A problem with the Swimming Pool

During the Summer I noticed that the water level was descending faster than usual. Normally, with evaporation I only had to top it up fortnightly. But I noticed that I was losing that much in 2 days. I have not stopped the leak yet, but I assume that the egress is occurring through the underwater light assembly. During the Winter I will monitor the level to see to where it descends. The problem with a pool is that the side walls are weakened without water, and there is always a possibility that the structure will collapse.