Basin Routing

One of a detention basin's functions is to reduce the total volume of water that gets downstream.

• True

• False

Which type of basin does not see the entire inflow hydrograph pass through it?

• Flow-By

• Flow-Through

• Retention Basin

• Debris Basin

What might the outflow hydrograph look like? Draw it on the graph.

So the inflow hydrograph has been routed through the detention basin - what has changed? (multiple answers may be correct)

• the volume of water ultimately getting downstream is reduced

• the time the peak flow of the storm occurs is delayed

• the peak flowrate coming out of the basin is reduced

• the storm duration is longer than it was before

To perform basin routing calculations, what information do you need to have?

• the basin geometry

• the size of the outlet

• the size of the inlet

• the inflow hydrograph

• the size of the downstream receiving system

Shade in the area under the curve that represents the volume storage of the basin.

We use the _____ calculation method for basin routing.

Subcritical flows have an upstream (inlet) control.

• True

• False

Which statements are true?
Critical Depth Control is an Outlet Control
Orifice Control is an Inlet Control
Friction Control is an Outlet Control

• A & B

• A & C

• B & C

• A, B, & C

If the tailwater elevation is above the pipe soffit at the outlet, what is type of control affects the outflow?

• Critical Depth Control

• Orifice Control

• Friction Control

• Remote Control