How To Calculate Storm Drainage for Secondary Roads In this article you will learn to calculate the drains that locally maintained secondary, or vecinal, roads must have. The first thing to do is to calculate the maximum flow, and then the drainage area we need. The formulas for this are here.
Low Head Hydropower We have been using rivers to power the turbine of low head hydropower schemes for some time. However, there has been an innovative small hydropower design under test at Technische Universitat Munchen in Germany that uses very low heads. The complete unit is integral and concealed in a shaft.
Excel Spreadsheets for Design of Storm Water Drains and Their Inlets Download Excel spreadsheets to design storm water drains using either U.S. units or S.I. units. An orifice equation or broad crested weir equation is used to size inlets for storm drains to handle the design storm water runoff rate. The inlet may be a curb inlet, gutter inlet, or combination inlet.
River Litter Traps Litter traps prevent litter from going further downstream and polluting water sources. They are a must if a river has to maintain its pristine quality.
Sizing of Storm Water Detention Ponds with Excel Formulas The Excel spreadsheets that can be downloaded from this article use Excel formulas to calculate the volume needed for storm water retention or detention ponds. Parameters needed in the equations include, watershed time of concentration and peak storm water runoff rate.
Open Channel Flow Measurement with a Critical Flow Broad Crested Weir Broad crested weir flow rate calculations can be made with the equation, Q = 1.6 L H^1.5 if there is critical flow over the weir crest due to a minimum weir height. The broad crested weir is more robust than a sharp crested weir and is good for open channel flow measurement in natural channels.
Runoff Coefficients for Use in Rational Method Calculations Rational method runoff coefficient tables are provided in this article. Watershed runoff coefficients depend upon the land use, soil type and slope of the watershed. Runoff coefficients are needed to calculate storm water runoff rate using the Rational Method.
Excel Spreadsheets for Broad Crested Weir Flow Rate Calculations Broad crested weir flow rate calculations can be made with the Excel spreadsheets that can be downloaded from this article. The open channel flow rate can be found using a broad crested weir equation for critical flow over the weir, along with the minimum weir height needed for critical flow.
Open Channel Flow Measurement: Parshall Flumes Parshall flumes are one of several types of open channel flow measurement devices. The Parshall flume equations in this article are used for flow rate calculations with free flow conditions in the flume. See also, dimensions for Parshall flumes and conditions for free flow and submerged flow.