Stormwater Management Practices Flashcards
7 cards from real CESSWI practice questions. Tap to flip, then mark Knew It or Still Learning — missed cards come back until you master them.
Read the first 7 Stormwater Management Practices flashcards as text
Which soil hydrologic group has the highest infiltration rates and is best suited for infiltration-based stormwater BMPs?
Answer: Group A
HSG A soils (deep sands, well-drained gravels) have the lowest runoff potential and highest infiltration rates, making them ideal for infiltration trenches, basins, and permeable pavement.
A stormwater inspector finds that the emergency spillway of a detention pond has been blocked by debris. What is the primary risk this creates?
Answer: Potential for dam overtopping and embankment failure during extreme storms
The emergency spillway protects the embankment from overtopping; if blocked, flows exceeding the principal outlet capacity could overtop and rapidly erode the embankment, leading to failure.
Green roofs reduce stormwater runoff volume primarily by:
Answer: Retaining rainfall in growing media and releasing it through evapotranspiration
Green roof growing media absorb rainfall and plants release stored water through evapotranspiration, significantly reducing the volume and peak rate of runoff from rooftops.
What design feature of a wet detention pond prevents short-circuiting of flow from inlet to outlet?
Answer: Placement of inlet and outlet at opposite ends with a minimum 3:1 length-to-width ratio
Separating the inlet and outlet at opposite ends and maintaining a 3:1 or greater length-to-width ratio maximizes flow path length, promoting settling and reducing short-circuit pathways.
When performing a post-construction stormwater inspection, which document should the inspector reference to verify that BMPs were installed as approved?
Answer: The approved stormwater management plan and construction drawings
The approved stormwater management plan and associated construction drawings define the required BMP types, sizes, locations, and specifications that the inspector verifies against field conditions.
Which pollutant is most effectively removed from stormwater by a vegetated filter strip?
Answer: Coarse sediment and associated particulate pollutants
Vegetated filter strips excel at removing coarse sediment through deposition and filtration as sheet flow passes through dense vegetation, along with particulate-bound pollutants.
The concept of 'channel protection volume' in stormwater management addresses which specific problem?
Answer: Preventing streambank erosion caused by increased frequency of bankfull flows in urbanized watersheds
Urbanization increases the frequency and duration of channel-forming flows; channel protection volume controls are designed to reduce the frequency of bankfull events that cause streambank erosion.