Sammamish Unified Development Code

Town Center | Development Standards—Landscaping and Irrigation

6. Type VI Landscaping – Bioretention.

a. Type VI landscaping refers to vegetated areas that function as bioretention for the treatment of stormwater runoff from hard surfaces. These areas feature vegetation and subsurface drainage features that treat, retain, and infiltrate stormwater runoff. b. Type VI landscaping shall be constructed, planted and maintained in general accordance with the 2005 Puget Sound Action Team Low Impact Development Technical

Guidance Manual for Puget Sound, or equivalent. (Reference Figure 6.1.2 from 2005 PSAT Manual.

c. Type VI landscaping shall minimally consist of:

i. Trees, shrubs, perennials and groundcovers tolerant of summer drought, ponding fluctuations and saturated soil conditions for prolonged lengths of time anticipated by the facility design and hydrologic conditions. ii. Plants should be tolerant of typical pollutants from surrounding surfaces, such as petroleum hydrocarbons, dissolved metals, and fertilizers. iii. Plantings should consist of native plant types; at least 15 percent of the plant palette shall be evergreen. Planting and grading for drainage features should be designed to be integrated aesthetically with the surrounding landscape and urban design elements. iv. Visual buffering, sight distances and setbacks should be considered for landscaping adjacent to roadways.

5. Type V Landscaping.

a. Type V landscaping refers to all other landscaped areas that do not qualify as Type I through VII landscaping. While native and low maintenance trees and shrubs are encouraged in these areas, lawn areas may be used for recreational or design purposes. These areas also could include flower beds and perennial beds. b. Type V landscaping may include any combination of plant materials provided the area complies with SDC 21.07.070F. and 21.07.070G.

c. No plants included in the King County noxious weed list.

512 | Title 21: Sammamish Development Code

Effective | January 1, 2022

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