CPII Drainage & Stormwater Management

Question 1

What is the primary purpose of a stormwater detention basin in a public infrastructure project?

Accepted Answer

To temporarily hold stormwater runoff and release it at a controlled rate

Answer

Detention basins temporarily hold stormwater runoff and release it at a controlled rate to prevent downstream flooding.

Question 2

According to standard drainage design, what does the term 'return period' or 'recurrence interval' refer to?

Accepted Answer

The frequency with which a given storm event is statistically expected to occur

Answer

Return period (recurrence interval) expresses the statistical probability that a storm of a given magnitude will occur in any given year.

Question 3

When inspecting a culvert, which condition is considered the most structurally critical defect?

Accepted Answer

Joint separation or cracking at the crown

Answer

Joint separation or cracking at the crown indicates structural failure that can lead to collapse and loss of hydraulic capacity.

Question 4

What is the minimum slope typically recommended for concrete-lined drainage channels to maintain self-cleaning velocities?

Accepted Answer

0.5%

Answer

A minimum slope of 0.5% is typically required in concrete-lined channels to achieve the minimum velocity needed to prevent sediment deposition.

Question 5

Which federal regulation primarily governs stormwater discharges from construction sites disturbing one or more acres?

Accepted Answer

NPDES Construction General Permit under the Clean Water Act

Answer

The NPDES Construction General Permit issued under the Clean Water Act requires stormwater pollution prevention plans for construction sites disturbing one or more acres.

(CPII) Certified Public Infrastructure Inspector Practice Test

(CPII) Certified Public Infrastructure Inspector Practice Test

CPII Drainage & Stormwater Management