Python implementation of Gauckler–Manning formula, used to estimate flow in an open channel. No warranty, do with as you please. To install run python setup.py install (may require sudo). To test run python test.py Arguments (in order): y,b,n,S,k=1.0,g=9.8066 where: y = Water depth measured normal (perpendicular) to the bottom of the culvert. b = Channel bottom width. n = Manning coefficient. n is a function of the culvert material, such as plastic, concrete, brick, etc. See http://www.engineeringtoolbox.com/mannings-roughness-d_799.html for a list of materials. S = Slope of channel bottom or water surface. Vertical distance divided by horizontal distance. k = unit conversion factor = 1.49 if English units = 1.0 if metric units. g = acceleration due to gravity = 32.174 ft/s2 = 9.8066 m/s2, defaults to 9.8066. Example usage: from mannings import ManningsEquation m=ManningsEquation(5,10,0.012,0.05,1.49, 32.174) m.cross_section m.wetted_perimeter m.hydraulic_radius m.average_velocity m.froude_number m.flowrate