Every building sits on land that rain hits. How that rainwater moves across the site, where it collects, and how it leaves the property are questions that construction documents must answer with precision. Stormwater and grading documentation translates three-dimensional terrain and drainage strategies into two-dimensional drawings that contractors can build from and reviewers can verify.

For PDD, this topic sits under Objective 2.2, where NCARB expects you to evaluate the documentation of site features and coordinate with civil engineers and setting architects. You won't be designing the drainage system from scratch on the exam. Instead, you'll analyze whether documentation accurately represents grading, drainage paths, and stormwater controls. Can you look at contour lines and tell if water flows toward or away from a building? Can you identify when a retention basin is undersized relative to the impervious area it serves? Can you spot a coordination gap between the civil grading plan and the architectural site plan?

The documentation toolkit includes contour lines showing existing and proposed grades, spot elevations at critical points like building corners and catch basins, flow arrows indicating drainage direction, and symbols for BMPs like bioretention areas, permeable pavement, and rain gardens. Getting any of these wrong creates real problems: flooded basements, eroded slopes, polluted waterways, and regulatory violations.