In order therefore to make a tide-level canal, some means must be found for disposing of the waters of the Chagres and other rivers. De Lesseps's tide-level project was rather an aspiration than a plan. He proposed to conduct the waters of the Chagres to the sea by other channels. The magnitude of this task would be scarcely less than that of cutting the Canal itself. The other rivers on both sides of the Canal would likewise require diversion channels, so that the final result would be roughly the formation of three channels, of which the centre one would be for navigation. The Board of Consulting Engineers summoned by President Roosevelt in 1905 to advise the Isthmian Canal Commission recommended, in a majority report, a tide-level canal as practicable and best fulfilling the national requirements, defined by the Spooner Act of 1902. But whereas they had detailed schemes for high-level canals before them, they were in the matter of the sea-level project at the disadvantage of having to act in a constructive capacity and elaborate the details of a scheme before they could criticise it. Moreover, five of the eight who constituted the majority were European engineers, who returned to their duties as soon as the report was drafted. The report of the minority in favour of the 85-foot-level scheme having been adopted by Congress in 1906, all available engineering talent has for the last two years been devoted to improving the details of this scheme. The tide-level project of the majority of the Board has had no such advantage, and the difficulty of estimating the relative advantages of the two schemes is therefore all the greater. Both schemes depend for their success upon the security of dams. The tide-level scheme has a dam at Gamboa, near Obispo, thus making a lake of the upper waters of the Chagres, whose surface would be 200 feet above sea-level.[8] The floodwater would partly be accommodated in the lake by reason of the great height of the dam above low-water stage, and partly by running the excess into the Canal, by which it would escape to the sea, generating currents which the Board calculated would not attain an injurious velocity. [8] Report, Board of Consulting Engineers, p. 205. Streams entering the Chagres in its lower reaches would be dammed back or diverted--a considerable, but not momentous, undertaking. The three great objections to the scheme appeared to be:-- 1. The extra cost, and above all the extra time, required to complete the immensely greater quantity of excavation required for the last 85 feet; 2. The fact that the artificial lake was to be above the Canal, so that, if the dam burst, the Canal might be ruined; and, 3. That the velocity of currents in the Canal due to discharge of the surplus waters might perhaps be a serious drawback to navigation in a narrow channel. It will be seen presently that the second disadvantage is offset by corresponding disadvantages in the dam required for the high-level canal.