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SGRA_ECWP (FeatureServer)

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Service Description: Polygon file displaying significant groundwater recharge areas (SGRA) across the Toronto Region Source Protection Area (TRSPA) in the CTC Region. The SGRA layer was developed to satisfy requirements of the Source Protection Plan for the Credit Valley, Toronto and Region and Central Lake Ontario region (CTC-SPC 2015) under the Clean Water Act (2006). Groundwater recharge occurs when rain/snow seeps down into an aquifer and generally this is associated with particular soil types (e.g., loose sand/gravel). SGRAs are delineated using a water budget modelling process, where the high potential recharge areas are delineated by the method outlined in full in CTC-SPC (2015). Details of the methodology used to develop this layer can be found in CTC-SPC (2015). SGRAs have permeable soils such as sand or gravel that allow the water to soak easily into the ground. Under the Clean Water Act, 2006, a recharge area is considered significant when it helps maintain the water level in an aquifer that supplies drinking water (including private wells), and has higher than average recharge across the Source Protection Area. SGRA are provided with vulnerable scores at the 2, 4 and 6 level. (Areas with a score of 2 are least vulnerable to contamination and areas with a score of 6 are most vulnerable). This file was updated in 2018 and was approved as part of CTC's first Sec34 amendment in 2019.

Service ItemId: a3439d2d507f47b6a0c7bf57ae3828be

Has Versioned Data: false

Max Record Count: 2000

Supported query Formats: JSON

Supports applyEdits with GlobalIds: False

Supports Shared Templates: False

All Layers and Tables

Layers:

Description:

Entity Name: SW Significant Groundwater Recharge Area

Table Name: SignificantGroundwaterRechargeArea

An area can be considered a significant groundwater recharge area if (1) the area annually recharges water to the underlying aquifer at a rate that is greater than the rate of recharge across the whole of the related groundwater recharge area by a factor of 1.15 or more; or (2) the area annually recharges a volume of water to the underlying aquifer that is 55% or more of the volume determined by subtracting the annual evapotranspiration for the whole of the related groundwater recharge area from the annual precipitation for the whole of the related groundwater recharge area.

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ATTRIBUTE/COLUMN NAME

DATATYPE

REQ

DESCRIPTION

1

OBJECTID

OBJECTID

NUMBER(13)

Yes

A unique numeric identifier assigned to each feature.

2

Source Protection Area ID

SPP_ID

NUMBER(2)

Yes

Identifier for the source protection area that provided the original data about the feature. SPP_ID values range from 0 to 48 chosen from Lookup Table: SOURCE_PROT_AREA_LIST.

3

Vulnerability Score

VULNERABILITY_SCORE

NUMBER(1)

Yes

Ranges from 2, 4 or 6, with 6 being most vulnerable. Technical rules outline how to assign this, typically based on the Time of Travel zone and/or the relative Vulnerability Level.

4

Effective Datetime

EFFECTIVE_DATETIME

DATE

Yes

Date/time the record was created or last modified in the source database.

5

SHAPE

SHAPE

SDO_GEOMETRY

Yes

Geometry attribute.

Clipping SGRAs

The jurisdictional identification of SGRA was approved by the SPC. However, Technical Rule (45) requires that “an area shall NOT be delineated as a SGRA area unless the area has a hydrological connection to a surface water body or aquifer that is a source of drinking water for a drinking water system.” This includes private systems (O. Reg. 170/03). This Technical Rule introduces the idea of clipping out SGRAs that are of no significance from a drinking water point of view, since it would not make practical sense to protect them. These areas may be important in other contexts, but they are not considered significant under the CWA. In the CTC Region, the SGRA located within the municipal service boundary that are on the Lake Ontario shoreline and sourced from Lake Ontario have been clipped out if no drinking water systems (as defined in the Safe Drinking Water Act, 2002) depend on those SGRAs.



Copyright Text: CTC, TRCA, TRSPA

Spatial Reference: 26917 (26917)

Initial Extent:
Full Extent:
Units: esriMeters

Child Resources:   Info

Supported Operations:   Query   ConvertFormat   Get Estimates   Create Replica