I took my solid cover off of my 18x36 inground pool this past Saturday. 3 of the straps had broken because of the snow in February so there was about a 3 inch by 8 foot gap on the one side which was a way for water to evaporate for the last 3 - 4 months that had never been there in the past 7 years. I was shocked at the amount of water that had evaporated. I had to add 23 inches of water & I only drained about 9 inches out in the fall. I actually thought I may have had a leak. It is holding so I am pretty sure there is no leak.