# Calculators

by Glenn M. Duffield, President, HydroSOLVE, Inc.

### Nonleaky Confined Aquifer

Compute well function or drawdown under transient conditions using the **Theis Equation**.

Compute transmissivity of a nonleaky confined aquifer under steady-state conditions using the **Thiem Equation**.

### Unconfined Aquifer

Compute drawdown around a pumping well in an unconfined aquifer using the **Theis Equation** and Jacob's correction for partial dewatering.

Compute transmissivity of an unconfined aquifer under steady-state conditions using the **Thiem Equation** with Jacob's correction for partial dewatering.

### Radius of Influence

Compute the radius of influence for a pumping well in a nonleaky confined aquifer.

### Specific Capacity to Transmissivity Conversion

Estimate the transmissivity of an aquifer from the specific capacity of a well using an exact or approximate formula.

### Groundwater Mounding

Compute the maximum height of the water table beneath a circular or rectangular recharge area.