A cylindrical culvert has an internal diameter of 1.05 m. What is its internal surface area?

The internal diameter of the cylindrical culvert is $d = 1.05$ m.

The internal surface area of a cylindrical culvert refers to its lateral surface area. The formula for the lateral surface area ($A$) of a cylinder is:

where $d$ is the diameter and $L$ is the length of the culvert.

The length ($L$) of the culvert is not provided in the question. Without this value, the numerical internal surface area cannot be calculated.

Substituting the given diameter into the formula:

The internal surface area of the culvert is $\boxed{\text{}1.05 \pi L \text{ m}^2\text{}}$, where $L$ is the length of the culvert.