FEMA P 2181 2022

$13.00

FEMA P-2181: Hurricane and Flood Mitigation Handbook for Public Facilities, March 2022

Published By	Publication Date	Number of Pages
FEMA	2022

Guaranteed Safe Checkout

Category: FEMA

If you have any questions, feel free to reach out to our online customer service team by clicking on the bottom right corner. We’re here to assist you 24/7.
Email:[email protected]

Description

PDF Catalog

PDF Pages	PDF Title
44	Fact Sheet 1.0: Roads Hurricane and Flood Impacts Mitigation Fact Sheets Fact Sheet 1.0: Roads Hurricane and Flood Impacts Mitigation Fact Sheets
45	Figure 1.0.1. Road System Components.
46	Mitigation Solutions Mitigation Solutions
47	Icons Icons Table 1.0.1. Icons Used to Represent Considerations about Hazard Mitigation Strategies
49	Fact Sheet 1.1: Road and Highway Surfaces Fact Sheet 1.1: Road and Highway Surfaces Table 1.1.1. Common Mitigation Solutions
50	Mitigation Solution: Stabilize Roadway Mitigation Solution: Stabilize Roadway
51	Figure 1.1.1. Reshaping the roadway can improve drainage and decrease flood impacts.
52	Figure 1.1.2. Geosynthetics can be used to improve drainage and subgrade strength.
53	Figure 1.1.3. Geotextiles that do not drain well can be hydraulically connected to a drain.
54	Mitigation Solution: Reduce Flood Hazard on Roadway Mitigation Solution: Reduce Flood Hazard on Roadway Figure 1.1.4. Increasing the roadway elevation above the base flood elevation
55	Figure 1.1.5. Relocating the roadway away from the flood source can help protect the road from flooding.
56	Figure 1.1.6. Permeable pavement includes pavers, permeable concrete, and permeable asphalt (USGS, 2018).
57	Mitigation Solution: Reduce Frost Heave Mitigation Solution: Reduce Frost Heave Figure 1.1.7. “Rock caps” can improve both drainage and structural stability of roads susceptible to frost heaves (Yu and Beck, 2009).
58	Figure 1.1.8. A capillary barrier can help prevent surfaces from frost heaving (Roberson et al., 2006).
59	Figure 1.1.9. Improve subgrade soils by injecting a polymer into the soil to fill voids (Source: Fakhar and Asmaniza, 2016).
62	Fact Sheet 1.2: Road Shoulders and Embankments Fact Sheet 1.2: Road Shoulders and Embankments
63	Table 1.2.1. Common Mitigation Solutions for Road Shoulders and Embankments
64	Mitigation Solution: Protect Shoulders Mitigation Solution: Protect Shoulders
65	Figure 1.2.1. Geosynthetics can be used to stabilize roadways.
66	Mitigation Solution: Protect Embankment Slopes Mitigation Solution: Protect Embankment Slopes Figure 1.2.2. Riprap can help reduce erosion of roadway slopes adjacent to streams.
67	Figure 1.2.3. Bioengineered slopes can protect against erosion.
68	Figure 1.2.4. Spillways can concentrate flows at selected locations to help control erosion.
69	Figure 1.2.5. A wall constructed of gabion baskets protects the toe of the slope.
70	Figure 1.2.6. Changing slope geometry to a more gradual slope can reduce erosion.
72	Fact Sheet 1.3: Drainage and Culverts Fact Sheet 1.3: Drainage and Culverts
73	Table 1.3.1. Road Culvert and Drainage Mitigation Solutions
74	Figure 1.3.1. Components of a culvert.
75	Mitigation Solution: Increase Design Capacity Mitigation Solution: Increase Design Capacity Figure 1.3.2. Alternative stream crossing designs.
76	Figure 1.3.3. Increasing ditch capacity can help protect against overland flooding.
77	Figure 1.3.4. An arch culvert or a box culvert can provide increased flow capacity. Figure 1.3.5. Replacing a culvert with a bridge can protect the stream bed and the road.
78	Figure 1.3.6. Installing multiple culverts can increase flow capacity.
79	Mitigation Solution: Reduce Embankment Erosion Mitigation Solution: Reduce Embankment Erosion Figure 1.3.7. Shaping the culvert entrance can reduce erosion at the intake.
80	Figure 1.3.8. A cutoff wall can reduce undermining. Figure 1.3.9. Wingwalls, headwalls and endwalls can protect embankment slopes.
81	Figure 1.3.10. Ditch lining can reduce erosion and improve flow capacity.
82	Figure 1.3.11. Check dams help slow water and decrease scouring.
83	Figure 1.3.12. Energy dissipaters can be installed at culvert discharges to decrease erosion and scour.
84	Mitigation Solution: Improve Alignment Mitigation Solution: Improve Alignment Figure 1.3.13. Realigning the culvert to the stream centerline can reduce damage to the culvert.
85	Figure 1.3.14. Approach berms can direct flow away from embankments.
86	Figure 1.3.15. Flow diverters can realign the stream channel.
87	Figure 1.3.16. Installing additional culverts can reduce velocity and clogging.
88	Figure 1.3.17. Realigning the stream can protect embankments.
89	Mitigation Solution: Reduce Obstructions Mitigation Solution: Reduce Obstructions Figure 1.3.18. A debris barrier can protect a culvert from damage.
