Technical Abstract: Biofuels are a major area of interest and technology development globally. Whereas bioenergy crop production is highly dependent on water, bioenergy development requires effective allocation and management of water. The objectives of this investigation were to assess the bioenergy production relative to the impacts of four water related factors: 1) water limitation; 2) climate and weather; 3) water use; and 4) water competition. Shifts to alternative bioenergy crops with greater water demand may produce unintended consequences for both water resources and energy feedstocks. Sugarcane and corn require 458 and 2036 m3 water/m3 ethanol produced, respectively. The water requirements for corn grain production to meet the US-DOE Billion-Ton Vision may increase 7-fold from 8.6 to 50.1 km3. Furthermore, climate change is impacting water resources throughout the world. In the western US, runoff from snowmelt is occurring earlier, altering the timing of water availability. Weather extremes, both drought and flooding, have occurred more frequently over the last 30 years than the previous 100 years. All of these weather events impact bioenergy crop production. These events may be partially mitigated by alternative water management systems that offer potential for more effective water use and conservation. These include controlled drainage and new generation livestock waste treatment systems. Controlled drainage can increase water available to plants and simultaneously improve water quality. New livestock waste treatments systems offer the potential to utilize treated wastewater to produce bioenergy crops. New technologies for cellulosic biomass conversion via thermochemical conversion offer the potential for using more diverse feedstocks with dramatically reduced water requirements.