Seawall and bulkhead glossary.
Terms on Gulf Shores bids, surveys and permits.

Terms A to C

Terms run A to Z by first letter.

A

• ADEM. The Alabama Department of Environmental Management. It issues coastal permits and enforces them; State Lands handles planning and policy. ADEM coastal program
• AE zone. A FEMA flood zone with a published base flood elevation. FEMA flood hazard layer
• ALGP. Alabama General Permits: Corps permits for minor work such as piers, boat slips and dredging, in effect October 1, 2026 to September 30, 2031. Mobile District ALGP program
• Avulsion. Sudden loss of land, such as a storm taking a strip of shore. State Lands approves refilling only if you show avulsion or man-made erosion. ADCNR rule 220-4-.09(4)(b)5

B

• Backfill. Soil placed behind a wall. Gulf Shores bans clay and sand-clay backfill citywide. Gulf Shores Sec. 7-21 See bulkhead materials.
• Base flood elevation (BFE). The flood height FEMA maps for a 1 percent yearly chance. New floors must sit at or above it, plus freeboard. See flood zones and elevation.
• Bulkhead. A retaining wall at the water's edge. "Seawall" means much the same thing. ADEM counts it as a structure. ADEM coastal rule definitions

C

• Cap. The beam on top of a wall, usually concrete or timber, that ties the face together and gives a walking edge.
• Coastal Area. Water and shoreland seaward of the continuous 10-foot contour. Fort Morgan, Bon Secour and the lower Fish and Magnolia rivers fall inside it. See Fort Morgan bay side. ADEM rule 335-8-1-.02(k) ADEM coastal area rule
• Coastal Construction Line (CCL). Also called the Construction Control Line. ADEM sets it on the Gulf shore 40 feet inland of the dune crest. ADEM rule 335-8-1-.02(p) No new structure may go seaward of it. ADEM rule 335-8-2-.08(1) See Gulf-front seawall rules and West Beach.
• Conditional Use Permit (CUP). A Gulf Shores approval for marinas and boat docks in the Waterway Village Overlay. It costs $300 plus advertising and takes about ninety days. See Waterway Village. Gulf Shores CUP page
• Consent of Use. State Lands authorization, instead of a paid easement, for small private docks, riprap near the tide line (within 10 feet waterward of it) and some wall replacements. ADCNR rule 220-4-.09(4)(e)2
• Corps of Engineers. The U.S. Army Corps of Engineers, Mobile District. It permits work in waters of the United States: (251) 690-2658. Corps Mobile District contact
• CRS (Community Rating System). A FEMA discount program for flood insurance. Gulf Shores is Class 10 (no discount). Baldwin County and Foley are Class 7 (15 percent). FEMA CRS list

Terms D to I

D

• Deadman. A buried block or plate that anchors the tieback rod. If it shifts or the rod rusts, the wall leans. See tiebacks and anchors.
• Design flood elevation. Base flood elevation plus freeboard. It is the height a new or substantially improved floor must clear. Foley Floodplain Ordinance Art. 4

E

• Elevation Certificate. A survey form that records a building's floor height against the flood map. Baldwin County requires one stamped by an Alabama design professional. Baldwin County flood zone page Gulf Shores keeps certificates for structures built from 1998 on. Gulf Shores FAQ

F

• Filter fabric. Geotextile cloth behind a wall face or under rock. It lets water through but holds soil. Foley's code asks for it beneath riprap and bulkhead materials. Foley Code Sec. 4-229
• Fill. Material that raises the level of wetlands or water bottoms. ADEM does not usually count vertical pilings as fill. ADEM rule 335-8-1-.02(ii)
• Floodplain development permit. A city or county permit needed before any change to land in a mapped flood hazard area, including filling, grading and dredging. Gulf Shores flood ordinance
• Form 166. The older joint Corps and ADEM application for work in Alabama waters. Drawings must show mean high water and mean low water. ADEM Form 166 Form 166 drawing rules The Corps now points applicants to its online Regulatory Request System. Corps Mobile District contact
• Freeboard. Extra height a local code adds above base flood elevation. Gulf Shores and Baldwin County use 1 foot, and Foley uses 2 feet. Gulf Shores flood ordinance Baldwin County flood zone page Foley Floodplain Ordinance

H

• Hardened shoreline. Shore held by a bulkhead, riprap or concrete. The Fish and Wildlife Service says more than half of Little Lagoon is hardened. See Little Lagoon north shore. USFWS lagoon notice
• High-tide flooding. NOAA's term for shallow flooding that happens on ordinary high tides, with no storm. Its 2026 outlook for Dauphin Island, the nearest active gauge, is 9 days. NOAA high tide flooding outlook

I

• Incidental take permit (ITP). A Fish and Wildlife Service permit for building where the endangered Alabama beach mouse lives. The processing fee for a single-family home is $100. USFWS beach mouse guidance
• Intracoastal Waterway (ICW). The Corps channel behind the Gulf shore. Alabama reaches are listed at a 12-foot depth and 150-foot width. See Waterway Village. Corps channel framework

Terms L to N

L

• Land Use Certificate. A Town of Magnolia Springs approval that must be issued before the county gives a building permit inside the town. Magnolia Springs permit page
• LiMWA. Limit of Moderate Wave Action: a FEMA map line where smaller breaking waves still do damage. Baldwin County has 35 mapped lines. FEMA flood hazard layer
• Living shoreline. A soft edge of plants, oyster shell, sand or a little rock instead of a wall. State Lands says fill placed this way does not change title to state water bottoms. ADCNR rule 220-4-.09(4)(b)7 See living shorelines.

