Appendix CD-3 Yadkin River System Modeling Results
Total Page:16
File Type:pdf, Size:1020Kb
Appendix CD-3 Yadkin River System Modeling Results Simulation of Proposed Concord – Kannapolis Interbasin Transfer From the Yadkin River Basin November 6, 2006 Division of Water Resources North Carolina Department of Environment and Natural Resources Simulation of Proposed Concord –Kannapolis Interbasin Transfer from the Yadkin River Basin November 6, 2006 Table of Contents TABLE OF CONTENTS............................................................................................................................................ I LIST OF FIGURES..................................................................................................................................................... I LIST OF TABLES......................................................................................................................................................II PURPOSE ............................................................................................................................................................... - 1 - MODEL BACKGROUND..................................................................................................................................... - 1 - MODEL DESCRIPTION ...................................................................................................................................... - 2 - Input Data ................................................................................................................................................................... - 3 - Scenario Assumptions................................................................................................................................................. - 4 - RESULTS SUMMARY.......................................................................................................................................... - 5 - Low Inflow Protocol (LIP) ......................................................................................................................................... - 5 - System Energy............................................................................................................................................................ - 9 - Reservoir Levels ......................................................................................................................................................... - 9 - Discharge .................................................................................................................................................................... - 9 - APPENDICES ...................................................................................................................................................... - 25 - A. Draft - Low Inflow Protocol for the Yadkin & Yadkin-Pee Dee River Hydroelectric Projects........................... - 26 - B. Water Use Data .................................................................................................................................................... - 43 - C. Hydrologics, Inc.’s Review of Model Inputs ....................................................................................................... - 52 - List of Figures Figure 1 - Yadkin Model Schematic................................................................................................................................ - 2 - Figure 2 – Low-Inflow (LIP) Stages – Maximum Daily Demands ................................................................................. - 6 - Figure 3 - Low-Inflow (LIP) Stages – Constant Withdrawals Comparison .................................................................... - 7 - Figure 4 – Total System Annual Generation – Maximum Daily Demands................................................................... - 10 - Figure 5 - Total System Annual Generation – Constant Withdrawals Comparison ...................................................... - 11 - Figure 6 - High Rock Lake Level Duration Curves – Maximum Daily Demands ........................................................ - 13 - Figure 7 - High Rock Lake Level Duration Curves – Constant Withdrawals Comparison........................................... - 14 - Figure 8 - High Rock Reservoir 2001-2002 Drought Lake Levels................................................................................ - 15 - Figure 9 -- High Rock Reservoir 2001-2002 Lake Levels for Constant Withdrawal .................................................... - 16 - Figure 10 – Narrows (Badin) Lake Level Duration Curves – Maximum Daily Demands ............................................ - 17 - Figure 11 – Narrows (Badin) Lake Level Duration Curves – Constant Withdrawals Comparison............................... - 18 - Figure 12 - Narrows (Badin) Reservoir 2001-2002 Drought Lake Levels .................................................................... - 19 - Figure 13 - Narrows (Badin) Reservoir 2001-2002 Lake Levels for Constant Withdrawal.......................................... - 20 - Figure 14 – Falls Reservoir Total Outflow Duration Curves – Maximum Daily Demands .......................................... - 21 - Figure 15 - Falls Reservoir Outflow Duration Curves – Constant Withdrawals Comparison....................................... - 22 - Figure 16 – Rockingham Gage Outflow Duration Curves – Maximum Daily Demands .............................................. - 23 - Figure 17 - Rockingham Gage Outflow Duration Curves – Constant Demands Comparison....................................... - 24 - i Simulation of Proposed Concord –Kannapolis Interbasin Transfer from the Yadkin River Basin November 6, 2006 List of Tables Table 1 – Summary of Low-Inflow (LIP) Stages ............................................................................................................ - 8 - Table 2 – Summary of Total System Annual Generation.............................................................................................. - 12 - Table 3 - Summary of Concord – Water-Use Projections ............................................................................................. - 43 - Table 4 - Summary of Concord – Kannapolis Water-Use Projections .......................................................................... - 50 - Table 5 - Monthly Demand Patterns for No Transfer.................................................................................................... - 51 - ii Simulation of Proposed Concord –Kannapolis Interbasin Transfer from the Yadkin River Basin November 6, 2006 Purpose The purpose of this study is to update the impact analysis of a proposed Interbasin Transfer (IBT) of water from the Yadkin River Basin to the Rocky River Basin for the cities of Concord and Kannapolis. The basic differences between this updated analysis and the earlier analysis done for the Final Environmental Impact Statement for the Cities of Concord and Kannapolis Proposed Interbasin Transfers to the Rocky River Subbasin, April 2006 (FEIS) are: • The FEIS version of the model was based on the operating parameters of the current FERC license. This analysis is based on the proposed operations likely to occur when the new FERC hydropower license is issued. • The FEIS version of the model included model nodes for individual withdrawals and discharges of 100,000 gpd or greater. This analysis uses a version of the model that has net aggregated withdrawals from the mainstem of the Yadkin River. The transfer of water and the impacts due to this transfer were analyzed using a hydrologic simulation computer model called OASIS with OCL™ (Operational and Simulation of Integrated Systems). OASIS is a software model developed by Hydrologics, Inc. The basic OASIS program was customized for Alcoa Power Generating, Inc. in preparation for the relicensing of their four hydroelectric stations on the Yadkin River. This analysis of the effects of the proposed IBT is not part of relicensing; however, the Division of Water Resources (DWR) used the model to study the impacts of the proposed IBT because it is the best tool available. APGI has allowed the State to use their model to evaluate basin-wide water resources issues. Some of the model inputs and outputs are confidential pursuant to NC Public Records Law. These simulations represent the best information available on the operational changes that could occur in the new license and the potential impacts of the proposed IBT. This analysis will be updated when the new license is issued by the Federal Energy Regulatory Commission if the provisions of the license are significantly different from the assumptions modeled in this analysis. Model Background OASIS with OCL™ is a generalized program for modeling the operations of water resources systems. OASIS uses a linear programming (LP) "engine" to simulate the movement (or "routing") of water through a system. The patented Operations Control Language (OCL) is an integral part of OASIS and provides the ability to customize the model for specific situations. The customized Yadkin OASIS model was used during relicensing to analyze short-term and long-term water management options for the Yadkin Basin as well as potential drought management protocols. - 1 - Simulation of Proposed Concord –Kannapolis Interbasin Transfer from the Yadkin River Basin November 6, 2006 Model Description OASIS is currently being used to address water supply issues associated with hydropower relicensing of the Yadkin Hydroelectric Project operated by Alcoa Power Generating Inc. (APGI) and the Yadkin-Pee Dee River Hydroelectric