Tailing Dam Capacity Calculator

No -- these are rough planning estimates from simplified geometry (impoundment area times an assumed average depth and fill ratio), not a substitute for a licensed geotechnical or mining engineer's detailed capacity survey, which real tailings storage facility permitting requires. Use this calculator for early feasibility screening only, and have any figure used for permitting or facility raise planning verified by a qualified engineer against actual site survey data.

No -- it subtracts a flat, illustrative allowance from Dam Height and is not a substitute for an actual freeboard determination. Real tailings dam freeboard depends on site-specific flood routing (often the Probable Maximum Flood), wind-wave runup analysis tied to the impoundment's fetch length and local wind speeds, and the facility's hazard classification under applicable dam-safety regulations -- none of which this calculator has the inputs to compute. Never use Effective Height as a design or compliance freeboard figure.

Years of Capacity divides total Storage Capacity (a fixed figure determined by the dam's geometry and tailings density) by Annual Tailings production, so producing tailings faster fills the same storage volume sooner, shortening the facility's useful life at that production rate. This is why growing production volume without a corresponding facility raise or new impoundment shortens the runway before the next capacity decision is needed.

It uses standard trapezoidal cross-section geometry: the embankment's base width equals the crest width plus dam height multiplied by the sum of the upstream and downstream slope ratios (horizontal-to-vertical), and cross-sectional area is the average of crest and base width times dam height, extended along the full Dam Crest Length. Since Upstream Slope Ratio is expressed as horizontal-to-vertical, a SMALLER ratio number means a steeper slope, which reduces how far the embankment's base extends horizontally and therefore reduces Embankment Volume -- but steeper slopes also reduce the embankment's stability margin, which is exactly the kind of tradeoff a geotechnical stability analysis, not this calculator, needs to evaluate before a slope ratio is finalized. This captures the basic embankment shape but not internal zoning (core, filter, and shell materials) that a real embankment design includes.

Water Volume is not an independent 30% slice of Storage Volume -- reusing the same total volume that way would double-count space Storage Tonnes already claims via Tailings Density. Instead, the calculator converts Storage Tonnes back into a solids' particle volume using a typical mineral-tailings solids specific gravity (2.7 t/m3) and reports whatever volume is left over as Water Volume, assuming freshly deposited slurry tailings are fully saturated (their void space is water-filled) before any drainage or consolidation reduces it. A denser Tailings Density input therefore shrinks Water Volume, since more of the same Storage Volume is implied to be packed with solids rather than sitting as void water.