The degree to which water balance objectives are met will depend on the underlying native soil type on which the system is located. Several Ontario studies have assess the performance of exfiltration systems in cold climates.
+
+
{| class="wikitable"
+
|+ Volumetric runoff reduction achieved by exfiltration systems
+
|-
+
! Practice
+
! Location
+
! Underlying soil type
+
! Runoff reduction
+
|-
+
|Grass swale/perforated pipe||Nepean, ON<ref name=Sabourin>J.F. Sabourin and Associates Incorporated. 2008a. 20 Year Performance Evaluation of Grassed Swale and Perforated Pipe Drainage Systems. Project No. 524(02). Prepared for the Infrastructure Management Division of the City of Ottawa. Ottawa, Ontario.</ref>||Silty till||73 %
|Perforated pipe||Etobicoke, ON<ref name=SWAMP>Stormwater Assessment Monitoring and Performance (SWAMP) Program. 2005. Synthesis of Monitoring Studies Conducted Under the Stormwater Assessment
+
Monitoring and Performance Program.. Toronto and Region Conservation Authority,
+
Toronto, Ontario.</ref>||Clay/clayey silty till over silty sand||95 %
+
|-
+
|Perforated pipe||North york, ON<ref name=SWAMP/>||Silty sand||89 %