Sewer Connection by Line Size

Houses per Sewer Line

This program determines how many houses can be up-stream from a pipe using an average slope and Manning's 'n' number. The program determines this by assuming that the pipe is flowing full and using Manning's formula and the ratio of extreme to daily flows from the MDEQ sewer design manual.
Input Data:
Diameter = in.
Pipe Slope = ft/ft
Mannings 'n' =
People per house =
Area = ft2
Perimeter = ft
Hydraulic Radius = ft
Velocity = ft/s
Flow = cfs
Population = people

Ratio of Extreme Flow to Daily Average Flow

Qmax/Qave= 18 + P1/2
4 + P1/2
          P = population in thousands

Manning's Formula

Q = A x
x R2/3 x S1/2
  • A = area in sq. ft.
  • n = Manning's roughness number
  • R = hydraulic radius (A/P)
  • P = perimeter of pipe in ft.
  • S = slope of pipe in ft./ft.

Houses at Minimum Slope

Pipe Size Minimum Slope Houses