Considering Water Use Efficiency for the Environmental Sector

The goal of this report is to provide a starting point from which the water planning community can move toward improving the allocation of water within the environmental sector. To facilitate that process, this report presents:

1.  A discussion that highlights the water community’s points of agreement on the concept of analyzing the application of water to the environment
2.  A term, Managed Environmental Water Use Efficiency (MEWUE), to reflect that concept, and a definition of that term
3.  A survey of existing methods that could be used to develop MEWUE
4.  Suggestions about how to proceed with implementing MEWUE

Based on our analysis, we found that there was genuine interest in understanding and improving how water is allocated to the environment. The idea of maximizing environmental benefits for a given amount of allocated water is a unifying thread among stakeholder interests. We focus on this idea throughout the report as the central concept that MEWUE is intended to achieve.

We propose a new term to reflect the stated concerns of stakeholders that other terms, Environmental Water Use Efficiency and Ecosystem Restoration Water Use Efficiency, did not fully address. We propose Managed to indicate that MEWUE does not evaluate the environment’s use of water per se but rather the effectiveness of water in controlled systems.

We propose Environmental to reflect the range of “uses” of water in the ecosystem, including ecosystem maintenance, restoration, and water quality. Lastly, we support the use of the word Efficiency because efficiency communicates the intent of maximizing benefit for a given amount of water, providing a basis for comparison of the benefits obtainable from different uses of that water.

MEWUE: a mechanism to analyze alternative uses of managed environmental water to determine which allocation of a given amount of water will maximize environmental benefits, and a means to improve decision-making over time.

We address the issue of why having an explicit decision-making mechanism is essential. It is hard to allay the fears that some have of incorrectly measuring environmental benefits. However, it is even more difficult to claim that decisions based on implicit measures and beliefs are better for the environment than those based on some imperfect but explicit consideration of environmental benefits.