SPDSS_Task5_KeyStructure_FRICO-Marshall

• Title: SPDSS Task 5 - Key Structure, FRICO-Marshall Lake Division
• Description: The FRICO–Marshall Lake Division has been identified as a key structure for the South Platte Decision Support System ‎(SPDSS)‎ consumptive use and surface water modeling efforts. The purpose of this Task 5 memorandum is to document physical, legal, and operational aspects of those key structures identified.
• Decision Support - Doc Type: Task Memorandum
• Date: 3/3/2005
• DSS Category: Surface Water
• DSS: South Platte
• Basin: South Platte
• Contract/PO #: C153954
• Grant Type: Non-Reimbursable
• Bill Number: SB01-157, HB02-1152, SB03-110, HB04-1221, SB05-084, HB06-1313, SB07-122
• Prepared By: Leonard Rice Engineering

1) Upper Community Ditch (Structure ID 0600564)
The Upper Community Ditch headgate is located on
the south side of South Boulder Creek at the Town of
Eldorado Springs and travels in a northeasterly
direction for about four miles to Marshall Lake. The
ditch conveys storage water to the reservoir as well as
direct flow diversions through the reservoir to the City
of Louisville and irrigators within the Marshall Lake
Division. The South Boulder and Coal Creek Ditch,
operated by the South Boulder and Coal Creek
Irrigating Company, diverts water out of South
Boulder Creek and Dowdy Hollow.
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Community Ditch
Since 1940, the South Boulder and Coal Creek Ditch water rights have also been diverted
through the Community Ditch. The South Boulder and Coal Creek Ditch has direct flow water
rights from South Boulder Creek as well as storage rights in Marshall Lake. The City of
Louisville has shares in the South Boulder and Coal Creek Ditch.
Length: The ditch travels approximately 4 miles from the headgate to Marshall Lake and
continues for over 20 miles from the Marshall Lake outlet.
Capacity: Originally constructed in 1885 with a capacity of around 83 cfs, the Upper
Community Ditch was enlarged in 1905 to a capacity of around 575 cfs. In 1994, Camp
Dresser & McKee Inc. conducted a ditch survey in support of the City of Louisville water
rights Case No. 92CW079 which showed a capacity ranging from 360 cfs in sections to
over 1,000 cfs in other sections3. The maximum daily flow rate reported in HydroBase is
around 175 cfs.
Conveyance Efficiency: Conveyance losses from the Upper Community Ditch headgate to
Marshall Lake are estimated to be around 5%. The ditch is only lined through El Dorado
Springs.
Irrigated Acreage and Crop Types: There are approximately 31,500 acres of land under the
Marshall Lake Division. Approximately 18,815 acres are irrigated solely with
Community Ditch and Marshall Lake water (15,000 acres were used in the City of
Louisville Decree No. 92CW079 as a conservative interpretation of FRICO's decrees) 3.
For the remaining lands, Community Ditch and Marshall Lake water is used to
supplement and extend the irrigation season for other water rights including the South
Boulder and Coal Creek Ditch, Leyner Cottonwood Ditch, Erie and Coal Creek Ditch,
Goodhue Ditch, and the Equity Ditch. No lands are irrigated with FRICO-Marshall
diversions between the Upper Community Ditch headgate and Marshall Lake. All
irrigated lands are below Marshall Lake.
Groundwater Use: There is no known ground water use on FRICO-Marshall lands.
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