What is Hydro Excavation, and How Does It Work?

What is Hydro Excavation, and How Does It Work?

Commonly referred to as vacuum excavation, hydro excavation is a process of soil removal through the use of pressurized water. Unlike the old-school way of digging deep into the ground, a vacuum system extracts the mixture of water and soil (slurry) from the ground much faster. 

How Hydro Excavation Works

Hydro excavation services typically involve using specially designed machinery to perform the job. Here is a list of crucial equipment needed;

  • A water tank to hold hundreds of liters of clean water. The water will be delivered into the soil at high pressure. 
  • An electric pump system to boost the water’s pressure into a desirable psi that can cut through compacted soil and dirt.
  • A boom with suction hoses. Its function is to bring the slurry from the ground into the truck’s storage tank. 
  • A vacuum blower generates the suction at the boom.
  • A debris tank to hold slurry from the ground.
  • Some models may require a boiler to heat the water before pressurization, especially on frozen ground. 

The Process

During hydro excavation services, the operator administers the pressurized water onto the targeted area. The jet effortlessly goes through the topsoil or grass and loosens the soil in the area. As water goes deeper, it mixes with the soil to form a thick substance known as slurry.

Another operator draws away from the loosened soil and water through the boom connected to vacuum horses. The more slurry is removed, the deeper the water jet loosens more soil until it reaches the desired depth. These two processes continue simultaneously until the size and depth of the hole are accomplished. 

Once the process is complete, the hydro-vac trailer or truck is taken to a designated dumping site where the slurry is deposited. The tank is cleaned and prepared for other hydro excavation services.

Applications of Hydrovac

Hydro excavation is used in several applications as it comes with a bunch of benefits, such as minimal damage, accuracy, and time consciousness. It is also the best excavation process to use during winter when the ground is frozen. Typical applications that use hydro excavation include;

  • Slot trenching: basically digging narrow ditches for pipes and cable installations.
  • Daylighting: involves extracting dirt layers from utility services like cables and service lines to give way for inspection, maintenance, and repair.
  • Residential excavation, where the soil is removed on a particular area to a suitable depth for the purpose of installing signs, poles, posts, and pilings for structure support.
  • It can also be used to perform other industrial and rehabilitation applications such as debris removal, landscaping, potholing, and sewer inspection. 


Hydro excavation services are one of the logical ways to remove soil and dirt from the ground in an efficient manner. Its quick process ensures the project is done on time. You’re also less likely to damage structures and service lines compared to traditional digging. You need to contact a reliable hydro-vac company, and they’ll assess the area before the process begins.