To maintain Non Revenue water in Western Central area below 30% and below 18% that in Colombo City in 2020.



To provide smooth and reliable drinking water facilities to inhabitance of Western Central area and save our resources.



In any water supply system, water that produced and released to the distribution system does not fully generate revenue for the Water Authority. This is mainly due to the loss of water through the distribution system. The quantity of water that does not produce any revenue is usually termed as Non Revenue Water (NRW). This is usually expressed as a percentage of water supplied to the system. While NRW is a threat to the financial sustainability of Water Authority, it is commonly used as a key performance indicator in a Water Authority.

Under Construction

How to identify why your water consumption has gone up?


Inform the relevant Area Engineer office by using the complaint form

Inspection team will visit your place and they will carry out the initial visual and manual inspection. This initial inspection will be carried out free of charge.

Tips to identify an internal leak by yourself
  • Take the meter reading daily at the same time.
  • Close all the taps and check whether your water meter is still working.
  • If it is still working then check the cisterns for leaks.


How to check your cisterns?


  • Fill up the cistern and close the inlet valve. Mark the water level. Wait for 2 hours and check the level. If it reduces, then the piston of cistern is leaking. Get it repaired as soon as possible. Till it repaired, close the valve (Stop tap) in the cistern supplies line.
  • Check the ball valves in the cistern. If it is not working properly then water from the cistern will overflow in to the water closet. Get it repaired as soon as possible. Till it repaired close the valve (stop tap) in the cistern supplies line.
  • Check the surrounding (inside your premises after the water meter) during the night time (as the pressure in the system is high to night you can observe if there is a leak in your garden.), if you can observe wet patches in the garden or wet areas in walls, it can be a leak in a covered pipeline. Check the covered pipe lines in those places and get them repaired.
  • Check the ball valve in your overhead tank. If it is not functioning properly, your overhead tank can overflow during the night time.
  • Check the underground sump for leaks.

How to check?

  • Fill your overhead tank to full.
  • Then wait till your ground sump get filled
  • Close the valve after the water meter.
  • Mark the water level in the ground sump
  • Do not use water from the sump or do not pump water to the over head tank after closing the valve.
  • Observe for 24hours. (As you have enough water in your overhead tank you can wait for 24 hours without pumping water to overhead tank.) Some time you will be able to observe reducing the water level after few hours. Then no need to wait for 24 hours.
  • If the water level reduces, it means your ground sump is leaking. Ground sump should be covered to minimize the evaporation losses. If it is having leaks take necessary measures to get it repaired as soon as possible. (Empty the sump, check for cracks, and repair the cracks with a suitable water proofing material.)
  • Check your garden taps whether they are turned off tightly to stop drips and functioning properly.

If inspection team cannot identify any leak by visual and manual inspection they will inform you to decide whether to request for inspection using specific instruments for leak detections. If you request for inspection using specific instruments for leak detection, you have to make a payment of Rs. 2,300.00 (including VAT) to the relevant Area Engineer Office.


If cannot identify any leak using instrument, then you can request for checking the water meter. For water meter testing you have to make a payment of Rs. 3,450.00 (including VAT) to the relevant Area Engineer Office. If the error percentage in the test report indicates more than ±2%, NWSDB will take action to correct the bill to an average consumption considering the previous months. If the water meter is defective, the meter testing charges will be refunded.


If you have helpers at home, aware them for closing the taps properly. Water loss due to partly opened taps is appended below.




Checklist to Save Water









Main Meter (NWSDB)

Take main meter reading regularly. (To monitor any abnormal increase of water consumption.)





Install flow controlling section valve at all sink taps & mixers and bib taps. (Control to a efficient flow rate)




Kitchen/Cooking Area

Install sub-meter to monitor water consumption.




Install section valve (stop valve/stop tap) to control the flow at sink taps & mixers and bib taps.




Wash vegetables and dishes in a filled bowl instead of under running taps and use for gardening.





Install sub-meter at the public toilets to monitor water consumption.




