The pool will only overflow by the amount of rain in excess of the amount of rain needed to fill the pool to the top. So if your pool is the normal 3” below the top, the rain would need to exceed 3” before any additional rain would be available to overflow onto the deck.
If the pool overflows, now only will the pool chemicals be diluted, but they may contaminate the pool deck and surrounding landscape. Removing excess water quickly is important to prevent this.
Heavy rains will dilute your pool alkalinity level, causing it to fall by 5-10 ppm a day. Low Alkalinity and low pH levels in pools can create a corrosive water environment. Corrosive pool water can result in the damage of underwater metal surfaces, such as pool lights, ladders and rails.
When preparing your pool for a storm, leave it uncovered. Installing any kind of cover across the pool will not do much to protect against dust and contaminants because storms often bring strong winds and heavy rain that can cause the cover to lift off your pool.
The extra filtering will help clean out the impurities rain has introduced into your pool's water. Pool pumps are made to withstand rain and it is beneficial to run your pump during or after rain.
Pool Losing Water After Heavy Rain
Due to a heavy rainstorm, water loss is more common with vinyl liner pools that can be damaged, come loose, or float to the top. With other types of inground pools, it is vital to get the water level down. If not drained, the water balance will change, causing cloudy water and more.
Too much rain can raise the water level in your pool to overflowing if you're not careful. If the water in your pool is in danger of overflow, you may need to drain the pool. There are numerous how-to videos online that go over this process.
When your pool overflows, your pool becomes diluted and throws the chemical balance off. Not only that, but rainwater also tends to carry pollutants with it that can cause contamination that needs to be dealt with.
If your swimming pool is one of those designed with a filtration tank that can hold and recycle excess water, the pool overflow will go to the tank. The tank's filtration system will then process the water to get rid of debris and bacteria before it is pumped back into the pool when necessary.
You don't need to drain your pool, as there is no risk to your pool by it being full. The only thing you lose with a pool filled to the rim is your skimmer's surface cleaning action. Overall, it still draws water and the equipment is just fine.
How often should I have to fill my pool? This will vary depending upon several factors including: weather, if the pool is covered or not, bather load, and if it is heated or not. With pools that are covered, a good rule of thumb is that they should not have to be refilled more often than once every 2 weeks.
On average, swimming pools lose about a quarter of an inch of water each day, yet variations in wind intensity, humidity and sunlight can drastically change water loss rates.
Protect the pump motor from water damage
In addition to removing circuit breakers, consider moving the motor indoors or covering it with a waterproof material to prevent water from getting inside.
Your pool also loses water in summer, up to 2 inches per week, due to the heat of the air. You can employ a swimming pool cover to protect the pool from these powerful rays. A pool cover will also keep heat in your pool when the weather is cold. In summer, the air around the pool is hotter than the pool water.
Most pools experience between 3mm - 7mm of water loss each day, depending on where you live.
For evaporation, anywhere between 2 millimeters to 2 inches per week is about what you should expect in terms of pool water loss.
Nearly all inground concrete pools will develop leaking problems at the skimmer throat at some point. Expansion and contraction of the pool and deck moves the skimmer slightly, breaking the cementitious seal between the pool wall and the skimmer.
If your pool lost water overnight and it is more than the quarter-inch due to evaporation, you probably have a leak. Evaporation accounts for a minor amount of water lost each day. Losing a half-inch or more overnight indicates a problem.
If the water went down a similar amount in the pool as well as the bucket, then you lost water due to evaporation. If it went down more in the skimmer and not much at all in the bucket then you have a pool leaking.
Since the pool is already full, the incoming water automatically spills over into the water tank, creating the overflow effect. Although the circuit is “technically” not closed, it is always the same water that flows in and out of the filtration system. So, no need to worry about issues of water consumption.
The average pool water evaporation rate is about a quarter of an inch of water per day or more than two inches in a week, which on a 33′ x 18′ swimming pool (an average pool size) is more than 2500 liters or approximately 600 gallons a week; this may vary depending on your climate and the factors listed above.
It is recommended you have your water level between one-third and one-half up the swimming pool skimmer box opening. If the level is higher than that, it may slow or even stop debris from being pulled into the skimmer box through the plate or valve.
The differential that occurs between the pool water temperature and the air temperature on late summer nights causes water to evaporate at an accelerated rate. In some cases you might see a water level difference of 1-3 inches overnight. Depending on the size of your pool, that can be over 500 gallons of water loss!