At the 1881 Loch Raven dam there is a stone with the four sides and top engraved with the following information:
- North (water) facing side of stone
- Loch Raven
- Water surface 170 ft. A.M.T. [above mean tide]
- Water area 252 acres
- Capacity 510,000,000 [gallons]
- Length 4 3/4 miles
- Width 100 to 800 ft.
- Depth 4 to 20 feet
- Loch Raven
- South (Loch Raven Drive) facing side of stone
- Number of stones like this on face of dam 2530.
- From Beaver Dam Marble Quarry Baltimore County MD.
- Each stone averaging one perch [24 3/4 cubic feet].
- Total number of perches in dam 20376.
- East facing side of stone
- Dam
- Built of rubble and cut stone on solid rock
- Thickness of masonry at foundations 62 feet
- Depth of foundation below bed of stream 13 feet
- Width of overfall 300 feet
- Length of wings 256 feet
- Height from foundation to overflow 29 feet
- Thickness of earth in rear of foundation 45 feet
- Dam
- West facing side of stone
- Tunnel
- Diameter 12 feet
- Length 7 miles
- Depth below surface from 65 to 360 feet
- Two miles arched with brick
- Five miles through solid rock not arched
- Fall 1 foot per mile
- Capacity of discharge per day 170,000,000 gallons
- Tunnel
- Top of stone
- Robert K. Martin Chief Engineer
- Wm. L. Kenly Prin. Asst. Engineer [William L. Kenly Principal Engineer]
- Wm. R. Warfield Res. Engineer of the Dam [William R. Warfield Resident Engineer of the Dam]
- Key stone laid Oct. 6th. 1881 [October 6, 1981]