Every excavation job has a choice: mechanical (backhoe, mini-ex, shovel) or hydro (high-pressure water plus vacuum). Both work. Both are the wrong answer in the wrong situation. Here's how to decide.
Use hydro-excavation when
- You're within 24 inches of a known utility line - this is the OSHA best-practice zone
- You're daylighting to verify a locate before boring or trenching
- You're working around fiber, gas, or high-voltage where a strike is a five-figure incident
- The site is tight-access or landscape-sensitive and a machine would cause collateral damage
- Central Texas rock or clay makes mechanical digging slow anyway
Trenching still makes sense when
- You're in a green-field site with confirmed no-utility ground
- You need to move a large volume of soil and the utility risk is genuinely low
- The soil is well-suited to mechanical excavation (loose, dry sand or loam)
- Budget is tight and utility strike risk is genuinely zero
The real cost comparison
Hydro-excavation looks more expensive on paper - typically $250–$400 per hour with a 4-hour minimum. But factor in strike liability, damage to fiber or gas lines (which is on you, not 811), and the delay of a shutdown investigation, and hydro almost always wins the total-cost math on any dig near known utilities.