Back to top
These pages provide Harris County residents with information and
resources regarding flooding, and establish easy access to Harris County’s
regulations and programs related to flooding and floodplain management.
Floods are one of the most common hazards in the United States. Flood effects
can be local, impacting a neighborhood or community, or very large, affecting entire
river basins and multiple states. It is important to be aware of flood hazards no
matter where you live. Even very small streams, gullies, creeks, culverts, dry streambeds,
or low-lying ground that appears harmless in dry weather can flood.
Additional information on flood insurance coverage and requirements, flood protection measures,
flood safety, and property and building protection is available in floodplain “libraries”
maintained by Harris County both at the Harris County Permit Office and the 26 branches
of the Harris County Public Library. Property owners can take actions in advance of a flood
to provide protection for their property. Floodplain maps and helpful FEMA publications
“Design Guidelines for Flood Damage Reduction” and “Homeowner’s Guide to Retrofitting”
are in these libraries, as are a number of other useful documents.
Back to top
- Floods are the #1 natural disaster in the United
- Just an inch of water can cause costly damage to
property. As little as six inches of moving water
can knock you off your feet or move your car.
- Everyone is at risk.
- Most homeowners insurance doesn't cover flood
- More than 50 percent of properties in high-risk
areas remain unprotected by flood insurance; all
properties in high-risk areas need to be protected
with flood insurance.
- Between 20 and 25 percent of all flood insurance
claims are filed in low-to moderate-risk areas.
- New construction can increase flood risk, especially
if it changes natural runoff paths.
- More than 5 million Americans are protected with
flood insurance but millions more are unaware of
their personal risk for property damage or options
- For building in high flood risk areas, there is a 26
percent chance of experiencing a flood during the
life of a 30-year mortgage, compared to a nine
percent chance of experiencing a fire.
- Flood losses in the United States averaged $2.4
billion per year for the last decade.
- The National Flood Insurance Program (NFIP) has paid
nearly $16 billion in flood insurance claims to
policyholders during the 2005 hurricane season (as
of August 31, 2006.)
- Federal disaster assistance is usually a loan that
must be paid back with interest and is only
available when a disaster has been federally
- In the last 52 years, nearly 1,000 flood events have
been designated as federally declared disasters.
- Nearly 75 percent of all federally declared
disasters over the past five years involved
Harris County is the third
largest county in the United States with a
population greater than three million. It covers
1,788 square miles with 1,500 channels totaling
about 2,500 miles in length within twenty-two
watersheds. The land use consists of urban,
residential, commercial, and heavy industrial areas.
In the last century, over 30 thunderstorms, tropical
storms, and hurricanes have caused flooding in
Harris County. Each bayou and creek include areas
known as "floodplains," where water collects, pools,
and flows during the course of a natural storm
A floodplain is defined as any land area susceptible
to being inundated by water from any source. These
areas are classified as Special Flood Hazard Areas
(SFHA), and are located in a 100-year flood zone.
The term "100-year flood" can be misleading. It does
not mean that the flood will occur every 100 years;
rather it is the flood elevation that has a 1-
percent chance of being equaled or exceeded each
year. Harris County has Flood Insurance Rate Maps
(FIRM) that identify all floodplain areas within the
Harris County strives to protect the natural and
beneficial functions of floodplain areas. Harris
County has some unique situations. After devastating
flooding in 1935, the state legislature created the
Harris County Flood Control District (HCFCD). As
stated in the Flood Insurance Study, HCFCD governs
drainage and flood control, while the county
engineer governs floodplain management and permit
programs with technical assistance from HCFCD.
Although both agencies are under the jurisdiction of
Commissioners’ Court, they are separate agencies. In
2003, Harris County Commissioners’ Court adopted the
Draft Floodplain Management Plan for qualification
to participate in the National Flood Insurance
Program’s (NFIP) Community Rating System (CRS).
