CSM CSM Urban Stormwater Systems & Infrastructure 2

Question 1

What is green infrastructure in the context of urban stormwater management?

Accepted Answer

An approach that uses natural processes and vegetation to manage stormwater at or near its source, mimicking the natural water cycle

Answer

Green infrastructure uses vegetated systems such as rain gardens, bioretention cells, and green roofs to infiltrate, evapotranspirate, or filter stormwater close to where rain falls, reducing runoff volume and improving water quality.

Question 2

What is a bioretention cell (also known as a rain garden) and what pollutants does it remove?

Accepted Answer

A landscaped depression filled with engineered soil and plants that filters stormwater, removing sediment, nutrients, heavy metals, and bacteria

Answer

Bioretention cells use a soil media-plant system to filter and infiltrate stormwater, removing suspended solids, excess nutrients, heavy metals, hydrocarbons, and pathogens through physical, chemical, and biological processes.

Question 3

How does permeable pavement reduce stormwater runoff compared to conventional pavement?

Accepted Answer

By allowing rainfall to infiltrate through the pavement surface into the subbase and underlying soil, reducing runoff volume and peak flow

Answer

Permeable pavement has an open pore structure that lets rainfall pass through to a stone storage bed below, where it infiltrates into native soils, significantly reducing surface runoff volume and peak discharge rates.

Question 4

What is the primary stormwater management function of a vegetated swale?

Accepted Answer

To convey stormwater runoff while slowing its velocity, promoting infiltration, and filtering pollutants through the vegetation and soil

Answer

Vegetated swales are shallow, grass-lined channels that slow runoff, allow infiltration into the soil, and filter suspended solids and nutrients through contact with vegetation and soil media.

Question 5

What is the purpose of a stormwater outfall structure in an urban drainage system?

Accepted Answer

To provide the controlled discharge point where the storm sewer system releases collected runoff to a receiving water body or channel

Answer

An outfall is the terminal structure of a storm sewer where collected stormwater is discharged to a receiving water body, stream, or other drainage feature under the authority of an NPDES permit.

(CSM) Certified Stormwater Manager Practice Test

(CSM) Certified Stormwater Manager Practice Test

CSM CSM Urban Stormwater Systems & Infrastructure 2