Boating Is All About The Water Outside and Inside Your Narrowboat
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Fri Mar 25, 2016 at 11:24am

How to look after the water on your boat

When you own a narrow boat you need to maintain your water supply. This requires you to replenish your system regularly. Unlike in a bricks and motor home the water on a narrow boat has to be thought about; you can't simply turn on the tap and there is a continuous supply of clean fresh water. On a boat it’s up to you to make sure there’s enough water on board for everyone to use and it also means that you need to keep it clean and sterile.


How To Store Water and Where To Get It From

Storage - water is kept in a large storage tank on board which is usually situated in the bow of the boat.

Fill up point - this should be clearly marked on the boat and can be filled from one of the many water points around the canal system or at a marina.

Connection - on most boats the water tank will be connected to a tap at the sink, where it is pumped out by hand or by electric pump.

Capacity and Replenishment - the boat's water tank will have a suitable capacity for a number of people on board. But you will need to replenish the water fairly frequently from the water points, depending on usage. Narrowboats will have a water filler point on the deck and will have a hose to connect it to the water point.

Water Points - water points are clearly identify in navigation guides, such as Nicholsons or Pearsons. When out on the network or mooring, it is good practice to make a daily check on the water level and the whereabouts of where the next stop point is if you are out and about.

Hot water – is provided either by instant gas/diesel heating systems or a calorifier; a water storage heater is linked to the engines cooling system or back boiler.

Emergency supply – having a large container stored on the boat for emergencies is a good idea. At least you will have enough water for a cuppa till you reach the next water point. A few bottles of water in the fridge is also a good back up plan should you run low.  

How much water to keep on board

You will only be able to keep as much water as your tank size allows, plus what ever emergency supplies you keep alongside your tank. How often you will need to refill the tank is dependent on how much water you use each day. If you are a family of four, you are obviously going to  use more than a single person.

As a bare minimum you should have enough water to drink, cook and clean with. If you are prepared to rough it at times, then forgoing the odd shower can reduce the amount of water you use.

It is a very important to ensure that your water is sterile and clean. Maintaining the water levels and cleanness is a job that should not be overlooked.

Keeping a clean water supply on your boat

Three simple methods

1. Boiling – If you want small quantities of water for drinking, cooking and cleaning then you can use the very simple and effective method of boiling your water in a saucepan. Heat the water to a rolling boil keeping the lid on to speed up the process and save energy. Then leave to cool and store in bottles or large container. The disadvantages of boiling are; it uses energy, it is in small quantities and it takes a long time to cool down.

2. Filters - Not the most effective way of cleaning your water and should be used mainly to clean larger particles of dirt out of the water. The cheaper filters have pore sizes too large to filter out bacteria so are not the best way to clean your water, but it is still an option.

3. Iodine – Is available as a liquid or tablet form, both of which are very easy to use. After 30 minutes the chemical water purifier will have got rid of most micrirganisms BUT not all. So again this is not the perfect solution for treating your water.

Maintaining your water system

If your vessel has a fitted water system then the 3 above methods are not going to be enough to purify your water system. If you have a complete water system in your boat, then it should be obvious by now that you need a more comprehensive water purification system than any of the methods listed above.

Chlorine is best used for cleaning the pipes as it needs to be flushed out of the system, fill the water tank leave for 24 hours, and then flush thoroughly.

Hydrogen Peroxide based water purification solutions are very closely related to water (H2O2) so it will not require any flushing once the water has been treated, it will naturally break down into the water supply. Simply follow the dosage on the bottle, allow 30 minutes for the solution to take affect and you'll have clean, fully oxygenated water which is as good as fresh water supplies.

Toilets, Bilge & Waste Water


The toilets on your boat must not discharge sewage into the waterway. There are pump-out facilities for chemical or closed toilet systems at marinas and sanitary stations. Try to use the minimum amount of chemicals to avoid upsetting the sewage treatment system. If you have a closed toilet system, you may not need to use chemicals at all - so check your manual.

Everything you need to know about toilets is in this article; Narrow boat toilets 


Oily water that is collected in your bilge should be disposed of responsibly, it should not be emptied into the canal. Check the drip tray under the engine and gearbox regularly for any leaks and deal with the contents carefully. Where possible try and use biodegradable oils.

Mop up all spills from petrol and diesel and don’t add detergents to clear away spillages.


Unlike the waste water from your toilet, the waste water from your sink and shower/bath can be allowed to enter the canal system. However it is better for all concerned if your cooking waste is put straight into the bin. And when using detergents or toiletries, opt for environmentally friendly products where possible.

Saving Water at Locks

You can also do your bit and save water at locks. How? By seeing if the lock is set up for a boat approaching in the opposite direction, if no boat is approaching then by all means enter the lock. You can also see if there is space to share the lock with another boat.You will have to spare some time to put these ideas into practice, but it's a good time to have a cuppa or take a stroll until you can perhaps share the lock. An extra boat in a broad lock can save the equivalent of 1,000 bath fulls of water, that's quite a saving!

For more help and advice about water issues please do give our friendly team a call!


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