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.