Flood hazard maps, also called "Flood Insurance
Rate Maps" or "FIRMs" are important tools in the
effort to protect lives and properties in Harris
County. By showing the extent to which areas of
the County and individual properties are at risk
for flooding, flood maps help business and
property owners make better decisions about
protecting their property. These maps also allow
engineers, community planners, local officials,
builders and others to make important
determinations about where and how new
structures and developments should be built.
Flood Insurance Rate Maps are used to determine
the flood risk to your home or business. The low
and moderate-risk zones are represented on the
maps by the letter "X". The inland high-risk
zones will be labeled "A", "AE" or "AO".
If you would like to research the flood hazards
near your home or business, please access the
Harris County Flood Control District's
Interactive Map (http://maps2.tsarp.org/tsarp/).
Click here (http://www.hcfcd.org/) for
instructions on how to use this mapping tool.
If you would like to find out whether or not
your property is located within a special flood
hazard area, please contact the Harris County
Permit Office at (713) 956-3000 for an
unofficial determination. This service is
provided free of charge for properties located
within unincorporated Harris County limits.
You can also view copies of the Flood Insurance
Rate Maps in the Harris County Permit Office.
Unlike most standard homeowner's
policies, flood insurance covers losses to your
property caused by flooding. Property owners,
renters and businesses can purchase flood insurance
through the National Flood Insurance Program (NFIP)
as a result of Harris County’s participation in the
program. By participating in the NFIP, communities
are required to adopt sound floodplain management
ordinances to reduce future flood damage. In
exchange, the NFIP provides federally backed flood
insurance at affordable rates.
Communities that participate in the NFIP are rated
by the Federal Emergency Management Agency (FEMA)
through the Community Rating System (CRS). FEMA
encourages communities to implement floodplain
management standards which exceed the minimum NFIP
standards. In return, FEMA rewards communities with
higher standards by offering a discount on flood
The current Harris County CRS rating is an 8. This
rating gives residents a 10% discount on
non-preferred risk flood insurance policies.
(For more information about the rating system please
Why Purchase Flood Insurance?
Flood insurance is required by law for property
owners living in a high-risk area, or Special Flood
Hazard Area, with a federally backed mortgage. For
example, if you have a FHA or VA loan, or if your
mortgage company is federally insured, you must
obtain flood insurance if you live in a high risk
area. Regardless of the type of mortgage, Harris
County recommends that all residents in high-risk
areas be protected. For buildings in high flood risk
areas, there is a 26% chance of experiencing a flood
during the life of a 30-year mortgage, compared to a
9% chance of experiencing a fire.
Remember that everyone has some risk of flooding.
Flooding events can also occur in low-to-moderate
risk areas and flood insurance in these areas is
also strongly recommended. Most homeowners' policies
do not cover flood losses.
How Much Does Flood Insurance Cost?
The average premium for a yearly flood insurance
policy is approximately $500. People in
low-to-moderate risk areas may be eligible for the
Preferred Risk Policy with flood insurance premiums
as low as $119 a year. Contact your insurance agent
for more details.
How Do I Purchase Insurance?
Flood insurance is sold through more than 85 private
insurance companies and agents, and is available to
homeowners, business owners, and renters. Contact
your insurance agent to help you decide what kind of
flood protection is best for you. Information on how
to purchase a flood insurance policy is also
Back to top
Property Protection Measures
Home and business owners can
protect themselves from future floods or reduce the
effect of future floods by various means including:
- Elevating the structure
- Floodproofing the structure
- Facilitating future evacuations
- Buying flood insurance
For more information on
protecting your property from flood damage, please
Additional information on flood protection measures
and building protection is also available in
floodplain "libraries" maintained by the Harris
County both at the 26 branches of Harris County Public Library and
at Harris County Permit Office.
