The Cottonwood Water and Sanitation District (Cottonwood) is one of many South Metro water providers whose initial water supply came mainly from nonrenewable ground water. Starting in 2004, Cottonwood and its long-term partner, the Arapahoe County Water and Wastewater Authority, planned and developed the Joint Water Purification Plant whose treatment (MF+RO+AOR) provides a high-quality supply with low TDS and eliminates Chemicals of Emerging Concerns. Moreover, the plant allows for full use of Cottonwood’s renewable supplies on Cherry Creek that, combined with the WISE Supply, should meet 75% of Cottonwood’s buildout demands. Cottonwood and its partners continue to refine their strategy for drought supply to ensure a long-term sustainable water system for the District’s customers and the region combined.