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{{:Depth to GW}}
The target separation between the base of an LID practice and the water table is 1 meter. This is to mitigate risks due to short periods of groundwater monitoring and potentially unobserved seasonal fluctuations. In areas where a 1.0 m separation cannot be provided, or where conditions dictate that an even greater separation may be warranted, additional discussion and/or analysis specific to the physical characteristics of the site and the proposed design should be completed.
Retention of this unsaturated zone:
The design practitioner is advised to consult with approval agencies to understand their requirements and/or expectations prior to undertaking work, and to complete an appropriate level of analysis to support their conclusion. The requirement for additional investigation and/or documentation supporting a proposed design may be reduced in areas where ≥ 1.0 m separation is anticipated.
 
Retention of an unsaturated zone beneath the practice :
*Minimizes the potential for functional impacts associated with reduced percolation rates,
*Minimizes the potential for functional impacts associated with reduced percolation rates,
*Maintains the physical and biochemical water quality treatment benefits provided within the vadose zone,
*Maintains the physical and biochemical water quality treatment benefits provided within the vadose zone.
*Minimizes the potential for localized groundwater mounding to affect nearby buildings or infrastructure, and/or
 
*Provides a factor-of-safety against potential uncertainties related to the elevation of the seasonally high groundwater elevation in areas of limited monitoring.
The requirement for additional investigation and/or documentation supporting a proposed design may be reduced in areas where ≥ 1.0 m separation is anticipated. 
In areas where a 1.0 m separation cannot be provided, or where conditions dictate that an even greater separation may be warranted, additional discussion and/or analysis specific to the physical characteristics of the site and the proposed design should be completed.
The design practitioner is advised to consult with approval agencies to understand their requirements and/or expectations prior to undertaking work, and to complete an appropriate level of analysis to support their conclusion.
 
==Groundwater mounding==
==Groundwater mounding==
Groundwater mounding describes the localised raising of the water table beneath infiltration practices. It may be of concern if it affects nearby structures including building foundations.
Groundwater mounding describes the localised raising of the water table beneath infiltration practices. It may be of concern if it affects nearby structures including building foundations.

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