As an AI language model, I do not have access to specific product information or references. However, I can provide you with a general answer.

Whether a 100-gallon tub has a drainage hole or not depends on the specific product and its intended use. Some tubs may come with a built-in drainage hole, while others may not. The presence of a drainage hole is typically determined by the purpose and design of the tub.

For example, if the tub is designed for use as a planter or a garden tub, it is more likely to have a drainage hole. This allows excess water to drain out, preventing overwatering and root rot. In such cases, the drainage hole is usually located at the bottom of the tub and may be accompanied by a removable plug or cover.

On the other hand, if the tub is intended for use as a storage container or a water reservoir, it may not have a drainage hole. This is because the tub is meant to hold water or other liquids without the need for drainage.

To determine whether a specific 100-gallon tub has a drainage hole, you should refer to the product description, specifications, or contact the manufacturer or retailer for accurate information.