Developed to mitigate the economic burden of freshwater transportation and subsequent disposal, novel water- flexible fracturing systems use non-freshwater sources for hydraulic fracturing operations. This type of "fluid-first" solution can reduce or eliminate freshwater use and its associated transportation and disposal costs, while decreasing environmental impact. Water-flexible fluid systems have been tailored even to the most difficult water sources and require little or no treatment—and no disposal. Rather than focusing on expensive treatments to meet fracturing fluid specifications, the fluid-first holistic water management approach looks to fluid upgrades to replace treatment. The integrated approach requires detailed water characterization data, innovative fluid design, proactive scale modeling, analysis of rock-fluid interactions, and comprehensive assessment of full water-cycle costs. Benefits of the approach have included superior proppant placement, clay stability without additional stabilizers, no operational issues, and no negative impact on production rates in field trials. In addition, some surprising benefits were realized including less pumping horsepower required, higher fluid viscosity, and increased production. From a financial perspective, the overall water cycle costs were reduced, with fewer trucks on the road for transport, and disposal costs were eliminated. These engineered systems use extensive information gained from field, water, and reservoir characterization exercises, laboratory testing, and modeling to plan, execute, and evaluate the success of the overall water management program. By accommodating alternative sources of water, these systems can provide superior economics and allow operators to reuse produced water and other non-freshwater sources obtained near-site, while greatly reducing water handling, transportation, and disposal well costs. In addition, as stricter regulations for freshwater use and disposal go into effect, operators can prevent downtime by proactively lowering their environmental impact. Actual case studies utilizing water-flexible fracturing systems demonstrate the technical and economic benefits of this approach.