wet weather flow calculations wet weather flow calculations Chronics (Military) (OP) 7 Feb 08 15:47 How do I calculation wet & dry weather peak flow? examples would be great. thanks. RE: wet weather flow calculations stanier (Mechanical) 7 Feb 08 18:43 Suggest you go to https://www.wsaa.asn.au/frameset2.html and buy WSA 02 code. RE: wet weather flow calculations RWF7437 (Civil/Environmental) 7 Feb 08 20:31 Chronics,Not sure I understand your question or why it is posted on this forum. Are you interested in water demand flows? Will the Australian standards Stanier has cited be useful to you ? Are you interested in wet weather sanitary sewer flows, perhaps ?Where is your project or practice and which kind of flows are you seeking? RE: wet weather flow calculations bimr (Civil/Environmental) 7 Feb 08 20:38 Sewers are sized for peak hour flow. The ratio of peak hourly flow to daily average flow is given in empirical charts based on population. The larger the population, the lower the ratio. Here is such a chart:http://www.ilga.gov/commission/jcar/admincode/035/03500370ZZ9996dR.htmlAs for wet weather flow, that is a good question. Wet weather flow depends on many factors such as the quality of design, quality of installation, depth of groundwater, age of your sewer system, etc., etc. Older systems tend to have more wet weather flow.Wet weather flow is probably best determined by actual data from the sewer system in question.