90	Figure 1.3.19. A sediment basin can help settle suspended sediment and decrease culvert clogging potential.
91	Figure 1.3.20. Install a relief culvert as a second route for floodwaters if the main culvert gets clogged.
92	Mitigation Solution: Relocate or Replace with Water Crossing Mitigation Solution: Relocate or Replace with Water Crossing Figure 1.3.21. A low-water crossing in place of a culvert will accommodate flows during emergency events.
93	Figure 1.3.22. Installing an overflow section in the roadway can accommodate stream overflows.
96	Fact Sheet 1.4: Bridges Fact Sheet 1.4: Bridges Figure 1.4.1. Basic bridge structure.
97	Table 1.4.1. Common Mitigation Solutions for Various Types of Bridge Damage
98	Mitigation Solution: Improve Flow Under the Bridge Crossing Mitigation Solution: Improve Flow Under the Bridge Crossing Figure 1.4.2. Reducing the number of spans can increase the flow amount under the bridge. In this figure, the dashed piers would be removed to accomplish this.
99	Figure 1.4.3. Increasing the size of a bridge opening by raising the bridge deck can increase flow volume under the bridge.
100	Figure 1.4.4. Lengthening a bridge can provide additional overflow capacity beneath the bridge.
101	Figure 1.4.5. Building a relief opening can help prevent flooding of bridges.
102	Figure 1.4.6. Low water crossings can be cost effective in areas with low traffic where flooding is seasonal.
103	Mitigation Solution: Construct Erosion and Scour Countermeasures Mitigation Solution: Construct Erosion and Scour Countermeasures Figure 1.4.7. Riprap can protect bridge piers and abutments against erosion and scour.
104	Figure 1.4.8. Wingwalls can help direct the flow of water and prevent erosion and scour at the bridge.
105	Figure 1.4.9. Spur dikes can direct flood flows, reducing erosion and scour around bridges.
106	Figure 1.4.10. Realigning piers and abutments can decrease the damage from erosion and scour.
107	Figure 1.4.11. Increasing footing depth can protect bridge foundations against scour.
108	Figure 1.4.12. Installing flow deflectors immediately upstream of bridge piers can help protect them against scour.
109	Mitigation Solution: Reduce Debris Damage Mitigation Solution: Reduce Debris Damage Figure 1.4.13. Debris deflectors can protect bridge piers and abutments from impact damages and debris accumulation.
110	Figure 1.4.14. Endnoses installed on the upstream end of piers (shown by red arrows) can protect piers from debris impacts.
111	Figure 1.4.15. Steel plate batters protect piers from the impact of floating debris.
112	Figure 1.4.16. Replace a multiple timber pier structure with a concrete column to protect against debris impact.
113	Figure 1.4.17. Replacing a solid deck with an open deck can reduce trapped debris.
114	Figure 1.4.18. Debris catchments trap debris before it reaches bridge piers and abutments.
115	Figure 1.4.19. A debris sweeper can be attached directly to a pier to deflect debris (FHWA, 2005). Figure 1.4.20. Pile-mounted debris sweepers can effectively direct debris away from bridge piers (FHWA, 2005).
116	Mitigation Solution: Relocate the Bridge Mitigation Solution: Relocate the Bridge
118	Fact Sheet 1.5: Roadway Lights, Poles, and Signage Fact Sheet 1.5: Roadway Lights, Poles, and Signage Table 1.5.1. Common Mitigation Strategies for Various Types of Damage
119	Mitigation Solution: Traffic Signal Controllers Mitigation Solution: Traffic Signal Controllers Figure 1.5.1. Elevating signal controller cabinets protects them against flooding.
121	Mitigation Solution: Traffic Signal Support Structures and Luminaires Mitigation Solution: Traffic Signal Support Structures and Luminaires Figure 1.5.2. Mast arm poles protect traffic signals against wind damage.
123	Figure 1.5.3. Vibration dampers can protect poles and signals against wind vibration damage.
124	Mitigation Solution: Roadway Sign Support Structures Mitigation Solution: Roadway Sign Support Structures
125	Figure 1.5.4. Increase sign connectors and pole embedment depth. Left image is before mitigation occurs. Right image is after mitigation occurs.
126	Figure 1.5.5. Helical anchors can be used as foundation support for street signs and light poles.
128	Fact Sheet 2.0: Water Control Facilities Hurricane and Flood Mitigation Mitigation Fact Sheets Fact Sheet 2.0: Water Control Facilities Hurricane and Flood Mitigation Mitigation Fact Sheets
129	Figure 2.0.1. Channels, aqueducts and canals collect, carry, and distribute water. Figure 2.0.2. Basins are in-ground structures used to hold water.
130	Mitigation Strategies Mitigation Strategies Figure 2.0.3. Dams are used to retain and control the flow of water.
131	Icons Icons Table 2.0.1. Icons Used to Represent Considerations about Hazard Mitigation Strategies
136	Fact Sheet 2.1: Channels, Aqueducts, and Canals Fact Sheet 2.1: Channels, Aqueducts, and Canals Table 2.1.1. Channel, Aqueduct and Canal Mitigation Solution
138	Mitigation Solution: Armor Channels and Canals Mitigation Solution: Armor Channels and Canals Figure 2.1.1. Concrete lining of a channel.
139	Mitigation Solution: Stabilize Channels and Canals Mitigation Solution: Stabilize Channels and Canals Figure 2.1.2. Typical ACB cross-section. Figure 2.1.3. Typical cross-section of slope protection.
140	Mitigation Solution: Lessen the Energy of Flood Flow Mitigation Solution: Lessen the Energy of Flood Flow Figure 2.1.4. Energy dissipators such as stone drop structures can help slow themovement of water to decrease erosion and scour.
