Layers:

Layer: Overland Flow Path Spill Points from Roads 2021 (2)

Name: Overland Flow Path Spill Points from Roads 2021

Display Field: CATCHMENT_AREA

Type: Feature Layer

Geometry Type: esriGeometryPoint

Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="margin:0 0 11 0;"><SPAN STYLE="font-weight:bold;">Rationale</SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>A common problem with properties located immediately downstream of overland flow paths leaving the road is that the runoff is not well managed resulting in potential flood risk for the property. Typical situations are shown in the following Figures 3 to 5. The spill points provide a useful reference indicator when investigating flooding issues and can be used when assessing building consent applications to identify potential flood risks and the need to ensure suitable surface conveyance of stormwater through the affected properties.</SPAN></SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN STYLE="font-weight:bold;">Method</SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Road spill points are defined as the location where an overland flow path leaves the road parcel. Using Safe Software FME, a process was developed to automate the identification of road spill points by intersecting the OLFPs with LINZ Road Parcels. This results in a point dataset locating both road spill points and road entry points. Using the directionality inherent within the flow path spatial data, road entry points can be removed.</SPAN></SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN>By design, OLFP paths commonly follow road kerbs before entering the piped network or an open channel. Minor deviations from the road corridor are common due to limitations relating to the accuracy of the LiDAR data, and these should not be considered valid spill points. To account for these minor deviations, road parcels were first buffered by 1.5m. That is, to be considered a valid road spill point, a flow path must deviate from the road parcel by at least 1.5m. Road spill points are categorised by the flow path catchment size, which is indicative of the magnitude of flow. </SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN /></P><P STYLE="margin:0 0 11 0;"><SPAN STYLE="font-weight:bold;">Disclaimer</SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>The analysis provided here is a useful indication of road spill points, however there are number of limitations that should be understood. </SPAN></SPAN></P><UL STYLE="margin:0 0 0 0;padding:0 0 0 0;"><LI><P STYLE="text-align:Justify;margin:0 0 8 0;"><SPAN>Road spill points are located at points where OLFPs depart from flowing along or across a road parcel. Road parcels defined by LINZ may be misaligned or include additional roads (i.e. paper roads). Road spill points may also flag bridges and large culverts as road spill points. For these reasons, ground-truthing should be undertaken in areas of particular concern to inform decision making.</SPAN></P></LI><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>OLFPs and any related road spill points represent a synthetic flow path network and do not necessarily indicate where water will flow under specific storm events or represent specific flow rates. </SPAN></SPAN></P></LI><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Delineated flow paths and any related road spill points have one-dimensional geometry, i.e. they represent the centre-line of potential surface flow routes and do not provide information on flow width, depth or velocity. </SPAN></SPAN></P></LI><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>OLFPs and any related road spill points are derived from a bare-ground DEM and therefore do not account for the effects of buildings or other built structures such as fences which may deflect surface flows. Ground-truthing of road spill points should be undertaken in areas of particular concern to inform decision-making. </SPAN></SPAN></P></LI><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Flow paths may follow the road parcel edge, resulting in multiple road spill points clustered within one area (see Figure 9). To prevent duplication of spill points, the most downstream spill point is provided for each reach segment. </SPAN></SPAN></P></LI><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Road spill points will also be identified where there are streams with bridges or culvert crossings conveying the overland flow, rather than the flow being directly on the road surface. These may be of interest for other reasons such as indicating potential fish passage issues where a culvert discharges to a stream.</SPAN></SPAN></P></LI></UL></DIV></DIV></DIV>

Service Item Id: 7a9fc3d738ea4b5a9611e1b7ca8170e8

Copyright Text: Morphum Environmental, July 2021

Default Visibility: true

MaxRecordCount: 2000

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 10000

Max Scale: 0

Supports Advanced Queries: true

Supports Statistics: true

Has Labels: false

Can Modify Layer: true

Can Scale Symbols: false

Use Standardized Queries: true

Supports Datum Transformation: true

Extent:
XMin: 1708319.4000000004
YMin: 6009182.4141
XMax: 1739596.0210999995
YMax: 6084014.1243
Spatial Reference: 2193  (2193)



