| The Reservoir is approximately 47 meters (155 feet) above sea level. By comparison, Spy Pond and the Lower Mystic Lake are both just about 1 meter above sea level. The primary feed to the Res is Munroe Brook (also called North Brook) from Lexington. The Arlington Great Meadows (in Lexington) is drained by Sickle Brook which does not feed the Reservoir but flows below the earthen dam on its Southern edge to join the discharge from the Res to form Mill Brook. Mill Brook then flows north of Mass Avenue to discharge into the Lower Mystic Lake at Arlington Center. |
| The dashed line through the center of the Reservoir is the Arlington-Lexington town boundary. The railroad line (with crosshatches) is now the Minuteman Bikeway. The contour lines are at 3 meter (10 ft) intervals. |
| The image is scanned from the USGS Boston North topographic map (42071-D1-TM-025) 1985. |