SEA Development Standards


What are Development Standards?

The SEA Ordinance establishes Development Standards to ensure that development is designed in a manner that supports the long-term sustainability of each SEA. Projects must comply with all applicable Development Standards in order to obtain approval for a Ministerial SEA Review or request modification of Development Standards through a SEA Conditional Use Permit.

Please see the Zoning Code for a complete list of SEA Development Standards. You can also refer to Chapter 4 of the Implementation Guide for further explanation and guidance for each development standard.


Is it required to meet all the Development Standards?

No, you will be required to meet only the development standards that are applicable to your project. One of the requirements to receive a Ministerial SEA Review is to meet all applicable development standards.


What are SEA Resource categories?

SEA Resources are the biological and physical natural resources that contribute to and support the biodiversity of SEAs and the ecosystem services they provide. The SEA Ordinance divides SEA Resources into five categories, with each category afforded a certain level of protection consistent with its relative abundance in the County and sensitivity to disturbance.

What are the thresholds and preservation ratios for SEA Resource categories?

Are the SEA Resource categories mapped and available online?

No, the SEA Resource categories are not mapped. The applicant is required to survey and depict the SEA Resource categories found on the property through the Biological Constraints Map (BCM). A BCM is a map of the project site that identifies all SEA Resources on the property. A BCM must be prepared by a qualified biologist on the SEATAC Certified Biologist List.

See Chapter 6 of the Implementation Guide for the required details and examples of a BCM.

See our SEATAC Certified Biologist List to search for a biological consultant who can prepare a BCM.


How do you measure the 200 ft distance requirement for the Natural Open Space Buffer Development Standard?

The 200 ft distance requirement correlates to the 200 ft fuel modification zone that is required by the Fire Department for structures in the Very High Fire Hazard Severity Zone. Typically, fuel modification zones can encroach onto neighboring properties. However, the Natural Open Space Buffer Development Standard prohibits that encroachment onto the neighboring property if it is a protected open space. Protected open space can be land owned by conservancies or private properties that were required to set aside open space easements to mitigate previous development.