SPDSS_Task5_KeyStructure_FRICO-Standley

• Title: SPDSS Task 5 - Key Structure, FRICO-Standley Lake Cities
• Description: FRICO–Standley Lake Cities 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: 12/22/2006
• 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

City of Thornton
The City of Thornton uses Standley Lake for municipal supplies through the Thornton WTP (20
MGD capacity). In addition, municipal demands are met through the Wes Brown WTP (50 MGD
capacity) which takes water from Thornton’s gravel lakes system including West Gravel Lakes
(Structure ID 0203707, capacity 2,840 ac-ft), Brannan Lakes (Structure ID 0703339, capacity
528 ac-ft), East Gravel Lakes (Structure ID capacity 7,228 ac-ft), Dahlia Lakes (South Dahlia-
Structure ID 0203705 and North Dahlia pits -Structure ID 0203706, capacity 7,153 ac-ft) and
Thornton’s well field (Thornton Well 58526-F through 58535-F and 58631-F, each with 2.0 cfs
capacity; and 63647-F with 3.0 cfs capacity).
Thornton’s current pro-rata ownership of majo r water rights in the Clear Creek basin is
Table 8
summarized in .
Table 8
City of Thornton Water Rights Portfolio
Share Ownership
Percent
Ditch Name
Ownership
Total City
Croke Canal / FRICO 2,373.525 365.07 15.38
Church Ditch 5,710.64 389.68 6.82
Farmers’ High Line Canal 1,110.8858 175.5786 15.81
Kershaw Ditch 112.89 1.61 1.43
Rocky Mountain Ditch 7090 2 0.03
Fisher Ditch 1,344 193.5 14.40
Lower Clear Creek Ditch 320 207.79 64.93
Colorado Agricultural Ditch 260.5 146.75 56.33
Source: City of Thornton
Notes: Percent ownership based on City ownership / Total shares
The Thornton annual demand is currently abou t 23,000 ac-ft with an anticipated build out
demand of about 48,000 ac-ft for the currently pl anned service area. The service area may
expand in the future.
Winter – Thornton typically takes its winter supplies from Standl ey Lake and/or East Gravel
Lakes. Water from Coors and Golden via the Cosm ic Agreement is stored in West Gravel Lakes
and Brannan Lakes.
Summer – Thornton typically meets its summer demand with supplies from its Clear Creek and
South Platte changed ditch shar es, exchanges, and storage releases from Standley Lake and
Thornton’s gravel lakes system. Reusable s upplies from the Metro WWTP are stored in
Thornton’s gravel lakes system or in Standley Reservoir, by exchange.
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