H₂OCalc is an easy-to-use, stand-alone program designed as a hydraulic and hydrology (H&H) toolbox to assist civil, environmental and water resources engineers with solving complex hydraulic problems quickly and accurately. Its powerful and comprehensive modeling capabilities let engineers streamline the hydraulic analysis and design of pipes, pumps, open channels, weirs, orifices, culverts, and inlets. Calculations for both steady uniform flow and gradually varied flow are supported. The program also performs useful calculations for stormwater runoff and groundwater flow.

H₂OCalc can be effectively used to perform pressurized pipe calculations for pipe length, begin and end elevations, roughness coefficient, diameter as well as flow rate and pressure drop using the Hazen-Williams, Darcy-Weisbach, Manning, and Kutter headloss methods. The user can design and analyze channels, ditches, and free surface pipes of various shapes including circular, box, trapezoidal, triangular and irregular channels. Both steady uniform slow and gradually varied flow are supported. Under steady uniform flow, H₂OCalc solves for discharge, normal depth, channel dimensions, or slope. Gradually varied flow calculations for flow and depth are carried out using the direct step method and the standard step method.

With H₂OCalc, you can design and analyze grate, curb, ditch, slotted, and combination inlets using calculations based on the FHWA Hydraulic Engineering Circular No. 12 and Circular No. 22 methodologies. In sag or on grade conditions with a continuously or locally depressed gutter are supported and water spread and gutter depth for a gutter or pavement section are computed.

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You can also size various types of weirs considering discharge, weir coefficients, and crest, headwater and tailwater elevations including rectangular, v-notch, cipolletti, broad crested and generic. Weirs can be free flowing or submerged depending on the depth of tailwater elevation. Three types of orifice are also considered including circular, rectangular and generic.

H₂OCalc can perform surface water hydrology calculations for stormwater runoff using the rational method to determine peak discharge as well as various types of rainfall-runoff models including the Colorado Urban Hydrograph Procedure (CUHP), NRCS Dimensionless Unit Hydrograph, NRCS Triangular Unit Hydrograph, Delmarva Unit Hydrograph, Clark Unit Hydrograph, Snyder Unit Hydrograph, Santa Barbara Hydrograph (SBH), Espey Unit Hydrograph, and San Diego Modified Rational Hydrograph (SDMRH); groundwater flow calculations for steady flow in confined and unconfined aquifers; and well hydraulics calculations of confined and unconfined steady flows. Other calculations include transient flow in a pipeline, hydraulic jump, pump characteristic curve, specific speed, torque, power and inertia, parallel and series pump arrangements, head-flow relationship for flow regulating devices, discharge from an open or closed tank and equivalent pipe length.

The program can also perform complex hydraulic calculations for culverts such as determining the headwater elevation, hydraulic grade line, discharge and size. It uses the U.S. Federal Highway Administration (FHWA) Hydraulic Design of Highway Culverts (HDS-5) methodology for performing both inlet control and outlet control and overtopping calculations. Backwater and drawdown conditions, including hydraulic jumps, are considered. Free-surface, pressurized and transitional flow can be handled. Calculations apply for circular and rectangular culverts as well as for rectangular and trapezoidal stream channels. Simplified culvert equations that classify culverts into various categories depending on headwater and tailwater elevations, slope, size and other characteristics are also supported.

A unit converter is also provided to help you find the equivalent value of inputted parameters in different units. Conversion factors are available for length, area, volume, mass, density, velocity, acceleration, flow rate, temperature, force, pressure, energy and power.