Laserfiche WebLink
lop <br />MWH <br />MONW-OMERYINATSONROZZA <br />Subject: Pueblo Minimum Flow Requirement Modeling <br />From: Jerry Cribbens <br />Date: January 31, 2002 <br />As part of on-going investigations into the impacts of potential minimum flow requirements in the <br />Arkansas River through the City of Pueblo, two scenarios have been modeled and are summarized in the <br />attached spreadsheet (pbl inst p0pl2v.xls). This memorandum gives a brief description of the model and <br />the spreadsheet contents. <br />Model Description <br />The base model for the analysis is the Arkansas River Preferred Storage Options Plan (PSOP) model that <br />has been developed to investigate impacts of the proposed PSOP components, including reoperations, <br />enlargements of Pueblo and Turquoise Reservoirs, and the supply, exchanges and demands associated <br />with these facilities. This model simulates the 2040 demand level using historical hydrology from water <br />year 1966 through 1995. The PSOP model explicitly includes impacts at the Above Pueblo gage, which <br />is located just downstream of Pueblo Reservoir. To investigate the impacts of minimum flow <br />requirements at the Moffat Street gage and a combined flow location (located immediately downstream of <br />West Plains Energy return flows), the Moffat Street gage data was filled prior to 1988 (its period-of- <br />record is 1988 through present) and a gage record was constructed for the combined flow location using <br />available diversion and return flow data. <br />Table 1 summarizes the two scenarios included in this analysis. Scenario PO is the existing river system <br />with the proposed PSOP facilities and no minimum flow requirements. Scenario P12 includes a <br />minimum flow of 100 cfs at the Above Pueblo gage with return flows from the fish hatchery included in <br />the gage flow (the existing gage does not include fish hatchery return flows). In addition, scenario P12 <br />includes the Pueblo Board of Water Works (PBWW) diversions moved to Pueblo Dam from their current <br />location between the Above Pueblo and Moffat Street gages. <br />Table 1. Summary of Model Scenarios <br />Scenario <br />PO <br />P12 <br />Minimum Flow Requirement, Above Pueblo Gage (cfs) <br />0 <br />100 <br />Location of PBVWV Diversions: <br />Existing <br />Pueblo Dam <br />Fish Hatchery Returns in Above Pueblo gage <br />(gage located just below Pueblo Dam) <br />Not Included <br />Included <br />