CERTIFIED STORMWATER MANAGER (CSM)
QUESTIONS AND CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A |INSTANT
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1. What is the primary purpose of a stormwater management
system?
A. Generate hydroelectric power
B. Reduce flood risk and control runoff
C. Increase groundwater contamination
D. Promote urban heat islands
Correct Answer: B. Reduce flood risk and control runoff
Rationale: Stormwater management systems are designed to
manage runoff, prevent flooding, and improve water quality.
2. Which of the following is considered a best management
practice (BMP) for stormwater?
A. Pervious pavements
B. Detention basins
C. Rain gardens
D. All of the above
Correct Answer: D. All of the above
Rationale: BMPs are methods to control the quantity and
,improve the quality of stormwater. Pervious pavements,
detention basins, and rain gardens are all effective BMPs.
3. What is the main difference between a detention basin and
a retention basin?
A. Detention holds water permanently; retention drains quickly
B. Detention temporarily stores water; retention holds water
permanently
C. Retention discharges water to streets; detention infiltrates
D. They are exactly the same
Correct Answer: B. Detention temporarily stores water;
retention holds water permanently
Rationale: Detention basins temporarily store runoff and
release it slowly, while retention basins maintain a permanent
pool to improve water quality.
4. What does the term “impervious surface” refer to?
A. Soil that allows water infiltration
B. Surfaces like asphalt and concrete that prevent water
infiltration
C. Natural wetlands
D. Grass and landscaped areas
Correct Answer: B. Surfaces like asphalt and concrete that
prevent water infiltration
,Rationale: Impervious surfaces prevent rainwater from soaking
into the ground, increasing runoff volume.
5. Which pollutant is commonly associated with stormwater
runoff?
A. Sediment
B. Nutrients (Nitrogen, Phosphorus)
C. Heavy metals
D. All of the above
Correct Answer: D. All of the above
Rationale: Stormwater can carry sediment, nutrients, heavy
metals, and other pollutants into water bodies.
6. What is the function of a bioswale?
A. Channel stormwater and allow infiltration
B. Pump water into rivers
C. Prevent rainfall
D. Heat urban areas
Correct Answer: A. Channel stormwater and allow infiltration
Rationale: Bioswales are vegetated channels that slow runoff,
remove pollutants, and promote infiltration.
7. Which regulatory framework governs stormwater
management in the United States?
, A. Clean Water Act (CWA)
B. Safe Drinking Water Act (SDWA)
C. Resource Conservation and Recovery Act (RCRA)
D. Endangered Species Act (ESA)
Correct Answer: A. Clean Water Act (CWA)
Rationale: The CWA regulates discharges of pollutants to
waters of the United States, including stormwater.
8. What is the purpose of Low Impact Development (LID)?
A. Increase impervious surfaces
B. Mimic natural hydrology to reduce runoff and improve water
quality
C. Promote flooding in urban areas
D. Reduce air pollution
Correct Answer: B. Mimic natural hydrology to reduce runoff
and improve water quality
Rationale: LID techniques aim to manage stormwater close to
its source using natural processes.
9. Which of the following is a common method to treat
stormwater pollutants?
A. Sedimentation
B. Filtration
QUESTIONS AND CORRECT ANSWERS (VERIFIED
ANSWERS) PLUS RATIONALES 2026 Q&A |INSTANT
DOWNLOAD PDF
1. What is the primary purpose of a stormwater management
system?
A. Generate hydroelectric power
B. Reduce flood risk and control runoff
C. Increase groundwater contamination
D. Promote urban heat islands
Correct Answer: B. Reduce flood risk and control runoff
Rationale: Stormwater management systems are designed to
manage runoff, prevent flooding, and improve water quality.
2. Which of the following is considered a best management
practice (BMP) for stormwater?
A. Pervious pavements
B. Detention basins
C. Rain gardens
D. All of the above
Correct Answer: D. All of the above
Rationale: BMPs are methods to control the quantity and
,improve the quality of stormwater. Pervious pavements,
detention basins, and rain gardens are all effective BMPs.
3. What is the main difference between a detention basin and
a retention basin?
A. Detention holds water permanently; retention drains quickly
B. Detention temporarily stores water; retention holds water
permanently
C. Retention discharges water to streets; detention infiltrates
D. They are exactly the same
Correct Answer: B. Detention temporarily stores water;
retention holds water permanently
Rationale: Detention basins temporarily store runoff and
release it slowly, while retention basins maintain a permanent
pool to improve water quality.
4. What does the term “impervious surface” refer to?
A. Soil that allows water infiltration
B. Surfaces like asphalt and concrete that prevent water
infiltration
C. Natural wetlands
D. Grass and landscaped areas
Correct Answer: B. Surfaces like asphalt and concrete that
prevent water infiltration
,Rationale: Impervious surfaces prevent rainwater from soaking
into the ground, increasing runoff volume.
5. Which pollutant is commonly associated with stormwater
runoff?
A. Sediment
B. Nutrients (Nitrogen, Phosphorus)
C. Heavy metals
D. All of the above
Correct Answer: D. All of the above
Rationale: Stormwater can carry sediment, nutrients, heavy
metals, and other pollutants into water bodies.
6. What is the function of a bioswale?
A. Channel stormwater and allow infiltration
B. Pump water into rivers
C. Prevent rainfall
D. Heat urban areas
Correct Answer: A. Channel stormwater and allow infiltration
Rationale: Bioswales are vegetated channels that slow runoff,
remove pollutants, and promote infiltration.
7. Which regulatory framework governs stormwater
management in the United States?
, A. Clean Water Act (CWA)
B. Safe Drinking Water Act (SDWA)
C. Resource Conservation and Recovery Act (RCRA)
D. Endangered Species Act (ESA)
Correct Answer: A. Clean Water Act (CWA)
Rationale: The CWA regulates discharges of pollutants to
waters of the United States, including stormwater.
8. What is the purpose of Low Impact Development (LID)?
A. Increase impervious surfaces
B. Mimic natural hydrology to reduce runoff and improve water
quality
C. Promote flooding in urban areas
D. Reduce air pollution
Correct Answer: B. Mimic natural hydrology to reduce runoff
and improve water quality
Rationale: LID techniques aim to manage stormwater close to
its source using natural processes.
9. Which of the following is a common method to treat
stormwater pollutants?
A. Sedimentation
B. Filtration
