The EnDrain computer program calculates the
drainage discharge, hydraulic head, or spacing
between parallel subsurface (sub-surface) drains:
pipe/tile drains or open ditches, with or without
entrance resistance and shows the curve of the
The computations are needed
for the design of subsurface drainage systems
of rainfed or irrigated agricultural land for
waterlogging (water logging), watertable
(water table) and soil salinity control.
EnDrain can be used for the
reclamation (remediation, rehabilitation,
restoration) of saline (salty) soils.
The simulation software is free for download. It
can be called shareware (freeware) and is in
The drainage equation used is an amplified
version of Hooghoudt's equation.
The drain spacing
calculations are based on the
concept of the energy balance of groundwater
(ground-water) flow. However, the traditional
concepts based on the Darcy and waterbalance
(water balance, budget) or mass conservation
equations are also used.
The program allows for the
presence of three different soil layers with
different hydraulic conductivity and
one layer above and two below drain level. The
last two layers can also have different
horizontal and vertical hydraulic conductivity or
Examples are given.
On 21 May 2012 the auxiliary Fortran programs of
the EnDrain model were eliminated and the
contents were integrated into the Delphi program.
The program starts clicking on EnDrain.Exe.
More information is given in the program itself.
On 10 August 2010 the program was improved thanks
to comments of Nicolas Deeks.
On 14 June 2011 the user interface was improved
thanks to a request of Robin Johnston.
On 17 May 2012 the EnDrain program was improved
thanks to suggestions by Pepe del Monte.
On 30 June 2017 the input menu was given a
Help-Recharge function at a comment of
Publications on the physical and mathematical
theory of the energy balance of groundwater
(ground-water) flow and examples of EnDrain
applications are found on the
articles page or
directly as PDF
A list of publications using EnDrain is found on
A comparison of required drain and well spacings
for horizontal resp. vertical drainage under the
same conditions can be seen in the
When it is required to sumulate the drain discharge
as a function of time, given a time sequence of
rainfalls of irrigation applications, use can be
made of the hydrological runoff model
RainOff. It gives an
example of drain discharge simulation in the
"Data" file. The drainage system is to be
characterised by a response function (or reaction
factor) alpha = A * runoff + B, as can be seen
using the option "Predict discharge or runoff
from rainfall given the alpha function" in the
See the example in the last figure hereunder.
The RainOff program gives also a time series of
hydraulic heads (water levels) in the output file.
These data can be used to depict the fluctuation
of the level of the water table with time.
For improvement, I am interested to learn about
your experiences with EnDrain. For this there is
a contact form.