The Texas town of Kingwood is no stranger to flood plains. After flooding events in 2017 and again in 2019, many residents here consider these occurrences to be the result of a perfect storm of inefficient urban planning, inadequate drainage, and weather. A working knowledge of flood pains, 100-year floods, and the benefits of having flood insurance has never been more critical, which has many turning to local insurance agents who have firsthand experience with flooding in their community.
Flood Plains
By general definition, a flood plain is a relatively flat land located near a body of water such as a creek, stream, or river that is known to experience occasional flooding. Once these bodies of water come out of their banks, the areas they touch usually become known as a flood plain.
Flood plains have two major components:
- the floodway
- the flood fringe
A floodway is a primary channel the body of water. The flood fringe includes the area from the banks of the body of water to the valley wall. Depending on the area, rural and urban flood plains can extend feet or even miles.
How Flood Plains are Created
Flood plains generally come into existence in one of three ways: erosion, aggradation, or inefficient urban planning. Erosion is a natural process that refers to the wearing away of land via water. Aggradation is the natural process of a creek, stream, or river rising due to the deposit of sediments. Inefficient urban planning is a man-made process that can contribute to the creation of a flood plain.
Areas of Kingwood, Texas experienced catastrophic flooding during Hurricane Harvey in 2017 and more recently in heavy rains during May of 2019 that many believe is in large part due to inefficient urban planning.
A little more than two decades ago, the greater Lake Houston area was comprised of thousands of acres of wetlands, but local research groups say the number is now falling by the thousands as wetlands are filled in and paved over. With once absorbent vegetation-covered soil giving way to concrete roads and new developments, the lay of the land and its ability to manage floodwater is changing.
Hundred Year Flood Plains
As flooding, unfortunately, becomes a frequent headline on the national and world news, viewers are increasingly hearing terms like 100-year flood or 500-year flood. But what does that really mean?
According to the United States Geological Survey’s (USGS) website, the federal government declared the one percent annual exceedance probability as the basis for the National Flood Insurance Program in the 1960s. More simply explained, this translates to a one percent chance of a particular flood being equaled or exceeded in the general interval of one hundred years. The statistic is often more commonly referred to as the 100-year flood.
The term 500-year flood is often used to refer to larger floods and is categorized as having a one in five hundred chance or 0.2 percent chance of happening during the course of a year.
To put things in perspective, not long after Hurricane Harvey left a trail of flooding and destruction behind, some at the Harris County Flood Control District likened the circumstances to that of a 500-year rainfall and flood. Other researchers estimate that certain areas of Houston impacted by Harvey may have reached the 1,000-year flood benchmark.
The misleading thing about terms such as a 100-year flood and a 500-year flood is that they seldom translate into having exactly one hundred or five hundred years in between floods of a similar magnitude. For this reason, it may be more advisable for residents to think of these floods in terms of annual exceedance probability rather than centuries.
However you choose to think of these particular flooding events, it is worth noting that their benchmarks can change. On average, the circumstances usually responsible for these types of floods can be:
- long-term climate patterns
- urbanization
- lack of flood control installation
How do I know if I live in a flood plain?
Residents usually consult the Federal Emergency Management Agency (FEMA) for a look at their Flood Insurance Rate Map (FIRM) to see if they are considered to be at risk for flooding. In general, these maps are divided into zones based on a location’s proximity to a floodway. The maps should also show those locations found in a Special Flood Hazard Area, an area within the boundary of a 100-year flood.
In addition to providing potential or current homeowners with flood risk data, the same information is frequently used by engineers, city officials, and builders to determine the viability of new developments and structures.
Flood maps are formulated using a variety of different data and for that reason are constantly being adjusted and redrawn, which can pose a challenge to residents seeking a current and accurate flood map.
In cases like these, an experienced and knowledgeable local insurance agent who personally knows your area may be able to provide:
- Firsthand knowledge of actual flood zones in your community rather than those based on a formula
- Compassion and understanding not always shared by national providers that are unaffected by local circumstances
Do I need flood insurance if I’m not in a flood plain?
In a word, yes. Even if you are not living in an official flood plain now, as mentioned above, the designation of a 100-year or 500-year flood can change based on a number of fluid factors. In addition, FEMA estimates that more than twenty percent of flood claims come from properties outside a high-risk flood zone, and homeowners and renters insurance typically do not cover flood damage.
Benefits of having flood insurance can include:
- Peace of mind
- Protection of property
- Saving money compared to the cost of repairing or rebuilding a non-insured home
With recent flooding creating millions of dollars of damage in the Houston and Kingwood area, having a flood insurance policy in place is more crucial than it is optional. Enlist the help of a local insurance agent for a more locally tailored experience that may better serve you and your family.
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