Reduce uncertainty in reservoir water loss estimates. Enter geometry, soil data, and liner performance assumptions. See seepage flow, drawdown depth, and export reports instantly.
Estimate reservoir seepage losses with proven hydraulic methods. Account for liners, temperature, and changing wetted areas. Export daily, monthly, and annual results for planning teams.
| Scenario | Method | Wetted Area (m²) | k (m/s) | i (–) | Liner (%) | Estimated Loss (m³/day) |
|---|---|---|---|---|---|---|
| Unlined clayey base | Darcy | 8,000 | 0.0000002 | 0.3 | 0 | 4.15 |
| Compacted fill with liner | Darcy | 8,000 | 0.0000010 | 0.5 | 90 | 3.46 |
| Measured seepage rate | Empirical | 8,000 | — | — | 0 | 40.00 |
Values are illustrative for demonstration. Field conditions can vary widely, so validate inputs with site tests and monitoring records.
Darcy seepage flow:
Computed gradient option:
Empirical seepage-rate option:
Liner impact:
Seepage is controlled by soil permeability, hydraulic gradient, and the extent of wetted contact. Higher head, coarse foundations, and unsealed joints increase losses. This calculator converts those drivers into measurable discharge and equivalent surface drawdown for routine reporting.
Use the Darcy options when you have conductivity and gradient information from tests, design reports, or calibrated models. The computed-gradient option is useful when a head difference and an assumed seepage path are known. Use the empirical option when seepage is observed as a depth loss rate.
Wetted area equals the bottom area plus the submerged side area, which can be measured from drawings or estimated from simple shapes. For early-stage planning, rectangular or circular approximations provide quick values. For irregular basins, manual areas remain the most dependable approach.
Daily loss (m³/day) supports water-balance checks and pumping schedules, while L/s is convenient for comparing with inflow or leakage monitoring. Surface drawdown (mm/day) highlights how losses translate into level changes. Apply liner reduction to represent geomembranes, clay blankets, or grout curtains.
Pair calculations with level sensors, inflow meters, and evaporation estimates to isolate seepage. Reconcile predicted losses against observed storage change during stable weather and low withdrawals. If results drift, update conductivity assumptions, revise wetted areas for seasonal pool elevation, and document liner condition.
For Darcy inputs, keep units consistent and representative of saturated conditions. As a check, k=1×10-6 m/s, i=0.3, and A=10,000 m² gives Q≈0.003 m³/s before liner reduction. Because k and i can vary by an order of magnitude, document every assumption in the exported report.
Improve confidence by comparing predicted daily loss with level trends during inflow and low withdrawals. If observations disagree, refine wetted areas for seasonal pool elevation, reassess seepage path length, and inspect liners, joints, and penetrations for defects.
1) What wetted area should I use?
Use the submerged bottom area plus the wetted side area. For irregular basins, measure areas from drawings or surveys. Geometry approximations are acceptable for early planning, then refine later.
2) When should I choose the empirical option?
Choose it when seepage is observed as a depth or volume loss rate, such as mm/day from monitoring. It is also useful when soil properties are unknown but historical performance exists.
3) What does liner reduction represent?
It represents the expected reduction in seepage from liners or treatments. Enter a percentage reduction relative to the unlined condition. Validate reductions with inspections, leak detection, and performance monitoring.
4) Why does temperature correction change results?
Water viscosity decreases at higher temperature, which can increase flow through pores for the same gradient. The correction adjusts conductivity using a simplified viscosity ratio, so treat it as an approximation and verify with site data.
5) How do I estimate hydraulic gradient?
Use i = Δh/Lp if a head difference and seepage path length are known. If using a direct gradient, base it on geotechnical assessment of flow paths, stratigraphy, and boundary conditions.
6) Is this suitable for final design?
It is best for screening, planning, and reporting. Final design should rely on detailed site investigations, seepage modeling, and local standards. Use monitoring to calibrate k, gradients, and liner performance.
Important Note: All the Calculators listed in this site are for educational purpose only and we do not guarentee the accuracy of results. Please do consult with other sources as well.