M

• Marine Accessory permit. Baldwin County's flood permit category that covers walls, piers and boat lifts outside city limits. Baldwin County marine accessory checklist
• Mean high tide (MHT). The average high-tide line. Tidal lands below it belong to the state, and a new wall must stand on or behind it. ADCNR rule 220-4-.09(3)(p) ADCNR rule 220-4-.09(4)(e)2(iv)
• Mean high water (MHW). The same idea in NOAA language. Permit drawings must show mean high water and mean low water. Form 166 drawing rules
• Mean higher high water (MHHW). The mean of each day's higher high tide. At the Gulf State Park Pier gauge it sits about 0.7 foot above the NAVD88 datum. NOAA station 8731269

N

• NAVD88. The North American Vertical Datum of 1988, the common zero point for land elevations on flood maps and elevation certificates.
• NFIP. The National Flood Insurance Program. Its standard dwelling policy leaves out seawalls, bulkheads, wharves, piers and docks. NFIP policy form
• NWP 3. Nationwide Permit 3, the maintenance permit. It covers fixing or swapping a working structure. A storm-damaged one qualifies if repairs begin or are contracted within two years. 2026 NWP 3
• NWP 13. Nationwide Permit 13 covers bulkheads and riprap up to 500 feet. Fill stays near one cubic yard per running foot below high tide, unless the Corps waives it. 2026 NWP 13
• NWP 54. Nationwide Permit 54 covers living shorelines with a real plant or oyster component, reaching no more than 30 feet past mean low water. Every new one needs a pre-construction notice. 2026 NWP 54

Terms O to S

O

• Outstanding Alabama Water (OAW). A top-tier water quality class with stricter discharge limits. The Magnolia River and Wolf Bay carry it. See Magnolia Springs. ADEM rule 335-6-11-.02 Wolf Bay designation
• Outstanding National Resource Water (ONRW). The highest class: no new point-source discharges. It covers Weeks Bay and upstream tributaries such as the Fish and Magnolia rivers. See Weeks Bay and Fish River. ADEM rule 335-6-10-.10

P

• Piling. A post driven into the bottom to carry a dock, pier or wall. A pile is the same thing.
• Police jurisdiction. Land outside city limits where a city still applies some codes. Gulf Shores lists the County Roads 6 and 8 areas, the northeast area and Plash Island. Gulf Shores annexation page
• Pre-construction notification (PCN). A notice to the Corps before work starts. NWP 13 requires one for walls over 500 feet, over the fill limit, or reaching special aquatic sites. 2026 NWP 13

R

• Repetitive loss. A building flooded two or more times in 10 years, with repairs averaging at least 25 percent of its value. Gulf Shores treats it like substantial damage. Gulf Shores Sec. 7-86(16)
• Request to Impact State Owned Submerged Land (RTI). The State Lands form, with a $100 fee, that starts a Consent of Use, a riparian easement or a dredge permit. ADCNR rule 220-4-.09(4)(e)
• Revetment. A sloped covering of rock or similar armor on a bank, as opposed to a vertical wall. NWP 13 covers both. 2026 NWP 13
• Riparian line. The line dividing your water frontage from a neighbor's. Docks must sit at least 10 feet inside it, with exceptions. ADCNR rule 220-4-.09(4)(c)4 State Lands accepting a survey does not settle the line. ADCNR rule 220-4-.09(4)(b)17
• Riprap. Loose stone placed along a shore to absorb waves. State Lands prefers it to vertical walls on state water bottoms where feasible. ADCNR rule 220-4-.09(4)(b)6

S

• Sheet pile. Interlocking panels driven into the ground side by side to form the wall face. They come in vinyl, steel, aluminum, composite and concrete.
• Special Flood Hazard Area (SFHA). The part of the FEMA map with a 1 percent yearly flood chance. Baldwin County asks for a marine accessory permit only when work is inside one. Baldwin County marine accessory checklist
• State-owned submerged lands. Tidal lands waterward of mean high tide that Alabama took title to at statehood and has not conveyed. ADCNR rule 220-4-.09(3)(p)
• Substantial damage. Damage from any cause whose repair costs half or more of a building's value. Gulf Shores cannot waive the determination. Gulf Shores Sec. 7-86(16)
• Substantial improvement. Work costing half or more of a building's market value. The flood rule counts buildings, not seawalls. See flood zones. Gulf Shores Sec. 7-99.1 Gulf-front and ADEM rules count a bulkhead as a structure. Gulf Shores Sec. 7-121

Terms T to X

T

• Tieback. A steel or composite rod that runs from the wall back to a deadman and holds the face upright against soil pressure.
• Toe. The foot of a wall or slope, where it meets the water bottom. Scour (moving water digging out sand) at the toe is a common reason walls fail.

V

• VE zone. The FEMA coastal high-hazard zone, where waves add to the flood. In Gulf Shores a new building must sit on piles, landward of mean high tide, with its lowest member 1 foot above BFE. Gulf Shores Sec. 7-92 Baldwin County VE zones carry elevations of 10 to 18 feet. FEMA VE elevations

W

• Weep hole. A small opening in the wall face that lets water behind the wall drain. Filter fabric behind it keeps soil from washing out.
• Whaler (wale). A horizontal beam, often treated timber, bolted along the wall face to spread tieback loads across the panels.

X

• X zone. A FEMA zone outside the mapped high-risk area. Shaded X means a 0.2 percent yearly chance, and unshaded X means minimal hazard. FEMA flood hazard layer

Missing a term? The permits guide and cost guide define words in context. Flood zones and elevation covers the map terms, and hiring a contractor covers license words.