High Plains States Groundwater Demonstratior ProgramPart3

• Description: Part III - Demonstration Project Summary Reports - Recharge to the Arapahoe Aquifer
• State: CO
• Basin: South Platte
• Water Division: 1
• Date: 6/1/2000
• Author: U.S. Department of the Interior Bureau of Reclamation
• Title: High Plains States Groundwater Demonstration Program - Program Summary Report, Part III
• Water Supply Pro - Doc Type: Report/Study

Table 3.— Annual operation and maintenance costs
Cost
Item Quantity (dollars)
Labor to monitor the dam and basins
Site visit two times per week
Obtain water level measurements in
wells designated as monitor wells
and quarterly water quality samples
Laboratory analysis for two samples
per quarter
Reports to Arizona Department of
Environmental Quality
Operational subtotal
Inflatable dam and fuse plugs'
Off - channel basin
Alamo Wash drain
River Park (north bank)
River Park (south bank)
Maintenance
O &M total
' Includes replacement cost after 30 years.
2 $125 per cleanout, 32 cleanouts per year.
Operation
1 manhour per day, 5 days per week 6,000
2 manhours per visit, 2 days per week 4,000
Quarterly 20,000
Quarterly 20,000
Annually 2,000
Maintenance
34,000
52,000
5,000
4,000
10,000
20,000
91,000
125,000
Annual operation and maintenance costs for the project were estimated to be $61,000,
including replacement of the inflatable dam at 30 years (CHZMHill, 1993). Including
operation and maintenance increases the cost of the recharge to $55 per acre -foot.
Land acquisition costs were not included because the land purchased would otherwise be
used for flood control and open space purposes. Feasibility costs were not included
because the costs would reflect research and additional investigations beyond those
necessary for a typical project. River park costs were not considered attributable to the
recharge project because Pima County intends to construct a river park with or without
the Rillito Recharge Project.
The water thus recharged would flow to Tucson Water Department's central well field, as
well as to the small domestic and irrigation wells in the vicinity of the project. Although
Tucson Water Department's facilities would be in the benefitted area, the utility is not
interested in constructing or operating the facility.
The low flows that would be captured for recharge are also the flows most likely to
infiltrate prior to leaving the Tucson Active Management Area, so the ADWR will not
issue storage credits for stormwater recharged at the site. Without credits, no economic
16 High Plains States Groundwater Demonstration Program