WSP08285

• File Number: 8221.108
• Description: Holbrook Project
• State: AZ
• Basin: Colorado Mainstem
• Date: 3/1/1950
• Title: Report on Joseph City Unit - Holbrook Project Arizona
• Water Supply Pro - Doc Type: Report/Study

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short prospective life of any reservoir due to the heavy load of sediment
in the stream, and the poor quality of the undiluted river water.

40. Another plan examined but not recommended by this report was
to use the available runoff of the Little Colorado River without regulation,
provide a de silting basin to remove the sediment from the water, and
increase the withdrawal of groundwater. The use of additional ground-
water of better quality to dilute the surface water would improve the
quality of the water supply as well as increase the amount. As recon-
naissance investigations of groundwater made prior to the present
studies had left some uncertainty as to the quality of groundwater in
most of the area north of the river, the proved artesian basin on the
south side of the river was selected. Two 16-inch wells would be
drilled in the proximity of the company's flowing wells. The plan also
included the installation of 12-inch electrically driven deep well pumps,
2,400 feet of transmission line to deliver power to the pumps, and a
bank of transformers. The pumped water would be conveyed to the
river by a 2. 5-mile canal with a 10-second-foot capacity, conducted
under the river through an inverted siphon near Penzance Dam without
disturbing its operation, and discharged into the company canal on the
north side of the river at approximately the point of diverting Little
Colorado River water. The existing canal would be rehabilitated and
a de silting basin constructed. Preliminary field estimates indicated
that the cost of two features alone, the new canal on the south side of
the river and the siphon, would exceed $ 50, 000 at 1948 prices.
Because of its high cost this plan was eliminated and les s expensive
alternatives were investigated.

41. Another alternative was to pump the entire water supply for
the project area from groundwater. This would permit removal of
the Penzance and the lower diversion dams which would cause the
river to scour and lower its channel an estimated 6 to 10 feet thereby
reducing flood hazards upstream in the vicinity of Holbrook. This
alternative was discarded for several reasons. It did not fit into the
flood control plan later proposed by the Corps of Engineers. It was
also more expensive than other alternatives. Furthermore, it
appeared unlikely that the people of the Joseph City area would consent
to the removal of their diversion dams and relinquishing their right to
the use of surface water from the river by nonuse.

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42. The most feasible plan investigated involved continued use
of the unregulated flow of the Little Colorado River, desUting the
water, rehabilitating the upper canal by cleaning and enlarging where
necessary, and providing a supplemental water supply by pumping
groundwater from the Coconino sandstone on the north side of the
river. In addition to the need for more stable water supplies, the
local people have long recognized the need for removing the harmful
sediments from the river water. A desUting basin, privately con-
structed on a farm in the project area, has been operated success-
fully for several years. Previous to investigations of theBureau of
Reclamation, the Soil Conservation Service, U. S. Department of
Agriculture, had prepared plans for a de silting basin to be installed
at Tanner Wash, about 4.5 miles down the canal from Penzance Dam.

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