Drawing Info:
Renderer:
Simple Renderer:
Symbol:
Label: Locations Overland Flow Spills from Roads
Description: This point location where indicative (OLFP) Overland Flow Paths 2021 Spill from the Road Reserve onto downstream property parcels. These locations are important as they highlight where OLFP might need to be managed to minimise nuisiance flooding.
Transparency: 0
Labeling Info:
Advanced Query Capabilities:
Supports Statistics: true
Supports OrderBy: true
Supports Distinct: true
Supports Pagination: true
Supports TrueCurve: true
Supports Returning Query Extent: true
Supports Query With Distance: true
Supports Sql Expression: true
Supports Query With ResultType: false
Supports Returning Geometry Centroid: false
Supports Binning LOD: false
Supports Query With LOD Spatial Reference: false


HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Type ID Field: null

Fields:
• OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID )
• Shape ( type: esriFieldTypeGeometry, alias: SHAPE )
• CATCHMENT_AREA ( type: esriFieldTypeDouble, alias: Estimated Contributing Catchment (m2) )
• OLFP_ID ( type: esriFieldTypeString, alias: OLFP ID, length: 20 )

Layer: Overland Flow Paths 2021 (0)

Sub Layers:
• Modelled Catchment Flowpaths 2021
• Surface Depression Ponding Areas 2021
Name: Overland Flow Paths 2021

Display Field:

Type: Group Layer

Geometry Type: null

Description: <DIV STYLE="text-align:Left;font-size:12pt"><DIV><P><SPAN>Overland flow paths were derived from a flow accumulation surface that was extracted from a hydrologically corrected DEM. Flow paths were defined using a flow accumulation threshold of 500 cells, i.e. to qualify for inclusion in the flow path network, a minimum catchment area of 2,000 m2 was required (500 cells x 4 m2 each). OLFPs were delineated iteratively, with additional burn lines created with each iteration to correct flow paths that spill out of their channels and follow an incorrect trajectory. This is often caused by manmade structures such as bridges but also natural features such as dense vegetation incorrectly included within the DEM (as opposed to the surface model or DSM). Additionally, significant stormwater pipes were utilised as these pipes are unlikely to reach capacity and have a significant role in the conveyance of water. Several iterations using this approach were conducted until a fair representation of the flow paths was obtained. Flow paths were first converted to vector polylines. The resulting feature class can be visualized by symbolizing on the catchment area.</SPAN></P></DIV></DIV>

Service Item Id: 7a9fc3d738ea4b5a9611e1b7ca8170e8

Copyright Text: Morphum Environmental

Default Visibility: true

MaxRecordCount: 0

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 20000

Max Scale: 0

Supports Advanced Queries: false

Supports Statistics: false

Has Labels: false

Can Modify Layer: false

Can Scale Symbols: false

Use Standardized Queries: true

Supports Datum Transformation: true

Extent:
XMin: 1649923
YMin: 5989874
XMax: 1760924
YMax: 6096227
Spatial Reference: 2193  (2193)



Drawing Info:
N/A
Advanced Query Capabilities:
Supports Statistics: false
Supports OrderBy: false
Supports Distinct: false
Supports Pagination: false
Supports TrueCurve: true
Supports Returning Query Extent: true
Supports Query With Distance: true
Supports Sql Expression: false
Supports Query With ResultType: false
Supports Returning Geometry Centroid: false
Supports Binning LOD: false
Supports Query With LOD Spatial Reference: false


HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeNone

Type ID Field: null

Fields: None

Layer: Modelled Catchment Flowpaths 2021 (1)

