DrainageCalculators

Hydraulics Calculators

Calculate pipe flow, analyze open channels, and design drainage conveyance systems using Manning's equation and hydraulic principles.

12+ Calculators

About Hydraulic Analysis

Hydraulic calculators help you understand how water flows through pipes, channels, and drainage systems. These tools are essential for sizing conveyance infrastructure, ensuring adequate capacity, and preventing flooding.

Use these calculators to:

  • Calculate pipe flow capacity and velocity using Manning's equation
  • Determine normal depth and critical depth for open channels
  • Analyze flow regimes and classify flow as subcritical or supercritical
  • Design channel sections for maximum hydraulic efficiency
  • Calculate head losses at channel transitions and inlet structures
  • Size gutters, downspouts, and roadway drainage systems

Pipe Flow

Calculate flow capacity and velocity in closed conduits

Manning's Pipe Flow

Calculate pipe flow capacity and velocity using Manning's equation for circular pipes

Pipe Manning's

Open Channel Flow

Analyze flow in natural and constructed channels

Manning's Channel Flow

Calculate open channel flow capacity for trapezoidal, rectangular, and triangular sections

Channel Manning's

Critical Depth

Calculate critical depth for rectangular, trapezoidal, and circular channels

Critical Flow Energy

Normal Depth

Calculate normal depth for uniform flow using Manning's equation

Uniform Flow Normal

Froude Number

Classify flow regime as subcritical, critical, or supercritical

Flow Regime Classification

Gradually Varied Flow

Calculate water surface profiles using Standard Step Method

GVF Backwater

Channel Design

Design and optimize channel cross-sections

Best Hydraulic Section

Optimize channel dimensions for maximum hydraulic efficiency

Optimization Efficiency

Compound Channel

Analyze channels with overbank flow and floodplains

Floodplain Overbank

Channel Transitions

Calculate head losses and water surface changes at transitions

Transitions Head Loss

Channel Protection

Design erosion protection and channel linings

Channel Lining Design

Design flexible and rigid channel linings for erosion protection

Erosion Lining

Riprap Sizing

Calculate D50 stone size for channel and outlet protection

Riprap Stone Size

Roadway Drainage

Calculate gutter flow and roadway hydraulics

Gutter Flow

Calculate gutter capacity, spread width, and flow velocity

Roadway Gutter

Learning Resources

Understand the theory behind the calculations

Understanding Manning's Equation

How to apply V = (1.49/n) R^(2/3) S^(1/2)

Learn more: Understanding Manning's Equation

Open Channel Flow Basics

Uniform flow, critical depth, and flow classification

Learn more: Open Channel Flow Basics

Manning's n Values Reference

Comprehensive table of roughness coefficients

Learn more: Manning's n Values Reference

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