4_Water Forward 2024 Water Supply Project Update — original pdf

Backup

Water Supply Project Update April 8, 2025 Agenda  Overview of Indirect Potable Reuse and Lake Walter E. Long Strategies  Overview of Consultant Support  Work to date on Indirect Potable Reuse planning  Next steps on big picture water supply strategy evaluation and related work Water Forward 2080 Portfolio Utility-Side Water Loss Control • Production meter improvements • Expanded active leak detection programs • Additional analysis of smart meter data Customer Side Water Use Management • Expanded customer incentives for conservation • Use of smart meter data for customer-side leak identification, education, and outreach • Water use budgeting Native & Efficient Landscapes • New landscape ordinances & incentives • • Irrigation efficiency incentives Landscape conversion programs Non-Potable Reuse • Onsite Water Reuse Systems • Decentralized Reclaimed • Centralized Reclaimed Water Supply Storage Aquifer Storage and Recovery Use of Lake Walter E. Long Potable Reuse Indirect Potable Reuse New Water Supplies Brackish Groundwater Desalination Strategies reliant on Colorado River and LCRA supplies 3 Indirect Potable Reuse (Drought Emergency Strategy) Annual Yield Targets (acre feet per year) 2030 *** 2040 *** 2050 22,400 2060 22,400 2070 22,400 2080 22,400 Capital Cost of Infrastructure Capital Cost including Contingencies and Land Acquisition Annual Cost O&M and Debt Service ($ per year) Total Annual Cost ($ per acre foot per year) $114,104,000 $180,486,000 $19,710,000 $880 Five Year Implementation Actions • • • Develop IPR schematic design, design criteria, technical specifications (2024) Begin design-build procurement process and, pending Council approval, issue design-build contract (2025) Preliminary target for substantial completion of IPR project construction (2028) 4 Use of Lake Walter E. Long Annual Yield Targets (acre feet per year) 2030 0 2040 18,300 2050 18,300 2060 18,300 Annual Storage Targets (acre feet) 2030 0 2040 6,100 2050 6,100 2070 18,300 2060 6,100 2080 18,300 2070 6,100 Capital Cost of Infrastructure Capital Cost including Contingencies and Land Acquisition Annual Cost O&M and Debt Service ($ per year) Total Annual Cost ($ per acre foot per year) $331,634,000 $518,117,000 $55,507,000 $3,033 Five Year Implementation Actions • • • Complete feasibility report to evaluate off-channel reservoir configurations and recommend a preferred configuration (2025) Begin water quality sampling of Lake Walter E. Long (2025) Begin preliminary engineering of a conceptual project layout for the preferred strategy configuration, including Colorado River infrastructure, improvements to the intake pipeline, water treatment plant infrastructure, intake infrastructure, and distribution system integration. (2026) 5 IPR Consultant Support Rotation List Engineering Support 1. Overall project configuration evaluation, TPDES permit application & water quality modeling support (Plummer) Intake and pump station facilities (Hazen and Sawyer) 2. 3. Reclaimed transmission main routing study (CAS) 4. Sidestream wastewater effluent treatment facilities (TBD) Design Build Project  Full IPR project design and construction Work to date on IPR planning  Plummer has performed initial water quality modeling, which is anticipated to be revised/rerun  AW performed evaluation and analysis to decide on which plant would supply reclaimed water and AW’s preferred treatment and permitting approach  AW and Plummer began evaluation and costing of three possible IPR configurations Interdepartmental Coordination  Water quality modeling • AW has met with WPD staff to regroup on water quality modeling for IPR through Lady Bird Lake and to provide updates on next steps related to the broader water supply strategy evaluation being performed by Plummer. • WPD has provided initial information related to Lake Walter E. Long water quality and existing data. • AW will continue to meet with WPD monthly on this topic.  Lake Walter E. Long Coordination • AW also meets with AE and PARD on a monthly basis to coordinate on Lake Walter E. Long lake levels and related issues. • Discussion of Lake Walter E. Long’s use as a water supply reservoir will be incorporated into these ongoing meetings. Big Picture Supply Strategy Evaluation  Based on internal planning and new information, Plummer’s evaluation of IPR project configurations will be expanded.  This expanded analysis will evaluate and compare: • IPR configuration options featuring whole-plant process improvements at SAR WWTP, • Using Lake Walter E. Long as a water supply reservoir, and • Direct potable reuse as a possible emergency strategy. Big Picture Supply Strategy Evaluation  This evaluation will inform AW’s decision on which water supply strategy to prioritize for near-term implementation.  The submittal of a TPDES permit for sidestream treatment facilities at SAR will be pending the outcome of this broader evaluation.  The reclaimed transmission main routing study being performed by CAS and the intake and pump station study being performed by Hazen and Sawyer will be moving ahead as previously planned. Big Picture Supply Strategy Evaluation Task Begin Date End Date Option 1: Indirect Potable Reuse through Lady Bird Lake Analysis Option 2: Lake Water E. Long as a Water Supply Reservoir Analysis Option 3: Direct Potable Reuse Analysis Feb 2025 Jun 2025 Apr 2025 Jun/Jul 2025 May 2025 Jul 2025 Feasibility Report May 2025 Sep 2025 Other Related Work  AW is developing an interlocal agreement with TWDB to perform sediment and bathymetric surveys of Lake Austin and Lady Bird Lake.  This will include scans of intake structures at Davis, Ullrich, and the former Green WTP.  Execution of this agreement will be dependent on Council approval and is currently planned for Summer of 2025. Questions?