Grading Permit and Erosion Control

BulldozerWashington County Department of Land Use &Transportation Planning and Development Services Division uses a grading permit system to ensure that erosion control and other measures are used to address site drainage, site slope stability and other site development activities comply with life safety and private properties protection requirements of the County code. Grading includes, but is not limited to, excavations, earthwork, fills and embankments, and private road construction.

In 2008, Washington County adopted grading Ordinance 689 (codified as WCC 14.12) to regulate civil engineering-related work, including site grading inside the unincorporated areas of the County. Before 2008, grading and other site-related work was regulated under Uniform Building Code Chapter 33 provisions. Ordinance 689 focuses on local conditions and grants developers more flexibility to develop their project sites - providing prescriptive provisions for constructing private roads up to 200 feet without the involvement of engineering consultants. The ordinance also regulates agricultural grading (fill importation) to ensure that fill placement preserves natural drainage basin characteristics to protect surrounding properties.

Specific benefits identified from the County grading permit system include:

  • Mitigating cross-lot drainage and preventing concentrated flows across property lines
  • Providing appropriate grading to prevent local stormwater ponding
  • Requiring sufficient design of grading projects to address potential site slope instabilities and landslides which may present future life safety concerns to surrounding properties
  • Allow a single point of contact for outside agencies (Oregon Department of State Lands, Oregon Department of Fish and Wildlife, project district Fire Marshalls, etc.) permits coordination to streamline the site grading and other work permitting process

  • Preventing erosion, stream sedimentation and other adverse off-site effects.
  • Preserving existing natural drainage characteristics and ensuring design of detention ponds will adequately reduce the peak rate of runoff and also provide water quality benefits.

The grading permit is not considered a land use permit, and it does not go through the same type of review process. In most cases, it is part of casefile permit conditions of approval to be met. The erosion control measures required for a grading permit may involve multiple permitting agencies, depending on the size of site disturbance. Other local and state permitting processes include those required by Clean Water Services (CWS) and the Oregon Department of Environmental Quality (DEQ) National Pollutant Discharge Elimination System (NPDES) permits.

Erosion control measures are required by CWS within their jurisdiction and applicants use CWS permit forms and standards in lieu of following the County's grading requirements in those areas. A similar approach is used for DEQ through the NPDES permit for all areas outside CWS jurisdiction and where grading work proposed is more than 1 acre. For grading work less than 1 acre, and outside CWS jurisdiction, erosion control measures follow County standards and forms. Generally, the grading permit process is as follows:

Grading Permit Flow Chart


Permit Review Timeline

The County is required by ordinance to send either a plan review comment letter to the permit applicant within 30-working days once permit application package (plans, reports, etc.) submittal is deemed complete or approved the documentation submitted. Once initial review comments are sent, the time required to process the comments is the responsibility of the developer and consultants involved, and is outside the control of Washington County grading permit review staff. For this reason, permitting approval time can vary, depending on plan comments turn-around time and level of completeness in addressing plan review comments.



Grading Permit and Erosion Control Fact Sheet

Grading and Engineering Applications and Forms