The Old City Hand Dug Well in the Seneca City Park is the last visible sign of Seneca, Kansas's original water system, installed in 1895. The 65 foot deep by 34 feet wide, rock/brick-lined well may be the widest and second largest hand-dug well in Kansas. Water depth is approximately 15 feet. A domed house with shingled roof covers the well and is topped by a cupola. It was encircled by a six foot chain link fence about 1975 as a safety measure. Children used to scramble up the shingle roof and then slide back down.
The first levels of the wall are constructed of rock set in mortar while the lower portions are of brick and mortar. The rock walls are laid in sections about four feet high, constructed from ground level downward. Heavy planks are still visible beneath each section. During construction, 3 to 4 feet of soil was removed. Then bridge planks were sharpened (tapered) on one end and driven about 3 feet out into undisturbed soil, while resting on the dirt at that level. A ring section of rock wall was laid upon the exposed inner ends of the planks. After the mortar had set in the first ring, the well was dug another four feet deep. Soil was removed from under the driven planks, to allow the next section of wall to be laid directly under the ring above. A ring of planks was driven each time to support the rock. The process was repeated several times until the well was approximately 50 feet deep. At that point the diameter was decreased about three feet forming an offset ledge in the rock wall. Digging probably became more difficult once the water table was reached. Water had to be pumped out to allow for continued digging and wall construction. Soil instability, within water bearing strata, may have been the reason well diameter was decreased. If the soil was too unstable, driven planks could not have supported a wall section while the succeeding ring was dug out and laid.