Install self-closing delayed action taps at all wash basins & shower points.




Install flow controlling section valve at all wash basin mixers, shower mixers and bib taps.




Place a flexible bag with water/ water saving bottle (for 1.5litres) in the 9litres cistern.




Install dual flush low capacity flushing cisterns which uses only 4.5litre or less for full flush and 3litres or less for low flush.




Reduce flush volume of urinals to 0.5, 1, 1.5litres for small, medium and large urinals respectively.




Display contact numbers for public to inform about any water leakage or faulty fittings for proper rectification




Assign cleaners to take the responsibility in leakages and rectifications.




Landscaping and Vehicle

In large premises, install sub meters to monitor the usage




Use a watering can instead of a running hose to water the plants




If a hose is used, fix a spring-loaded nozzle to the hose




Use drought resistant plants/ less water required plants and group plants with similar water requirements




Water the plants only before 7am and after 5pm in the evening to minimize the evaporation losses.




Install drip irrigation system.




Use alternative sources of water such as rainwater for watering plants.




Wash the floor using a mop and bucket instead of open end hose. (If a hose is used, fix a spring loaded nozzle to the hose)




Wash vehicles taking water to a bucket.




Swimming Pools

Install sub-meter at the balancing tank to monitor incoming water




Lay exposed pipes where possible




Display contact numbers for public to inform about any water leakage for proper rectification




Conduct regular checks for leaks and repair promptly




Reuse backwash water for gardening




Keep the pool chemically balanced to prevent water quality problems and therefore reduce the frequency of backwash and cleaning.




Use spray loaded nozzle for cleaning




Washing/ Laundry

Install sub-meter to monitor water consumption of the laundry.




Operate washing machines only when fully loaded.




Do not wash under running tap




Wash in a filled sink/basin/bucket




Collect the last rinse water from the washing machine for flushing the toilet or for mopping the floor




Recycle the final rinse water for the next pre-wash in the next load.




Presort the garments, linen, etc just before loading the machine.




Adhere to the manufacturer’s recommended settings and regularly check that the water level is correct during operation.




Carry out regular maintenance to ensure water valves and dump drains are free from leaks.




Turn off and isolate the steam supply to equipment when not in use.





Check for overflow in toilet cisterns.




Taps are turned off tightly to stop drips




Remove loose head handles of bib taps to avoid misuse.




Set up water recycling system to reuse water for non-potable purposes.




Inspect the water reticulation system and water fittings regularly for leaks. Repair any leaks found properly.




Educate workers / employees on the need to conserve water through pre-work briefing, talks, discussion, publicity materials, etc. in your organization.




Engage employees to come up with new water conservation ideas and reward them accordingly.






All citizens of the country have the right to request for an individual drinking water supply. National Water Supply & Drainage Board (NWSDB) evaluates the request based on the availability of distribution system, availability of water system pressure etc. To install the water connection and send the bill, address proof is needed. It could be in the form of assessment tax or number assigned by the local authority.

 A legal water supply would have a connection provided by NWSDB, quantity of water consumed will be measured by a meter, having NWSDB marked on it. Property of the NWSDB ends with the meter. Only authorized persons could tamper with NWSDB property, in the event unauthorized person tampers with NWSDB property it is a punishable offence. It is the responsibility of the water user to ensure that all the consumption are quantified by the meter.

Employees of the NWSDB have the authority to enter private premises to check legality of consumption of water. NWSDB has a separate section specialist in detection of unauthorized consumption. On average 13,000 premises are checked and over 1,200 detection are made.













(up to April)

Premises Checked (Nr.)












Detection made (Nr.)












LOR levied (Rs. million)














There are free water common outlets in the distribution system to serve the population who do not have legal water supply. These outlets have been installed when the water was supplied free by the local authority. The current trend to have a green environment by reduction of wastage is managed by measuring the quantity of water consumed and sending monthly bill. To encourage persons to obtain individual connections a program called “Randiya” was initiated in 2000.

 Under Constructrion