“The wall is 48 ½ feet at the base and 120 feet in height. Its least width is 18 ½ feet … The extreme length of the wall is 1251 feet, and contains about 76,000 perches of stone.” (A perch is enough stone to lay a course a foot deep and a half a yard wide across a distance of one rod – fortunately, for our comprehension, just about a cubic yard.) Those 76,000 perches of stone came from a limestone hill above Kemper Lane. The abandoned quarry was later developed as the Twin Lakes Overlook, one of the most beloved features of Eden Park.
What is not visible at the ruins is the fact that the 120-foot high wall is mostly underground! To prevent it from sliding or toppling down the ravine, the engineers piled the back side of the wall with 50 feet of waste rock and earth as well as 75 feet of fill under the bottom of the reservoir. Before the backfill, the wall was not as high as the steeples going up on Walnut Hills Churches – but higher than their sanctuary roof lines. Beneath the wall the site was honeycombed with sewers between two and six feet across. The surface of the reservoirs covered about 14 acres with water twenty-five feet deep.