Where the numbers come from

Measured, from published data

Flood zones and base flood elevations. FEMA's National Flood Hazard Layer, queried by point against the flood hazard zone layer on 5 August 2026. Collier County's effective panel at that date was 12021C0393J, in force since 8 February 2024. Every elevation on this site is feet NAVD88 because that is what the layer publishes. A point query returns the zone the point falls in, and a parcel can straddle two, so the figures here describe an area rather than a deed.

Tidal datums and storm water levels. NOAA's Center for Operational Oceanographic Products and Services, stations 8725110 (Naples) and 8725114 (Naples Bay, North), retrieved on the same date. Datums are the published 1983 to 2001 tidal epoch, converted to NAVD88 by subtracting each station's NAVD88 value from the datum on station datum. Storm figures are verified water level, the highest six-minute observation in the window around each landfall. The Hurricane Ian figure is the last reading gauge 8725110 transmitted before it stopped reporting, so it is a floor rather than a peak, and it is labelled that way everywhere it appears.

Permitting requirements. Read off the agencies. Collier County's own application requirements page for the Marine permit type, its contractor licensing and building code pages, the Florida Statutes as published by the Legislature, the Florida Administrative Code as published by the Department of State, and the Department of Environmental Protection's own program pages for environmental resource permitting, the coastal construction control line, and federal coordination. Nothing on the permitting page is sourced from a contractor's website.

Ours, and open to argument

Embedment multipliers. The take-off orders panel length at exposed height plus 1.0 times exposed for an anchored wall and 1.5 times for a cantilever. These are planning figures for buying material in loose coastal sand, not a design. Real embedment comes out of a geotechnical report and moves with soil density, surcharge behind the wall and dredged depth in front of it. Organic layers under canal fill push it up.

Deadman setback. At least twice the exposed height and never under 6 feet. This is the field rule for keeping an anchor outside the failure wedge. A designed anchor is placed against a calculated wedge angle, not a multiplier.

Waste and conversion factors. Ten percent on cap concrete, rounded up to the quarter yard the way a ready-mix plant takes an order. Riprap at 1.4 tons per cubic yard placed, voids included. Filter fabric with a 10% lap. Bag yields are the ones printed on the bag: 0.60 cubic feet from 80 pounds, 0.45 from 60, 0.375 from 50.

Service lives and symptom verdicts. Observed ranges and practitioner judgement, marked as such on the pages that carry them. They are there to let you sanity-check what a contractor tells you, not to substitute for it.

How the arithmetic stays honest

Every quantity published here, in a table or in a sentence, is computed by the same code the calculator runs in your browser. The build evaluates it once for the static figures and ships it once for the live tool, so a number in the prose cannot drift away from the number the form produces. If you find a table that disagrees with the calculator, that is a bug and worth an email.

What this site is not

It is not a contractor and does not want to be. Nobody here will come and look at your wall. It takes no referral fee, carries no lead form, and has no arrangement with any marine contractor in Collier County; if that ever changes it will be disclosed on the page where it changes rather than in a footer. It also publishes no prices, because there is no defensible source for a per-foot figure that would survive contact with your particular wall, and a made-up range would be worse than saying so.

Nothing here is an engineered design, a code determination, or legal advice about your permit. A Florida licensed engineer with a boring log makes those calls, and where this site disagrees with a professional standing on your dock, the professional is right.