What discharge coefficient does an ogee spillway have?

Ogee spillway designed for design head H_d has C ≈ 2.0-2.2 (SI units). At lower heads C decreases; at higher heads C increases slightly. Broad-crested weir C ≈ 1.7.

What is PMF and why does it matter for spillway design?

Probable Maximum Flood (PMF) is the largest flood that could conceivably occur. Most dams require spillways to safely pass PMF without overtopping. Failure to do so can cause dam break and catastrophic flooding.

How is crest elevation determined for a gated spillway?

Gated spillway crest is typically at or below normal reservoir level. Gate height determines capacity. Gates allow better reservoir level control than ungated spillways.

Spillway Capacity Calculator

Calculate spillway discharge Q = C·L·H^1.5 for broad-crested and ogee spillways. Discharge coefficients C = 1.7-2.1. Determine spillway sizing for Probable Maximum Flood (PMF) and dam safety.

2D stress state at a point. All stresses in MPa.

σx — Normal Stress X (MPa)

σy — Normal Stress Y (MPa)

τxy — Shear Stress (MPa)

⚙ Mechanical Note: Results are based on standard textbook formulas and ISO/AASHTO references. Always verify critical designs with applicable codes (ISO 898, AASHTO 1993, AISC, Eurocode 3) and a qualified engineer.

How to Use

Enter the values for the patient or scenario you are assessing. Calculate spillway discharge Q = C·L·H^1.5 for broad-crested and ogee spillways. Discharge coefficients C = 1.7-2.1. Determine spillway sizing for Probable Maximum Flood (PMF) and dam safety. Use the spillway capacity result to inform your clinical assessment.

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Frequently Asked Questions

What discharge coefficient does an ogee spillway have?

What is PMF and why does it matter for spillway design?

How is crest elevation determined for a gated spillway?