Civil Engineering PE Environmental Engineering and Stormwater Management

Question 1

In the rational method Q = CiA, the variable i represents:

Accepted Answer

Rainfall intensity for a storm duration equal to the time of concentration

Answer

In Q = CiA, i is the design rainfall intensity (in/hr) corresponding to the time of concentration and the selected return period storm.

Question 2

The NRCS Curve Number (CN) method estimates:

Accepted Answer

Direct runoff depth from storm rainfall depth

Answer

The CN method calculates direct runoff Q from rainfall P using Q = (P − 0.2S)²/(P + 0.8S), where S is the potential maximum retention based on CN.

Question 3

Time of concentration (Tc) for a watershed is defined as:

Accepted Answer

Travel time from the hydraulically most remote point to the outlet

Answer

Tc is the travel time of runoff from the farthest point in the drainage area to the outlet, and it governs the critical storm duration for design.

Question 4

A dry detention basin is designed primarily to:

Accepted Answer

Attenuate peak flows by temporarily storing runoff

Answer

Dry detention basins temporarily store excess runoff to reduce peak discharge rates, releasing water through a controlled outlet after the storm passes.

Question 5

A typical Manning's roughness coefficient (n) for a natural earthen channel is:

Accepted Answer

0.025–0.035

Answer

Natural earthen channels have n ≈ 0.025–0.035, considerably higher than smooth concrete linings (n ≈ 0.012–0.015).

Civil Engineering PE Practice Test

Civil Engineering PE Practice Test

Civil Engineering PE Environmental Engineering and Stormwater Management