Sumps SRSC can manufacture custom sumps to suit your requirements. The purpose of a sump is to collect the storm water from the box gutter before it flows down through the downpipe. Sumps are usually attached between a box gutter & the downpipe. Features/benefits Custom Made Typically made from .55bmt flashing feed however if you require a heavy gauge we can accommodate. Tapered sumps available. Finishes available Colorbond®, Colorbond® ULTRA, Colorbond® MATT, Zincalume, Galvanised, Stainless Steel 304 & 316, Copper, Colorbond® Metallic.