2019-08-27_HYDROLOGY - M1977436

• Permit No: M1977436
• IBM Index Class Name: Hydrology
• Doc Date: 8/27/2019
• Doc Name: Substitute Water Supply Plan
• From: DWR
• To: DRMS
• Email Name: JLE
• Media Type: D
• Archive: No

Amended Aggregate Industries South Platte Combined SWSP August 27, 2019
Plan I Ds 3614, 47731 3624, 47721 4616, 3437, 3376, 3650, 3668, and 5475 Page 9 of 21
14.0 acre-feet of fully consumable water stored in Heaton Reservoir (WDID 0504089). A copy of the
lease agreement, dated December 19, 2018, is attached. Heaton Reservoir is part of the Hamm Pit
(M-1987-176), and is located in the N1/2 of the NE1/ of Section 9, Township 2 North, Range 68 West,
6t" P.M., adjacent to the confluence of Boulder Creek with St. Vrain Creek. There are no intervening
water rights between the Distel and Tull Pits (upstream points of depletion) and the Heaton
Reservoir (downstream point of release). The slurry wall liner for the Heaton Reservoir was approved
as having been lined to the design standard referenced in the August 1999 State Engineer Guidelines
for Lining Criteria for Gravel Pits in a letter dated April 7, 2003 and it is therefore classified as a
lined reservoir. Deliveries from Heaton Reservoir will made be to Boulder Creek during the period of
April through October 2019 pursuant to the attached delivery schedule.
South Platte Mai nstem
Projected
Replacement Sources 2019 Yield Comments
acre-feet
Centennial 30.00 Perpetual lease
Westminster 1998 265.24 Available throughout the year-perpetual lease;
265.24 acre-feet proposed to be used in 2019
Westminster Annual Lease 146 Annual lease with Westminster
Thornton Effluent 10.53 November- March only
Fulton Ditch 86.70 96 shares total; 62 to be used in 2019
Brighton Ditch 209.96 1.038 shares total
Note: Projected 2019 yields may vary from previous estimates of the net yield due to the computed return flow
obligations based on the previous year's actual water deliveries.
Centennial Lease
Aggregate conveyed water rights in exchange for a perpetual lease of augmentation water in
an agreement with Centennial Water and Sanitation District in 1996. The agreement requires
Centennial to provide Aggregate with 30 acre-feet of fully consumable water each year. The rate of
delivery for the 30 acre-feet cannot exceed 0.5 cfs, but can be taken at any time throughout the
year. For this plan period, Aggregate intends to utilize this source during the months of April, May,
September, and October. Aggregate will not claim credit from Centennial releases on days when the
Burlington Ditch is sweeping the river. The Applicant is working on ways to bypass the Centennial
credits past the Burlington Ditch for future SWSP approvals.
Westminster 1998 Lease
The 1998 effluent lease with the City of Westminster is a perpetual lease that provides 0.28
cfs of fully consumable water every day of each year (averaging 16.89 acre-feet per month) and an
additional 0.17 cfs every day from October 1 to June 30 during each year (averaging 10.25 acre-feet
per month) at the outfall of the Metro Wastewater Treatment Plant. The lease provides 294.79
acre-feet annually, of which 265.24 acre-feet are anticipated to be utilized in this SWSP. (The
remaining 29.55 acre-feet are reserved for use in case no. 2007CW198.)
Westminster Annual Lease
Pursuant to a March 4, 2009 Consumable Water Lease Agreement with the City of
Westminster, Aggregate may lease up to 519 acre-feet of consumable water annually, with a
minimum lease of 150 acre-feet per year unless changed by mutual agreement between the parties.
The agreement is valid through December 31, 2019. Deliveries under this lease are available from
November 1 ot" through March 201" from either the Metro Wastewater Treatment Plant or the Big Dry
Creek Wastewater Treatment Plant. For 2019, Aggregate and Westminster have agreed to a total