I need some help dealing with storm water. I'm trying to get a site plan approved and the township engineer wants to see "calculations in the form of a storm water management brief to indicate how post development floes will be managed such that they do not exceed pre development flows for a 100 year event." The building is 50x60 feet and the new aspalt parking area will be 500 sq metres. I have allready set slopes off the building to be 2% as well as 2% on the asphalt to the sides and ditch at the front of the lot. A Civil Engineer wants 3,000 dollars to do a site grading and storm water managment plan. Thats too much the owner of the property is not happy because the same company allready charged him 3,000 for a topo plan. Anyways just wondering if anyone could provide me with a link or point me in the right direction on how i could attempt these calcs. Thanks.