Design rule purpose

The purpose of this design rule is to ensure that water pipeline options generated or evaluated by Optioneer satisfy minimum (and maximum) cover criteria. Pipes are buried for protection and cover limits exist to ensure that the protection is sufficient.

Maximum cover is optional but practical as very deep trench construction would increase construction costs significantly.

How to configure

This design rule is fairly simple to configure. It works with conjunction with a design rule which calculates installation costs (primarily earthworks, in case of water design rules). The longitudinal profile for water pipelines is different than other assets as it has to maintain minimum gradients and resembles a 'sawtooth'. This means that staying at the minimum required cover isn't possible. This design rule employs the same costing logic as outlined in the general installation design rule but allows for a variable depth.

Terrain elevation is sampled at typical 'sampling points' along the option chainage. The depth at these points is sampled with respect to terrain elevation at point. The sampling points are usually separated by circa. 30 meters.

Minimum cover is defined with respect to the top of the pipe.

Maximum cover is defined with respect to the bottom of the pipe.

A feasible vertical profile fits between the two limits and in practice, almost always tries to stay as close to minimum cover as possible, to minimize construction costs.

Important notes

  • Sampling resolution in an area where there is a high variation of terrain height might lead to counterintuitive results. This is usually due to quality of the data. Areas around crossings of existing infrastructure (such as roads or railways) is particularly challenging as terrain elevation might differ by a few meters across a relatively short (horizontal) distance.

Input / output summary

Input parameters


Default value


Minimum cover required



Maximum cover allowed



Output parameters


Example value


Cover depth at every point along the route

[0.94, 0.99 ... 1.21, 1.34]

plotted on Vertical Profile Chart

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