This objectionable feature here exists because of the combination of a stone dam and an embankment , while it could not exist in either a continuous stone dam or , on the other hand , a continu- ous embankment and core wall . As to the second chan- nel by which the water could reach the wall there is also little doubt , for it would be afforded freer access through the refilled material of the great pit , than it would have STONE DAM البلد TOP OF 290 - FEET_ . CORE WALL MARCH 1ST 1901 EMOVED DISINTEGRATED FLIMESTONE SHATTERED LIME STONE THE NEW CROTON DAM LONGITUDINAL SECTION ON AXIS OF DAM , SHOWING CORE WALL REMOVED AND ITS DEFECTIVE LIME STONE FOUNDATION , WHICH HAS BEEN EXCAVATED FOR THE EXTENSION OF THE DAM . AK GATE HOUSE . CHAMBERS TO BE REMODELED AND REINFORCED in ordinary cases , where the wall below the original sur- face of the ground is in a narrow trench and protected by original soil . It would be useless to consider any proposi- tion to increase the width of the embankment , because the means afforded the water to reach the core wall along the face of the dam would always remain ; this is a most dan- gerous feature , as the core wall would not have sufficient weight or strength to resist the pressure of the water that would come against it . A fourth objection might here be stated , namely , the permeable and light character of the earth of which the embankment was made , but even with the best of ma- terial , an embankment so constructed would be insecure . Thus it will be seen that the safety of this reservoir was dependent not only uponan embankment of a problematic section , resting upon an unstable foundation , but also upon a core wall of phenomenal height , unprotected and unsupported by original soil and attended with the great- est of all possible risks , that is the means afforded water to reach the center of the embankment against the core wall .