I put up a slide for my University of New Mexico water resources graduate students during class yesterday afternoon with two pictures – the emerging canyons at the upper end of Lake Powell, and a smallmouth bass.

When Lake Powell gets low, we get a) the remarkable emergence of Cataract Canyon, and b) warm water invasive smallmouth bass sneaking through Glen Canyon Dam’s outlets, headed downstream to dine on the endangered humpback chub. My University of New Mexico colleagues and collaborators Benjamin Jones and Bob Berrens famously dubbed these “green-vs-green” tradeoffs:

The Anthropocene epoch is characterized by extensive interactions among natural systems and managed human systems and institutional arrangements. Complex coupled human and natural systems, such as river systems with managed flows intended to produce a mix of community, ecosystem, energy, water and recreational services, will necessarily implicate multiple dimensions of societal value….

Managing for one – keeping Lake Powell high to keep smallmouth bass out of the Grand Canyon – inevitably conflicts with the other – keeping Lake Powell low to protect the emerging environmental values of Cataract Canyon.

In a new white paper out today, my colleagues Jack Schmidt, Eric Kuhn, and I argue for the creation of a process to better incorporate and manage the multiplicity of values along the Cataract Canyon/Lake Powell/Glen
Canyon/Grand Canyon/Lake Mead stretch of the Colorado River as we develop new post-2026 river operating guidelines. We recognize that keeping water flowing to taps and headgates across the Colorado River Basin is the primary motivation behind the new operating guidelines being developed by the Bureau of Reclamation. We argue that, as the community is writing those rules, we have an opportunity to incorporate a broader set of community values.

In particular, we argue that more creative water accounting methods would allow water to be either held upstream in Lake Powell for later delivery, or send downstream early to Lake Mead, in order to better take into account what Benjamin and Bob called the “multiple dimensions of societal value.”

The white paper elaborates on our formal proposal submitted in March to Reclamation as part of the agency’s Post-2026 decision process.