Mitigating Corrosion Under Insulation and Supporting the Longevity of Industrial Pipe Insulating Systems

# Water Transmissibility

Last updated: July 19, 2024

## What Does Water Transmissibility Mean?

Water transmissibility is the rate of water flow measured in gallons per day from a foot long aquifer vertical strip that extends to the full height of the aquifer under a 100% hydraulic gradient. A 100% hydraulic gradient is equal to a one foot drop in height per one-foot of flow distance.

Water transmissibility is expressed in terms of the coefficient of transmissibility.

## Corrosionpedia Explains Water Transmissibility

Water transmissibility is a property of aquifer water transmission. It is expressed by the formula:

T = Ky

where:

T = water transmissibility

y = aquifer thickness

K = hydraulic conductivity

Since water transmissibility is also expressed in terms of the coefficient of transmissibility, the Thiem method is used to determine the coefficient of transmissibility. The storage of water bearing material is based on the rate of discharge of a pumped well and the amount of drawdown in two or more observation wells at known distances from the pumped well. Per the Thiem method, transmissibility is expressed:

T = (527.7 x Q x log (r2/r1)) / (s1 – s2)

where:

Q = discharge rate

r1 and r2 = distance from the pumped well of two observation wells

s1 and s2 = drawdowns of water level at distances r1 and r2