Description:This geographic information system (GIS) layer contains wetland location and extent information for Canterbury Region. Information comes from a variety of sources and has varying levels of detail or precision on wetland location, type, condition and significance.Database coverage over most of Canterbury Region was completed in March 2019. However, wetland mapping is less comprehensive for land over 900m in some parts of the region.The Canterbury Wetlands GIS Layer distinguishes between ‘ground survey’ and ‘aerial survey’ wetlands. Most of the mapped wetlands are in the ‘aerial survey’ category. ‘Ground survey’ and ‘aerial survey’ methodologies are described below.What is a ground survey?“Ground survey” wetlands have been field inspected and mapped/described in some detail. Ground surveys have been carried out by Environment Canterbury staff, or wetland ground survey information provided by other agencies such as the Department of Conservation and New Zealand Defence Force. Information from wetlands that had been ecologically surveyed as part of Resource Consent Applications was also included.For vegetated wetland survey areas, wetland boundaries were delineated where more than 50% of the dominant plant species from all vegetation strata are ‘Obligate’, ‘Facultative Wetland’ or ‘Facultative’ (i.e. the plant community is considered hydrophytic – Clarkson 2013). Descriptions of wetland hydrosystems, wetland class and vegetation types listed in the attributes tables for ground surveyed wetlands follow Johnson and Gerbeaux (2004), while assessment scores for wetland condition and threat follow Clarkson et al. (2003).  An assessment of ecological significance against Canterbury Regional Policy Statement criteria is also provided for most ground surveyed wetlands.What is an aerial survey?“Aerial survey” wetlands have been mapped by delineating the outline of known and likely/potential wetland habitats from the latest high-resolution aerial imagery available at the time of mapping. Characteristic vegetation types, colours, patterns, presence of visible water were used to identify wetlands on aerial photos; with hydrological and topographical information also considered. Note that there may be errors or omissions in this part of the dataset. Because of precision limitations and uncertainties, apart from date of base imagery and data capture, no further information is provided in the attributes for ‘aerial survey’ wetlands.Currency:Current at time of survey date for “ground survey” sites and current to date of aerial imagery for “aerial survey” sites. Data owner:Canterbury Regional Council (Environment Canterbury)Data interpretation and limitations:The Canterbury Wetlands GIS Layer is not a ‘schedule’ in a plan and has not been tested through a statutory planning process. The GIS layer is not comprehensive, nor does it attempt to systematically apply the Canterbury Land and Water Regional Plan definition of ‘wetland’.  It is not ‘locked in’ and can potentially be changed or updated with more information.Terms of Use:1. Copyright in this work is owned or licensed by Canterbury Regional Council (Environment Canterbury).2. Copyright in this work is licenced for re-use under a Creative Commons Attribution 4.0 International licence.3. Under the terms of that licence you must attribute your use of the work to Environment Canterbury using this attribution statement: This work uses material sourced from Canterbury Wetlands GIS Layer, which is licensed under a Creative Commons Attribution 4.0 International licence by Environment Canterbury. 4. Environment Canterbury uses reasonable endeavours but does not warrant that this information is current, complete or accurate. To the extent permitted by law, Environment Canterbury will not be liable for any loss, liability, damage, cost or expense suffered or incurred by any person as a result of use, reference to or reliance on this information.Attributes of the Canterbury Wetlands GIS Layer(Note: the attributes tables will only be complete for ground surveyed wetlands)OBJECT IDDefault GIS polygon identification numberAREA NAMEName of wetland or survey area.HYDROSYSTEMWetland ecosystems are differentiated by landform and hydrological setting, and by water salinity, chemistry and temperature. Estuarine, riverine, lacustrine and palustrine hydrosystems have been recorded for ground-surveyed wetlands in Canterbury.SUBSYSTEMHydrosystems can be further described according to the water regime. Periodicity of inundation is the main feature e.g. permanent, seasonal, tidal, non-tidal, ephemeral.WETLAND CLASSMain wetland classes for Canterbury are swamp, marsh, fen, bog, seepage, shallow water, ephemeral wetland and saltmarsh.WETLAND FORMLandforms that wetlands occupy, and forms they create or contain.VEGETATION TYPEDominant vegetation type(s) within wetland. A general description of the growth form (or structure) and composition of the vegetation. For example: raupō reedland, saltmarsh herbfield, willow forest.SURVEY TYPE‘Ground survey’ or ‘Aerial survey’.SURVEY DATEDate of wetland ground survey or delineation by aerial survey.IMAGERY DATEDate of imagery used when delineating wetlands by aerial survey method.RECORD NORecord number of wetland assessment reports for ground-surveyed wetlands. Stored in Environment Canterbury’s HP Content Manager.ECOLOGICAL SIGNIFICANCEAssessment of ecological significance for ground surveyed wetlands against Canterbury Regional Policy Statement (CRPS) criteria and associated guidelines (Wildland Consultants, 2013). Three level score:High: Meets one or more significance criteria; Regionally, Nationally or Internationally SignificantModerate: Meets one or more significance criteria; Locally SignificantLow: Does not meet any CRPS ecological significance criteriaReferencesClarkson, BR, Sorrell BK, Reeves PN, Champion PD, Partridge TR, Clarkson BD. 2003. Handbook for monitoring wetland condition. Coordinated monitoring of New Zealand wetlands. A Ministry for the Environment SMF funded project. Ministry for the Environment, Wellington. 74pp.Clarkson, BR. 2013. A vegetation tool for wetland delineation in New Zealand. Landcare Research contract report prepared for Meridian Energy Limited. 62pp.Johnson P. Gerbeaux G. 2004. Wetland Types in New Zealand. Department of Conservation. Wellington. 184pp.Wildlands Consultants. 2013. Guidelines for the application of ecological significance criteria for indigenous vegetation and habitats of indigenous fauna in Canterbury Region. Contract Report No. 2289i.This dataset can be found internally as GIS.DBO.WETLANDS_NZTM_Canterbury_Wetlands_Updated2019