Appendix A – Site Assessments – Page 1

A preliminary site assessment was conducted on two potential sites to determine the viability of hydropower development and if further feasibility studies are warranted. Both sites are on the Wheatland Irrigation District’s system: one on the outlet of Wheatland Reservoir No. 1 and the other on a drop structure in a canal. The available flows were estimated and obtained from the Wheatland Irrigation District (WID). The net head was estimated from the gross head obtained from the WID. Cost estimates are generalized based on the generator output and Bureau of Reclamation cost index formulas, Electric Power Research Institute Plant Cost Elements, and experience with similar projects. It was assumed a loan would be secured to finance 100 percent of the project capital costs (4 percent over 30 years). The Bureau of Reclamation’s Hydropower Assessment Tool was used to estimate the power generation potential at each site.

Joe Drop

Site Location, Ownership and Access
The Joe Drop is on a lateral owned and operated by the Wheatland Irrigation District (WID). Joe Drop is near the intersection of Highway 34 and Sybille Creek Road approximately 7 miles southwest of Wheatland. The lateral supplies water to agricultural producers within the boundaries of the Wheatland Irrigation District. The WID has an easement to access and maintain the drop structure, and the existing access roads are adequate.

Water Rights
The Wheatland Irrigation District owns the water rights that would be used for hydropower production; however, the beneficial use is permitted as irrigation. WID would have to file for an enlargement to add power generation as a beneficial use to the water rights. The water right for power generation would be non-consumptive and secondary to irrigation. The need for any additional water rights is not anticipated, as the hydropower facility would utilize existing rights.

Estimated Head and Flow
The elevation difference across the drop is approximately 20 feet. Water levels upstream of the drop can vary slightly depending on the flow rate in the canal; however, for the level of this analysis, the variation in elevation was assumed to be insignificant. The length of the penstock will be very short and assumed sized to minimize friction loss; therefore, the gross head of 20 feet was also assumed to be the net head available. A more detailed analysis is required to properly determine the net head and is beyond the scope of this assessment.

The available flows in the canal were obtained from the WID. The available flow for hydropower generation is seasonal and occurs during the irrigation season assumed to be from May 15 to September 15. The minimum flow is 80 cfs, and the maximum flow is 240 cfs. The minimum flows occur early and late in the irrigation season, and the maximum flows occur during July and August. The design flow was estimated to be the maximum flow or 240 cfs, since the turbine can handle the variable flow rates fairly efficiently. Daily flow data should be obtained in future studies to accurately assess the energy generation of the hydropower facility. For this analysis, the following flow characteristics were assumed:

Month Average Monthly Flow
May 80 cfs
June 150 cfs
July 240 cfs
August 240 cfs
September 100 cfs


Utility Connection
The proposed hydropower facility is in a rural but fairly developed area. Several residences are within close proximity to the proposed site, and a major electrical transmission line is approximately 4,000 feet away. Smaller distribution electrical lines are along Sybille Creek Road, approximately 500 feet away. The capacity of the distribution line is unknown but was assumed to be the location of interconnect.

Political and Environmental Concerns
The proposed site is in a rural area where agriculture is the driving industry. The nearest residence is approximately one-eighth of a mile away. Noise from the turbine is not anticipated to impact the nearby residences. Since the hydro turbine would be on an existing canal and flows are already seasonal, the environmental impact associated with hydro would be very minimal. Fish and wildlife mitigation would not be required, and the federal permitting process would be streamlined and take minimal effort.

Generation and Turbine Selection
The Bureau of Reclamation’s Hydropower Assessment Tool was used to estimate capacity and energy generation of the proposed hydropower facility. Based on a rated flow of 240 cfs and a net head of 20 feet, the plant would have a design capacity of 343 kW and generate 795 MWh of energy annually. The head and flow conditions indicate the turbine would likely be a Kaplan. A cross flow turbine may be an option; however, the design flow would be on the high end of a cross-flow turbine. The following tables show the plant generation summary.

Plant Generation Summary
Plant Design Capacity (kW) 343
Number of Days 365
Data Years 1.00
Total Data Period Energy (kWh) 795,000
Average Plant Capacity (kW) 93
Plant Peak Capacity (kW) 343
Plant Factor 0.270


Plant Monthly Generation
Month Days with Data Average Capacity (kW) Average Energy (MWH)
January 31 0 0
February 28 0 0
March 31 0 0
April 30 0 0
May 32 61 44
June 30 242 174
July 31 337 243
August 31 343 247
September 30 121 87
October 31 0 0
November 30 0 0
December 31 0 0
Annual 795


Plant costs were generalized and based on the generator output, Bureau of Reclamation’s Cost Index, Energy Electric Power Research Institute “Quantifying the Value of Hydropower in the Electric Grid: Plant Cost Elements” and experience with similar projects. The cost estimate is conservative and should be estimated with more detail in future studies. For small, low-head hydro installations, the Electric Power Research Institute indicates the range of turbine, generator, and controls could cost $1,200 to $1,400 per kW of output. This assessment assumed a cost of $1,400/kW or $480,000 for the turbine, generator and controls. The civil infrastructure would consist of an intake, short penstock, powerhouse, and tailrace and was estimated to be 40 percent of the turbine and generator costs or $193,000. A summary of the total plant costs is shown below.

