Public scrutiny of all oilfield activities and regulations regarding water usage is becoming progressively more restrictive, so the need for water reuse has never been more important. Water is essential to oilfield operations. Sourcing, storage, logistics, production, and disposal of water represent huge costs to our industry, but can have major impacts on the environment. Smart water management saves money and yields environmental benefits.Smart water management integrates the well and water life cycles to holistically design a system that reduces, controls, and reuses water. This approach reduces unproductive water in the formation, proactively controls water-induced issues (such as scaling and bacteria), and maximizes reuse of produced water. The results are better productivity, less freshwater usage, better logistics (reducing heavy truck traffic), and improvements to the environmental footprint.Subsurface water shutoff treatments, like water inflow detection, mechanical shutoff tools, permanent cement retainers, and gel and chemical remediation for water conformance, effectively decrease unproductive water in producing wells to extend the life of oil and gas fields. Minimizing water production at the source reduces energy required for lifting as well as trucking, which translates into less associated emissions and road damage.Flow assurance can be improved by solid chemicals that counteract water-related bacteria and corrosion, as well as inhibit scale, paraffin, asphaltenes, and salt. These solid chemicals minimize safety hazards because they are mixed onsite, making it safer for transportation and spill mitigation.Surface water treatments using environmentally preferred solutions such as chlorine dioxide, electrocoagulation, and filtration enable operators to reuse produced and flowback water in hydraulic fracturing fluids. Virtually any oilfield water can be treated. Unwanted water is converted into reusable water onsite, further reducing disposal, trucking, and emissions.Technology and best practices exists for smart water management, and it's good for the environment, too. This paper will detail the best of these technologies and give examples of best practices that have saved operators money, improved production, and reduced their environmental impact.