Swimming pools

When a swimming pool has been affected by floodwater or a long power outage, it is important to make sure the pool is safe before using it.

A well maintained swimming pool that has not been used is not likely to transmit or become a source of diseases in the short term unless it has been contaminated by sewage. Long power outages mean filtration and auto dosing of the pool will not occur. The longer power is out the more the quality of the water will deteriorate.

Assess your pool

Secure or restrict access to your pool area after a flood, particularly if fences have been damaged or debris has made the area dangerous. Make sure you check for physical hazards before entering the area such as missing pavers, debris or animals.

Severe damage may mean the pool area will need to be kept secured until a consultant or insurance assessor is able to give professional advice. If the pump, timer or other electrical equipment have been under flood waters, have a licensed electrician check each fitting before coming into contact with any component.

You may need to consult with your local pool shop if electrical components need to be replaced.

Do not pump out a swimming pool suddenly as this may cause more damage than leaving the pool full.

An empty pool, particularly a fibreglass pool, may pop out of the ground in wet conditions.

Mosquitoes and algae

If the pool remains full of water and non-functional for a long period of time, it may provide a place for mosquitoes to breed and should be checked regularly. Lack of movement of the water, lack of chemicals and debris in the pool all favour mosquito activity. Keep the pool free of leaves and debris, this can be done manually using a leaf scoop.

Manually dosing the pool with chemicals during this time will help to prevent mosquito breeding. Seek advice from your local pool shop regarding concentrations and appropriate chemicals.

If mosquitoes are breeding in the pool and treatment with chlorine is not practical, you can add one cup of household kerosene to the water weekly.

If the pool starts to turn green, then algae is forming. Consult your local pool shop for the best way to treat algae.

Water quality

After a flood or long power outage your pool water is likely to be dirty and attempting to filter the water using the pool filter may clog the system.

Visible dirt or debris should be scooped out and vacuumed before the pool filter is turned back on.

It is advisable at this stage to take a water sample to your local pool shop or contractor, to obtain tailored advice and chemical dosage to undertake treatment.

Where advice from a pool shop is not practical, add the necessary amount of chlorine to reach a free chlorine level of 5mg per litre and an alkalinity increaser to reach a pH level of 7.2. Refer to the product label for correct amounts and leave the pool filter running overnight.

If the pool is a salt water pool, the salt concentration should be readjusted accordingly. The local pool shop or contractor should be consulted to assist in this situation.