Understanding Water Main Flushing

Everything You Need to Know About Water Main Flushing

Chances are that at some point in the month, you have noticed blowdowns being flushed and releasing large amounts of water into the ditches. While it may appear that hundreds of gallons are going to waste, there are actually several benefits to this blowdown flushing process. Water main flushing is an important preventative maintenance activity that:

  • verifies proper operation of the blowdown
  • evaluates the available flow to the blowdown
  • allows utilities to deliver the highest quality water possible to their customers
  • removes mineral and sediment build up from the water mains

High-Quality Water

Over time, water settles, ages, and is affected by biofilm (a thin layer of microorganisms) that grows on the inside of the distribution piping. Each of these factors affects the quality and taste of the water, so it is important to flush the water out of the mains and hydrants regularly. Flushing can remove water from areas of the distribution system that have low water use, since the older water may no longer have the desired chorine residual.

Mineral and Sediment Build Up

Throughout the course of several months or a year, loose sediment and mineral deposits may slowly build up inside of the water mains resulting in discolored water and reduced capacity. Flushing the water mains can remove the sediment and mineral build up, and improve the color, odor and taste of the water if it has been problematic.  Unidirectional flushing at the minimum required velocity will improve the carrying capacity of the mains.


Now that we’ve discussed the benefits of flushing our water mains and hydrants, you may have some questions about the process and how it will affect your day-to-day life. We’re here to help!

When will a blowdown near me be flushed?

Blowdown flushing normally takes place at least one time a month, unless a leak is being repaired in your area. CCWSC will notify you of what streets will be undergoing flushing and when.

What can I do to prepare for flushing?

Prior to blowdowns being flushed, you may want to obtain water (in pitchers prior to flushing) for your everyday use including drinking, cooking, etc.

When the flushing is taking place, water quality may temporarily be reduced. Using water for tasks such as dishwashing, laundry, or showering may result in the discoloration/staining of your clothes or household items. Plan ahead and be sure your laundry and dishes are done before the flushing process begins!

How does water main flushing work?

Water main flushing usually takes place in one of two ways – conventional flushing or unidirectional flushing (UDF). In conventional flushing, hydrants are opened in different targeted areas and discharge water until accumulations are removed and water runs clear. While easy to conduct by water operators and crews, this method requires a lot of water, and may not always clean the pipe completely. With UDF, each pipeline is isolated to create flow in a single direction and quickly clean the pipe. By concentrating the flow, UDF creates higher velocities to clear the pipes and requires less water.

How will flushing affect my water?

During the process, you might experience a difference in the water pressure in your faucets as well as some discoloration in the water.

How long does it take to flush the blowdown?

Typically, this process takes between 30 and 60 minutes.

When will my water be back to normal?

Once the blowdowns in your area have completed their flushing, it won’t be long until your water is ready for normal use again. In most cases, water should run clear with just a few minutes of faucet flow. Turn your faucets on cold and let the water run for 5 minutes or so. If you are still seeing discolored water or sediments in the water, continue running cold water on all your faucets until it is clear. Should your water still be discolored after several hours, please contact your water supplier.

Is water main/blowdown flushing a waste of water?

Although you will see water flowing for up to an hour, rest assured that most of the water that was flushed will return to the aquifer.  Flushing is a necessary process to help keep our water mains clean and clear of sediment, allowing your public water supplier to provide excellent water quality, and increased pressure and flow

For your convenience, we have compiled the following list of the best resources on how to fix leaky faucets and other household tasks related to water.  

Helpful Hints – Information & Resources


Prepping your pipes for winter

Before the temperatures drop below freezing, it is important to prepare your pipes using these simple tips that could potentially save you thousands of dollars in water damage repairs.

  1. Locate and exercise your master water shut-off valve: The valve is located in the black box that is out in front of your property on the street side. Once the valve is located, make sure everyone in the household knows where it is and exercise it regularly so that it can easily be shut off in case of an emergency.
  2. Disconnect and drain outdoor hoses: Before freezing temperatures strike, it’s important to disconnect and drain your outdoor hoses. This allows the water to drain from the pipe so an overnight freeze doesn’t burst the faucet or the pipe it’s connected to.
  3. Insulate pipes or faucets in unheated areas: If you’ve got water pipes in unheated areas like the garage or a crawl space, it’s best to wrap them in insulation before temperatures drop. Pipe wrapping materials and supply can be found at hardware stores.
  4. Seal off access doors, air vents and cracks: When cold air seeps through overlooked openings, exposed water pipes may freeze. But remember; do NOT plug air vents by your furnace or water heater.

Preventing frozen pipes when temperatures dip below freezing

  1. Leave cabinet doors open for warm air circulation.
  2. Let water trickle to keep it flowing.
  3. Keep the garage door closed.

What if it’s too late?

Even if you take all the proper precautions, your pipes may still freeze during an extended cold spell. If that occurs, the best solution is to call a plumber.

