To plan storm water drainage for a factory, start with a level survey, set finished levels so water flows away from buildings, size drains for heavy rain from paved and roof areas, plan road and trench crossings early, confirm the outfall, and give easy access for cleaning. Build drains together with roads so the levels match.
1. Start with a level survey
Drainage is about levels. Survey the plot and the outfall, then set finished levels for roads, yards and floors so water always flows away from buildings.
2. Size drains for heavy rain
Drains must carry the run-off from paved and roof areas in a heavy downpour, not an average shower. Your designer sizes them for the catchment.
3. Plan crossings early
Drains cross roads, pipe routes and cable trenches. Fix these crossings in the design so finished work is not broken later.
4. Know where the water goes
Confirm the outfall: the estate drain or another approved point. A network with no outfall simply moves the flood.
5. Make cleaning easy
Silt collects every year. Removable covers, gratings and chambers at intervals keep the system working.
6. Build it with the roads
Drains and roads should be built together by the same team, so levels match and nothing is fitted in afterwards.