141	Mitigation Solution: Prevent Pipe and Tunnel Issues Mitigation Solution: Prevent Pipe and Tunnel Issues
144	Fact Sheet 2.2: Basins Stormwater Basins Fact Sheet 2.2: Basins Stormwater Basins Table 2.2.1. Basin Mitigation Solutions
145	Bioretention Areas Bioretention Areas Figure 2.2.1. Typical stormwater basin cut.
146	Dry Swales Dry Swales Figure 2.2.2. Typical bioretention facility.
147	Wet Ponds Wet Ponds Figure 2.2.3. Typical dry swale with check dams.
148	Figure 2.2.4. Wet pond plan view. Figure 2.2.5. Wet pond section view.
149	Extended Detention Ponds Extended Detention Ponds Figure 2.2.6. Extended Detention Pond.
150	Mitigation Solutions Mitigation Solutions
154	Fact Sheet 2.3: Mitigation of Dams and Reservoirs Dam Hazard Potential Classifications Fact Sheet 2.3: Mitigation of Dams and Reservoirs Dam Hazard Potential Classifications
155	Figure 2.3.1. This dam is considered low hazard potential because, if it failed, it would only impact the forest around it. Figure 2.3.2. This dam is considered high hazard potential because its failure would impact the community directly downstream and could result in loss of life and property.
156	Table 2.3.1. Common Mitigation Solutions for Dams and Reservoirs
158	Importance of Emergency Planning for Dams Importance of Emergency Planning for Dams
160	Mitigation Solution: Improve Stability Mitigation Solution: Improve Stability Figure 2.3.3. Example of failed downstream slope. Figure 2.3.4. Use of compacted fill to reduce the downstream slope angle.
162	Figure 2.3.5. Buttressing can give additional stability to embankment dams.
163	Figure 2.3.6. Anchoring can give resistance to overturning and sliding.
164	Mitigation Solution: Increase Spillway Capacity Mitigation Solution: Increase Spillway Capacity
165	Figure 2.3.7. To increase spillway capacity, widen an existing spillway or build a second spillway.
166	Mitigation Solution: Increase Temporary Storage Capacity Mitigation Solution: Increase Temporary Storage Capacity
167	Figure 2.3.8. Raising the height of a dam can increase temporary flood storage capacity.
169	Mitigation Solution: Control Surface Erosion Mitigation Solution: Control Surface Erosion Figure 2.3.9. Wave action can erode the upstream slope of a dam.
170	Figure 2.3.10. Initial embankment overtopping can lead to a complete overflow. Figure 2.3.11. Headcut erosion could lead to an accidental release from the impoundment.
171	Figure 2.3.12. Riprap layouts can be designed to protect against wave action.(Source: NRCS, 1983) Figure 2.3.13. Riprap blankets can protect against wave action. (Source: USFWS, 2008)
172	Figure 2.3.14. ACBs (left) and RCC (right) can protect spillways from overtopping erosion.
173	Figure 2.3.15. A parapet wall can give additional freeboard to protect against wave overtopping.
174	Figure 2.3.16. Cutoff walls can improve the stability of some unarmored auxiliary spillways.
175	Mitigation Solution: Reduce Seepage and Internal Erosion Mitigation Solution: Reduce Seepage and Internal Erosion Figure 2.3.17. Blanket drains increase seepage flow paths and reduce the risk of seepage-related piping.
176	Figure 2.3.18. Filter diaphragms can prevent seepage around conduits.
177	Figure 2.3.19. Reverse filters can be used to address sinkholes.
178	Figure 2.3.20. Seepage cutoff walls can be achieved through deep soil mixing.
179	Figure 2.3.21. Plan view of a secant pile wall.
180	Mitigation Solution: Address Foundation Issues Mitigation Solution: Address Foundation Issues Figure 2.3.22. Plan and profile of a grout curtain design.
181	Figure 2.3.23. Foundation cutoff walls can help control seepage through a dam foundation.
185	3.X: Fact Sheet Series Number [X.X.X] Fact Sheet 3.0: Buildings, Systems and Equipment Hurricane and Flood Impacts Mitigation Fact Sheets Fact Sheet 3.0: Buildings, Systems and Equipment Hurricane and Flood Impacts Mitigation Fact Sheets
186	Mitigation Solutions Mitigation Solutions Figure 3.0.1. Small public building elements (before mitigation). Figure 3.0.2. Large public building elements (before mitigation).
189	Figure 3.0.3. Large public building elements with primary electrical system components mitigated.
190	Figure 3.0.4. Flood risk for large public building reduced by relocating primary HVAC components from a subgrade basement level to a higher floor.
191	Icons Icons Table 3.0.1. Icons Used to Represent Considerations about Hazard Mitigation Strategies
194	Fact Sheet 3.1: Foundations Fact Sheet 3.1: Foundations
195	Figure 3.1.1. Foundation characteristics.
196	Table 3.1.1. Common Mitigation Solutions
197	Mitigation Solution�: Relocate Mitigation Solution�: Relocate Figure 3.1.2. Relocation of a small flood-prone public building.
199	Mitigation Solution�: Elevate Mitigation Solution�: Elevate
200	Figure 3.1.3. Elevation of small public building on piles in coastal flood zone.
201	Figure 3.1.4. Abandoning the lowest floor can elevate usable space above the BFE.
202	Figure 3.1.5. Constructing a raised floor or filling in a basement can elevate occupied space above the BFE.
203	Mitigation Solution�: Floodproof Mitigation Solution�: Floodproof Figure 3.1.6. Wet floodproofing opening retrofit diagram for a small public building.
