(D)AMP // TR-55 Visual (Simple)

Screening hydrograph from CN + Tc. Numbers are only as good as your assumptions. STATUS: ONLINE

MODE: US Customary (mi², inches, hours, cfs)

Drainage Area (acres)

Curve Number (CN)

Time of Concentration Tc (hours)

Storm Depth P (inches)

Excess Duration D (hours)

Note: TR-55 uses a dimensionless unit hydrograph concept. Here we use a common symmetric approximation for visualization.

Not for permitting/construction without PE review and a full hydrology + hydraulics workflow.

What you’re seeing: Runoff depth Q from SCS CN, then peak flow Qp from TR-55 peak equation (Qp = 484·A·Q/Tp) using Tlag = 0.6·Tc and Tp = D/2 + Tlag. Hydrograph shape is scaled from a dimensionless UH curve.