Bring baby carrots and water to a boil in a saucepan. Reduce heat to medium-high and simmer, uncovered, stirring occasionally, until carrots are tender, about 10 minutes. Drain.
Melt butter in a skillet over medium heat; stir in honey, lemon juice, and ground ginger. Increase heat to medium-high, then stir in carrots until well coated. Cook, stirring occasionally, until glaze is thickened, about 5 minutes. Garnish with walnuts and lemon zest.