Why is water pooling on my pool safety cover?
Water pools on a safety cover when debris blocks the mesh, the straps have gone slack, the pool level is too low to support the cover, or a solid or automatic cover's pump is not working. Sweep the top from the deck, tighten the straps and restore the water level. Stay off the cover, because standing water is a drowning risk.
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By Kasra Taheri, Founder, LoclisPublished
Researched and drafted with AI, then checked claim by claim against the sources listed below before it was published. Prices and rules change; the dates beside each source say when it was last checked.
Step by step
Read when to stop and call a pro, further down this page, before you start.
Step 1: Stay off the cover
Do not walk on the cover except in an emergency, and keep children and pets away from it.[1]
Step 3: Sweep the top from the deck
Clear leaves and debris from the edge with a soft broom or leaf rake so rain water can drain into the pool.[1]
Step 5: Look at the springs and straps
A mesh cover's springs should be compressed about 50 percent; slack straps need tightening.[1]
Step 6: Tighten in small steps
Release a loose spring with the installation rod, shorten the strap at its buckle by 2 inches, and refasten it.[1]
Step 7: Check the pump on a solid or automatic cover
Confirm the pump is upright on its base, plugged into a GFCI-protected outlet, and that its power cord and discharge hose are free of kinks.[2]
Step 8: Watch the next rain
If water still collects, stop and call a pool pro; do not leave it standing.[2]
Water pools on a pool safety cover for one of four reasons: debris is blocking the top, the straps have gone slack, the pool level is too low to support the cover, or the pump on a solid or automatic cover is not working. Sweep the top from the deck, tighten the straps, correct the water level, and keep everyone off the cover until the water is gone.
Treat any standing water as a safety problem, not a cosmetic one. A cover with water on it poses the same safety hazard as an open pool.[2]
Why water collects
Water on top of a cover can come from rain, snow, over-spraying sprinklers, or leaks that develop in the cover.[2] What decides whether it stays is the cover and how it is set up.
Debris on a mesh cover. Tara Safety Covers, a maker of mesh covers, says that as debris collects on top of the cover, it must be swept so that rain water can drain into the pool, and failing to keep the top of the cover clear may cause water to puddle and the cover to fail.[1] Leaves on their own are not a fault. Tara says leaves collecting on the cover is a normal circumstance, and to allow them to dry and blow off; if they tend to stay, make sure the straps are taut across the pool so the leaves can blow away.[1]
Slack straps. A sagging cover makes a basin. Loose straps can cause premature cover wear,[1] and the springs on a mesh cover should be compressed 50 percent, and 60 to 75 percent on a solid cover.[1]
Water level too low. A cover is held up partly by the water beneath it. Tara's care guide says the pool water level must be between 15 and 18 inches below the cover at all times, or the warranty will be voided.[1] Coverstar's own guide for its automatic covers says to keep the water at the mid-skimmer level, and not to overfill.[2] For an automatic cover, Coverstar says that if the water level is too low, add water to the pool immediately to better support the water or ice on the cover.[2]
A solid or automatic cover with no working pump. These covers do not drain through the fabric. Coverstar says any accumulation of water on the surface of the cover must be removed immediately using the cover pump.[2]
Why a little water is a big deal
Even what appears to be small amounts of water spread over the whole surface of the cover can migrate and accumulate in depressions.[2] A child can create a depression on the cover great enough to collect a dangerous amount of water.[2] Tara's warning is blunt: standing water on top of a cover can let a child drown, and nobody should walk on the cover except in an emergency.[1]
The weight matters for the cover too. Just one inch of water on a cover can weigh thousands of pounds,[2] and even a few inches of water on top of the cover is an enormous weight and can pull the cover and tracks into the pool.[2]
What to do
Work from the deck, never from the cover. Start with the simple fixes: sweep or rake leaves and debris off the edge with a soft broom or leaf rake, then check the gap between the cover and the water. If the straps look slack, tighten them. Tara's method is to remove the spring from the anchor with the installation rod, adjust the length of the strap by 2 inches at a time, and refasten the spring, repeating until the springs are compressed to the right amount.[1] The installation rod is the same tool used when you put the cover on.
On a solid or automatic cover, check that the pump is doing its job. Coverstar says to plug the pump into a GFCI-protected outlet only.[2] Its pump manual warns that electric shock is possible if you touch accumulated surface water while the pump is on the cover.[2] If the pump or its cord becomes damaged, replace the pump immediately.[2]
Stop and call a pro if
- Water keeps collecting after you have swept, tightened and checked the level. The cover may have stretched, torn or lost its fit. Tara's guidance is to inspect the cover annually for damage and not to use it if it is damaged.[1]
- The pump will not run or the cord is damaged. The pump is an electric appliance used over water, so replacing it and diagnosing a power problem is a job for a pool pro or an electrician.[2]
- The cover is already dragging into the pool. Even a few inches of water on top of the cover is an enormous weight and can pull the cover and tracks into the pool.[2] Do not stand on it to fix it.
- A person or pet is in the water or on the cover. Call 911.
- The cover never fit properly. Anchors and strap lengths are set to your pool, and first-time installation is a pro's job. See how to put on a pool safety cover.
Getting help in Virginia
If the cover is beyond saving, read how much a pool safety cover costs in Virginia and whether Virginia requires a fence or barrier around a pool before you buy. See all of our pool and spa answers or browse local pool pros.
When you are ready, describe the problem and local pool pros can quote it in writing.
Common questions
- Is water on a pool safety cover dangerous?
- Yes. Tara warns that standing water on top of a cover can let a child drown, and Coverstar says a cover with water on it poses the same safety hazard as an open pool. Stay off the cover and clear the water from the edge.
- Why does a mesh cover hold water at all?
- Usually because debris has built up on the fabric or the cover has gone loose and sagged. Tara says as debris collects on top of the cover, it must be swept so that rain water can drain into the pool, and loose straps cause premature wear.
- Do I need a cover pump?
- On a solid or automatic cover, yes. Coverstar says any accumulation of water on the surface of the cover must be removed immediately using the cover pump. A mesh cover drains through the fabric, so it relies on a clear top and tight straps instead.
- Should I drain the cover into the pool or onto the deck?
- Where the system uses a pump, follow its manual for the discharge hose and keep it free of kinks. For a mesh cover, the water is meant to pass through the fabric into the pool once the top is swept clear.
- Why is my cover sagging in the middle?
- Common causes are slack straps, a pool level that has dropped below where the manufacturer wants it, or weight from water, snow or ice. Tighten the straps in small steps and restore the water level, then look again after the next rain.
Sources
- [1] Mesh Safety Cover Installation & Care Guide, Tara Safety Covers, Inc.. Checked October 28, 2026.
- [2] Automatic Safety Pool Cover Use & Care Guide, Latham Pool Products (Coverstar), manufacturer's guide. Checked October 28, 2026.
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