Name: Modelled Catchment Flowpaths 2021

Display Field: US_Catchment_Area

Type: Feature Layer

Geometry Type: esriGeometryPolyline

Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="text-align:Justify;"><SPAN>Overland flow paths were derived from a flow accumulation surface that was extracted from a hydrologically corrected DEM. Flow paths were defined using a flow accumulation threshold of 500 cells, i.e. to qualify for inclusion in the flow path network, a minimum catchment area of 2,000 m2 was required (500 cells x 4 m2 each). OLFPs were delineated iteratively, with additional burn lines created with each iteration to correct flow paths that spill out of their channels and follow an incorrect trajectory. This is often caused by manmade structures such as bridges but also natural features such as dense vegetation incorrectly included within the DEM (as opposed to the surface model or DSM). </SPAN><SPAN>Additionally, significant stormwater pipes were utilised as these pipes are unlikely to reach capacity and have a significant role in the </SPAN><SPAN>conveyance of water</SPAN><SPAN>. </SPAN><SPAN>Several iterations using this approach were conducted until a fair representation of the flow paths was obtained. Flow paths were first converted to vector polylines</SPAN><SPAN>. </SPAN><SPAN> The resulting feature class can be visualized by symbolizing on the catchment area</SPAN><SPAN>.</SPAN></P><P STYLE="text-align:Justify;"><SPAN>Disclaimer</SPAN></P><P STYLE="text-align:Justify;"><SPAN><SPAN>This overland flow path layer provides a high-level understanding of routes where surface stormwater may flow during rainfall events. </SPAN></SPAN></P><P><SPAN><SPAN>It is subject to the following limitations:</SPAN></SPAN></P><OL STYLE="margin:0 0 0 0;padding:0 0 0 0;"><LI><P STYLE="text-align:Justify;"><SPAN><SPAN>The layer uses a surface generated by LiDAR only and does not account for the stormwater reticulation network or for any surface obstructions such as buildings or fences.</SPAN></SPAN></P></LI><LI><P STYLE="text-align:Justify;"><SPAN><SPAN>The layer is subject to limitations in the LiDAR data. These include lower precision under dense foliage and lack of LiDAR data in some rural areas in the District.</SPAN></SPAN></P></LI><LI><P STYLE="text-align:Justify;"><SPAN><SPAN>The layer is generated through a GIS algorithm which divides terrain into a grid of squares. Water is modelled to flow from each grid square to the lowest adjacent grid square. This method means that fine features such as kerbs may not be accurately represented.</SPAN></SPAN></P></LI><LI><P STYLE="text-align:Justify;"><SPAN><SPAN>The layer does not include any assessment of depth, width, or rate, of flows.</SPAN></SPAN></P></LI><LI><P STYLE="text-align:Justify;"><SPAN><SPAN>In some locations, change to landform since LiDAR was generated will have altered overland flow paths from those displayed on the layer.</SPAN></SPAN></P></LI></OL><P STYLE="text-align:Justify;"><SPAN>These limitations mean that overland flow paths represented on the layer should not be considered definitive and are subject to further investigation. Likewise, flow paths that exist in reality, may not be represented on this layer.</SPAN></P></DIV></DIV></DIV>

Service Item Id: 7a9fc3d738ea4b5a9611e1b7ca8170e8

Copyright Text: Morphum Environmental

Default Visibility: true

MaxRecordCount: 2000

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 20000

Max Scale: 0

Supports Advanced Queries: true

Supports Statistics: true

Has Labels: false

Can Modify Layer: true

Can Scale Symbols: false

Use Standardized Queries: true

Supports Datum Transformation: true

Extent:
XMin: 1649923
YMin: 5989874
XMax: 1760924
YMax: 6096227
Spatial Reference: 2193  (2193)



