Conventional Method 

Underground work is done for a reason, for laying utilities like wirings and pipe beneath the ground so that it does not clutter up the space above. Usually trenches are dug using conventional methods like a crane, shovels and pickaxes. But these methods are non-controllable, meaning that if something already exists under the ground, chances are, you will be breaking that apart or damaging it using the conventional means. Unless that is the plan you are digging the trench or hole with, you would want to avoid that thing at any cost. Usually utility pipes and wires lay beneath the ground which are not suitable for the usual shovel digging. For it you need something that will not only be able to dig out the whole affair without using force, but also be able to keep whatever is underneath the ground intact. That is where non destructive excavation in Melbourne method comes in, which does not involve damaging anything under the ground. 

Benefit of Non Destructive Digging 

While it does require machines to do, it is the by far the safest method of digging available which is actually cost effective. If we talk about shovel or crane digging, you will be doing more damage not only to the surroundings but also will be damaging what is underneath the ground. Not to mention if you can hire a crane in the first place you can also hire services for non destructive digging and get yourself a clean, damage free hole or trench in which you need to work on. 

Methodology 

This method uses high water pressure for breaking dirt apart, which if you think about it is quite a concept. Since the dirt washes away and softens up with water, it is easier to navigate through, then a high powered vacuum is used to clean out the mud, dirt and stone out of the trench. This way whatever is already underground, stays underground, without being damaged in the slightest. This also helps the environment as well with a clean and efficient digging. 

Cost Effectiveness 

Non destructive digging is cost efficient because if you end up damaging whatever lies underneath the ground, you will have to repair it or you might get fined for destroying public property. And if that is a conduit you had installed to pass electrical wires or even more expensive fibre, you are going to end up paying way more than you would have on the advanced method of digging without force. The repair cost along with replacement costs of that conduit and the wires inside would become a headache. Not to mention the risks of breaking electrical wires might include shorting the whole connection. 

So in case you are wondering what will be more expensive, non destructive digging or conventional method digging, you know your answer.