RESUMO
Colorado has recently experienced a significant increase in unconventional oil and gas development, with the greatest concentration of activity occurring in Weld and Garfield counties. Water for oil and gas development has received much attention mainly because water resources are limited in these regions and development is taking place closer to populated areas than it did in the past. Publicly available datasets for the period 2011-2014 were used to identify water acquisition strategies and sources of water used for oil and gas. In addition, the annual average water used in these two counties was quantified and compared to their total water withdrawals. The analysis also quantified the water needed for different well types, along with the flowback water that is retrieved. Weld and Garfield counties are dissimilar in respect to development practices for water acquisition, preferred well type and the fate of flowback water. But at the same time, this difference displays how geological characteristics, water availability, and administration localities are the key elements along with economics in the decision making process within the oil and gas sector. This effort also revealed data challenges regarding accessibility and reliability of reported information, and the need for additional data. Improving the understanding of the unconventional oil and gas sector's water use will help identify possible effects and tradeoffs on the local/regional level, which could diminish the conflicting perspectives that shape the water-energy discussions. This would complement the ability to make informed water resources planning and management decisions that are environmentally and socially acceptable.
