Houston residents are all too familiar with destructive water events. One of the worst in recent memory, Hurricane Harvey in 2017, stalled over Texas and dropped 30 inches of rain–16 of that in a single day! While that would cause major flooding anywhere, Houston seems to experience more news-making floods than many other metros. The flooding in Houston impacts millions that call the metro home.

And yet, the Gulf Coast city remains a popular place to live. For those new to Houston and looking for a home, be aware the flood hazard isn’t the same across Houston neighborhoods. Dive into the causes and explore the ongoing mitigation efforts. Learn a few proactive steps you can take to minimize flood risk and build a more resilient future. Let’s safeguard our Texas community together!

Houston has a well-documented flood history. Its geography makes it more flood-prone. The city barely sits above sea level and is waterfront on Houston Bay. That land stays rather flat for miles inland, rising roughly one foot for every mile away from the Bay. Underneath the top ground layer is clay-based soil that absorbs water slowly.

Poor City Planning

Additionally, Houston’s rapid urbanization has reduced natural drainage areas, exacerbating the risk of flooding from excessive rainfall. Paved surface area in Harris County, central in the metro, increased 25% since 2000, while it lost 30% of its wetlands from 1992 to 2010. 

Even through Houston experienced major floods in its early years, little infrastructure or careful zoning was incorporated into the early city planning. In fact, the City of Houston has no zoning policy, enabling a pro-developer environment with little oversight on flood prevention measures.

The US Army Corps of Engineers built some reservoirs in the 1940s to control floods. The flood control district has also built levees, retention ponds, and man-made drainage channels. Houston’s streets are designed to flood in major storms, keeping excess stormwater out of homes and buildings.

Still, few citywide efforts have been taken with big-picture flood control in mind. A few flood risk reduction projects underway, like the Inwood Forrest Stormwater Detention and the North Canal Diversion Project. Houston’s understanding of flood potential is evolving as these severe weather events become more common and more of the flat flood plain is developed.

Changing Climate

Finally, weather patterns contribute to its heightened flood risk. Hurricanes, and tropical storms are common. Being bay front increases Houston’s storm surge risk. These storms also bring heavy rainfall and worsens the risk for flooding. Climate change has brought increased how often ten-inch rainfalls dump on Houston. It’s also heightened the severity of tropical storms.

These combined factors–a flat flood plain and more wet weather– result in severe flooding being more frequent across Harris County than other cities of similar size. Knowing these factors helps grasp why specific areas might be more vulnerable to flood damage.

What is Being Done About It

Infrastructure Improvements

The City of Houston has been actively investing in infrastructure to mitigate flood risks, especially since Hurricane Harvey. Projects include:

• Bayou Widening: Expanding waterways to handle higher volumes of water.
• Reservoir Enhancements: Strengthening and expanding reservoirs to control water flow during heavy rain events.
• Drainage System Upgrades: Modernizing and expanding drainage networks to improve water runoff.

All these flood damage reduction projects take time and hundreds of thousands of dollars. 

After recent major floods, and with a better understanding of flood potential, Houston is redrawing its flood plain maps. However, these new maps won’t be ready until 2025. When they do release, expect changes to the flood insurance rate maps. 

How to Minimize Your Houston Flood Risk

Eight flooding disasters have occured since 2015. That’s almost one a year as of 2024.

Some 322,000 homes in the Greater Houston metro lie in a designated flood plain. That represents about 25% of Houston homes! One out of every seven properties is at risk of catastrophic flooding by 2050. 

While tropical storms and hurricanes get a lot of additional, more of the natural disasters have been caused by heavy rains from thunderstorms. Annual rainfall typically causes flooding Houston 4-5 times a year.

One of the most critical steps in buying a Houston home is to assess the flood risk. Many resources can help you identify whether your property is in a moderate risk or high-risk zone:

• FEMA Flood Maps: The Federal Emergency Management Agency provides up-to-date flood maps detailing areas at risk.
• Harris County Flood Control District: It has an interactive flood map based on FEMA maps where you can assess rainfall and floodplain maps.
• First Street Foundation: Its flood hazard maps account for rainfall totals and climate risks.

However, studies have found that 75% of reported flood damage in Harris County was outside the 100-year flood plain. So even if the flood map says the property is in a 500-year floodplain, consider it at risk from flooding. 

Texas sellers are require to disclose any prior flooding, but a “did not flood” designation does not mean the property is not at exempt from future flood events.

Low-Flood Houston Neighborhoods

Floods can happen anywhere, even in these lower-risk Houston communities. Still, their risk of flooding is lower than other neighborhoods. Their history of flooding is less than that of other parts of the city. These tend to be in northwest Houston, where the ground level is higher.

Briargrove

Outside I-610 in greater Uptown, this midcentury development is a suburban neighborhood with well-established landscaping. Locals live near Galleria Mall and River Oaks.

Houston Heights

The name hints at its higher elevation, which is about 38 feet above sea levels in different spots. The Victorian-era community was built up on a sandy ridge.

EaDo

Short for East Downtown, this neighborhood will have its streets flood in heavy rains, but that’s part of its runoff system. Homes are near downtown and the Central Business District.

Afton Oaks

Another northwest addition, the Inner Loop suburb is well-established, with some of its ranch-style homes dating to the 1950s. Oaks shade the streets, while it has a civic club running local amenities.

Southgate

Ideally near Rice University and Texas Medical Center, Southgate is a mix of single-family homes and newer, high-rise condos.

