Session One: Water, Water Everywhere
January 29th, 2005by Sue Stachowiak, David Irons, and Tom Acpenny
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What You Should Know About FloodsWhat is a flood?The National Flood Insurance Program defines "flood" as a general and temporary condition of partial or complete inundation of normally dry land areas from overflow of inland or tidal waters or from the unusual and rapid accumulation of runoff of surface waters from any source.
100-year Flood Plain The 100-year floodplain is the land adjacent to a river, lake or stream that will be flooded by water, which has a 1% chance of occuring of being exceeded in any given year. Every lake or stream has a floodplain associated with it.
The flood elevations for rivers and streams are based on engineering analyses of the hydrology (how much water will runoff the land during a flood event) of the watershed and the hydraulics of the river stream.
There are numerous factors in regards to the amount of runoff during a 100-year flood event:
These factors must be considered in computing the flow rates used in hydraulic analysis. The hydraulic analysis uses the flood flows to determine how high the water will get during the 100-year (1% chance) flood. There are also factors that influence the amount that a stream will rise during a flood event:
"How can my property be floodplain when I've lived here for so long?"
The standard flood for floodplain management is the 1% chance (100-year) flood. It is possible to go long lenths of time without experiencing the 1% chance flood. At the same time, it is possible to have those floods two consecutive years. There are areas along the Grand River that have not had a flood since the early 1900's, while others have had numerous consecutive floods.
If your house is located within the 100-year floodplain, it has a 26% chance of being flooded during the life of a 30-year mortgage.
There are various sources that may be checked to see if a floodplain map exists for your community. Flood Insurance Rate Maps published by the Federal Emergency Management Agency (FEMA) are availabe online.
 The alteration of a floodplain of a river, stream, or drain which has a draingage area greater than or equal to 2 square miles will require at state floodplain permit.
Construction, for the most part, may be permitted in the portions of the floodplain that are not floodway, as long as local ordinance and building codes are met.
Current building codes in Michigan require that new construction within the 100-year flood floodplain have the lowest floor, elevated at least one-foot above the 100-year flood elevation.
Floodways include the channel fo a river or stream and area adjacent to the channel that will carry moving water during times of a flood. This is a high hazard portion of the floodplain. The floodway is that portion of the floodplain that we see on television, in which houses have been swept away from the foundation.
Residential construction is prohibited within the floodway portion of the floodplain. Commercial construction is permitted as long as a hydraulic analysis is done demonstrating that the proposal will not harmfully increase flood stages or shift flood flows onto adjacent property owners.
Floodplain Permit (Part 31)
Floodplain Permit is required for any construction performed within the Floodplain of a stream or river. The permit application is obtainable at the County Public Works office.
Floodplain Management includes zoning ordinances, subdivision regulations, building codes, health regulations, special purpose ordinances (such as floodplain ordinance, grading ordinance and erosion control ordinance), and other applications of regulatory authority.
Building Houses/AdditionsA state floodplain (part 31) permit is not required for the construction of a house within the floodplain of a lake, provided the construction is not being proposed on the inlet or outlet of the lake. Local building codes will require that the house be constructed above the 100-year flood elevation.
If an addition will increase the size of a "foot print" of the house, and the addition is in the floodplain, a permit under Part 31 will be required. If the addition does not increase the foot-print, a permit will not be required.
The following are other activities that do not require a permit under Part 31:
What is a "harmful" interference?Under the Part 31 rules, harmful interference means causing an increased stage or change in direction of flow of a river or stream that causes or is likely to cause; damage to property, a threat to life, a threat of personal injury or the pollution, impairment, or destruction of water or other natural resources.
Your project may be permitted under Part 31 if it does not cause harmful interference.
A harmful increase in flood stage can vary in different locations. In an urban setting, it is possible that any increase in flood stage will be harmful. In this condition, you would have to demostrate that the project would not cause any increase in flood stage, for a range of discharges up to and including the 100-year flow.
If a project results in a flood increase, and the increase is not contained on the property of the individual proposing the project, you might need to obtain damage waivers from upstream property owners that could be impacted by increased flood conditions. The damage waivers are to notify the upstream property owners and make sure they are aware of a potential flood increase.
National Flood Program Insurance (NFIP)The National Flood Program is a federal program which enables property owners to purchase flood insurance. The federal government makes flood insurance available to communities that agree to enforce requirements that will reduce future flood losses to new construction within the special hazard area (100-year floodplain).
The goal of the NFIP is to mitigate future flood damages by requiring proper construction methods, and to provide a method of insuring against flood damage.
Flood insurance is only available through the NFIP, and is not included in Home Owners insurance. Your community must participate in the National Flood Insurance Program in order for you to purchase flood insurance. In that case, you can purchase it from any insurance agent.
If a community is not apart of the NFIP, and would like to join, they would have to pass a resolution indicating they would like to join, pass a resolution directing the building official to strictly enforce the flood resistant cocnstruction standards of the building code, and submit the application.
Under the NFIP Reform Act, if a building securing a loan is located within a federally identified special flood hazard area (100-year floodplain), and the lender is federally regulated, supervised or insured, flood insurance must be required as a condition of the loan.
If a community does not have a flood insurance rate map, it means that there are currently no federally identified special flood hazard areas in the community. In that case, there would be no federal mandatory flood insurance purchase requirements as terms of a loan. There is a floodplain associated with every river, lake, stream, or drain, even if it has not been identified by the FEMA.
Cost of Flood InsuranceThe cost of flood insurance varies depending on how much is being insured, when the house was built, if the house has a basement, and the elevation of the lowest floor of the house. When applying for insurance, there is a 30-day waiting period. The exception to the waiting period would involve new real estate transactions, when title is being transfered.
If the house was built before the date of the existing flood insurance rate map, if qualifies for a subsidized rate. For example, for $100,000 worth of structural coverage for a house with a basement in the 100-year floodplain, built before the date of the map, the coverage would cost about $700/year.
Before, After, and During a Flood
There are numerous precautions to take when preparing for a flood. It is very important to make sure that your home is insured, not only does the law require it, mother nature demands it!
Before a FloodBesides having insurance on your home, there are many ways that you should prepare for a flood to minimize potential loss to your home and belongings. Here are a few precautionary things:
During a FloodAt this point, hopefully you have done everything that you could to prepare for a flood. Your home is flood ready, and you have secured a flood insurance policy.
Now that the floods are beginning, there is no turning back. Here is what you can do at this point :
After a FloodThe floods have come and gone, and your community and home are full of water. Try not to panic, and remain safe by following these instructions:
Hazards of Flood Cleanup
Workers and other people involved with flood cleanup should be aware of the potential dangers involved and the proper safety percautions.
The level of experience varies among workers, cleanup crews must collaborate to ensure safety. The National Institute for Occupational Safety and Health (NOISH) warns flood workers that when the flood waters recede, they will continue to face a number of hazards associated with cleanup activities.
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Learn
how to manage water in and around your house before it becomes a hazard.
Property improvements, DEQ requirements, the scale of new additions,
and other water-usage problem solving issues are addressed.
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