**2. Water impacts of modern bioenergy programs**

Reporting of water impacts on ecosystems caused by the implementation of bioenergy systems is both variable and incomplete (**Figure 1**). While some assessments include only active human uses such as irrigation and water used in biofuel conversion processes, others include hydrologic processes such as evapotranspiration, infiltration, runoff, and baseflows, which are natural ecosystem processes influenced by human activity (**Figure 2**) [2]. Water limitations may reduce the opportunities to use bioenergy in some ecosystems. However, there are many situations where bioenergy may advance both socioeconomic and sustainable landscape objectives [9, 12]. The objective of good bioenergy management is to keep water flow on the right side of the diagram in **Figure 2**.

**Figure 2.** Hydrologic processes governing the water cycle and the distribution between desired good water supply, fair water supply, and poor water supply in ecosystems (From [12]).
