Assuming surface on which rainfalls in thickly built residential district as follows:  `40 %` area consist of roofs and pavements having impermeability factor `C` as `0.85`, `40 %` of area consists of lawns and gardens having `C` as `0.20` and remaining area consists of ground surface having `C` as `0.1` .If total area draining to sewer is `5` hectares and maximum intensity of rainfall is `50` mm/hr, estimate probable runoff from area. 

An impervious area of `20` hectares is to be served by a sewer line. This area is subjected to three storms X, Y, Z with equal frequency of occurrence. The duration of the three storms is `20` minutes, `30` minutes and `35` minutes respectively. Taking the time of concentration equals to `30` minutes. Determine the maximum runoff from the each storm. [Ans : `0.938` `m^3`/s ,`1.134` `m^3`/s , `1.03` `m^3`/s] 

Assuming surface on which rainfalls in thickly built residential district as follows:  `40 %` area consist of roofs and pavements having impermeability factor `C` as `0.85`, `40 %` of area consists of lawns and gardens having `C` as `0.20` and remaining area consists of ground surface having `C` as `0.1` .If total area draining to sewer is `5` hectares and maximum intensity of rainfall is `50` mm/hr, estimate probable runoff from area. 

Assuming the surface on which rainfalls is thickly built residential district as follows :  

Calculate the average impermeability factor. If the total area draining to the sewer is `6` hectares and maximum intensity of rainfall is `55` mm/hr. Estimate the runoff from the area.[TU 2006]