Localized Drainage Concerns (Residential Properties)
Under Texas Water Law, "No person may divert or
impound the natural flow of surface waters in this
state, or permit a diversion or impounding by him to
continue in a manner that damages the property of another by
the overflow of the water diverted or impounded."
Essentially, this means that the natural path of
storm water runoff is not to be blocked.
- If you have experienced minor flooding in your home
or ponding water in your yard, you may simply have a
localized drainage problem that can be corrected
with minor grading.
- Property owners are responsible for runoff from
private property or between private properties.
- Become familiar with your lot's intended drainage
pattern. In most cases, the runoff is intended to
flow to the street around each side of the home. In
some cases, portions of your lot may naturally drain onto
a neighbor's lot, or perhaps you have neighbors
whose yard drains onto yours.
- Before you decide to make landscaping improvements
to your yard, including the construction of a pool,
make sure that you are not blocking the path of
storm water runoff and inadvertently causing damage to
your property, or the surrounding properties.
- The Harris County Permit Office has experienced
staff members available to offer suggestions which
might alleviate minor drainage problems. Call (713)
956-3000 to speak with a representative.
- Consider purchasing flood insurance, even if your
property is not within a FEMA designated Special
Flood Hazard Area. Most homeowner's insurance does
not cover damages caused by flooding. Harris County recommends
that all residents purchase flood insurance, even if
it is not mandated by your home mortgage company.
Every year, 25% of flood damages occur on properties
outside of the floodplain.
Back to top
Nobody can stop a flood, but there are actions
you can take before, during, and after a flood to
protect your family and keep your property losses to
BEFORE THE FLOOD
Listen to your radio, TV, or
Service radio for the latest information on weather
conditions that can cause flooding. Learn about NOAA
Weather Radios by clicking
Learn and Understand
Flash Flood Warning -
Flash flooding has been reported.
Flash Flood Watch -
Conditions exist that may lead to flash
Urban and Small Stream
Advisory - Flooding of small streams, streets, and low-lying areas is occurring.
Avoid unnecessary travel during severe weather. Poor
visibility can make trips dangerous. Warn children
not play near swollen creeks, storm drains, or
Do not go near creeks and low-water crossings.
Beware of rising, swift-moving water. Creeks can
rise to dangerous levels in as little as one hour.
Man-made features such as storm drains, fences, and
culverts create additional "strainers" that can snag
and drown even the strongest swimmer.
If you see major obstructions such as downed trees
or telephone poles in a creek, or if you see a
blocked culvert or bridge opening, call (713)
If Time Allows...and Your House Is In the Path of
- Turn off all utilities at the main power switch and
close the main gas valve if evacuation appears
- Move valuables, such as papers, furs, jewelry, and
clothing to upper floors or higher elevations.
- Fill bathtubs, sinks, and plastic soda bottles with
clean water. Sanitize the sinks and tubs first by
using bleach and rinsing.
- Bring outdoor possessions, such as lawn furniture,
grills, and trash cans inside, or tie them down
DURING THE FLOOD
Do not drive or walk into water that is
flowing across low water crossings, bridges, or
roadways. If you come upon a flooded road, turn around
and go another way. Heed all warnings and street
barricades - if you go around once, you are subject to
a fine. For more information on road closures, call
These areas are especially dangerous because:
- As little as six inches of moving water can knock
you off your feet or move your car.
- More people drown in their cars than anywhere else.
- The road may be washed out below the water surface.
- Your car may stall or get stuck in the water, and
then get pushed off the road. Once off the road,
cars often start to roll, making escape impossible.
Do not go near downed power lines and electrical
wires. Electrocution is another major source of
deaths in floods.
Move to a Safer Area
Evacuate your house if instructed to do so. Follow
emergency instructions. It is much safer and easier
to evacuate before flood waters become too deep.
If the waters start to rise inside your house before
you have evacuated, retreat to the second floor,
attic or roof. Take dry clothing, a flashlight, and
a portable radio.
