Seawall Height & Survey Guidance for Brevard
A wall’s cap elevation, the waterline and a building flood elevation are different measurements. Start with the survey reference before comparing any number.
- Top of the capMeasured from a fixed survey reference.
- WaterlineRises and falls with tides and weather.
- Survey reference (datum)A named reference, such as NAVD88.
Use the survey reference printed beside the elevation.
Which measurement answers your question?
| Measurement | What it tells you | What it does not prove |
|---|---|---|
Top-of-cap elevation | Height of the wall’s top relative to the named survey datum. | That the wall or its supports are structurally adequate. |
Observed waterline | Water level at that place and time. | A fixed elevation standard or the next storm’s level. |
Building elevation | The surveyed floor or building feature identified in the record. | The top of the seawall or a permitted wall height. |
A useful request to your surveyor
Please identify the seawall cap elevation, the datum and benchmark used, the measurement date, nearby ground and outlet elevations, and any older datum that needs reconciling for this project.
Send the same reference to each design professional. Keep a screenshot of a tide app out of the elevation column; record it separately as an observation.
Ask the authority for the applicable rule
This guide does not assign one numerical seawall height to all Brevard properties. Identify the parcel, existing wall, proposed work and shoreline type before asking for the applicable minimum, maximum or design requirement.
County natural-lagoon provisions and residential-canal rules differ. Cocoa Beach oceanfront property can also involve DEP coastal-construction review. A height from another Florida city is not a Brevard requirement.
Brevard Code chapter 62, article X, surface water protection · Coastal Construction Control Line
What if two surveys use different datums?
Keep the original labels such as NAVD88 and NGVD29 with the numbers. Ask a surveyor to reconcile the references for the property; do not apply a remembered offset or measure down from a tide mark.
Brevard’s marine checklist asks for a recent survey and drainage information. Request the wall, adjacent grades, outlets and adjoining cap transitions to be shown clearly enough for the designer’s questions.
NOAA National Geodetic Survey: datum questions · Brevard County residential marine construction
Why can a lagoon waterline be misleading?
SJRWMD explains that wind has a strong influence on lagoon movement and that Canaveral locks limit ocean exchange. The lock’s operation responds to harbor and Banana River water levels. An ocean tide prediction does not establish the cap elevation behind a Merritt Island house.
Use water observations to describe the event; use the survey and project design for elevation decisions.
Questions to take to the designer
- Which datum and benchmark support the cap measurement?
- Does the applicable rule govern the existing wall, the proposed work or both?
- Can the retained panels, anchors and foundation support a proposed change?
- Where will rainfall go if the edge is raised?
- How will transitions to neighboring walls and public outlets work?
Bring those answers into the repair-versus-replacement decision.
Find these two items on your survey.
Find the elevation for the top of the seawall cap and the survey reference used with it. The example below shows what to look for.
Seawall cap elevation
- Top of seawall cap
- 6.00 ft
- Survey reference (datum)
- NAVD88
This example shows 6.00 ft NAVD88. Use the number and reference on your own survey.
Match the value and the reference.
- The elevation: use the number for the top of the wall cap, not a building floor, water depth or the wall’s full height.
- The reference: copy the name beside the elevation, such as NAVD88 or NGVD29. You can compare elevations only when they use the same reference.
- Cannot find both? Choose “No / not sure” in the checker. Ask a surveyor to help find them; measuring from the water will give a different result.
Show sourcesHide sources
- NOAA National Geodetic Survey: datum questionsSource reviewed 2026-10-25
- Brevard Code chapter 62, article X, surface water protectionSource reviewed 2026-10-25
- Coastal Construction Control LineSource reviewed 2026-10-25
- Brevard County residential marine constructionSource reviewed 2026-10-25
- SJRWMD Indian River Lagoon fast factsSource reviewed 2026-10-25
- CanaverallockSource reviewed 2026-10-25
Prepare your property notes
Add the location, the decision you face and the records you already have. Save a copy for your chosen professional.