two located outside the UGB and designated as an Urban Reserve. The Concept Plan is a cohesive look at the entire area to guide future development based upon an overall strategy. It also addresses important questions about the future development of the area: "Where should we build? Where should we preserve and enhance? What should be the qualities of each area? Where should we invest in infrastructure and how do we pay for it?"

Why is Washington County taking over planning efforts for North Cooper Mountain?

A February 2013 Inter-governmental Agreement between the City of Beaverton and Washington County identified the city to lead long range planning efforts and to look cohesively at the entire study area.

The City of Beaverton completed its outreach and planning for the Cooper Mountain area and is scheduled to bring the Draft Concept Plan and South Cooper Mountain Community Plan before their City Council for consideration in January 2015. The South Cooper Mountain Annexation Area was incorporated into the Beaverton City Limits in 2013. The North Cooper Mountain area will remain unincorporated for the foreseeable future and land use authority for this area will remain with the county.

Washington County will carry forward the land use, natural resource, and transportation proposals generated by the city in preparation for amending the county's Comprehensive Plan documents, which will be addressed during the 2015 land use ordinance season, occurring annually between March 1 and October 31.

What is important to area residents?

In open houses, surveys, and workshops, residents and community members stated they like the existing character of North Cooper Mountain. They also stressed they like the Cooper Mountain Nature Park and that the natural resources of the area are  important to the area's livability.

Existing and future transportation conditions are the primary concerns residents and community members cited during the City of Beaverton's recently-completed 18-month concept planning period.

What land use changes are proposed for North Cooper Mountain?

In February 2015, Long Range Planning staff released two issue papers specific to land use and transportation options on Cooper Mountain for public review; land use issue paper 2015-01A and transportation issue paper 2015-01B.

Both issue papers were submitted to the Board of Commissioners to inform their deliberations on the Draft 2015 Long Range Planning Annual Work Program.

Three land use options are addressed in Issue Paper 2015-01A. These are:

  • To apply the county's existing R6 low-density residential designation (at up to six dwelling units/acre) to the northern third of North Cooper Mountain and a new R1-CM low-density designation (average of one dwelling unit/acre) to the southern two-thirds area;
  • To apply a R1-CM designation to all of North Cooper Mountain; or
  • To leave the existing Future Development 20-acre designation (FD-20) on all properties.

Discussion of each of the above options is found in the 2015-01A issue paper.

Ordinance development to enact future land use changes in North Cooper Mountain is not recommended for 2015. The Board is scheduled to finalize the 2015 Work Program at their March 24, 2015 meeting.

What natural resource changes are proposed in North Cooper Mountain?

Public comment reflects the concern that the headwaters of two tributary streams located in the North Cooper Mountain area are not currently listed on Washington County's Significant Natural Resource map. These tributaries are the headwaters of Johnson Creek east of SW 185th Avenue and a headwater stream to McKernon Creek located just east of Stonecreek Drive. Based on this public input, county staff proposes to add both of these headwater streams to the Significant Natural Resource map.

What future transportation improvements are planned for the North Cooper Mountain area?

Within and adjacent to the North Cooper Mountain area, future road improvements to improve capacity and traffic flow are proposed for SW Grabhorn Road and portions of SW 175th Avenue and SW Kemmer Road. A new road connection between SW 175th Avenue and SW 185th Avenue is proposed although the exact alignment has not yet been determined. As of October 2014, none of these proposed improvements have dedicated funding. The Concept Plan notes the approximate timing of these and other transportation improvements as 10-20 years in the future, at the earliest. Further discussion and proposed maps of transportation improvements throughout the concept planning area begins on page 36 of the Concept Plan document.

SW 175th Avenue is an important north-south regional transportation route and proposed transportation improvements for this road corridor have received much attention. A SW 175th Avenue information sheet was prepared October 9, 2014 by county staff in response to questions posed by the public.


Will I have to connect to a sewer line based upon the Concept Plan proposals?

State law requires that a permit to install, alter, or repair a septic system for a single-family dwelling cannot be granted if sanitary sewer service is available within 300 feet of any property (OAR 340-071-0160(4)(f)).

There are two distinct drainage patterns within North Cooper Mountain, which was a significant consideration in determining the proposed land use designations. Drainage for the northern one-third of the area flows to the north. Future sewer service in this area can be easily provided by the extension of existing sewer lines within the SW Gassner Road right-of-way. Drainage for the southern two-thirds flows to the south and the area is far from any existing sewer infrastructure. Future provision of sewer service to this area will require a new pump station and an extensive network of piping to connect existing lots to public sewer. Provision of these facilities is expected to be many years into the future.

What are the next steps and how can I participate?

Long Range Planning staff submitted the Draft 2015 Annual Work Program to the Board of Commissioners on January 26, 2015. Public comment on the Annual Work Program can be submitted:
  • Mail or In Person: 
    Department of Land Use & Transportation - Long Range Planning Section
    155 North First Avenue, Suite 350-14, Hillsboro, OR 97124

The Board is scheduled to adopt the Long Range Planning 2015 Annual Work Program at their public hearing on March 24, 201


Stay Informed!

Upcoming events and project information are listed on Washington County's North Cooper Mountain webpage. On the website, you can sign-up for the project mailing list to receive notification of new information and to leave comments for county staff.