(Note: The ongoing Palo Verde Historical Museum & Society contributions are from a collection of “History of the Communities of the Palo Verde Valley” submissions dated and published November 2001.)
When Thomas Blythe established the Colorado River water rights for 40,000 acres in the Palo Verde Valley, on a gravity flow basis, he probably did not realize the value of being the number one claimant with gravity flow rights.
All of the later claims for additional acreage in the Palo Verde Valley contained the same rights, which has made irrigation water in the valley the least expensive of most irrigation areas in the nation.
For many years, no dam was necessary to divert water for irrigation use. The gravity flow right meant that they could cut the riverbank and let the water flow naturally for irrigation purposes. The shape of the valley made it ideal for gravity flow, since the valley slopes south and the west side of the valley is lower than the east side.
Interruption of gravity flow was no problem for many years and seasonal flooding created the greatest problem until the late 1930s, when the river bottom began to scour and lower the level below the level of the valley intake. After centuries of seasonal flooding of the Colorado River Basin, it was decided that a series of dams along the Colorado River would stop the flooding and stabilize the river for safety and more beneficial use. Hoover Dam was the first dam completed and was quickly followed by Davis and Parker Dams in the mid-1930s. The result of the control and release of water from the dams soon became evident by the scouring of the riverbed because the water was clean and clear and no longer carried the silt and sand that it previously carried.
This was a serious threat to farming in the valley so the Bureau of Reclamation built and maintained a rock weir across the river a short distance above where the Palo Verde Dam is now located, thus diverting water into the Palo Verde Valley intake.
The weir served well in the 1940s, except for an occasional small breach, which was repaired by dropping cable buckets of rock in the breach until it was repaired.
In January 1951, there was a major breach in the weir and it became clear that the weir was not a permanent solution for the Palo Verde Valley.
The Irrigation District Board, interested farmers and businessmen lobbied the Bureau of Reclamation and Congress for a solution to our problem.
They were successful and three options were considered to meet the need. One option was to build a canal from Headgate Dam in Parker, down the east side of the river to the Palo Verde Valley.
The second option was to install large pumps in the area of the weir and pump irrigation water from the river, and the third option was to build the Palo Verde Dam.
Our gravity flow dam entitled us to a free dam. The government did pay most of the cost and loaned the Palo Verde Irrigation District interest free money for 50 years to pay their part. The Palo Verde Dam was completed in 1957.