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Area Flooding

With flooding events occuring within in the Clear Lake area, the following form has been developed to report these events to the district’s engineer. Using this form will help direct the engineers efforts to these areas for inspection. These forms will be sent to our engineering consultant directly. You can email it back to, fax it to 281-488-6644, drop it off by our office at 900 Bay Area Blvd., or mail it in. Thank you for your cooperation.

Flood Education Mapping Tool

A Short History (excerpt taken from:

The Flood Education Mapping Tool was initially developed as a mapping tool for the Tropical Storm Allison Recovery Project (TSARP), which was launched shortly after Tropical Storm Allison struck Harris County in June 2001. Its purpose was to serve as a tool for Harris County residents to learn the location of their properties in relation to mapped 1 percent (100-year), 0.2 percent (500-year) and coastal floodplains. The Flood Education Mapping Tool includes regularly-updated floodplain information from the Federal Emergency Management Agency’s Flood Insurance Rate Map (FIRM or floodplain map) for Harris County, interactive legend options, a simple map display and easy map navigation. While the floodplains shown on the Flood Education Mapping Tool are the floodplains delineated on the FIRM for Harris County, the Flood Education Mapping Tool is not the effective FIRM.


To view the maps, visit:

Topography and Drainage


The general area of the Authority ranges in elevation from 10 feet mean sea level along the extreme eastern boundary to about 35 feet mean sea level along the northwestern boundary. Substantially all existing areas or areas proposed for development within the Authority are above the projected 100-year flood plain. In the general area of the Authority, there are three well-defined major watersheds. The three major drainage channels are Horsepen Bayou on the west, Armand Bayou in the central area, and Cow Bayou on the south and discharge through Clear Lake into Galveston Bay. Drainage of the developed subdivisions is accomplished by means of enclosed storm sewer systems which outfall into improved channels of the three major streams.

Stormwater Brochure

Clean water is your business too. View our brochure on ways to protect our waterways.


