Channel migration zone (CMZ) definition

Channel migration zone (CMZ) means the area along a river within which the channel(s) can be reasonably predicted to migrate over time as a result of natural and normally occurring hydrological and related processes when considered with the characteristics of the river and its surroundings.
Channel migration zone (CMZ) means the area where the active channel of a stream is prone to move and this results in a potential near-term loss of riparian function and associated habitat adjacent to the stream, except as modified by a permanent levee or dike. For this purpose, near-term means the time scale required to grow a mature forest. (See board manual section 2 for descriptions and illustrations of CMZs and delineation guidelines.)
Channel migration zone (CMZ) means the lateral extent of likely movement along a stream or river during the next one hundred (100) years as determined by evidence of active stream channel movement over the past one hundred (100) years. Evidence of active movement over the one hundred (100) year time frame can be inferred from aerial photos or from specific channel and valley bottom characteristics. The time span typically represents the time it takes to grow mature trees that can provide functional large woody debris to streams. A CMZ is not typically present if the valley width is generally less than two (2) bankfull widths, if the stream or river is confined by terraces, no current or historical aerial photographic evidence exists of significant channel movement, and there is no field evidence of secondary channels with recent scour from stream flow or progressive bank erosion at meander bends. Areas separated from the active channel by legally existing artificial channel constraints that limit bank erosion and channel avulsion without hydraulic connections shall not be considered within the CMZ.

Examples of Channel migration zone (CMZ) in a sentence

Channel migration zone (CMZ) – The area along a river within which the channel(s) can be reasonably predicted to migrate over time as a result of natural and normally occurring hydrological and related processes when considered with the characteristics of the river and its surroundings.

Channel migration zone (CMZ) Checkerboard ownershipThe active floodplain where a stream is likely to move around or migrate during a period of decades or forest management cycle.

Channel migration zone (CMZ) means the lateral extent of likely movement along a stream reach with evidence of active stream channel movement over the past one hundred years.


More Definitions of Channel migration zone (CMZ)

Channel migration zone (CMZ) means the area along a river or stream within which the channel can
Channel migration zone (CMZ) means the area along a river within which
Channel migration zone (CMZ) means the lateral extent of likely movement along a stream or river during the next one hundred years as determined by evidence of active stream channel migration movement over the past one hundred years.
Channel migration zone (CMZ) means the lateral extent of likely movement along a stream or river during the next 100 years as determined by evidence of active stream channel migration movement over the past 100 years.
Channel migration zone (CMZ) means the area along a river or stream within which the channel can reasonably be expected to migrate over time as a result of normally occurring processes. It encompasses that area of current and historic lateral stream channel movement that is subject to erosion, bank destabilization, rapid stream incision, and/or channel shifting, as well as adjacent areas that are susceptible to channel erosion. There are three components of the channel migration zone: (1) the historical migration zone (HMZ) – the collective area the channel occupied in the historical record; (2) the avulsion hazard zone (AHZ) – the area not included in the HMZ that is at risk of avulsion over the timeline of the CMZ; and (3) the erosion hazard area (EHA) – the area not included in the HMZ or the AHZ that is at risk of bank erosion from stream flow or mass wasting over the timeline of the CMZ. The channel migration zone may not include the area behind a lawfully constructed flood protection device. Channel migration zones shall be identified in accordance with guidelines established by the Washington State Department of Ecology.
Channel migration zone (CMZ) means the lateral extent of likely movement along a stream reach with evidence of active stream channel movement over the past one hundred years.
Channel migration zone (CMZ). - means the area along a river within which the channel(s) can be reasonably predicted to migrate over time as a result of natural and normally occurring hydrological and related processes when considered with the characteristics of the river and its surroundings. The CMZ is comprised of two areas defined as severe and moderate channel migration zones, which are delineated on maps maintained by Okanogan County. (Currently only maps for the Okanogan, Similkameen and Methow Rivers are available, and are attached as Appendix I).