Skip to main content
Calcimator

Groundwater Flow (Darcy's Law)

Calculate groundwater flow rate using Darcy's Law from hydraulic conductivity, hydraulic gradient, and cross-sectional area.

Inputs

Results

Flow Rate (Q)

10 m³/day

Flow Rate

10,000 L/day

Flow Rate3,650 m³/year
Darcy Velocity (q)0.1 m/day
Seepage Velocity (n=0.3)0.33333 m/day
Flow Rate Per Day10%
How to Use This Calculator
  1. Enter the Hydraulic Conductivity K in m/day for the aquifer material being analyzed.
  2. Enter the Hydraulic Gradient (i) — the change in head divided by the flow distance.
  3. Enter the Cross-Section Area in m² through which groundwater flows.
  4. Review Flow Rate Q in m³/day and liters/day as the primary Darcy flux output.
  5. Check Darcy Velocity and Seepage Velocity (assuming 30% porosity) for contaminant transport analysis.

How the result changes with Hydraulic Conductivity K (m/day)

Hydraulic Conductivity K (m/day)Flow Rate (Q)Flow Rate
1,0001,000 m³/day1,000,000 L/day
3,5003,500 m³/day3,500,000 L/day
6,5006,500 m³/day6,500,000 L/day
9,0009,000 m³/day9,000,000 L/day

What each input means

Hydraulic Conductivity K (m/day)
Hydraulic conductivity in m/day. Gravel: 100–1000, Sand: 1–100, Silt: 0.001–0.1, Clay: <0.001.
Hydraulic Gradient (i)
Dimensionless ratio of head difference to distance (dh/dl). Typical values: 0.001–0.1.
Cross-Section Area (m²)
Cross-sectional area of the aquifer perpendicular to flow direction in square meters.

How this is calculated

Formula

Q = K × i × A

Worked example, using the default values

  1. Identify Input Parameters
    Hydraulic Conductivity K (m/day) = 10, Hydraulic Gradient (i) = 0.01, Cross-Section Area (m²) = 100 = 3 input(s) provided
  2. Calculate Flow Rate
    Flow Rate
    10 = 10
  3. Calculate Flow Rate
    Flow Rate
    10000 = 10000
  4. Calculate Flow Rate
    Flow Rate
    3650 = 3650
  5. Calculate Darcy Velocity
    Darcy Velocity
    0.1 = 0.1

Related Calculators

The questions that sit next to this one — chosen by subject, including calculators filed under a different category.

Geology

Well Drawdown Calculator

Calculate well drawdown using the Theis/Cooper-Jacob equation from pump rate, transmissivity, storage coefficient, time, and distance.

Geology

Sediment Transport Calculator

Calculate bedload transport rate, shear stress, and transport mode from stream velocity, grain size, water depth, and slope.

Remediation

Groundwater Treatment Calculator

Size a pump-and-treat system from plume dimensions, aquifer properties, and cleanup targets.

Hydrology

Groundwater Recharge

Estimate annual groundwater recharge from precipitation, runoff coefficient, and evapotranspiration using the water balance method.

Geology

Geologic Time Scale Calculator

Look up the geologic period, era, and eon for any age in millions of years ago (Ma) using the international geologic time scale.

More in Science & Physics.