Drawing Info:
Renderer:
Unique Value Renderer:
Field 1: Flow_Classification_WDC
Field 2: N/A
Field 3: N/A
Field Delimiter: ,
Default Symbol:
N/A
Default Label: N/A
UniqueValueInfos:
• Value: 0.2 ha to 0.4 ha
  Label: 0.2 ha to 0.4 ha
  Description: N/A
  Symbol:
  Style: esriSLSDash
  Color: [0, 169, 230, 255]
  Width: 1
• Value: 0.4 ha to 1.0 ha
  Label: 0.4 ha to 1.0 ha
  Description: N/A
  Symbol:
  Style: esriSLSDash
  Color: [0, 112, 255, 255]
  Width: 0
• Value: 1.0 ha to 3.0 ha
  Label: 1.0 ha to 3.0 ha
  Description: N/A
  Symbol:
  Style: esriSLSSolid
  Color: [0, 112, 255, 255]
  Width: 1
• Value: 3.0 ha to 100.0 ha
  Label: 3.0 ha to 100.0 ha
  Description: N/A
  Symbol:
  Style: esriSLSSolid
  Color: [0, 92, 230, 255]
  Width: 1
• Value: 100.0 ha and above
  Label: 100.0 ha and above
  Description: N/A
  Symbol:
  Style: esriSLSSolid
  Color: [0, 92, 230, 255]
  Width: 1
Transparency: 0
Labeling Info:
Advanced Query Capabilities:
Supports Statistics: true
Supports OrderBy: true
Supports Distinct: true
Supports Pagination: true
Supports TrueCurve: true
Supports Returning Query Extent: true
Supports Query With Distance: true
Supports Sql Expression: true
Supports Query With ResultType: false
Supports Returning Geometry Centroid: false
Supports Binning LOD: false
Supports Query With LOD Spatial Reference: false


HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Type ID Field: null

Fields:
• OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID )
• Shape ( type: esriFieldTypeGeometry, alias: Shape )
• US_Catchment_Area ( type: esriFieldTypeDouble, alias: Contributing Catchment (m2) )
• Shape.STLength() ( type: esriFieldTypeDouble, alias: Shape Length )
• Creator ( type: esriFieldTypeString, alias: Creator, length: 255 )
• Reference ( type: esriFieldTypeString, alias: Reference, length: 255 )
• ForUser ( type: esriFieldTypeString, alias: For User, length: 255 )
• Flow_Classification_WDC ( type: esriFieldTypeString, alias: OLFP Classification (in Hectares), length: 255 )

Layer: Surface Depression Ponding Areas 2021 (3)

Name: Surface Depression Ponding Areas 2021

Display Field: SURFACE_AREA

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: <DIV STYLE="text-align:Left;"><DIV><DIV><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Surface depressions are defined as areas on the DEM that are surrounded by cells of higher elevation and which could therefore potentially fill if their outlets were blocked. The extent to which depressions are formed on the DEM surface therefore depends on the degree to which the DEM has been corrected. </SPAN></SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN>To map surface depressions for this project, </SPAN><SPAN>the supplied OLFP network was analysed to identify areas where surface pooling of water may result in localised flooding</SPAN><SPAN>. </SPAN></P><P STYLE="margin:0 0 11 0;"><SPAN>Many surface depressions are either artefacts of the DEM or so shallow as to be of little interest from a flood hazard perspective. In order to refine the depressions dataset to those of potential interest from a management perspective, all cells of less than 50 mm depth were therefore removed, and the remaining areas were required to meet all the following criteria to qualify as a depression:</SPAN></P><UL STYLE="margin:0 0 0 0;padding:0 0 0 0;"><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Surface area &gt; 100 m2 </SPAN></SPAN></P></LI><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Maximum depth &gt; 0.20 m </SPAN></SPAN></P></LI><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Volume &gt; 20 m3</SPAN></SPAN></P></LI></UL><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>Surface depressions matching the above criteria have been converted into polygon features and attributed with the following fields</SPAN></SPAN></P><UL STYLE="margin:0 0 0 0;padding:0 0 0 0;"><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>SURFACE_ARA: Area (m2) of surface depression</SPAN></SPAN></P></LI><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>VOLUME: Estimated volume of the surface depression (m3)</SPAN></SPAN></P></LI><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>MIN_DEPTH: Minimum estimated depression depth within the surface depression</SPAN></SPAN></P></LI><LI><P STYLE="margin:0 0 11 0;"><SPAN><SPAN>MAX_DEPTH: Maximum estimated depression depth within the surface depression</SPAN></SPAN></P></LI></UL><P><SPAN /></P></DIV></DIV></DIV>

