APPENDIX B: GUIDANCE CONCERNING FENCING AND WALLS IN SPECIAL FLOOD HAZARD AREAS.

   Fencing and walls located in the special flood hazard are require floodplain development permits, unless they are considered de minimis development as defined by local ordinance.

Fence or Wall Type	Fencing and walls allowed?
	Floodway Fringe (Riverine)	Regulatory Floodway (Riverine)	Shallow/Sheetflow/ Ponding Zones	Coastal Velocity Zones
Open barb or barbless wire. Open means no more than one horizontal strand per foot of height	Yes	Yes	Yes	Yes
Open pipe or rail fencing (for example, corrals). Open means rails occupy less than 10% of the fence area and posts are spaced no closer than eight feet apart	Yes	Yes, with limited cross channel fencing	Yes	Yes
Collapsible fencing	Design review required1	Design review required1	Design review required1	Design review required1
Other wire, pipe, or rail fencing (for example, field fence, chicken wire, and the like)	Yes, if open at base to BFE	No2	Yes, if open at base to BFE	Yes, if installed parallel to shore, otherwise design review required
Chain link fencing	Yes, if open at base to BFE	No2	Yes, if open at base to BFE	Yes, if installed parallel to shore, otherwise design review required
Continuous wood fencing	Yes, if adequate openings at base to BFE	No2	Yes, if adequate openings at base to BFE	Design review required3
Masonry walls	Yes, if adequate openings at base to BFE	No2	Yes, if adequate openings at base to BFE	Design review required3
Retaining walls, bulkheads	Yes, if adequate openings at base to BFE	No2	Yes, if adequate openings at base to BFE	No
1 Ensure fence will collapse under anticipated base flood conditions. Debris impact must be considered. 2 Unless shown, using FEMA-approved engineering/modeling standards, to cause no rise in BFE. 3 Fences and walls in V zone must be analyzed for their effects on flood conditions, including ramping effects on adjacent buildings and effects of debris during flood events (TB 5).