Stormwater FAQ

  • What is stormwater?
    Stormwater is rain that travels down gutters into the storm drains, flowing directly into waterways such as bayous, lakes and Galveston Bay. Impervious surfaces like driveways, sidewalks, and streets prevent storm water runoff from naturally soaking into the ground. Dumping materials into storm drains has chemicals, dirt, and other pollutants. It is never treated, so everything stormwater collects as it travels through storm drains end up in local waterways.
  • What is the difference between a stormwater drainage system and a sewer system?
    The sanitary sewer system collects household wastewater from toilets, showers, and sinks. The wastewater is sent to a facility where it is first treated before being released back into the environment. Stormwater is not treated since it is intended for rain runoff only and flows directly to waterways.
  • What is the purpose of a storm drain system?
    A storm drain system’s purpose is to prevent flooding of streets and highways by quickly and efficiently transferring rainwater into our bayous, creeks, rivers, and Galveston Bay. After the water has filled up waterways, then the streets are designed to handle the overflow, to try and prevent flood damage to property.
  • How serious is the problem of stormwater quality?
    Very serious. The contaminated stormwater can affect vegetation, wildlife, aquatic life, and restrict swimming areas. For example: Health: Stormwater pollution poses a serious health risk to people swimming or fishing in our local bayous, lakes, etc. Environment: Countless marine plants and animals living in our local waterways may become sick or die from contact with stormwater pollution. Neighborhoods: Clogged storm drains significantly decrease the quality of life in many neighborhoods throughout the city and county. These “nests” of trash and debris can attract rats and cockroaches and create foul odors affecting neighborhood aesthetics and property values. It also creates the potential for local flooding during heavy rain events.
  • What can you put down the storm drains?
    Local ordinances and regulations prohibit anything other than uncontaminated rainwater from entering the storm drain system. Under Chapter 47-741(a) of the City of Houston Code of Ordinances, “A person commits an offense if the person threatens to introduce, introduces or causes to be introduced into the MS4 (Municipal Separate Storm Sewer System) any discharge that is not composed entirely of storm water.”
  • How should I properly dispose of oil, tires, and batteries?
    Oil can be taken to our oil recycling drop-off point located at 17507 El Camino Real. From El Camino Real, turn onto Beacon Road and drive towards the water storage tank. Please leave the used oil in a sealed container (to prevent spills) and outside the gate in the visibly marked concrete box. Please do not drop off any other chemicals, liquids, or other items that need disposal. CLCWA is only able to recycle oil at this time. Check with your local hardware stores about recycling batteries. Businesses where you buy car batteries or tires usually recycle or properly dispose of these items.
  • How does pet waste left on the grass affect storm water?
    Pet waste can be picked up by rain as it travels down the storm drain, carrying with it bacteria and other harmful materials into waterways. When walking your pet, remember to pick up the waste and dispose of it properly. Flushing pet waste is the best disposal method.
  • Why are grass clippings harmful to storm water?
    Yard waste contributes nutrients, such as nitrogen and phosphorous, which cause unwanted and uncontrolled growth of algae and aquatic weeds. Grass clippings also clog storm sewer drains, contributing to flooding.
  • What lawn care precautions can I take?
    Don’t overwater your lawn. Consider using a soaker hose instead of a sprinkler. Use pesticides and fertilizers sparingly. Consider using organic products when possible and use chemicals in the recommended amounts. Compost or mulch yard waste. Don’t leave yard waste in the street or sweep it into storm drains or streams. Cover piles of mulch or dirt being used for landscaping projects.
  • Who do I call if I see someone dumping oil or other hazardous materials down a storm drain?
    You can call the Clear Lake City Water Authority (CLCWA) at 281-488-1164. CLCWA overlaps into 5 other cities including Taylor Lake Village, Webster, Pasadena, Houston and La Porte. City of Houston: 3-1-1, the Anonymous City of Houston Neighborhood Protection Complaint line City of Houston Environmental Health Information and Industrial Discharge line at 713-640-4399 Harris County Public Health and Environmental Services can also be contacted at 713-920-2831
  • Is it okay to sweep or water down dirt, grass, and/or other natural elements down the storm drain?
    Actually dirt can clog spawning areas for fish and cover the water channel floor resulting in fish food being covered and the fish unable to sustain life.
  • Is it okay to wash my paintbrushes out in the gutter?
    No. Paint can be toxic to aquatic life by interfering with breathing, plant growth, and reproduction. Rinse paintbrushes out in the sink.
  • What about car washing?
    Use a commercial car wash that treats or recycles its wastewater, or wash your car on your yard so the water infiltrates into the ground. Use a biodegradable soap sparingly.
  • What can I do to make a difference at home?
    You can make a difference in storm water quality by simply changing a few practices at home. Here are some easy steps: Use less harsh, safer, cleaning alternatives. Please see this Cleaning Alternatives Guide. Recycle or properly dispose of household products that contain chemicals such as insecticides, pesticides, batteries, paint, solvents, used motor oil and other car fluids. Use fertilizers sparingly and sweep up driveways, sidewalks, and gutters. Never dump anything down storm drains or in streams. Vegetate bare spots in your yard. Compost your yard waste. Use the least toxic pesticides possible, follow labels, and learn how to prevent pest problems. Direct downspouts away from paved surfaces; consider a rain garden to capture runoff. Take your car to the carwash instead of washing it in the driveway, or wash your car on the lawn. Check your car for leaks and recycle your motor oil. Pick up your pet waste; flush it in the toilet or bag it.
  • Where can I get more information?
    Harris County Clean Waterways: Water Environment Federation (WEF): Environmental Protection Agency (EPA): Disclaimer: Links to and information about Web sites outside the CLCWA are provided solely for the convenience of the user and do not constitute an official endorsement of the information, products, or services contained therein.
  • Information obtained from:
    Harris County Clean Waterways: Environmental Protection Agency (EPA): Disclaimer: Links to and information about Web sites outside the CLCWA are provided solely for the convenience of the user and do not constitute an official endorsement of the information, products, or services contained therein.
  • What causes high bacteria levels in water?
    Stormwater runoff that picks up contaminants along the way from leaking septic tanks, sewage, livestock agriculture pollution, pet/animal wastes, or dead and decaying animals. Ways you can help. Reduce the amount of runoff from your own yard. o Connect rain barrels to your gutters and use that to water your lawn or garden. o Consider a rain garden/grassy swale or the use of pervious pavers for your walkway/decorative pad site. These will allow water to soak through into the soil instead of unfiltered directly into our waterways. o Install a vegetation strip of native grass / plants along roadways or near streams. They act as a natural filter to trap the pollutants stormwater picks up as it flows across lawns, driveways, and streets. o Redirect downspouts so that rainwater flows into grass /plants instead of a driveway or sidewalk. o Consider Installing a dry well in your yard to capture excess runoff. · Properly dispose of Pet Waste Pet waste can carry high levels of harmful E. coli bacteria and other pathogens, when washed into storm drains then our recreational and commercially fished waterways, that could cause public health risks. o When walking your dog, carry a plastic bag with you so that you can pick up the waste to properly dispose of it. By either flushing it (not in the bag) or throwing it in the trash.

Stormwater Quality Management Plan

The Clear Lake City Water Authority has adopted a Stormwater Quality Management Plan in compliance with state regulations. The following forms are required to be submitted annually to satisfy compliance requirements.

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