Service Item Id: 7a9fc3d738ea4b5a9611e1b7ca8170e8

Copyright Text: Morphum Environmental, July 2021

Default Visibility: true

MaxRecordCount: 2000

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 20000

Max Scale: 0

Supports Advanced Queries: true

Supports Statistics: true

Has Labels: false

Can Modify Layer: true

Can Scale Symbols: false

Use Standardized Queries: true

Supports Datum Transformation: true

Extent:
XMin: 1707936
YMin: 6008967
XMax: 1739836
YMax: 6084575
Spatial Reference: 2193  (2193)



Drawing Info:
Renderer:
Class Breaks Renderer:
Field: MAX_DEPTH
Min. Value: 0.2
ClassBreakInfos:
• Class Maximum Value: 0.6
  Label: 0.200000 - 0.600000 m
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [115, 255, 223, 153]
  Outline:
  Style: esriSLSSolid
  Color: [110, 110, 110, 255]
  Width: 0
• Class Maximum Value: 1.2
  Label: 0.600001 - 1.200000 m
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [0, 168, 132, 138]
  Outline:
  Style: esriSLSSolid
  Color: [110, 110, 110, 255]
  Width: 0
• Class Maximum Value: 2
  Label: 1.200001 - 2.000000 m
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [0, 169, 230, 153]
  Outline:
  Style: esriSLSSolid
  Color: [110, 110, 110, 255]
  Width: 0
• Class Maximum Value: 4
  Label: 2.000001 - 4.000000 m
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [0, 92, 230, 135]
  Outline:
  Style: esriSLSSolid
  Color: [0, 77, 168, 255]
  Width: 0
• Class Maximum Value: 9.91
  Label: 4.000001 - 9.910000 m
  Description: N/A
  Symbol:
  Style: esriSFSSolid
  Color: [0, 38, 115, 133]
  Outline:
  Style: esriSLSSolid
  Color: [110, 110, 110, 255]
  Width: 0
Transparency: 0
Labeling Info:
Advanced Query Capabilities:
Supports Statistics: true
Supports OrderBy: true
Supports Distinct: true
Supports Pagination: true
Supports TrueCurve: true
Supports Returning Query Extent: true
Supports Query With Distance: true
Supports Sql Expression: true
Supports Query With ResultType: false
Supports Returning Geometry Centroid: false
Supports Binning LOD: false
Supports Query With LOD Spatial Reference: false


HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Type ID Field: null

Fields:
• OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID )
• Shape ( type: esriFieldTypeGeometry, alias: SHAPE )
• SURFACE_AREA ( type: esriFieldTypeString, alias: Areas of Ponded Surface (m2), length: 200 )
• MAX_DEPTH ( type: esriFieldTypeDouble, alias: Max Estimate Depth (m) )
• MIN_DEPTH ( type: esriFieldTypeDouble, alias: Min Estimate Depth (m) )
• VOLUME ( type: esriFieldTypeString, alias: Volume (m3), length: 200 )
• Shape.STLength() ( type: esriFieldTypeDouble, alias: SHAPE_Length )
• Shape.STArea() ( type: esriFieldTypeDouble, alias: SHAPE_Area )

Layer: Overland Flow Paths 2017 (15)

Sub Layers:
• Depression Storage Areas 2017
• Catchment Area 2017
Name: Overland Flow Paths 2017

Display Field:

