When a swimming pool has been affected by floodwater there are many issues that need to be considered.
An unused swimming pool is not likely to transmit or become a source of diseases in the short term unless it has been contaminated by sewage.
Assess your pool
Secure or restrict access to your pool area after a flood if possible, particularly if fences have been damaged or debris has made the area dangerous.
Check the pump house and other structures to ensure that snakes, spiders or other pests are not a threat.
Be cautious around reptiles and insects that appear dead as they may be still alive.
If the pump, timer or other electrical equipment have been under flood waters, have a licensed electrician check each electrical fitting.
This may need to be done in consultation with the local pool shop in case electrical components need to be replaced.
Severe damage may mean the pool area should be secured and made safe until a consultant or insurance assessor is able to give professional advice.
Do not pump out a swimming pool immediately as this may cause more damage than leaving the pool full.
An empty pool, particularly a fibreglass pool, may pop out of the ground.
Check the pool surrounds for washouts, missing pavers or debris.
Eventually the pool may need to be pumped out and cleaned to allow a full assessment of the damage.
Mosquitoes and algae
While the pool is full but not able to be restored it may provide a place for mosquitoes to breed and should be checked daily.
If mosquitoes are breeding in your pool, add one cup of household kerosene to the water weekly.
If the pool starts to turn green, then algae is forming. Consult your local swimming pool shop about the best way to get rid of algae.
If the pool has soil in it from flooding it may need to be pumped or bucketed out.
There may be unusual material washed into the pool that could be hazardous as well as affecting the water quality.
After a flood your pool water is likely to be very dirty and any attempt to filter the water will rapidly clog the filter.
Ask your local swimming pool shop how to clean your pool water.
Dirt should be scooped out and vacuumed before the pool filter is turned back on.
You will need to chlorinate your pool water. You should gradually add liquid chlorine, also known as sodium hypochlorite, to your pool to until the the free chlorine concentration is 5mg per litre and the pH is 7.2. Leave the pool filter running overnight.
If you're using salt-water chlorination, the salt concentration should then be readjusted.
Once you've completed these steps, you can use the pool as normal.