In conse- quence of this great additional depth , it was also neces- sary to greatly increase the width of the base of the dam . Thus again the cost was materially increased because of the additional quantity of excavation and masonry . Before the writer assumed the responsibility of this work , the foundation of the stone dam had been com- pleted to the surface of the ground and the core wall had been completed , excepting the stretch between the stone dam and the gate house , which lacked about 60 feet of its height . In the spring of 1901 , this core wall cracked in five places within a length of 100 feet . This caused the writer to believe that some serious disturbance had taken place , as in his opinion the cracks were too close together to be caused by contraction . After close study of the condi- tions , there was no conclusion to be arrived at except that there was a fundamental weakness here , and , therefore , it would be unsafe to proceed with the work . This close study brought to view objectionable features of the plans of the embankment and core wall , the most conspicuous of which were three . First the excessive height , narrow base and unstable foundation of the embankment ; sec- ond , the great height of the core wall , and , third , the double means afforded the water to reach the core wall . To take up the first , the embankment : It was to be 150 feet high , and only 650 feet thick at the base . This section , would be not only about 40 per cent . higher than any heretofore built , but in comparison with other high embankments its base was narrow for its height .