Type: Group Layer

Geometry Type: null

Description: <DIV STYLE="text-align:Left;font-size:12pt"><P><SPAN>The mapping of indicative Overland flowpaths (OLFPs) was developed in 2019 using the Digital Elevation Model (DEM) method. It has been developed from the 2017 LIDAR information sourced from NRC and WDC. (Refer Ref 1and 2) </SPAN></P><P><SPAN /></P><P><SPAN>Mapped overland flowpaths show the indicative path taken by stormwater run-off as a surface flow concentrates. An OLFP may act as either a primary or secondary stormwater conveyance system. </SPAN></P><P><SPAN /></P><P><SPAN>The purpose of these layers is for use by Council in the following ways: </SPAN></P><P><SPAN /></P><P><SPAN>- Identifying developments that may be affected by OLFPs </SPAN></P><P><SPAN /></P><P><SPAN>- To ensure adequate building provisions are considered in relation to nearby OLFPs and depression storage areas </SPAN></P><P><SPAN /></P><P><SPAN>- Quick catchment/sub-catchment boundary checks </SPAN></P><P><SPAN /></P><P><SPAN>- Checking contributing catchment areas </SPAN></P><P><SPAN /></P><P><SPAN>- Flow estimation (when used in conjunction with other data and assessments) </SPAN></P><P><SPAN /></P><P><SPAN>- Identifying location of streams (particularly in rural catchments) and support management of priorities </SPAN></P><P><SPAN /></P><P><SPAN>- Forms the framework for more bespoke analysis of pollution source control and environmental management</SPAN></P></DIV>

Service Item Id: 7a9fc3d738ea4b5a9611e1b7ca8170e8

Copyright Text: Morphum Environmental

Default Visibility: false

MaxRecordCount: 0

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 20000

Max Scale: 0

Supports Advanced Queries: false

Supports Statistics: false

Has Labels: false

Can Modify Layer: false

Can Scale Symbols: false

Use Standardized Queries: true

Supports Datum Transformation: true

Extent:
XMin: 1707637.2200999996
YMin: 6008181.9601
XMax: 1743311.2200999996
YMax: 6057118.9601
Spatial Reference: 2193  (2193)



Drawing Info:
N/A
Advanced Query Capabilities:
Supports Statistics: false
Supports OrderBy: false
Supports Distinct: false
Supports Pagination: false
Supports TrueCurve: true
Supports Returning Query Extent: true
Supports Query With Distance: true
Supports Sql Expression: false
Supports Query With ResultType: false
Supports Returning Geometry Centroid: false
Supports Binning LOD: false
Supports Query With LOD Spatial Reference: false


HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeNone

Type ID Field: null

Fields: None

Layer: Depression Storage Areas 2017 (16)

Parent Layer: Overland Flow Paths 2017

Name: Depression Storage Areas 2017

Display Field: Min_Depth

Type: Feature Layer

Geometry Type: esriGeometryPolygon

Description: Surface depressions can be mapped to define zones of potential inundation should the primary network become blocked.Depressions can be delineated under the assumption that these areas would fill to capacity prior tospilling. To qualify for inclusion in the depression’s dataset, individual depressions need to meet the following setof criteria relating footprint area, storage volume and maximum depth. Surface area > 100 m2 Maximum depth > 0.20 m Volume > 30 m3The Field "Valid_Depression" can be used to identify those depression features that meet the above criteriaDisclaimerThis overland flow path layer provides a high-level understanding of routes where surface stormwater may flow during rainfall events. It is subject to the following limitations:The layer uses a surface generated by LiDAR only and does not account for the stormwater reticulation network or for any surface obstructions such as buildings or fences.The layer is subject to limitations in the LiDAR data. These include lower precision under dense foliage and lack of LiDAR data in some rural areas in the District.The layer is generated through a GIS algorithm which divides terrain into a grid of squares. Water is modelled to flow from each grid square to the lowest adjacent grid square. This method means that fine features such as kerbs may not be accurately represented.The layer does not include any assessment of depth, width, or rate, of flows.In some locations, change to landform since LiDAR was generated will have altered overland flow paths from those displayed on the layer.These limitations mean that overland flow paths represented on the layer should not be considered definitive and are subject to further investigation. Likewise, flow paths that exist in reality, may not be represented on this layer.A draft disclaimer for the depression storage layer is provided as follows for your consideration.The depression storage layer provides an indicative extent of where ponding may form during prolonged rainfall.It is subject to the following limitations:It is assumed that the depression storage areas shown would fill to capacity prior to spillingThe depression storage areas shown exceed the following minimum criteria regarding ponding area, storage volume and depth.Surface area > 100 m2 Maximum depth > 0.20 m Volume > 30 m3The layer uses a surface generated by LiDAR only and is subject to the limitations of LiDAR. In some locations, change to landform since LiDAR was generated will have altered the potential depression storage area from those displayed on the layer.

