Chapter 18.28


18.28.010    Purpose.

18.28.020    Districts where permitted.

18.28.030    Permitted uses.

18.28.040    Prohibited uses.

18.28.050    Property development standards.

18.28.010 Purpose.

It is the purpose of this chapter to manage and preserve valuable resources and environmentally sensitive lands such as agricultural lands, steep slopes, wetlands, and others, yet allow for development where appropriate. Structures are to be concentrated on a portion of the site with the remaining reserved as a conservation easement. (Ord. 1694 § 1, 1995)

18.28.020 Districts where permitted.

The cluster overlay district may be applied with any base designation. (Ord. 1694 § 1, 1995)

18.28.030 Permitted uses.

The permitted uses are those as specified in the various base districts. (Ord. 1694 § 1, 1995)

18.28.040 Prohibited uses.

Any use not listed under the permitted principal or accessory uses is prohibited in a cluster overlay district unless authorized in chapters 18.36 or 18.46 SMC. (Ord. 1694 § 1, 1995)

18.28.050 Property development standards.

A. Property Development and Performance Standards. For residential-protection-cluster and agriculture-cluster designated properties, the development of clustered residential units shall conform to the property development and performance standards of the LDR-8.5 zone. For industrial-cluster designated properties, the development standards and performance standards of the base zone shall be met.

B. Density Standards. Densities and FARs would be as follows when a base designation is applied with the cluster overlay designation:




1 du/1 acre (clustered on 25 percent of site)


1 du/1 acre (clustered on 25 percent of site)


.3 – .7 FAR (clustered on 25 percent of site)

All other combinations shall use the base designation density or FAR, and clustering would occur in accordance with city critical area and natural resource ordinances and other implementing ordinances.

C. Open Space. Each cluster overlay development shall provide not less than 75 percent of the gross site area for open space or agricultural production, which shall be:

1. Concentrated in large usable areas;

2. If under one ownership, owned and maintained by the ownership; or

3. Dedicated as a conservation easement to the city of Sumner or other organization as designated by the city of Sumner.

D. Reduction in Open Space Requirement. A reduction in the open space requirement to 50 percent minimum may be conditionally allowed where the property area is greater than 60 acres, and the 50 percent remaining in open space provides a viable area for agricultural production, and is dedicated as a conservation easement. Such reductions shall be reviewed as a conditional use permit application is reviewed.

E. Open Space Uses. Uses allowed in the 75 or 50 percent open space area may include flood storage, septic systems, and recreation, in addition to agriculture. (Ord. 1739 § 21, 1996; Ord. 1694 § 1, 1995)