Tap water in Saint Lucia is chlorinated and considered safe to drink. However, it's best practice for travelers to drink bottled water anyways to avoid the possibility of ingesting bacteria or other microorganisms. Bottled water is readily available throughout the country and usually costs $1 USD.

In St. Lucia, the cost of a bottle of water varies significantly based on where you buy it. In a local supermarket or small grocery shop, a standard 1.5-liter bottle of local spring water (like Piton Water) typically costs about $3.00 to $5.00 East Caribbean Dollars (XCD), which is roughly $1.10 to $1.85 USD. However, if you are purchasing water at a luxury resort or a popular tourist attraction like the Sulphur Springs, prices can double or triple, often reaching $4.00 to $6.00 USD per bottle. While tap water in St. Lucia is generally chlorinated and considered safe to drink by the water authority (WASCO), most tourists prefer bottled water due to the different mineral content which can sometimes cause minor stomach upsets in those not used to it. Buying in bulk from a local grocery store is the best way to save money while exploring the island.