Changes

The technology, known as the Groundwater Emulation Management System (GEMS), was designed to maintain cool stream discharge from the SWM pond catchment at a level similar to that experienced prior to development. This is accomplished by draining water at a controlled rate from the permanent pool of a stormwater pond to a cooling/infiltration trench. The cooling trench lowers the temperature of pond water through below ground heat transfer and discharges to the receiving watercourse at a rate and volume mimicking the natural discharge of groundwater. Estimated reductions in groundwater recharge caused by the conversion of land from agriculture and open space to residential use provided the basis for setting continuous flow rates released into the system.

The technology, known as the Groundwater Emulation Management System (GEMS), was designed to maintain cool stream discharge from the SWM pond catchment at a level similar to that experienced prior to development. This is accomplished by draining water at a controlled rate from the permanent pool of a stormwater pond to a cooling/infiltration trench. The cooling trench lowers the temperature of pond water through below ground heat transfer and discharges to the receiving watercourse at a rate and volume mimicking the natural discharge of groundwater. Estimated reductions in groundwater recharge caused by the conversion of land from agriculture and open space to residential use provided the basis for setting continuous flow rates released into the system.

[[File:Rock pad energy dissipator.PNG|450px|thumb|An energy dissipater, also known as a "bed friction outlet" that utilizes coarse rip-rap or jagged concrete blocks to ford a rough bed to help slow higher velocity flows leaving the feature. By increasing the roughness of the dissipator the flow of water is spread out, energy is decreased and as a result reduces the chance of downstream erosion or bed scour.<ref>Catchments & Creek Pty Ltd. 2010. Energy Dissipaters, Drainage Control Technique. ED-1.doc. Version 2 - May 2010. International Erosion Control Organization (IECO), Australia. https://www.austieca.com.au/documents/item/307</ref>]]

[[File:Cooling Trenches.jpg|450px|thumb|Close up view of a 'cooling trench'. These trenches work by outflows of warm pond water coming into contact with cooler [[stone]]

media (along the top of the trench) and side walls, which in turn promotes heat transfer between the two, resulting in a reduction in outflow water temperatures beign discharged to a receiving waterbody (i.e., stream) (Van Seters and Dougherty, 2019).<ref> Van Seters, T., and Dougherty J. 2019. Data Synthesis and Design Considerations for Stormwater Thermal Mitigation Measures. Sustainable Technologies Evaluation Program. Ontario. https://sustainabletechnologies.ca/app/uploads/2019/04/Thermal-Synthesis-Final.pdf</ref>. Photo Source: [[Acknowledgements: Azimuth Environmental​]]]]

'''Design Considerations'''

'''Design Considerations'''