Morrisville Unified Development Ordinance - April 2019

Article 11: Interpretation and Definitions Section 11.5. Terms and Uses Defined 11.4.2. Exceptions and Variations

E NGINEER , L ICENSED P ROFESSIONAL A professional individual licensed by the State of North Carolina to practice in the field of engineering sciences. Also referred to as a Professional Engineer. E NGINEERED S TORMWATER C ONTROL A physical device designed to trap, settle out, or filter pollutants from stormwater runoff; to alter or reduce stormwater runoff velocity, amount, timing, or other characteristics; to approximate the pre- development hydrology on a developed site; or to achieve any combination of these goals. Engineered stormwater control includes physical practices such as constructed wetlands, vegetative practices, filter strips, grassed swales, and other methods installed or created on real property. “Engineered stormwater control” is synonymous with “structural practice,” “stormwater control facility,” “stormwater control practice,” “stormwater treatment practice,” “stormwater management practice,” “stormwater control measures,” structural stormwater treatment systems,” and similar terms used in this ordinance. It is a broad term that may include practices that do not require design by a professionally licensed engineer. E PHEMERAL S TREAM A feature that carries only stormwater in direct response to precipitation with water flowing only during and shortly after large precipitation events. An ephemeral stream may or may not have a well-defined channel, the aquatic bed is always above the water table, and stormwater runoff is the primary source of water. An ephemeral stream typically lacks the biological, hydrological, and physical characteristics commonly associated with the continuous or intermittent conveyance of water. • It either is built or has established a statutory or common-law vested right as of the effective date of this ordinance; or • It occurs after the effective date of this ordinance, but does not result in a net increase in built-upon area and does not decrease the infiltration of precipitation into the soil. E XISTING M ANUFACTURED H OME P ARK OR M ANUFACTURED H OME S UBDIVISION For purposes of floodplain management, a manufactured home park or subdivision for which the construction of facilities for servicing the lots on which the manufactured homes are to be affixed (including at a minimum, the installation of utilities, either final site grading or the pouring of concrete pads, and the construction of streets) was completed before the original effective date of the floodplain management regulations adopted by the community. E XISTING T REE C ANOPY Tree canopy that existed for at least two years prior to development as evidenced by the aerial photography and/or satellite imagery on file with or approved by the Town of Morrisville Planning Department. E VERGREEN Plant material that retains its leaf material year-round. E XISTING D EVELOPMENT Development not otherwise exempted by this ordinance that meets one of the following criteria:

E XPANSION An increase in the floor area of an existing structure or building, or the increase of area of a use.

E XTERIOR I NSULATION AND F INISH S YSTEM (EIFS) Multi-layered system of Styrofoam panels typically adhered to wood or gypsum sheathing and finished with a waterproof resin.

April 23, 2019

Morrisville, NC

Page 11-34

Unified Development Ordinance