204	Figure 3.1.7. Dry floodproofing sealants diagram for a portion of a building.
205	Figure 3.1.8. Dry floodproofing sealants and secondary drainage diagram.
207	Mitigation Solution�: Retrofit the Structure Mitigation Solution�: Retrofit the Structure Figure 3.1.9. Grouted micropile (left) and helical pile (right) can strengthen existing building foundations.
208	Figure 3.1.10. Improve connections—select approaches to address minor wood pile-to-beam misalignments.
212	Fact Sheet 3.2: Wall Systems and Openings Fact Sheet 3.2: Wall Systems and Openings
213	Table 3.2.1. Wall Systems and Openings Mitigation Solutions
214	Mitigation Solution�: For Wall Systems Mitigation Solution�: For Wall Systems Figure 3.2.1. Connectors help create an adequate building load path.
216	Figure 3.2.2. Features of typical high-wind siding and standard siding.
217	Mitigation Solution: For Door Openings Mitigation Solution: For Door Openings Figure 3.2.3. Examples of weather stripping (far left and center left) and drip protection (center right and far right) to prevent wind-driven rain entry at doors.
218	Figure 3.2.4. Examples of hinged (left) and lift out (right) flood shields with gaskets at entry doors. Some flood shields are automatic while others must be placed manually.
220	Figure 3.2.5. Recommended details for upgrading garage doors.
222	Mitigation Solutions: For Window Openings Mitigation Solutions: For Window Openings Figure 3.2.6. Use screw anchors to fasten window frames directly to concrete.
223	Figure 3.2.7. Connection of wall sheathing to window header (left) and window header to exterior wall (right) as part of a wall framing system.
224	Figure 3.2.8. Examples of storm shutter styles.
227	Fact Sheet 3.3.1: Roof Systems—Sloped Roofs Fact Sheet 3.3.1: Roof Systems—Sloped Roofs Figure 3.3.1.1. Basic elements of typical sloped roofs featuring gable-end roof system (top) and hip roof system (bottom).
229	Table 3.3.1.1. Mitigation Solutions for Sloped-Roof Systems
230	Mitigation Solution: Strengthen or Improve Mitigation Solution: Strengthen or Improve
231	Figure 3.3.1.2. Conceptual gable end retrofit without overhangs.
232	Figure 3.3.1.3. Conceptual gable end retrofit with overhangs.
233	Figure 3.3.1.4. Examples of proper roof connectors and fasteners for a wood-framed truss.
235	Figure 3.3.1.5. Examples of proper sheathing panel layouts for gable-end roof (top) and hip roofs (bottom)
236	Figure 3.3.1.6. Strong underlayment installation details applied to asphalt shingle roof sheathing in high-wind regions.
237	Figure 3.3.1.7. Proper and improper locations of shingle fasteners. Figure 3.3.1.8. The Dos and Don’ts of driving roof nails through asphalt shingles.
239	Figure 3.3.1.9. Improving soffits can decrease wind damage to sloped roofs.
240	Figure 3.3.1.10. Sheet metal straps (circled) attached to an existing gutter to increase wind uplift resistance.
242	Mitigation Solution: Add or Increase Mitigation Solution: Add or Increase
243	Mitigation Solution: Secure or Eliminate Mitigation Solution: Secure or Eliminate
245	Figure 3.3.1.11. Protecting gable end vents using shutters (left) and sealing gable rake vents using metal plugs as indicated by red arrows (right).
247	Fact Sheet 3.3.2: Roof Systems—Low‑Slope Roofs Fact Sheet 3.3.2: Roof Systems—Low‑Slope Roofs Figure 3.3.2.1. Basic components of typical low-slope roofs featuring overhangs (left) and parapet walls (right).
249	Table 3.3.2.1. Mitigation Solutions for Low Slope Roof Systems
250	Mitigation Solution: Secure or Eliminate Mitigation Solution: Secure or Eliminate
252	Mitigation Solution: Add or Increase Mitigation Solution: Add or Increase Figure 3.3.2.2. Condenser bolted down to concrete curb (blue arrows) with tie-down cables (red arrows), but the lightning protection system is no longer secured by its connector (green arrow).
254	Mitigation Solution: Strengthen or Improve Mitigation Solution: Strengthen or Improve
256	Figure 3.3.2.3. Both vertical faces of coping were attached with exposed fasteners (¼-inch diameter stainless steel fasteners spaced 12” on center) instead of concealed cleatsfollowing Typhoon Paka (1997) in Guam to prevent the flashing from tearing in
257	Figure 3.3.2.4. Sheet metal straps (circled) attached to an existing gutter to increase wind uplift resistance.
258	Figure 3.3.2.5. Rooftop periodic gas line supports using a steel angle welded to a pipe that was anchored to the roof deck for lateral and uplift resistance (left). Use of intermittent membrane flashing to secure a lightning protection system conductor
260	Mitigation Solution: Upgrade Mitigation Solution: Upgrade
262	Fact Sheet 3.4.1: Building Utility Systems—Heating, Ventilation and Air Conditioning Fact Sheet 3.4.1: Building Utility Systems—Heating, Ventilation and Air Conditioning
263	Key Terms and Definitions Key Terms and Definitions Figure 3.4.1.1. Basic components of a large public building fluid-based HVAC system. Note HVAC components on upper floors are not shown in this simplified graphic. Figure 3.4.1.2. Basic components of a small public building supplied by two forced-air HVAC systems.
