A. “Bioretention” means engineered facilities that store and treat stormwater by passing it through a specified soil profile, and either retain or detain the treated stormwater for flow attenuation. Refer to the current City of Lacey Stormwater Design Manual for bioretention design standards.

B. “Low impact development (LID) facility” means distributed stormwater management practices, integrated into a project design that strives to mimic pre-disturbance hydrologic processes of infiltration, filtration, storage, evaporation and transpiration. LID facilities include, but are not limited to: bioretention, rain gardens, permeable paving, roof downspout controls, dispersion, soil quality and depth, minimal excavation foundations, vegetated roofs, and water re-use.

C. “Low impact development (LID) principles” means land use management strategies that emphasize conservation, use of on-site natural features, and site planning to minimize impervious surfaces, native vegetation loss, and stormwater runoff.

D. “Native vegetation” means vegetation including trees, comprised of plant species that are either indigenous or naturalized to the Puget Sound region. Native vegetation does not include noxious weeds.

E. “Permeable paving” means pervious concrete, porous asphalt, permeable pavers or other forms of pervious or porous paving material intended to allow passage of water through the pavement section. It often includes an aggregate base that provides structural support and acts as a stormwater reservoir. Refer to the current City of Lacey Stormwater Design Manual for permeable paving design standards.

F. “Rain garden” means a non-engineered shallow, landscaped depression, with compost-amended native soils and adapted plants. The depression is designed to pond and temporarily store stormwater runoff from adjacent areas, and to allow stormwater to pass through the amended soil profile.

G. “Vegetated LID facility” means bioretention, rain gardens, dispersion, and vegetated roofs.

H. “Vegetated roofs” (also known as ecoroofs and green roofs) mean thin layers of engineered soil and vegetation constructed on top of conventional flat or sloped roofs. Refer to the current City of Lacey Stormwater Design Manual for vegetated roof design standards. (Ord. 1496 §3, 2016).