Section D. Before the Flood – Protecting Your Property
This home is elevated three feet above the BFE.
Don’t forget: a permit is needed for filling or re-grading a yard. There may be restrictions on bringing fill onto your site if it blocks the flow of flooding or displaces floodwater storage areas.
Precautions: Barriers can realistically only be built so high. A flood that was higher than planned for can also overtop them. Earthen berms are susceptible to erosion from rain and floodwaters if they are not properly sloped and covered with grass and maintained. Don’t plant trees or shrubs on a berm (their roots can cause leaks). Barriers can settle over time, lowering their protection levels. Some barriers have openings for driveways and sidewalks. Closing these openings is dependent on someone being available and strong enough to put the closure in place. You also need to account for water in the sewer lines that may back up under the barrier and flood inside your house.
This technique is only allowed for Pre-FIRM residential structures that have not been substantially damaged or improved and for any commercial structures that would be made compliant to BFE requirements. This term covers several techniques for sealing up a building to ensure that floodwaters cannot get inside it. For dry floodproofing, all areas below the flood protection level are watertight. Walls are coated with waterproofing compounds or plastic sheeting. Openings (doors, windows, and vents) are closed, either permanently, with removable shields, or with sandbags. Many dry floodproofed buildings do not look any different from those that have not been modified. Dry floodproofing should be done to a height of 18 inches above the BFE.
Dry floodproofing is only appropriate for buildings on concrete slab floors (without basements) and with no cracks. To ensure that the slab is watertight and sound, an engineering analysis is recommended. The maximum flood protection level is two feet above the slab, but you must add an additional foot for freeboard. The walls and slab floor were not built to withstand the type of pressures exerted by deeper water. It is smarter to let deep water into your house than to risk losing your walls or floor.Precautions: It is very tempting for the owner of a dry floodproofed building to try to keep the flood out if floodwaters get deeper than two or three feet. This can result in collapsed walls, buckled floors, and danger to the occupants. It is difficult to waterproof a crawlspace to protect it from underseepage.
Many commercial waterproofing compounds are designed to protect wood from rain, but they will not withstand the pressures of standing water. Some deteriorate over time, so check with the supplier to be sure the waterproofing compound is appropriate for sealing your walls from water. Installing closures and seals over doors and windows requires enough warning and having someone at the building who knows what to do.
Tip:
A berm or floodwall should be as far from the building as possible to reduce the threat of seepage and hydrostatic pressure. However, it must not interfere with drainage along your property line. Where the house is too close to the property line, you may to need place the berm next to the wall of the structure.
This technique is feasible for Pre-FIRM multi-story residential structures that have not been substantially damaged or improved and for any commercial structures that would be made compliant to BFE requirements. Wet floodproofing means letting the water in and removing everything that could be damaged by a flood. There are several ways to modify a building so that floodwaters are allowed inside, but minimal damage is done to the building and its contents. These techniques range from moving a few valuable items to rebuilding the floodprone area.
In the latter case, structural components below the flood level are replaced with materials that are not subject to water damage. For example, concrete block walls are used instead of wooden studs and gypsum wallboard. The furnace, water heater, and laundry facilities are permanently relocated to a higher floor. Another approach is to raise these items on blocks or platforms where the flooding is not deep. Wet floodproofing is not feasible for one-story houses because the flooded areas are the living areas.
Many people wet floodproof their garages and accessory buildings simply by relocating all hard-to-move valuables, such as heavy furniture and electrical outlets. Light or moveable items, like lawn furniture and bicycles, can be moved if there is enough warning. Fuse and electric breaker boxes should be located so you can safely turn the power off to the circuits serving floodprone areas.
Another approach is to wet floodproof a crawlspace. If your crawlspace has a furnace in it or is used for storage, these items could be moved to the first or second floor. Vents, which comply with local ordinances, must be placed on the foundation walls to ensure that floodwaters can get into the crawlspace to equalized water pressure.
Precautions:
Moving contents is dependent on adequate warning and the presence of someone who knows what to do. Flooding a garage where there is electricity, paint, gasoline, pesticides, or other hazardous materials creates a safety hazard. There will still be a need for cleanup, with its accompanying health problems. Moving water lines, furnaces, or electric services boxes requires a permit from your building department.
