In "Esperanza Rising" by Pam Munoz Ryan, when Esperanza tells Miguel that there is a "deep river" that runs between them, she means that there are significant differences between their social and economic backgrounds. Esperanza is the daughter of a wealthy ranch owner in Mexico, while Miguel is a poor farmworker who lives in the same town. Despite their different upbringings, Esperanza and Miguel have grown close and developed feelings for each other. However, Esperanza feels that the gap between their social statuses is too significant for them to bridge, and she worries about what her family will think of her if she pursues a relationship with Miguel.
In chapter 11, when Esperanza and Miguel dance together, Esperanza becomes acutely aware of the differences between them. She thinks to herself, "The thought that Mama might be watching made her feel self-conscious. More than that, the people in the fields might be watching too. The fieldworkers and their families. The same people she had always thought of as her inferiors." Esperanza feels that her social status is what separates her from Miguel and that their relationship can never be equal because of it.
The river metaphor is used again later in the book when Esperanza has to cross a river to get to California. She reflects on the "deep river" that separates her old life from her new life and how difficult it is to cross over to the other side. In this way, the "deep river" symbolizes the obstacles that Esperanza faces as she tries to adapt to her new life in the United States and leave behind the privileges of her old life in Mexico.
Overall, the river metaphor represents the social and economic barriers that Esperanza and Miguel face in their relationship, as well as the challenges that Esperanza must overcome as she navigates her new life in the United States.