sentences:  Its terminal chamber, a single-story granite Romanesque structure with a hip roof, stands across Beacon Street from the reservoir, and houses gates for controlling flow into the reservoir from both the Cochituate Aqueduct (now defunct) and the Sudbury Aqueduct (in backup service), and from the reservoir to the Brookline Reservoir.The other major structure in the district is the high service pumping station, a massive Romanesque structure designed by Arthur Vinal in 1887, which is now a museum.The Chestnut Hill Reservoir and pumping stations were designated a Boston Landmark by the Boston Landmarks Commission in 1989.