Swimming pool water typically contains a carefully measured amount of chlorine, which maintains the pool’s cleanliness by keeping algae, microbes, and other impurities at bay. Occasional splashes of chlorinated water on your lawn generally won’t do much harm. However, if the water has a high chlorine concentration, it’ll likely damage the grass, leading to discoloration and chemical burns. Over time, excessive chlorine can alter the soil’s pH balance and harm the grass.