BOULDER CANYON PROJECT — NELSON 433 



the Paria Eiver confluence. Thus the upper basin includes parts of Arizona, 

 Colorado, New ISIexico, and Utah, while the lower basin contains parts of 

 Arizona, California, Nevada, New Mexico, and Utah. 



2. Consumptive use of 7,500,000 acre-feet of water per annum was apportioned 

 to each basin and, in addition, the lower basin was given the right to increase 

 its consumptive use by 1,000,000 acre-feet per annum. 



3. The upper basin States were not to deplete the run-off below an average 

 of 75,000,000 acre-feet in 10 years, and the lower basin States were not to re- 

 quire the delivery of water which could not be reasonably used. 



4. The use of the river for navigation should be subservient to the use of its 

 w-aters for domestic, agricultural, and power purposes. 



5. The compact should not be binding until it was approved by the Congress 

 of the United States and by the legislatures of the seven basin States. 



All State legislatures, excepting Arizona, later ratified the com- 

 pact, but not before many years of disputes. 



Investigations of the Colorado River for suitable dam sites, lead- 

 ing to the ultimate and complete development of the river's re- 

 sources, have been in progress under the direction of the Depart- 

 ment of the Interior through the Bureau of Reclamation since 

 this Bureau was established by the Reclamation Act (ch. 1093, 32 

 Stat. 388) during the term of office of President Theodore Roose- 

 velt. In the lower basin, the principal dam sites were early recog- 

 nized to be at Black and Boulder Canyons. These two narrow 

 gorges are located on the Arizona-Nevada boundary, Boulder Can- 

 yon being immediately downstream from the Virgin River conflu- 

 ence, and Black Canyon 20 miles farther downstream. Bright 

 Angel Crossing in Grand Canyon is 270 miles upstream from Black 

 Canyon, and the Gulf of California 450 miles downstream. 



Geologic and topographic surveys were made of the two dam 

 sites and their reservoir areas starting in 1919, and examinations 

 of foundation conditions by diamond drilling were conducted at 

 Boulder and Black Canyons from 1920 to 1923. Owing to the haz- 

 ards in flood periods and the unbearable living conditions, where 

 shade temperatures of 130° were often noted in the reflected heat 

 from the canyon walls, drilling was done primarily in the fall and 

 winter. Nevertheless, on more than one occasion drill barges were 

 wrecked by sudden floods and drift wood, cloudbursts washed away 

 the roads leading to the camps, and high winds leveled their tents. 



Data obtained from investigations by the Bureau of Reclamation 

 on the Colorado River were compiled in 1924 by Chief Engineer 

 F. E. Weymouth and submitted to Secretary of Interior Hubert 

 Work in eight volumes entitled " The Problems of the Colorado 

 River." Preliminary plans and estimates were made of dam sites 

 located at numerous positions along the river and particular em- 

 phasis given to a projected high dam at Boulder or Black Canyon. 

 It is interesting to note that the preliminary estimate of $120,000,000 