Sanitary Sewer Backup Protection
The next four items of this Citizens Guide focus on protection measures that deal with sanitary sewer backup that occurs when the sewer main is overloaded and backs up through the sanitary service line into the house. There are four ways to stop sewer backup: floor drain plug, floor drain standpipe, overhead sewer, and backup valve. Each of these measures work for buildings with basements or below-grade floors.
Sewer backup: Sanitary sewers should not be affected by storm water because they are separate from the storm sewers. However, there can be cross connections and leaks in sewer pipes that receive inflows and infiltration which can overload a sanitary line during wet weather. With no place to go, sewers back up and flow into the lowest opening in the sewer line. Sanitary sewers back up into structures and storm sewers back up into streets.
Floor Drain Backup Prevention: The simplest way to stop sewer backup is to plug the opening where it first occurs. This is at the floor drain, the sanitary sewer system’s lowest opening in the house. Two inexpensive measures can be used: a plug or a standpipe. Both can be purchased at local hardware stores and are easy for the handyperson to install.
Plug: The flood drain plug stops water from flowing in either direction. Therefore, if the laundry tub overflows or other spillage occurs, it will stay in the basement unless the plug is removed. Because of this, it may be best to leave the plug out under normal circumstances and put it in place only during heavy rains.
One variation is a plug with a float. It allows water to drain out of the basement. When the sewer backs up, the float rises and plugs the drain. A float plug permanently installed will not interfere with the floor drain’s normal operation. If the plug is not tight enough, pressure can eject it. Therefore, a plug is not recommended for flood depths greater than one foot.
Standpipe: A standpipe is an inexpensive alternative to a floor drain plug. When the sewer backs up, the water moves up the pipe. If properly installed, water pressure cannot build up to blow a standpipe out of the floor drain. The system works unless the backup is so deep that it goes over the top of the pipe.
Precautions: A plug left in the floor drain may contribute to a wet basement if water from a laundry tub spill or a leaky pipe cannot drain out. Float plugs are known to have been jammed open by a small amount of debris. A plug does not tell you if there is a problem in your sewer service line.
Neither the plug or standpipe stops backup from coming out of the next lower opening, like a laundry tub or basement toilet. Sealing the base of the toilet to the floor will protect you until the water backs up higher than the top of the bowl.
Because water pressure depends on the height of water in the pipes, a standpipe does not reduce the pressure in the pipes or under the floor, if the pipes leak. Because the pressure under the floor is the same with a standpipe or a plug, standpipes and plugs are only recommended for flood depths of one foot or less and for buildings with cast iron sewer lines underneath the floor.
Typical basement drain and sewer arrangement Note: Your floor drain may or may not be connected to the sanitary sewer line
A Citizen’s Guide to Flood Protection Measures8
Overhead Sewer: An overhead sewer is generally viewed as the most effective sewer backup protection measure. It acts like a standpipe but without the shortcomings. A sump is installed under the basement floor to intercept sewage up above the flood level. From there it can drain by gravity into the sewer service line. Plumbing fixtures on the first floor continue to drain by gravity to the service line.
Unless the house is subject to overbank flooding, it is unlikely that the sewers will back up above ground level. If water does go higher, a check valve in the pipe from the ejector pump keeps it in the pipes. Backed up sewage is enclosed in the sewer pipes and doesn’t overflow laundry tubs or basement toilets.
Although more dependable than a standpipe, an overhead sewer is more expensive. A plumbing contractor must reconstruct the pipes in the basement and install the ejector pump. It can cost between 3,000 - 7,000.
Sewer Backup Valve: A backup valve stops the water in the sewer pipes. While not as foolproof as an overhead sewer, their installations are less disruptive of the basement.
Older versions of this approach were located in the basement floor and relied on gravity to close the valve. If debris got caught in the flapper, the valve did not close tight. Because of its unreliability, valves were discouraged and even prohibited in some communities. Today’s systems are more secure. They include installing two valves in line, using better, more watertight materials, or counterweights that keep the valve open all the time so debris will not catch and clog it. Larger valve systems are usually installed in a manhole in the yard, well away from the basement wall, so there is less disruption during construction and no concerns over breaking the pipes under the basement floor. The cost of this type of backup valve is comparable to the cost of an overhead sewer, in the 4,000 - 6,000 range.
Precautions: The ejector pump and the valve require maintenance. This work requires a licensed plumber and a permit from your building department.