  • Do not try to thaw the pipe with an open flame.
  • Do not heat only one spot on the pipe, as this can cause it to burst.

If you chose to try to thaw the pipe yourself, your best bet is a heat tape especially made to thaw water pipes. This tape is available at many hardware stores. Be careful when heating the pipe, as it may already be broken and just not leaking because the water inside is frozen. So be ready with the master shut-off valve in case water comes gushing out.

Possible Leak Problems

It is amazing how much water can be wasted through a very small leak.

Cape Carancahua Water Supply Corporation is always willing to help its customers conserve water wasted through leaks and help the customer keep their utility bill consistent.

If you believe that you may have a leak either in your residence or at the CCWSC meter, please contact the CCWSC immediately so an Operator can check your meter for any leaks. If the Operator determines there is a leak on our side, we will promptly correct the problem. If the problem is on your side, the Operator will notify you in person if you are at home, by telephone (if you request a return call).

The Operator or any of the Customer Service staff in our main office can provide you with leak detection tablets to test your toilets for leaks. The tablets are very easy to use and come with specific directions.

Taking advantage of calling us first and checking for leaks on your own can save you unnecessary and often expensive plumbing bills that may not be necessary.

Underground Leaks

Maintaining underground piping on the customer’s side of the water meter, beginning at the connection between the meter and the customer’s service line, is the responsibility of the customer.

 Leaks in underground plumbing can be caused by many different factors, including rusting through from age or from stray electric currents from other underground utilities that can prematurely rust metallic piping, driving over piping with heavy trucks or equipment, poor initial installation, freezing and thawing of a pipeline, leaking joints or valves, or high pressure transients from open and closing valves or starting and stopping pumps quickly.

Signs of underground leaks include:

  • Unusually wet spots in landscaped areas and/or water pooling on the ground surface.
  • An area that is green, moldy, soft, or mossy surrounded by drier conditions.
  • A notable drop in water pressure/flow volume.
  • A sudden problem with rusty water or dirt or air in the water supply (there are other causes for this besides a leak).
  • A portion of an irrigated area is suddenly brown/dead/dying when it used to be thriving (water pressure is too low to enable distant heads to pop up properly).
  • Heaving or cracking of paved areas.
  • Sink holes or potholes.
  • Uneven floor grade or leaning of a structure.
  • Unexplained sudden increase in water use, consistently high water use, or water use that has been climbing at a fairly steady rate for several billing cycles.

If any of these conditions exist at your facility or home, you may have a leak. If you suspect a leak, you may need to hire a professional leak detection company to pinpoint its exact location and a contractor to perform the repairs. There are leak detection service companies listed in the yellow pages under Leak and Pipe Locating. Any utility contractor should be able to repair a leak once the location is known.

How to read your water meter

Step 1. Locate your meter – At residential properties, the water meter is generally located in the ground near the curb in front of the house. The meter box will have a metal lid with “Water Meter” marked on top.

Step 2. Open the meter – To read the meter, remove the lid of your water meter box. Be careful! Lids can be heavy and sometimes bugs and small animals hide inside the meter boxes. Replace the lid each time you finish looking at the meter to avoid a safety hazard.

Step 3. Understand the dial – Water is measured in CCFs, which are units of 100 cubic feet or 748 gallons. The meter above reads 1935 CCF for billing purposes. The last two numbers on the register are not read for billing. The register does not reset to zero after each read. One complete “sweep” of the sweep hand means you have used one cubic foot or 7.48 gallons of water.

Step 4. Find the leak detection dial – Most residential meters have a leak detection dial. The leak detection dial may be a red or blue triangular-shaped dial or a blue snowflake-shaped dial. It may spin rapidly when water is running. If water is dripping, the leak detection dial may move slowly.

How is your water meter read?

Our meters are very similar to car odometers. The digits are read left to right the two black numbers should be ignored. To view video on how to read your meter click on the following link:

How to check a toilet for leaks

Toilets leak more than any other water-using item in the home, and they can be costly!

Save water and money by checking your toilets for leaks. Click on the video below.

How to check for toilet leaks:

  • Lift of the toilet tank lid.
  • Place 1 dye tablet (we have dye tablets available free at the main water office) or 10 drops of food coloring in the toilet tank.
  • Do not flush.
  • Wait 15 minutes (or more) without flushing.
  • Check the water in the bowl of the tank.  If color appears in the bowl, the toilet has a leak.

Commercial Leak Detection – Flush Valve Toilet Leaks

Flush Valve Toilet Leaks 

Leaks in flush valve style toilets are less obvious. Streaks of orange or blue staining on the fixture itself are often indication of a leak at the inlet valve. A larger leak might be visible as small streams of water continuously flowing down the inside of the fixture after the flush has completed. Sometimes a smaller leak might create tiny disturbances in the water surface in the bowl as droplets slide down the sides of the bowl. If there are always drops of water above the water surface even hours after the last flush, this could indicate a small leak. And if the water surface level declines significantly over time between flushes, there could be a leak in the outlet valve seal. Leaks in a flush valve type toilet need to be fixed by a plumber or maintenance staff member who is familiar with this procedure.