Service Item Id: 7a9fc3d738ea4b5a9611e1b7ca8170e8

Copyright Text: Morphum Environmental 2019

Default Visibility: true

MaxRecordCount: 2000

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 20000

Max Scale: 0

Supports Advanced Queries: true

Supports Statistics: true

Has Labels: false

Can Modify Layer: true

Can Scale Symbols: false

Use Standardized Queries: true

Supports Datum Transformation: true

Extent:
XMin: 1708161.9330000002
YMin: 6008380.9601
XMax: 1742490.0365000004
YMax: 6057073.0538
Spatial Reference: 2193  (2193)



Drawing Info:
Renderer:
Unique Value Renderer:
Field 1: Valid_Depression
Field 2: N/A
Field 3: N/A
Field Delimiter: ,
Default Symbol:
N/A
Default Label: N/A
UniqueValueInfos:
• Value: YES
  Label: Depression Storage Areas
  Description: N/A
  Symbol:
  Style: esriSFSBackwardDiagonal
  Color: [0, 197, 255, 255]
  Outline:
  Style: esriSLSSolid
  Color: [55, 149, 200, 255]
  Width: 2
Transparency: 0
Labeling Info:
Advanced Query Capabilities:
Supports Statistics: true
Supports OrderBy: true
Supports Distinct: true
Supports Pagination: true
Supports TrueCurve: true
Supports Returning Query Extent: true
Supports Query With Distance: true
Supports Sql Expression: true
Supports Query With ResultType: false
Supports Returning Geometry Centroid: false
Supports Binning LOD: false
Supports Query With LOD Spatial Reference: false


HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Type ID Field: null

Fields:
• OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID )
• Min_Depth ( type: esriFieldTypeString, alias: Minimum Depth in meters, length: 200 )
• Max_Depth ( type: esriFieldTypeString, alias: Maximum Depth in meters, length: 200 )
• Surface_Vol ( type: esriFieldTypeString, alias: Surface Volumn m3, length: 200 )
• Valid_Depression ( type: esriFieldTypeString, alias: Valid Depression, length: 200 )
• Shape ( type: esriFieldTypeGeometry, alias: Shape )
• Shape.STArea() ( type: esriFieldTypeDouble, alias: Shape.STArea() )
• Shape.STLength() ( type: esriFieldTypeDouble, alias: Shape.STLength() )

Layer: Catchment Area 2017 (17)