Working with Contractors
Most building departments in Mississippi require that only licensed contractors do certain work. Building departments usually have a register of licensed contractors, listed by their area of expertise. If you have been satisfied with work done by licensed local contractors, try them first. If they cannot help you, ask them for recommendations. If you must hire a contractor you do not know, talk to several contractors before you sign anything.
Valve Precautions:
The ejector pump requires electricity to work, so battery backups are recommended. The basement is disrupted during constructions and the ejector pump needs periodic maintenance. This work requires a licensed plumber and a permit from your building department.
Reputable contractors agree that you should take the following steps:
Check several firms and their reputations: The Better Business Bureau, Home Builders Association, or building trades council are excellent sources.
Look out for “special deals” or contractors who want to use your home as a “model home.”
Ask for proof of insurance: Worker’s compensation and general liability insurance are essential. If the contractor is not insured, you may be liable for accidents on your property.
Ask for references: Contractors should be willing to provide names of previous customers. Call some of the customers and ask if they would hire the contractor again.
Ask for a written estimate and check it carefully.
Ask for a contract. Never sign a blank contract or one with blank spaces. If a lot of money is involved, it may be worth your while to have the contract reviewed by a lawyer.
Avoid cash payments: Beware if you are asked to pay cash on the spot instead of a check made out to the contracting company. A reasonable down payment is 10% - 30% of the total cost of the project.
Don’t sign off before the job is finished: A reputable contractor will not threaten you or pressure you to sign if the job is not finished.
Get your permits: Most plumbing work, home improvements, filling, fences, and other year work require a permit from your building department to be sure that it meets code and will not cause a drainage problem on your neighbors.
Get your inspections: When the project is finished, make sure your contractor calls you and the building department to inspect work before it is covered over. Some will be hidden from view and you won’t know if there is a problem until the next flood.
Get help: If you are a victim of fraud or have problems with a less than reputable contractor, check with the Mississippi Attorney General’s Consumer Protection Division (601)-359-4230 or www. ago.state.ms.us). Your building department would also like to know of problems in case it needs to revoke a license.
Insurance
Flood Insurance: The majority of homeowners’ insurance policies do not cover property for flood damage, which is why flood insurance is highly recommended. Remember, even if the last storm or flood missed you and even if your home has been floodproofed, the next flood could be worse.
Almost all of the communities in Mississippi participate in the National Flood Insurance Program. Local insurance agents can sell a flood insurance policy under rules and rates set by the federal government. Any agent can sell a policy and all agents must charge the same rates.
Any house can be covered by a flood insurance policy. It does not matter if it is in the high-risk area (commonly called the floodplain) or out of it. Detached garages and accessory buildings are covered under the policy for the lot’s main building. Separate coverage can be obtained for the building’s structure and for its contents, except for money, valuable paper, and the like.
Some people have purchased flood insurance because the bank required it when they got a mortgage or home improvement loan. If you have a policy, check it closely. You may only have structural coverage (because that’s all that banks require). Don’t wait for the next flood to buy insurance protection. There is a 30-day waiting period before National Flood Insurance coverage takes effect. Contact your insurance agent for more information on rates and coverage.
Other Types of Coverage
Sewer backup insurance: Several insurance companies have sump pump failure or sewer backup coverage that can be added to a homeowner’s insurance policy. Each company has different amounts of coverage, exclusions, deductibles, and arrangements. Most are riders that cost extra. Most exclude damage from surface flooding that would be covered by a National Flood Insurance policy. The cost varies from nothing to up to about 75 dollars for a rider on your homeowner’s premium.
Basements, split-levels, and bi-levels: There is limited coverage for basements and the below grade floors of bi-levels and tri-levels. The National Flood Insurance Program defines “basements” as “any area of the building, including any sunken room or sunken portion of a room, having its floor below ground level (sub grade) on all sides.” This includes split-levels and bi-levels.
Building or structural coverage: These are limited to specific items needed for the operation of the building, such as a furnace, water heater, clothes washer and dryer. There is a very limited coverage for finishings, such as wallpaper and carpeting, and contents. Flood insurance only covers damage when there is a general condition of surface flooding in the area.
The structure generally includes everything that stays with a house when it is sold, including the furnace, cabinets, built-in appliances, and wall-to-wall carpeting.
There is no coverage for things outside the house, like the driveway and landscaping. Renters can buy contents coverage, even if the owner does not buy structural coverage on the building.
