Stormwater Source Control Design Guidelines 2005 - Waterbucket

Stormwater Source Control Design Guidelines 2005Glossaryperforated drain placed near the top of the drain rockreservoir provides an underground overflow. The surfaceswale and weir structures also convey larger storms(overflows) to a surface outlet. German literature refers toa Swale/Trench Element, and adds an outlet controlstructure to detain stormwater in the drain rock reservoirand soils, releasing the water either through infiltration orthrough small outlet orifices at the control structure.Treatment Chain – the application of a series of physicalstormwater best management practices to achieve managedhydrology and water quality . Often used to treatcontaminated runoff, the chain (or train) may incorporatechambers or units that first slow water and remove largeparticulates, followed by a unit to allow settling out of finerparticulates, and a third “finishing” unit to remove dissolvedcompounds. (See GVRD, 1999: 4-108, Western AustraliaWater and Rivers Commission, 1998: 3 or Argue, 2002 forfurther details and examples.)Greater Vancouver Sewerage & Drainage District131