Final answer:
The author describes the benefits of modifying culverts in paragraphs with clear transitions, which help indicate when a new idea is presented or when the narrative shifts to a different point.
Step-by-step explanation:
The author describes the unexpected benefits of modifying culverts in paragraphs that utilize effective transitions to guide readers through the presented ideas. Transitions are crucial in writing because they help readers understand the relationship between ideas, how they connect with one another, and what is to come next in the text. They also provide a smooth flow from one idea to another, which is particularly beneficial when an author is shifting to another success story such as the unexpected benefits of modifying culverts. Effective use of transitional phrases would typically be found at the start and within the body of paragraphs where such benefits are discussed.