Diligence · Glossary
Drainage
Updated 2026-07-20
Drainage is how water moves across and off a site. Even outside FEMA SFHAs, local drainage, creeks, and concentrated runoff can constrain building pads.
What it means
Drainage is how water moves across and off a site. Even outside FEMA SFHAs, local drainage, creeks, and concentrated runoff can constrain building pads.
Why it matters for land decisions
Confirm how the concept applies to your specific parcel with the city or county planning department and the controlling agency map or ordinance.
- Treat online GIS as a first-pass screen.
- Verify before design, escrow, or lending decisions.
People also ask
What is Drainage?
Drainage is how water moves across and off a site. Even outside FEMA SFHAs, local drainage, creeks, and concentrated runoff can constrain building pads.
Is a GIS overlay enough to decide?
No. Public GIS is a screening tool. Official determinations come from the governing agency, recorded documents, and licensed professionals when required.
Official sources
Related terms
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