PARCEL DILIGENCE FIELD GUIDE · RISK RESEARCH
How to research floodplain and drainage risk on Texas land
A flood map is a starting point, not a complete drainage or developability conclusion.
Updated October 14, 2026 · Ryze Property Solutions LLC1. Locate the exact parcel
Use parcel boundaries, survey information and current topography rather than relying on an address pin.
2. Review mapped flood information
Record the map panel, effective date, mapped zones and any available amendments. Preserve the source instead of copying only a screenshot.
3. Look beyond the mapped boundary
Review drainage paths, waterways, culverts, low areas, adjacent development and local complaint or capital-project information where available.
4. Identify the reviewing authority
Determine which city, county, drainage district, flood-control district or other entity applies and obtain its current criteria.
5. Estimate the site-plan impact
Separate gross acreage from areas that may require elevation, detention, setbacks, access protection or professional study.
6. Escalate to qualified professionals
A civil engineer, surveyor or floodplain professional should make project-specific technical determinations and prepare required studies or applications.