AFTER THE FLOOD
Call Your Agent
If your home, apartment, or business has suffered
damage, call the insurance company that handles your
flood insurance policy right away to initiate a
Take color photographs or video of any damages
resulting from the flood.
Before Entering a Flooded Building
- Check for structural damage. Don't go in if there is
any chance of the building collapsing.
- Do not use matches, cigarette lighters, or any other open flames, since gas may be trapped inside.
Instead, use a flashlight to light your way.
- Keep power off until an electrician has inspected
your system for safety.
- Look out for animals and snakes. Animals lose their
homes in floods too. They may seek shelter in yours.
Until local authorities proclaim your water supply
to be safe, boil water for drinking and food
preparation. Water should be boiled vigorously for
five minutes before using.
Flood waters pick up sewage and chemicals from
roads, farms, and factories. If your home has been
flooded, protect your family's health by cleaning up
your house right away. Throw out foods and medicines
that may have come into contact with flood water.
Be careful walking around. After a flood, steps and
floors are often slippery with mud and covered with
debris, including nails and broken glass.
Back to top
Structures within the Special Flood Hazard Area
(SFHA) in a community participating in the National
Flood Insurance Program (NFIP) are subject to
Floodplain Management Regulations that impact
building standards and are designed to minimize
flood risk. In addition to federal standards, Harris
Floodplain Management Regulations more
stringent than the federal standards in place which
govern development within the SFHA. These standards
apply to new structures and to substantial
improvements of existing structures. Harris County
defines a substantial improvement as any
reconstruction, rehabilitation, or addition to an
existing structure, the cost of which exceeds 50
percent of the structure's appraised or market
Key components of Floodplain Development:
- A Floodplain Development Permit is required for all
work in the floodplain.
- A post construction finished floor
Certificate is required for structures within the
SFHA. This certification must be made by a Texas
Registered Professional Surveyor, Engineer or
Architect. The Elevation Certificate form and
instructions can be downloaded by clicking the FEMA
link, or a copy can be picked up at the Harris
County Permit Office.
- The Finished Floor elevation of structures within
the SFHA must be a minimum of 18" above the Base
Flood Elevation (BFE).
Floodplain Development Permit
Any activity performed in the floodplain must have a
Floodplain Development Permit. This includes
grading, filling, residential construction and
To obtain a permit you must complete a
Permit Application and comply with
Management Regulations. Residential Permit
Applications can be picked up at the Harris County
Permit Office or downloaded from the Harris County
Permits website. Complete and return the form along
with 3 sets of plans of the project to the Harris
County Permit Office. The plans must clearly show
existing and proposed contours at the site with all
elevations submitted on NAVD 2001 datum.
If the structure is currently located in or adjacent
to a FEMA designated SFHA the applicant must submit
- With the form board survey before the slab is
- A post construction Finished Floor elevation
These certifications must be made by a Texas
Registered Professional Surveyor, Engineer or
Architect. This must confirm that the finished floor
of the actual construction is at least 18-inches
above the BFE. Copies of previously submitted
elevation certificates are available at the Harris
County Permit Office.
If your property lies within the SFHA, a Residential
Permit Application and compliance with
Management Regulations is required for any work,
- Construction of new structures including additions to the home
- Miscellaneous (pools, gazebos, retaining walls, fences, etc.)
You may be required to bring your home or business
into compliance with current
Regulation development standards if:
- Your home or business has been significantly damaged
due to flooding, resulting in the need for substantial improvements, OR
- You are proposing substantial improvements to your
home or business such as an addition or renovation.
County staff is available to make site visits, if
requested, to review flooding and drainage issues.
Contact the Harris County Permit Office at (713)
956-3000 for further information and prior to
undertaking any activity within the floodplain.
Back to top
Drainage System Maintenance
What is Storm Water?
The term storm water refers to rainwater. Storm
water washes down storm drains on the curbs of roads
and leads directly into lakes, rivers, and streams.
