Clackamas County Oregon Deck, Septic, and Inspection Planning Guide

Clackamas County deck planning should account for Oregon's 30-inch deck permit threshold, septic tank and drainfield setbacks, and county inspection timing.

Permit takeaway

Clackamas County's septic guidance notes that decks over 30 inches high require a building permit and are treated as structures for septic setback purposes.

Zoning and placement

Decks over 30 inches should maintain separation from septic tanks and drainfields, while all decks should avoid blocking tank pumping access or drainfield repair access.

Building and trade review

Residential inspections include site inspection with footing inspection, footing inspection before concrete, and other stage inspections depending on the approved work.

Call before applying when

Call before applying if the deck is over 30 inches, near a septic tank or drainfield, supported by pier blocks near septic components, or may obstruct septic maintenance access.

Documents to prepare

• Deck plan
• Septic tank and drainfield location
• Footing locations
• Site plan
• Permit application when required

Inspection planning

• Confirm permit need
• Check septic setbacks
• Schedule footing inspection before concrete
• Keep septic access clear
• Complete final inspection

Official sources

• Clackamas County Deck Setback Guidance
• Clackamas County Residential Inspections
• Clackamas County Building Mechanical Information

This guide is a planning summary. Always verify the current requirements with the local office before starting work.