Commercial Leak Detection – Equipment Malfunction

Equipment Malfunction

One of the largest sources of leakage at commercial properties is equipment malfunction. Often these kinds of “leaks” go on for extended periods because they are not causing any damage or disruption to daily operations. Common areas where malfunctions can occur include: 

  • Overflow valves or float valves on cooling towers, water features, swimming pool equipment, storage tanks, etc. can malfunction in the open position allowing equipment to continuously overflow water to the sewer.
  • By-pass valves can be left open following equipment maintenance, allowing a piece of equipment that is normally on a closed cooling loop to operate in a single pass mode, wasting thousands of gallons of water every day.
  • Temperature control valves fail, causing substantially more water to be passed through a piece of equipment than is necessary to cool it sufficiently.
  • Off/on switches or sensors can stick in the on position, running water through machinery that normally would be shut off when not in use.
  • Rusting through or separation of internal parts that allow water to escape and drain from a machine that normally contains and/or re-circulates the water.
  • Nozzles that are supposed to shut off drip continuously or stick on.

A weekly or monthly visual inspection of water using equipment will usually uncover these types of problems. Call the Water Efficiency Assistance Line at (503) 823-4527 to determine the probability of a leak by reviewing past and average consumption and by taking additional meter reads.  If a leak is suspected but its location unknown, customers may need to hire a professional leak detection service or appropriate plumbing company to pinpoint the exact location (see “Leak and Pipe Locating” in the Yellow Pages).  A licensed contractor should be contacted to repair the leak once the location is

Understanding your Water Utility Bill


Water Conservation Tips

Inside The House

  • Don’t let the water run needlessly when washing dishes, shaving, or brushing your teeth.
  • Take shorter showers. Keeping showers less than 5 minutes can save up to 1,000 gallons per month.
  • Plug the bathtub before turning the water on, and then adjust the temperature as the tub fills up.
  • Fix leaky faucets. Just one drip a second can waste 2,000 gallons of water per year.
  • If practical, try to run the dishwasher or washing machine only when completely full.
  • If you live in an older home, consider replacing your plumbing with low-flow fixtures and low-flush toilets.
  • Place a bucket in the shower to catch excess water to use to water plants later. This also works when washing dishes or vegetables in the sink.
  • Wash fruits and vegetables in a pan of water instead of running water from the tap
  • When doing laundry, match the water level to the size of the load.

Outside The House

  • Water your lawn only when necessary and consider landscaping with native plants adaptable to your climate’s conditions.
  • Place water collection vessels such as barrels or large buckets to collect rain water from down spouts and gutters. Use the water to water your plants.
  • Adjust sprinklers so only your lawn is watered and not the house, sidewalk, or street.
  • Choose shrubs and groundcovers instead of turf for hard-to-water areas such as steep slopes and isolated strips
  • Install covers on pools and spas and check for leaks around your pumps.
  • Use a broom instead of a hose to clean your driveway and sidewalk.
  • If water runs off your lawn easily, split your watering time into shorter periods to allow for better absorption.
  • Check outdoor faucets, sprinklers and hoses for leaks.
  • Check the root zone of your lawn or garden for moisture before watering using a spade or trowel. If it’s still moist two inches under the soil surface, you still have enough water.
  • Adjust your lawn mower to a higher setting. A taller lawn shades roots and holds soil moisture better than if it is closely clipped.
  • Install a rain sensor on your irrigation controller so your system won’t run when it’s raining.
  • Don’t water your lawn on windy days when most of the water blows away or evaporates.
  • Water your plants deeply but less frequently to encourage deep root growth and drought tolerance.
  • Set a kitchen timer when watering your lawn or garden to remind you when to stop. A running hose can discharge up to 10 gallons a minute.
  • Use a hose nozzle or turn off the water while you wash your car. You’ll save up to 100 gallons every time.
  • Let your lawn go dormant during the summer. Dormant grass only needs to be watered every three weeks or less if it rains.
  • Use sprinklers that deliver big drops of water close to the ground. Smaller water drops and mist often evaporate before they hit the ground.
  • Water only when necessary. More plants die from over-watering than from under-watering
  • Adjust your watering schedule each month to match seasonal weather conditions and landscape requirements.

For education from the Public Water Conservation please click link below:

Texas Water Development Board/Conservation

Groundwater Quality Gulf Coast Aquifer Maps

Gulf Coast Aquifer

Major Aquifers of Texas


TCEQ Capacity Comparison Chart

Isolation Valve Replacement/Upgrade Plan (1/30/21)