Parent Layer: Overland Flow Paths 2017

Name: Catchment Area 2017

Display Field: Catchment_Area

Type: Feature Layer

Geometry Type: esriGeometryPolyline

Description: Overland flow paths were derived from a flow accumulation surface that was extracted from a hydrologically corrected DEM. Flow paths were defined using a flow accumulation threshold of 500 cells, i.e. to qualify for inclusion in the flow path network, a minimum catchment area of 2,000 m2 was required (500 cells x 4 m2 each). OLFPs were delineated iteratively, with additional burn lines created with each iteration to correct flow paths that spill out of their channels and follow an incorrect trajectory. This is often caused by manmade structures such as bridges but also natural features such as dense vegetation incorrectly included within the DEM (as opposed to the surface model or DSM). Several iterations using this approach were conducted until a fair representation of the flow paths was obtained. Flow paths were first converted to vector polylines and smoothed to give a more appropriate visual representation. The resulting feature class can be visualised by symbolising on the catchment area field using the break values shown below.DiscalimaerThis overland flow path layer provides a high-level understanding of routes where surface stormwater may flow during rainfall events. It is subject to the following limitations:The layer uses a surface generated by LiDAR only and does not account for the stormwater reticulation network or for any surface obstructions such as buildings or fences.The layer is subject to limitations in the LiDAR data. These include lower precision under dense foliage and lack of LiDAR data in some rural areas in the District.The layer is generated through a GIS algorithm which divides terrain into a grid of squares. Water is modelled to flow from each grid square to the lowest adjacent grid square. This method means that fine features such as kerbs may not be accurately represented.The layer does not include any assessment of depth, width, or rate, of flows.In some locations, change to landform since LiDAR was generated will have altered overland flow paths from those displayed on the layer.These limitations mean that overland flow paths represented on the layer should not be considered definitive and are subject to further investigation. Likewise, flow paths that exist in reality, may not be represented on this layer.A draft disclaimer for the depression storage layer is provided as follows for your consideration.The depression storage layer provides an indicative extent of where ponding may form during prolonged rainfall.It is subject to the following limitations:It is assumed that the depression storage areas shown would fill to capacity prior to spillingThe depression storage areas shown exceed the following minimum criteria regarding ponding area, storage volume and depth.Surface area > 100 m2 Maximum depth > 0.20 m Volume > 30 m3The layer uses a surface generated by LiDAR only and is subject to the limitations of LiDAR. In some locations, change to landform since LiDAR was generated will have altered the potential depression storage area from those displayed on the layer.

Service Item Id: 7a9fc3d738ea4b5a9611e1b7ca8170e8

Copyright Text:

Default Visibility: true

MaxRecordCount: 2000

Supported Query Formats: JSON, geoJSON, PBF

Min Scale: 20000

Max Scale: 0

Supports Advanced Queries: true

Supports Statistics: true

Has Labels: false

Can Modify Layer: true

Can Scale Symbols: false

Use Standardized Queries: true

Supports Datum Transformation: true

Extent:
XMin: 1707637.2200999996
YMin: 6008181.9601
XMax: 1743311.2200999996
YMax: 6057118.9601
Spatial Reference: 2193  (2193)



Drawing Info:
Renderer:
Class Breaks Renderer:
Field: Catchment_Area
Min. Value: 0.2
ClassBreakInfos:
• Class Maximum Value: 1
  Label: 0.2 - 1.0 Ha
  Description: N/A
  Symbol:
  Style: esriSLSSolid
  Color: [0, 197, 255, 255]
  Width: 0
• Class Maximum Value: 2
  Label: 1.0 - 2.0 Ha
  Description: N/A
  Symbol:
  Style: esriSLSSolid
  Color: [0, 197, 255, 255]
  Width: 0
• Class Maximum Value: 5
  Label: 2.0 - 5.0 Ha
  Description: N/A
  Symbol:
  Style: esriSLSSolid
  Color: [0, 197, 255, 255]
  Width: 1
• Class Maximum Value: 2533.59872
  Label: > 5.0 Ha
  Description: N/A
  Symbol:
  Style: esriSLSSolid
  Color: [0, 197, 255, 255]
  Width: 2
Transparency: 0
Labeling Info:
Advanced Query Capabilities:
Supports Statistics: true
Supports OrderBy: true
Supports Distinct: true
Supports Pagination: true
Supports TrueCurve: true
Supports Returning Query Extent: true
Supports Query With Distance: true
Supports Sql Expression: true
Supports Query With ResultType: false
Supports Returning Geometry Centroid: false
Supports Binning LOD: false
Supports Query With LOD Spatial Reference: false


HasZ: false

HasM: false

Has Attachments: false

HTML Popup Type: esriServerHTMLPopupTypeAsHTMLText

Type ID Field: null

Fields:
• OBJECTID ( type: esriFieldTypeOID, alias: OBJECTID )
• FlowAccum ( type: esriFieldTypeDouble, alias: Flow Accumulation )
• Catchment_Area ( type: esriFieldTypeDouble, alias: Catchment Area in hectares )
• Shape ( type: esriFieldTypeGeometry, alias: Shape )
• Shape.STLength() ( type: esriFieldTypeDouble, alias: Shape.STLength() )