264	Table 3.4.1.1. Common HVAC System Mitigation Solutions
265	Mitigation Solution: Elevate or Relocate Mitigation Solution: Elevate or Relocate Figure 3.4.1.3. Elevation of indoor and outdoor HVAC components on platforms above flood protection level for small public building.
266	Figure 3.4.1.4. Elevation of indoor HVAC components from basement to first floor above flood protection level for large public building, with outdoor HVAC components relocated to the rooftop.
267	Mitigation Solution: Dry Floodproof Mitigation Solution: Dry Floodproof Figure 3.4.1.5. Dry floodproofing with a watertight wall and access gate can be used to protect HVAC and plumbing equipment (left); alternate dry floodproofing protective enclosures for protecting equipment (right).
269	Mitigation Solution: Wet Floodproof Mitigation Solution: Wet Floodproof
271	Fact Sheet 3.4.2: Building Utility Systems—Electrical Fact Sheet 3.4.2: Building Utility Systems—Electrical
272	Figure 3.4.2.1. Typical small public building electrical system components with an onsite standby or emergency generator. Figure 3.4.2.2. Simplified diagram showing primary components of a large public building electrical system with standby generator (before mitigation).
273	Table 3.4.2.1. Common Electrical System Mitigation Solutions
274	Mitigation Solution: Elevate or Relocate Mitigation Solution: Elevate or Relocate Figure 3.4.2.3. Simplified diagram showing elevation of main and standby power components on elevated platforms above flood protection level for large public building.
275	Figure 3.4.2.4. Combination meter socket and circuit breaker service disconnect (circled in red) used to allow the main panel to be elevated and protected from flooding when the meter (circled in yellow) cannot be moved.
276	Mitigation Solution: Dry Floodproof Mitigation Solution: Dry Floodproof
278	Fact Sheet 3.4.3: Building Utility Systems—Plumbing Fact Sheet 3.4.3: Building Utility Systems—Plumbing
279	Figure 3.4.3.1. Typical small public building drinking water plumbing system components served by the public water system. Figure 3.4.3.2. Typical small public building wastewater DWV system components served by the public sanitary sewer system.
280	Figure 3.4.3.3. Alternative small public building drinking water plumbing system components supplied by a well. Figure 3.4.3.4. Alternative small public wastewater DWV system components served by onsite waste disposal (septic).
281	Figure 3.4.3.5. Simplified large public building drinking water plumbing, wastewater DWV, and fire suppression system components with utilities supplied by public water and sanitary sewer. Figure 3.4.3.6. Typical small public building liquid fuel system.
282	Figure 3.4.3.7. Typical small public building flammable gas system liquid propane (LP) with tank and pressure regulator (left side); natural gas (NG) with meter (right side). Figure 3.4.3.8. Typical large public building supplied with liquid fuel (LP) or flammable gas (NG) systems.
283	Table 3.4.3.1. Common Plumbing System Mitigation Solutions
284	Mitigation Solution: Elevate or Relocate Mitigation Solution: Elevate or Relocate Figure 3.4.3.9. Elevation of primary plumbing system components to the upper floor of an existing small public building.
285	Figure 3.4.3.10. Elevation of primary fuel system components on pedestals for a small public building. Figure 3.4.3.11. Outdoor fuel tank elevated on supporting frame (left); fuel tank elevated on structural fill (right).
287	Mitigation Solution: Seal or Isolate Mitigation Solution: Seal or Isolate Figure 3.4.3.12. Backflow protection valves including a combination check valve and gate valve (left) and floor drain with ball float valve (right).
288	Figure 3.4.3.13. Protection of private well using a sanitary well cap (left) or concrete well cap (middle), and protection of septic tank with lids and gasketed access covers, concrete risers and riser caps (right).
289	Mitigation Solution: Secure Mitigation Solution: Secure Figure 3.4.3.14. Secure and seal underground tanks to protect them from flood damage.
291	Mitigation Solution: Dry Floodproof Mitigation Solution: Dry Floodproof
293	Fact Sheet 3.4.4: Building Utility Systems—Conveyances Fact Sheet 3.4.4: Building Utility Systems—Conveyances
294	Figure 3.4.4.1. Typical elements of hydraulic elevators common in low-rise construction (left) and traction elevators common in high-rise construction (right). (Source: Otis Elevator Company)
295	Figure 3.4.4.2. Typical elements of escalators used in some large public buildings. (Source: Otis Elevator Company) Table 3.4.4.1. Common Mitigation Solutions for Conveyance Systems
296	Mitigation Solution: Protect Mitigation Solution: Protect
297	Figure 3.4.4.3. Float switch in pit to stop cab descent. (Source: Otis Elevator Company)
299	Figure 3.4.4.4. Inclined (left) and vertical (right) platform lifts move people between floors of a building. (U.S. Access Board, 2015)
301	Public Utilities Fact Sheet 4.0: Public Utilities Hurricane and Flood Impacts Mitigation Fact Sheets Fact Sheet 4.0: Public Utilities Hurricane and Flood Impacts Mitigation Fact Sheets
302	Mitigation Solutions Mitigation Solutions
303	Icons Icons Table 4.0.1. Icons Used to Represent Considerations about Hazard Mitigation Strategies
306	Fact Sheet 4.1: Drinking Water Systems Fact Sheet 4.1: Drinking Water Systems
307	Figure 4.1.1. The typical water treatment process has opportunities for hazard mitigation.(Source: City of Rockville, Maryland, 2012)
308	Table 4.1.1. Common Mitigation Solutions for Drinking Water Systems
309	Mitigation Solution: For Water Intake, Distribution and Storage Mitigation Solution: For Water Intake, Distribution and Storage
311	Mitigation Solution: For Drinking Water Treatment Facilities Mitigation Solution: For Drinking Water Treatment Facilities
312	Figure 4.1.2. Constructing a floodwall around a water treatment plant can protect buildings and equipment from flood damage. (Source: U.S. Army Corps of Engineers, 2013)
313	Mitigation Solution: For Booster Stations and Other Pumps Figure 4.1.3. Installing an emergency backup generator can provide power to help a water treatment plant continue to operate during a flood. (Source: U.S. Environmental Protection Agency [EPA], 2014)
314	Mitigation Solution: For Booster Stations and Other Pumps
315	Mitigation Solution: For Chemical and Fuel Storage Tanks Figure 4.1.4. Water-tight doors can be used to protect pumps and other equipment in pump houses and booster stations.
