Why The Capacity of Your Hydrovac Matters

Why the capacity of your hydrovac matters

Not all hydrovac trucks are created equal, and yes, capacity plays a significant role (pun intended). But it's not just about the size or horsepower. 

There are many factors to consider when deciding on hydrovac capacity, and luckily, we’ve put together a list so you don’t have to think too hard. 

Size matters more than you think

What is one of the most crucial factors that can make or break your jobsite? Tank size. From water capacity to debris storage, the volume your truck can handle directly impacts how long you can run, how often you need to dump, and whether you’re finishing the job on time or scrambling to keep up. If you're regularly filling up before noon, it's maybe time to reassess your tank specs.

If you're working in cold climates, smaller tanks may be more prone to freezing without heated components or insulation. Frozen lines or tanks can bring work to a halt fast, so it’s worth factoring in how temperature could affect both storage and excavation performance.

Longer run times, fewer interruptions

If your hydrovac tank is too small, you’ll spend more time leaving the site to dump spoils or refill water than actually digging. Every trip off-site cuts into your productivity and crew hours, which adds up quickly during hydrovac excavation work when time is not on your side. 

A larger debris or water tank means you can keep working longer between stops, which adds up quickly in terms of jobsite efficiency. For reference, a debris tank in the 10–12-yard range usually pairs with a 1,000–1,200 gallon water tank and is a suitable choice for full-day excavation work, eliminating the need for extra trips for refills.

Match the truck to the job

Think fiber optic line installs, sidewalk panel replacements, or signpost excavations; the jobs where maneuverability matters more than maximum storage. But if you're handling pipeline work, utility repairs, or large-scale excavations, running a low-capacity hydrovac is like showing up to a buffet with only one plate available. 

Consider the volume of spoilage you'll remove in a day, as well as the associated costs and downtime of dumping mid-shift. For residential or tight urban work, a 6–8-yard tank may be ideal. Larger jobs may require 12 yards or more, plus onboard water capacity exceeding 1,000 gallons.

Must meet the legal limit

The size of your hydrovac tank isn’t just a matter of convenience. Staying within limits means staying on the right side of the law. Bigger tanks can mean heavier loads, and if you’re not paying attention to road weight limits, you could be looking at fines or something more serious. Repeated violations can result in license penalties or even disqualify companies from participating in certain bids; not worth the risk, we say.

That’s why some crews stick with trucks built for better balance or spec theirs with reinforced axles to handle extra weight without crossing the line. You can use a scale ticket or axle-load calculator before heading out. It's a quick way to avoid surprise DOT stops.

Fewer breaks, faster digs

Smaller tanks often mean more trips, more engine hours, and more wear. More trips also mean more wear on brakes, suspension, and hydraulic systems. Pushing smaller trucks to do big-job work can increase the chances of mechanical failure on-site or in transit. When you leave the site to dump or refill, you're burning fuel and putting extra hours on your engine. Do that too many times, and the wear starts to show. Overworked trucks are more prone to mechanical issues, which can compromise crew safety and jeopardize job timelines.

Sure, a bigger tank might come with a steeper price tag, but if your crew’s out there day for extended periods, it’s a tradeoff that’s worth considering. 

Future-proof your fleet

Even if your current projects don’t require maximum capacity, buying a higher-capacity hydrovac now gives you room to grow. Jobs evolve. Contracts scale. And no one wants to replace a truck just because the tank’s too small a year down the line. Choosing a size that fits today and tomorrow helps you stay ready for whatever project is next.

Looking for the right capacity?

Check out Summit Truck Equipment’s hydrovac truck inventory and find a model that fits your jobs, your crew, and budget. And if you're planning to upgrade, check out our hydrovac financing guide to explore flexible payment options.