Site Assessment and Planning Flashcards

What is the purpose of delineating drainage areas on a site plan?

Answer: To determine the volume of runoff each BMP must handle

Delineating drainage areas allows designers to calculate runoff volumes so that BMPs can be appropriately sized to manage the stormwater from each contributing area.

A soil's NRCS Hydrologic Soil Group classification affects site planning because it indicates:

Answer: The soil's runoff potential and infiltration rate

NRCS Hydrologic Soil Groups (A through D) classify soils by their runoff potential and infiltration rates, which are critical for calculating stormwater volumes and selecting appropriate BMPs.

Which site feature should be identified on a site plan as a receiving water?

Answer: Any stream, lake, wetland, or storm drain that receives runoff from the site

Receiving waters are the streams, lakes, wetlands, or storm drains that ultimately receive runoff from the construction site, and their location determines BMP placement and level of protection required.

The term 'disturbed area' on a construction site refers to:

Answer: Any land area where vegetation, topsoil, or surface has been removed or altered

Disturbed area refers to any land where the vegetative cover, topsoil, or ground surface has been removed or altered, exposing soil to erosion.

What is a 'critical area' in erosion and sediment control planning?

Answer: A location with high erosion potential such as steep slopes, stream banks, or inlet areas

Critical areas are locations with heightened erosion potential such as steep slopes, erodible soils, stream banks, or concentrated flow paths, requiring enhanced or priority BMP installation.

How does impervious surface coverage affect stormwater runoff on a site?

Answer: It increases runoff volume and velocity by preventing infiltration

Impervious surfaces prevent rainfall from infiltrating into the soil, resulting in greater runoff volumes and faster flow velocities that can increase erosive potential.