316	Mitigation Solution: For Chemical and Fuel Storage Tanks
317	Figure 4.1.5. Secure tanks with non-corrosive straps to prevent flotation. (Source: U.S. Environmental Protection Agency [EPA], 2014)
318	Mitigation Solution: For Instrumentation and Electrical Controls Mitigation Solution: For Instrumentation and Electrical Controls Figure 4.1.6. Elevating instrumentation can protect it from flood damage.(Source: U.S. Environmental Protection Agency [EPA], 2014)
320	Mitigation Solution: For Power Supplies Mitigation Solution: For Power Supplies
321	Figure 4.1.7. Microgrids can provide power to a facility to reduce its dependence on the main electrical grid. (Source: Sandia National Laboratories, 2020)
323	Fact Sheet 4.2: Wastewater Treatment Systems Fact Sheet 4.2: Wastewater Treatment Systems Table 4.2.1. Common Wastewater Treatment System Mitigation Solutions
325	Mitigation Solution: For Lift Stations Mitigation Solution: For Lift Stations Figure 4.2.1. Extend vent pipes and electrical controls above the flood elevation at lift stations.
328	Mitigation Solution: For Headworks Mitigation Solution: For Headworks
330	Mitigation Solution: For Wastewater Treatment Plants Mitigation Solution: For Wastewater Treatment Plants
331	Figure 4.2.2. Constructing a flood wall that extends above the 500-year flood elevation can help protect a wastewater treatment plant from flood damage. The blue lines indicate the approximate location of the planned floodwall for this treatment facilit
333	Mitigation Solution: For Chemical and Fuel Supplies Mitigation Solution: For Chemical and Fuel Supplies
334	Figure 4.2.3. Raise tanks above the 500-year flood elevation and secure them with non-corrosive hardware to keep them from floating.
336	Mitigation Solution: For Instrumentation and Electrical Controls Mitigation Solution: For Instrumentation and Electrical Controls Figure 4.2.4. Elevating instrumentation can protect it from damage during flooding. (Source: U.S. EPA, 2014)
338	Mitigation Solution: For Power Supplies Mitigation Solution: For Power Supplies
339	Figure 4.2.5. Installing renewable energy resources like solar panels can provide a standby source of power for wastewater treatment facilities. (National Renewable Energy Laboratory [NREL], 2017)
341	Fact Sheet 4.3: Electric Power Generation, Transmission and Distribution Fact Sheet 4.3: Electric Power Generation, Transmission and Distribution Table 4.3.1. Common Mitigation Solutions for Electric Power Systems
343	Mitigation Solution: For Transmission and Distribution Mitigation Solution: For Transmission and Distribution Figure 4.3.1. Cross-section of conductor types.
344	Figure 4.3.2. Dampers and detuners can help mitigate against gallop.
345	Figure 4.3.3. Interphase spacers can be used to help mitigate conductor gallop. (Source: INMR, 2021)
346	Figure 4.3.4. An armless composite utility pole helps mitigate against wind damage. (Source: Ramon Velasquez, 2013)
347	Figure 4.3.5. Typical utility pole with multiple guy wires and anchors. Figure 4.3.6. Poles can be directly embedded in the ground deep enough to help prevent overturning, then backfilled with materials that can help increase foundation stability. (Source: Yenumula et al., 2017)
349	Figure 4.3.7. Comparison of loop-fed line versus radial-fed line systems. (Source: Bharti, 2015)
350	Figure 4.3.8. Installation of underground power lines.
351	Mitigation Solution: For Substations Mitigation Solution: For Substations Figure 4.3.9. Elevating a control house in coastal areas can protect it against damage from storm surge and flooding. (Source: Modular Connections, 2020)
352	Figure 4.3.10. The existing battery bank can be modified or augmented to provide additional backup power to the substation. (Source: OSHA, No Date)
353	Figure 4.3.11. Indoor gas-insulated switchgears can be used in environments where water can penetrate the control house. (Source: Siemens Energy, 2021)
354	Mitigation Solution: For Power Plants Mitigation Solution: For Power Plants
355	Figure 4.3.12. Hurricane Maria severely damaged a solar array in Puerto Rico in 2017.
356	Figure 4.3.13. Individual building-based solar and wind form the backbone of widely distributed generation. (Source: U.S. Bureau of Labor Statistics, 2021)
357	Figure 4.3.14. A solar array on Vandenberg Air Force Base helps power facilities on the base.(Source: Defense Logistics Agency, photo by Airman First Class Clayton Wear, No Date)
359	Mitigation Solution: For the Smart Grid Mitigation Solution: For the Smart Grid Figure 4.3.15. Pole-mounted automatic transmission and distribution line feeder reclosers can help identify and isolate faults so power can be restored quickly.
