The short answer
A small ranch tank — say an eighth to a quarter acre of surface, 8–10 feet at the deep end — typically runs $3,000–$8,000 in the Valley depending on yardage, access and what happens to the spoils. Bigger or deeper ponds climb from there, and haul-off instead of spreading spoils on site can add thousands. The real number is a walked quote.
What drives the price
- Cubic yards moved — the tank is priced by the dirt that comes out of it. Doubling the surface area or adding depth multiplies yardage fast.
- What happens to the spoils — spreading or berming the dirt on your own land is cheapest. Trucking it off site means loaders, trucks and dump fees.
- Access and mobilization — an open ranch gate and firm ground is one price; soft ground, tight access or a long walk-in adds machine time.
- Soil and water table — Valley clay digs clean and holds water; hit sand or shallow water and the job changes.
- Drainage and floodplain rules — a tank that ties into a drainage ditch or sits in a mapped flood zone can need county sign-off. We flag it during the quote.
Will it hold water?
Most of the time in the Valley, yes — the same expansive clay that causes slab problems is exactly what you want lining a tank. If the site digs into sandier material, the fix is usually a compacted clay liner: clay spread on the bottom and sides and packed in lifts. A test hole before the full dig tells you what you're working with, and it's cheap insurance on a bigger pond.
Shape matters more than people think
A good tank isn't just a hole. Side slopes need to be gentle enough not to cave or gully — flatter where livestock walk in to drink. The deep end carries the tank through the dry months, because a shallow pan loses water to evaporation faster than the Valley sun can be argued with. And the spoil pile should become something useful: a berm on the low side, pad fill, or a windbreak base — that's free material you already paid to dig.
When to dig one
Dry season is dig season. A dry excavation goes faster, cuts cleaner walls, compacts better if a liner is needed, and doesn't fight groundwater. If you want the tank catching water by the fall rains, the time to dig it is the summer before — not the week the forecast turns.
Thinking about a tank?
Tell us roughly where the site is and what the tank is for — livestock, drainage, or just the look of water on the place — and we'll walk it, check the soil, and put a firm price on paper. Stock tank work lives under our trenching & excavation service.