Unlike wastewater, it is untreated and can carry
pollutants, sediments, and trash directly into our
natural water resources.
As storm water runoff travels over the land, it
picks up all kinds of chemicals, waste, and trash
that are not naturally found in our waterways. Storm
water runoff enters the storm drain system through
inlets, and discharges untreated into creeks,
bayous, channels, lakes, and rivers. Some chemicals
and other substances in storm water can be toxic,
even at small levels, endangering plants and animals
that depend on the water to survive. Pollution of
our waterways can also mean we cannot boat, swim, or
fish because it is unpleasant or even unsafe.
Storm water runoff from properties throughout Harris
County flows to one of 1,500 channels totaling about
2,500 miles in length within twenty-two watersheds
of Harris County, joining Galveston Bay and flowing
downstream to the Gulf of Mexico.
Storm water pollution can be controlled if everyone
plays a part in preventing these substances from
entering the storm drain inlets in the streets where
they live and work. You can help prevent storm water
pollution by eliminating illicit discharges,
exercising responsible use of herbicides,
pesticides, and fertilizers in lawn and landscape
maintenance, and proper disposal of used oil and
What Can We Do?
Please do your part to keep inlets and drainage ways
clear of brush and debris. Here are steps you can
take to protect the quality
of water in Harris County’s bayous, creeks and
- Maintain your vehicle so hoses and reservoirs do not
leak or break causing fluids to spill onto streets.
Don't pour used motor oil, antifreeze, old
pesticides or any other pollutants into the storm
- Use a mulching mower or bag your grass and leaves
instead of blowing the yard waste into the street.
Yard waste can clog storm drains.
- Pick up litter around your neighborhood or business
so that trash doesn't collect on drainage inlets or
clog storm sewer pipes.
- If you spot a blocked drain or notice illegal
dumping, call the Harris County Precinct Office in
your area, and someone will investigate. Putting
foreign substances into the storm sewer is a
violation of Harris County Storm Water Quality
Regulations and may result in a fine.
- Storm Drains and Roadside ditches in Precinct 1 call (713) 991-6881
- Storm Drains and Roadside ditches in Precinct 2 call (713) 455-8104
- Storm Drains and Roadside ditches in Precinct 3 call (281) 463-6300
- Storm Drains and Roadside ditches in Precinct 4 call (281) 353-8424
- All Channels, Bayous and Creeks call HCFCD at (713) 684-4000
Our Drainage System
Harris County and Harris County Flood Control
District maintain our county-wide system of drainage
improvements, including 1,500 channels totaling
about 2,500 miles in length within twenty-two
watersheds. When the drainage system is overwhelmed,
"localized flooding" can be the result. The drainage
system consists of:
- Roadside ditches
- Curb inlets
- Storm drain pipes
Harris County Flood Control District has a drainage
maintenance program in which crews clean out debris
that has collected within channels.
Back to top
Harris County and the FEMA have updated all of the
Flood Insurance Rate Maps (FIRMs) for Unincorporated
Harris County. Harris County adopted the effective
FIRMs dated June 18, 2007. The Map Modernization
project provides property owners throughout Harris
County with up-to-date, reliable, Internet
accessible information about their flood risk on a
property by property basis. Please visit
Flood Control District's Interactive Map to
see how the FEMA updated floodplain boundaries
impact your property.
It is important to note that the calculated flood
levels (based on extensive hydraulic modeling) in
Harris County are not changing with the issuance of
the maps. Rather, more accurate survey information
is allowing FEMA to show the limits of the
floodplain more accurately than ever before. In
other words, properties which are now shown on the
map to be within the floodplain were actually always
within the floodplain. No physical features have
changed which adversely impacted the properties and
caused the shift in floodplain limits. The
acquisition of better data revealed that the
existing maps, some of which are up to 12 years old,
were not correct. The risk was always there; FEMA is
now making the public aware of it.