Cary's Adaptive Water Strategy Through 2070

The Town of Cary, North Carolina, serves a dynamic and rapidly growing service area that includes Morrisville, RTP South, RDU Airport, and the Town of Apex. As a regional utility provider, Cary faces the challenge of supporting growth while maintaining long-term water reliability, affordability, and environmental stewardship. The 2025 Long Range Water Resources Plan (LRWRP) provides a strategic framework for managing water and wastewater needs through 2070, grounded in technical analysis and shaped by collaboration. The LRWRP was developed with input from regional partners and aligned with council priorities. A visioning workshop held early in the process brought together utility partners, planners, and regulators to shape the plan's direction and ensure alignment with broader regional goals. This collaborative approach was essential given Cary's joint ownership of key infrastructure, including the Cary-Apex Water Treatment Facility (CAWTF), the Western Wake Regional Water Reclamation Facility, and a shared interbasin transfer certificate with Apex. These shared assets require coordinated forecasting, investment planning, and regulatory engagement to ensure long-term reliability and capacity. The plan is built around three foundational planning elements: 1. Looking Back: Understanding System Performance A comprehensive Water Use Analysis examined historical trends across raw and finished water, wastewater, and reclaimed systems. The analysis included daily and seasonal consumption patterns, customer billing data, and system performance metrics from 2001 to 2022. Cary's residential per capita water use has declined to 49 gallons per capita per day (gpcd), well below the national average of 83 gpcd, reflecting the success of conservation efforts. 2. Planning Ahead: Forecasting Growth and Demand Water demand and wastewater flow forecasts were developed using probabilistic modeling and scenario evaluation, incorporating parcel-level growth projections, regional transportation plans, and the Imagine Cary Community Plan. The forecasts account for growth across multiple jurisdictions and include coordinated projections with Apex to reflect shared infrastructure needs. By 2070, Cary's finished water demand is projected to reach 33.6 MGD, with a combined Cary & Apex maximum day demand of 71 MGD for Cary and Apex- exceeding the current CAWTF capacity of 56 MGD. Wastewater treatment needs will also increase, with Western Wake Regional WRF projected to exceed capacity by 2046. 3.Balancing Supply and Demand: Strategic Resource Management Cary's strategy prioritizes optimizing existing resources before seeking new supply. Key initiatives include: •Process Loss Recovery at CAWTF: Backwash recycling and recovery could reclaim up to 5 MGD of raw water and add 5 MGD of finished water capacity, potentially deferring expansion needs by over a decade.

Conservation and Efficiency: Cary continues to promote low-flow fixtures, smart irrigation, and sustainable building practices. Reclaimed water use and the Living Buildings initiative support long-term reliability.
Jordan Lake Allocation: Cary and Apex currently hold a combined allocation of 46.2 MGD. The LRWRP positions Cary to pursue additional allocation in Round 5 and explore reallocation of storage pools to increase supply.
Regional Collaboration: As a member of the Triangle Water Supply Partnership, Cary aligns its planning with regional strategies and participates in the Triangle Regional Water Supply Plan. The LRWRP outlines a portfolio of strategies that balance infrastructure investment, environmental stewardship, and cost management. These include optimizing existing infrastructure, securing additional water supply, and planning for treatment capacity expansions. The plan also includes scenario evaluations to assess the impact of high and low growth trajectories, ensuring flexibility in decision-making. Outcomes and Benefits The LRWRP provides Cary with a robust roadmap to meet projected water and wastewater needs through 2070. It supports:

Infrastructure Timing: Clear triggers for expansion based on 80% capacity thresholds.
Cost Efficiency: Deferred capital investments through optimization and conservation.
Regulatory Alignment: Coordination with NCDEQ and EMC for interbasin transfer and allocation approvals.
Regional Resilience: Shared planning with Apex and other utilities to ensure sustainable growth.

This presentation will share Cary's strategic planning journey, highlighting lessons learned in stakeholder engagement, regional coordination, and navigating the complexities of joint infrastructure planning. Attendees will gain practical insights into how Cary's framework supports long-term resilience, infrastructure decisions, and adaptive planning in the face of growth, climate uncertainty, and evolving customer expectations.