National Dam Inspection Program. Lake Ashburton (NDI ID MD-108) Patapsco River Basin, Gwynns Run, Baltimore City, Maryland. Phase I Inspection Report,

Based on the visual inspection, available records, past operational performance, and in accordance with the guideline criteria established for these studies, Lake Ashburton is judged to be in good condition. The water level in Lake Ashburton is maintained at approximately elevation 352 by controlling the inflow of water from the Ashburton Water Purification Plant and the outflow of water through the gate house located along the southeast embankment of the impoundment. The outflow is either directed by gravity to the Baltimore City Second Service Zone or is pumped by the Ashburton Pumping Station to the Western Third Water Service Zone. The reservoir impounds finished water for Baltimore Citys water distribution system and was therefore constructed in a manner to prevent surface water runoff from the upstream drainage area from reaching the lake. Except for rainfall on the reservoir surface, all inflow into the lake is controlled, and therefore flood routing analyses are not required. No stability problems were evident for the embankment or the appurtenant structures at the time of the visual inspection.