River Oaks

Known for its grand homes and prime Inner Loops location, River Oaks has fared well in past flooding events. Some homes close to the Buffalo Bayou have experienced flooding, the vast majority away from the water course report fewer issues.

West U

Water gushed down West U streets, but surprisngly little wound up in homes after Hurricane Imelda’s deluge. That’s to the city’s street design. This residential enclave is also near Rice University and connected to Houston’s major arteries.

Keeping Your Houston Home Dry

If your home is in a flood-prone area, consider these measures to protect your property:

• Elevate Electrical Systems: Raise electrical panels, sockets, and wiring above potential flood levels.
• Install Flood Vents: These allow water to flow through your home’s foundation, reducing structural pressure and property damage.
• Use Flood-Resistant Materials: Opt for materials such as tile, concrete, and closed-cell insulation in areas below the expected flood water levels.
• Re-Engineering: If you’re building a home, consider lifting its foundation or using pier-and-beam construction. Get above any potential flood waters. Note that the City of Houston now requires new construction to be a minimum two feet about the 500-year flood plain elevation.

If severe weather conditions are approaching the area, stay alert to changing conditions. Homes in zones AO, AR, and AH have a average depth of flooding averaging 1 to 3 feet. Zone B averages less than a foot or may be protected by levees from 100-year floods.

Houston Flood Risk

Flood risk in Houston is a multifaceted issue, influenced by geography, urbanization, development practices, and weather patterns. While there are ongoing efforts to reduce flood risk through infrastructure improvements and city planning, it ultimately falls on the homeowner to check their flood risk and take preventative measures.

Take action today—check your home’s flood risk and ensure you are prepared for whatever nature throws your way. Embrace resilience and rise above the flood risk in Houston.

FAQs

What does 100-year flood plain mean?

A 100-year floodplain is an area that has a one percent chance of flooding in any given year. It is determined by taking into account historical flood data, rainfall patterns, and other factors. While it may seem like a rare occurrence, it’s important to note that flooding can happen outside of designated floodplains, especially in areas with heavy rainfall or other factors that contribute to flooding.

What does 500-year flood plain mean?

A 500-year flood plain is an area that has a 1 in 500 chance of flooding in any given year. This does not mean that the area will only flood once every 500 years, but rather that there is a 0.2% chance of flooding in any given year.

Should I carry flood insurance coverage?

If your Houston home falls inside a designated flood zone, and you’ve used a mortgage to purchase the home, chances are your lender will require you to carry flood insurance. Even if you don’t have a home loan, or are outside a zone, remember one in five Houston homes are at risk. Carrying flood insurance may be a wiser financial decision for those living in Harris County.

Additionally, with the redrawing of the floodplain maps, your may find your home now has a higher risk for flooding. Buying a flood insurance policy is likely a wise investment to protect your assets and financial well-being.

What is the Houston Flood Control District?

The Houston Flood Control District (HFCD) is a special-purpose district created in 1937 to manage flood control and drainage in Harris County, Texas. HFCD is responsible for maintaining and operating a system of reservoirs, channels, and detention basins to protect the Houston area from flooding.

HFCD’s flood damage reduction projects are funded by property taxes, construction fees, and grants. It has several ongoing flood control projects, including:

• The Addicks and Barker Reservoirs Expansion Project
• The North Canal Diversion Project
• The Buffalo Bayou and Tributaries Resiliency Study

What areas in Houston have a high flood risk?

Generally speaking, the southeast region of Harris County has a higher chance of flooding because it is a low-lying area near the bayou. More water has to move through its watershed, contributing to water backups in wet weather. Central Houston neighborhoods can also be at risk, especially if the homes are near levees, reservoirs, or watersheds. The neighborhoods with a higher flooding risks are:

• Belleaire
• Meyerland
• Friendswood
• Kashmere Gardens
• Trinity Gardens

How are FEMA flood insurance maps created?

Flood maps are created using a combination of science, technology, and data analysis from major flooding events to predict areas prone to water. Using hydraulic modeling, it shows how water from excessive rain events moves over the topography and absorbs into the ground. It accounts for how Harris County Flood Control measures handle extreme rainfall events.

The models are combined with statistical analyses to estimate the likelihood of flooding over different timeframes. For example:

• 100-year floodplain: An area with a 1% chance of flooding in any given year.
• 500-year floodplain: An area with a 0.2% annual chance of flooding.

The maps show potential flood depths, the risk of flooding, and special flood hazard areas. Flood maps undergo review by scientists, engineers, and local authorities. Public input may also be sought, especially for maps used for regulatory and flood insurance purposes. Insurance agents then take the maps to judge the future risk of flood insurance claims.

What are some historical flooding events in Houston?

Since record-keeping began, Houston has experienced notable events and significant flood losses. A few memorable ones that tested its flood protection measures:

• Great Galveston Hurricane (1990): The deadliest natural disaster in US history had widespread flooding
• Hurricane Harvey (2017): The slow-moving storm dropped over 60 inches of rain in some areas. It overwhelmed Houston’s flood protection measures and local bodies of water.
• Tropical Storm Allison (2001): The 35 inches of rain hit downtown Houston particularly hard, leading to new flood risk reduction projects.
• Tax Day Flood (2016): Showing that even non-tropical events can overwhelm Houston’s flood-prone area, 16 inches of rain dropped in half a day on the flat terrain.
• Memorial Day Flood (2015): The 12 inches of rain underscored vulnerabilities in Houston’s floodplain management.
• Houston Flood (1935): Twenty inches of rain prompted the construction of the Addicks and Barker reservoirs, vital elements in Houston’s flood control system.