360	Figure 4.3.16. Dedicated fiber-optic cables embedded in power cables can provide additional communication channels for SCADA systems. (Source: Transmission-line.net, 2010)
361	Figure 4.3.17. Simplified AMI system (Source: Christopher Villareal, 2020)
362	Figure 4.3.18. Data collection gateways should be protected against wind by placing them in storm shelters.
365	Fact Sheet 4.4: Communication Towers, Masts and Antennas Fact Sheet 4.4: Communication Towers, Masts and Antennas Figure 4.4.1. The collapse of a tower with antennas can damage the roof membrane, causing it to peel.
366	Table 4.4.1. Common Mitigation Solutions for Communications Systems
367	Mitigation Solution: Anchor Mitigation Solution: Anchor
368	Figure 4.4.2. Rooftop antennas often are mounted using ballast sleds. Figure 4.4.3. Antennas can be secured to the building structure to improve wind resistance.
370	Mitigation Solution: Strengthen Mitigation Solution: Strengthen Figure 4.4.4. Exterior and interior of an equipment shelter.
375	Mitigation Solution: Elevate or Relocate Mitigation Solution: Elevate or Relocate
377	Fact Sheet 5.0: Parks, Recreational and Other Facilities Hurricane and Flood Impacts Fact Sheet 5.0: Parks, Recreational and Other Facilities Hurricane and Flood Impacts
378	Mitigation Fact Sheets Mitigation Fact Sheets
379	Mitigation Solutions Mitigation Solutions
380	Icons Icons Table 5.0.1. Icons Used to Represent Considerations about Hazard Mitigation Strategies
384	Fact Sheet 5.1: Parks and Recreational Facilities Fact Sheet 5.1: Parks and Recreational Facilities
385	Table 5.1.1. Common Mitigation Solutions for Parks and Recreational Facilities
386	Mitigation Solution: For Accessory Structures Mitigation Solution: For Accessory Structures Figure 5.1.1. Bolted brackets or clamps can be used to anchor some structures.
387	Figure 5.1.2. Chains or steel cables attached to ground anchors can be used to anchor park structures.
388	Figure 5.1.3. Some park equipment can be embedded deep enough into the ground to improve stability. Figure 5.1.4. Poles and posts embedded in concrete can help resist wind.
389	Mitigation Solution: For Sport Courts Mitigation Solution: For Sport Courts Figure 5.1.5. New courts can be overlaid on existing cracked tennis and basketball courts.
390	Mitigation Solution: For Landscaping Mitigation Solution: For Landscaping Figure 5.1.6. A bioswale can help retain floodwaters (left), and a culvert pipe can direct flow under a road or trail (right).
392	Figure 5.1.7. Greenways can help direct and absorb floodwaters. Figure 5.1.8. Nature-based solutions or hybrid approaches to streambank stabilization (combining hardscapes with nature-based solutions) can protect trails and other park facilities.
394	Fact Sheet 5.2: Mass Transit Facilities Fact Sheet 5.2: Mass Transit Facilities
395	Table 5.2.1. Additional Information on Mass Transit Facility Vulnerabilities and Mitigation Solutions
397	Table 5.2.2. Table 5.2.2. Common Mitigation Solutions for Mass Transit Facilities
398	Mitigation Solution: For Tunnels Mitigation Solution: For Tunnels Figure 5.2.1. Subway tunnel cross section.
399	Figure 5.2.2. Inflatable plugs can prevent flooding in tunnels. (Source: Department of Homeland Security, 2017)
400	Figure 5.2.3. Elevated vent covers help protect against subway flooding while also acting as public sculptures. (Source: Jim Henderson, 2009)
401	Figure 5.2.4. Flood gates and flood barriers can help protect buildings and structures against rising water. Figure 5.2.5. Recessed passive barriers float into place automatically to protect against flooding.
402	Figure 5.2.6. Deployable covers for subway access stairways can help prevent flooding of underground stations. (Source: Metropolitan Transportation Authority, 2021)
403	Figure 5.2.7. Floodwalls can help protect buildings from being flooded.
405	Mitigation Solution: For Railways Mitigation Solution: For Railways Figure 5.2.8. Rail system components.
409	Mitigation Solution: For Catenary Overhead System Mitigation Solution: For Catenary Overhead System Figure 5.2.9. Catenary system.
412	Fact Sheet 5.3: Earth Slope Stabilization Fact Sheet 5.3: Earth Slope Stabilization
413	Slides Slides Figure 5.3.1. Examples and description of slides. (Source: Washington Geological Survey)
414	Table 5.3.1. Common Mitigation Solutions for Earth Slope Stabilization
415	Mitigation Solution: Excavate Mitigation Solution: Excavate Figure 5.3.2. Removing soil and replacing it with lightweight fill can help decrease loads that drive soil downslope.