Site Information
Unit Capacity (MW) 0.34
Number of Units 1
Plant Capacity (MW) 0.34
Turbine Type Kaplan
Design Head (ft) 20
Unit Speed (RPM) 600
Estimated Generation Voltage (KV) 0.48
Transmission Voltage (KV- 69,115) 115
T-Line Length (miles) 0.10
New Transformer YES
Fish and Wildlife Mitigation No
Recreation Mitigation No
Historical & Archeological No
Water Quality Monitoring No
Fish Passage Required No
State Sales Tax Rate ( percent) 4.00
Construction Year 2014


Total Direct Construction Cost 995,575
Civil Works 193,436
Turbine(s) 210,455
Generator(s) 171,144
Balance of Plant Mechanical 42,091
Balance of Plant Electrical 59,901
Transformer 24,404
T-Line 20,000
Contingency (20 percent) 144,286
Sales Taxes 0
Engineering and CM (15 percent) 129,858


Total Development Costs 1,152,565
Cost Escalation factor from 2010 1.1
Licensing Cost 50,000
Total Direct Construction Cost 1,098,929
T-Line Right-of-Way 3,636
Fish & Wildlife Mitigation 0
Recreation Mitigation 0
Historical & Archeological 0
Water Quality Monitoring 0
Fish Passage 0


Annual O&M Expense 15,508
Fixed Annual O&M 5,000
Variable O&M 5,000
FERC Charges 526
Transmission / Interconnection 1,000
Insurance 2,987
Taxes 0
Management / Office / Overhead 0
Major Repairs Fund 996


It was assumed a loan would be secured for the total development costs of $1,152,000. This amount was amortized at 4 percent interest over 30 years resulting in an annual loan payment of $66,620. Including annual operation and maintenance costs of $15,500, the total annual expenses were estimated to be $82,120. Irrigation districts typically are not able to subsidize hydropower projects; therefore, the revenue from power generation should nearly cash flow the project from year one of operation. For this proposed project, the energy would need to be sold at $0.10/kWh in order to cash flow the project from the first year of operation. At this rate, the project would have a simple payback period of 17.6 years.

Conclusions and Recommendations
Based on the assumptions listed above, this project does not appear to be very economically feasible. An avoided rate of $0.10/kWh is not out of the realm of possibility but is higher than current typical rates. Current avoided rates are typically around $0.04/kWh. This does not mean a more detailed analysis should not be completed. Without too much effort, more detailed flow rates can be estimated and cost estimates could be specific to the project area instead of using generalized costs. The cost index used for this analysis tends to be conservative, and actual quotes from suppliers should be used to better estimate construction costs. It is recommended to use daily average flow rates throughout a typical irrigation season and investigate whether supplemental flows can be sent through the turbine to increase energy generation. A field survey of the available head should also be completed. This information can then be used to obtain specific turbine efficiency curves, and a better estimate of plant capacity and energy generation can be completed. The following table shows the results of the preliminary analysis.

Results – Joe Drop – Wheatland Irrigation District
Data Set 1 years
Max Head 20 ft
Min Head 20 ft
Max Flow 240 cfs
Min Flow 80 cfs
Turbine Selection Analysis
Selected Turbine Type Kaplan
Selected Design Head 20 ft
Maximum Turbine Flow 240 cfs
Generator Speed 600 rpm
Max Head Limit 25.0 ft
Min Head Limit 13.0 ft
Max Flow Limit 240 cfs
Min Flow Limit 48 cfs
Power Generation Analysis
Installed Capacity 343 kW
Plant Factor 0.27
Projected Monthly Production:
January 0 MWH
February 0 MWH
March 0 MWH
April 0 MWH
May 44 MWH
June 174 MWH
July 243 MWH
August 247 MWH
September 87 MWH
October 0 MWH
November 0 MWH
December 0 MWH
Annual production 795 MWH
Benefit/Cost Analysis
Projected expenditure to implement project
Total Construction Cost $ 1,152,565
Annual O&M Cost $ 15,508
Projected Total Cost over 50-year period (present worth) $ 1,328,691
Projected revenue after implementation of project
Power generation income for 2014 to 2060 $ 2,936,219
Projected Total Revenue over 50- year period $ 1,042,542
Benefit/Cost Ratio 0.78
Internal Rate of Return 2.8 percent
Installed Cost $ per kW $ 3,360