416	Figure 5.3.3. Benching or terracing can help improve slope stability.
417	Figure 5.3.4. Reducing the slope angle removes some of the driving forces that can cause instability. (Source: USGS, 2004)
418	Mitigation Solution: Reinforce or Strengthen Mitigation Solution: Reinforce or Strengthen Figure 5.3.5. Geosynthetics can be used to reinforce and strengthen slopes. (Source: FHWA, 2009)
419	Figure 5.3.6. A toe berm adds resistance to sliding material.
420	Figure 5.3.7. Deep soil mixing (DSM) creates a soil-concrete column to provide additional stability against sliding.
421	Figure 5.3.8. Soil nailing can allow slope stabilization at steep angles. (Source: FHWA, 2015) Figure 5.3.9. Soil nailing can be combined with vegetation to improve slope stability and aesthetics for both shallow and deep failure surfaces. (Source: FHWA, 2015)
423	Mitigation Solution: Install Drainage Mitigation Solution: Install Drainage Figure 5.3.10. Interceptor trench drains can be used to direct surface runoff away from slopes.
424	Figure 5.3.11. Horizontal drains help lower the water table, which reduces driving forces by decreasing soil water content. (Source: USGS, 2008)
425	Figure 5.3.12. Check dams can be constructed of logs, rocks, or other materials to slow the flow of water in a channel on a slope. (Source: U.S. Forest Service, 2007)
426	Mitigation Solution: Install Retaining Walls Mitigation Solution: Install Retaining Walls Figure 5.3.13. MSE walls use geotextiles and granular soil backfill to retain slopes. (Source: FHWA, 2009)
427	Figure 5.3.14. Soldier pile walls can be used to reinforce failure planes. (Source: FHWA, 1999)
428	Figure 5.3.15. Gabions can be used to improve slope stability by resisting the sideways forces behind them. (Source: FHWA, 2001)
429	Figure 5.3.16. Crib walls can be constructed easily to retain soil on a slope. (Source: U.S. Forest Service, 2007)
431	Mitigation Solution: Install Nature-Based Solutions Mitigation Solution: Install Nature-Based Solutions Figure 5.3.17. Using vegetated stakes alone or in combination with a brush mat can help control erosion on slopes. (Source: NRCS, 1996)
432	Figure 5.3.18. Live fascine bundles can be used with stakes to help control erosion.(Source: USDA Forest Service, 2006) Figure 5.3.19. Live crib walls can provide stability and help control erosion. (Source: NRCS, 1996)
435	Fact Sheet 5.4: Shorelines Fact Sheet 5.4: Shorelines Table 5.4.1. Common Shoreline Mitigation Solutions
436	Mitigation Solution: Structurally Stabilize Shorelines Mitigation Solution: Structurally Stabilize Shorelines
437	Figure 5.4.1. Example seawall cross-sections.
438	Figure 5.4.2. Example of an anchored sheet-pile bulkhead.
439	Figure 5.4.3. Typical cross section of an armor stone revetment.
440	Figure 5.4.4. Typical plan view of a breakwater system.
441	Figure 5.4.5. Example sand accretion and erosion patterns around a groin system.
443	Figure 5.4.6. Rock cores can be used to build dunes that resist erosion from waves and surge.
444	Mitigation Solution: Use Non-Structural Stabilization Mitigation Solution: Use Non-Structural Stabilization Figure 5.4.7. Beach nourishment replaces sand lost through longshore drift or erosion and increases resilience. (Source: USACE, 2020).
445	Figure 5.4.8. Nature-based solutions for shoreline stabilization via a “Living Shorelines” approach. (Source: Adapted from NOAA, 2016)
448	Fact Sheet 5.5: Coastal Facilities Fact Sheet 5.5: Coastal Facilities
449	Table 5.5.1. Common Mitigation Solutions for Damage to Coastal Facilities
450	Mitigation Solution: Monitor, Inspect, Repair Mitigation Solution: Monitor, Inspect, Repair
451	Mitigation Solution: Retrofit, Reinforce Mitigation Solution: Retrofit, Reinforce Figure 5.5.1. Piles can be wrapped with PVC to protect them from damage (Source: Marine Fix Supply, 2018).
452	Figure 5.5.2. Fit aging piles with jacket encasements to strengthen and protect them (Source: Shoreline Plastics, No Date). Figure 5.5.3. Improve pier performance during future storms by replacing storm-damaged pre-cast concrete pier deck panels with reinforced cast-in-place concrete (Source: U.S. Army Corps of Engineers, No Date).
453	Figure 5.5.4. Reinforce wharves, docks and boardwalks by splicing and reinforcing the structural components of piers and piles (Source: Professional Diving Services, 2020).
454	Figure 5.5.5. Rendering of downtown San Francisco Terminal Expansion Project containing a marine terminal dock complex with in-water structural components joined together withshore-based structures (Source: Water Emergency Transportation Authority, 2021
455	Figure 5.5.6. An example of revetments protecting a boat launch ramp system. Figure 5.5.7. An example of an outdoor dry-stack storage facility (Source: Brendan McGinley, 2021).
456	Figure 5.5.8. An example of an indoor dry-stack facility.
457	Mitigation Solution: Elevate Mitigation Solution: Elevate Figure 5.5.9. Elevating piers can help protect them from the impacts of floods (Source: USACE, 2020)
459	Mitigation Solution: Upgrade, Relocate Mitigation Solution: Upgrade, Relocate
461	Appendices
462	A: Acronyms
463	B: Glossary of Key Terms
474	C: Codes, Standards, Best Practices and Mitigation 1. Codes
476	2. Standards
477	3. Best Practices
478	4. Mitigation
481	D: References
486	E: Comment Submission and Contacting FEMA How to Obtain Hurricane and Flood Mitigation Handbook for Public Facilities How to Send Comments on the Handbook How to Get More Information